International Society for the Study of the Lumbar Spine 40TH Annual Meeting SCOTTSDALE, AZ, USA May 13-17, 2013

Abstract Proceedings

40th Annual Meeting May 13-17, 2013

ISSLS 2013 - SCOTTSDALE

Institute for Clinical Sciences Sahlgrenska Academy PO Box 426 SE-405 30 Gothenburg • Sweden www.issls.org GENERAL POSTERS

overgrowth stiffness located superior end- GP1 plate by using PMMA maybe show an im- SUITABILITY EVALUATION OF RESTORING pact factor for further adjacent deformity. THE INTERVERTEBRAL DISC MECHANICS IN The change of pressure in disc with a dam- TREATING OSTEOPROTIC VERTEBRAL aged endplate was supposed to develop FRACTURE USING KYPHOPLASTY WITH abnormal intradiscal pressure in flexion also PMMA OR CALCIUM-P BASED CEMENT been shown to increase loading of the adja- Haoju Lo, Hung-Ming Chen cent anterior vertebral cortex. Our study The Orthopaedic Department, Ren-Ai indicated a compression fracture treated Branch, Taipei City Hospital, Taiwan with kyphoplasty by PMMA or CaP based cement must be evaluated according the INTRODUCTION: The biomechanical tests damaged structures. about the filler materials paid little atten- tion to vertebral endplate or intervertebral disc in treating compression fracture. Im- GP2 pact of cement leakage into disks on the ASSESSMENT OF PAIN BEHAVIOR IN A RAT development of adjacent fractures was not- MODEL OF INTERVERTEBRAL DISK INJURY ed. There is only a limited understanding USING THE CATWALK GAIT ANALYSIS SYS- how the load shift of the intervertebral disc TEM after a kyphoplasty with different cement. Masayuki Miyagi, MD, PhD *1,2, Tetsuhiro The intervertebral disc should be showed Ishikawa, MD, PhD *1, Hiroto Kamoda, MD, altered disc pressure profile. PhD *1, Miyako Suzuki, MD*1, Yoshihiro MATERIALS AND METHODS: 3D finite- Sakuma, MD*1, Sumihisa Orita, MD, PhD*1, element osteoporotic model of L1–L3 were Yasuhiro Oikawa, MD*1, Yasuchika Aoki, developed. The influence of augmentation MD, PhD*3, Tomoaki Toyone, MD, PhD*4, level as well as bipedicular filling with Kazuhisa Takahashi, MD, PhD*1, Gen Inoue, PMMA or CaP based cement was investi- MD, PhD*1, Seiji Ohtori, MD, PhD*1 gated. The risk factors (anterior wall defi- *1 Department of Orthopaedic Surgery, ciency and superior endplate cleft) were Graduate School of Medicine, Chiba Univer- also taken into consider as variables. Last, a sity, leakage of cement was also simulated. *2 Alan Edwards Center for Research on RESULTS: The stresses and strains in the Pain, Faculty of Dentistry, McGill University vertebrae close to an augmentation were *3 Department of Orthopaedic Surgery, increased, and change their distribution Toho University Sakura Medical Center with different risk factors. In PMMA groups, *4 Department of Orthopaedic Surgery, higher stresses and strains were noted over Teikyo University Chiba Medical Center endplate and disc when risk factors exist. The pressure in a bulge of the augmented INTRODUCTION: There are few reports ex- endplate and disc were increased to almost amining low back pain behavior in animal 20% of its value before the augmentation, models. The CatWalk is a computer-assisted resulting in a stiffening of the intervertebral gait analysis system that provides an auto- disc. In CaP cement, in leakage model, seem mated way to assess gait function and pain- to show more suitable in mechanics if leak- related alterations of this behavior. The age happened. purpose of current study is to investigate DISCUSSION: With an intact endplate, the pain behavior in a rat model of IVD injury two augmented cements shows no signifi- using the CatWalk gait analysis system. cantly difference in restoring of strength METHODS: In the IVD injury group, L5/6 and stiffness. With a damaged endplate, disks were injured with a 24-gauge needle. 98

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Simultaneously, the neurotracer Fluoro- Gold (FG) was injected into the L5/6 IVDs. In INTRODUCTION: Fractalkine (CX3CL1) and the sham group, FG was injected into the its receptor (CX3CR1) comprise a chemokine L5/6 IVDs only. Animals in an additional system involved in leukocyte recruitment control group received no operation. One, and adhesion in chronic inflammatory dis- 2, 3, and 4 weeks after surgery, the gait of ease, but its role in spinal degenerative dis- rats in the three groups was investigated eases is unknown. The purpose of this study using the CatWalk system. One, 2, and 4 is to investigate weeks after surgery, in IVD injury and sham 1) The role of CX3CL1/CX3CR1 chemokine groups, dorsal root ganglia (DRGs) from the on hypertrophy of the ligamentum flavum L1 to L6 levels were resected. DRGs were in lumbar spinal stenosis compared with immunostained for calcitonin gene-related that of non-degenerative spinal condition. peptide (CGRP). 2) Correlation between expression of RESULTS: In the IVD injury group, the mean CX3CL1/CX3CR1 chemokine and thickness of stands of hind paws and the mean duty cy- ligamentum flavum. cle of front paws at some time points were METHODS: The m RNA concentrations of significantly higher compared with the sham CX3CL1/CX3CR1 chemokine were analyzed group. Furthermore, the mean stride length in the surgically obtained ligamentum of the front and hind paws and the mean flavum specimens from lumbar spinal ste- swing speed of the front and hind paws at nosis (LSS) (n =10) and non-degenerative some time points were significantly shorter spinal condition (NDS) (n =11) by real-time compared with the sham group. The pro- PCR. The localization of CX3CL1/CX3CR1 portion of CGRP-immunoreactive, FG- chemokine within the ligament flavum was labeled neurons among all FG-labeled DRG determined using immunohistochemical neurons in the IVD injury group was signifi- study. Plasma levels of soluble FKN (sFKN) cantly higher than the corresponding pro- and CX3CR1 were measured by enzyme- portion in the sham group. linked immunosorbent assay (ELISA), re- DISCUSSION: These results suggest that IVD spectively. The thickness of the ligament injury produced significant changes in rat flavum was measured with axial T1- gait, including longer stance phases and weighted magnetic resonance imaging. shorter strides. In the future, we may be able to apply the CatWalk system to the evaluation of behavior associated with pain in rat and mouse models of low back pain.

GP3 HYPERTROPHY OF THE LIGAMENT FLAVUM IN DEGENERATIVE LUMBAR STENOSIS AS- SOCIATED WITH THE INCREASED EXPRES- SION OF FRACTALKINE (CX3CL1)/CX3CR1 CHEMOKINE In-Soo Oh, MD1, Dong-Whan Sur, MD1, Kee- RESULT: The CX3CL1/CX3CR1 chemokine Yong Ha, MD2. positive cell ratio in the LF observed in LSS Department of Orthopaedic Surgery, In- group as substantially higher than in NDS cheon St. Mary's Hospital1, Seoul St. Mary's group (P= 0.030). In ELISA, the plasma levels Hospital2, College of Medicine, The Catholic of sFKN were significantly increased in LSS University of Korea, Seoul, Korea 99

GENERAL POSTERS patients compared with patients in the oth- modulus and phase angle in the dynamic er groups (P = 0.006). There was greater test were worked out respectively with help CX3CL1/CX3CR1 expression in LSS patients of software. as quantified by RT-PCR (P = 0.004, 0.01). RESULTS: In the static compression test, Thickness of LF in patients was significantly mimic group have a similar stress/strain correlated with serum CX3CL1 level (r = curve with normal group, whereas control 0.48, P < 0.01) and with RNA Expression of group shows obvious difference. In the dy- CX3CL1/CX3CCX3CR1 (r = 0.62, P < 0.01)(r = namic test, results of the storage modulus, 0.64, P < 0.01) loss modulus and phase angle showed DISCUSSION: This study identified for the simlar tendency that the maximum mean first time that increases in Fractalkine and values (297.2~362.5KPa, 15.7~24.0KPa, CX3CR1-expresexpressing monocytes, T 2.4~4.6°, respectively) were in control group lymphocytes, and NK cells are significantly and the minimum (187.2~226.2KPa, related to LF hypertrophy, which may pro- 10.1~14.8KPa, 2.0~3.5°, respectively) in vide new conceptual and therapeutic ap- normal group. And the mean values in mim- proaches for treating spinal stenosis. ic group were 242.8~290.5KPa, 12.4~18.2KPa, 2.3~4.1°, respectively. It should be noted that values of the storage GP4 modulus were elevated with increasing fre- COMPARATIVE STUDY OF LUMBAR quency, while values of the loss modulus INTERVERTEBRAL DISC BIOMECHANICAL and phase angle were reduced with CHARACTERISTICS WITH OR WITHOUT inceasing frequency. HYDROGEL INJECTION AFTER NUCLEUS DISCUSSION: Injecting hydrogels after nu- DISCECTOMY cleus discectomy can not only better re- Gao Manman, Zhou Zhiyu, Deng Wenbin, serve the normal lumbar geometric struc- Dai Xuejun, Zou Xuenong ture but also improve the biomechanical Department of Spine Surgery/Orthopedic properties compared with simple discecto- Research Institute The First Affiliated my. hospital of Sun Yat-sen University

INTRODUCTION: Injecting hydrogels as sub- GP5 stitute of nucleus pulposus after nucleus SPINO-PELVIC-RHYTHM IN NORMAL SUB- discectomy partially restores the geometric JECTS AND HIGH-CLASS ATHLETES WHO structure of lumbar intervertebral discs. OVERCAME CHRONIC LOW BACK PAIN This study investigated both the static and Kiyotaka Hasebe1,2, Koichi Sairyo3, Yasushi dynamic mechanical properties of lumbar Hada1, Akira Dezawa3, Yu Okubo4, Koji intervertebral discs with or without hydro- Kaneoka2, and Yoshio Nakamura2 gels injection after nucleus discectomy. 1Department of Rehabilitation, Teikyo Uni- METHODS: The lumbar intervertebral discs versity Mizonokuchi Hospital, Kawasaki Ja- of three miniature pigs were randomized to pan 2Faculty of Sports Science, Waseda Uni- normal group (with respectively intact in- versity, Japan 3Department of Orthopedic tervertebral discs), mimic group (with hy- Surgery, Teikyo University Mizonokuchi drogel injection after discectomy) and con- Hospital, Kawasaki, Japan 4Faculty of trol group (without hydrogel injection after Health and Medicalcare, Saitama Medical discectomy). All of the specimens were sub- University, Japan jected to static and dynamic compression tests sequentially, then stress/strain curves PURPOSE: Spino-Pelvic-Rhythm (SPR) is re- in the static test and storage modulus, loss ported to be a good parameter to under- 100

GENERAL POSTERS stand the spine kinematics. We evaluated

SPR in normal subjects and high-class ath- GP6 letes who overcame chronic low back pain NOVEL TWO-COMPONENT INTERBODY (LBP). FUSION DEVICE IMPROVES BONE-IMPLANT METHODS: Eighteen male without LBP INTERFACE WITHOUT COMPROMISING (mean: 36 yrs) and three high-class athletes STABILITY: A CADAVER STUDY (mean: 37 yrs) who overcame LBP partici- Hans-Joachim Wilke1, David Volkheimer1, pated. They have a history of LBP at least 2 Bruce Robie2, Finn Bjarke Christensen2,3 years before, and presently, they have no 1University of Ulm, Institute of Orthopaedic LBP. First, we measured the finger-to-floor Research and Biomechanics, Ulm, Germany distance (FFD) at the upright posture, and 2FBC Device ApS, Risskov, Denmark 3Aarhus the value was indicated as 100%. Using a University Hospital, Orthopaedc Research spinal mouse, spinal alignment was meas- Laboratory, Aarhus, Denmark ured at the following 4 points, i.e., (1) up- right posture meaning 100% of FFD, (2) for- INTRODUCTION: A novel two-piece articu- ward bend at 50%, (3) 25% and (4) 0% of lating ALIF device allows limited motions of FFD meaning finger contacting the floor. the treated vertebral level for lordotic ad- The changes of the angle of thoracic and justments until a supplementary pedicle lumbar spine as well as the pelvis were cal- screw system is rigidly fixed. A potential culated. benefit is the reduction of bone-implant RESULTS: In the normal subjects, from point relative motions with a positive impact on 1 to 2 (phase I) spino-pelvic angle moved fusion time and sagittal balance. The aim of 104 degree entirely. In this phase, lumbar the study is to compare the rigidity and im- spine moved mainly. The lumbar/ pelvic (LP) plant alignment of the two-piece ALIF fusion ratio was 4.0. In the second phase (point 2 device with a one-piece ALIF in a 360° set- to 3), it changed only 16 degree and the ting. ratio was 1.0. In phase III (point 3 to 4), ma- METHODS: Seven lumbosacral (L3-S1) hu- jority of the entire motion was found in the man cadaver specimens were tested (age pelvis, and the ratio was 0.4. All three high- 50-60) in a universal spine tester. The flexi- class athletes including Olympic medalist of bility of the intact specimen, the specimens throwing, professional baseball player and instrumented with a two-component ALIF ex-world champion of mixed martial arts, (Statur® -L, FBC Device ApS, Denmark) and a showed totally different SPR. In phase I, one-piece ALIF (PezoTM –A, Ulrich, Germa- pelvis moved greater than normal subjects, ny), both supplemented with a pedicle and the LP ratio was 0.5, 1.2 and 1.3. In the screw system (tangoRSTM, Ulrich, Germany) second phase, lumbar spine mainly moved was tested using pure moments of ±7.5 Nm and, the LP ratio was 3.2, 4.0 and 3.2. in three principal motion directions. For DISCUSSION AND CONCLUSION: As the assessment of the bone-implant interface, normal SPR, the lumbar spine moved mainly fluoroscopic images were captured during at the initial phase. At the final stage, pelvis motion. Three-dimensional vertebral mo- moves mainly. Three athletes showed simi- tion was measured using an optical motion lar abnormal rhythm. They tried to move capturing system (Vicon Mx, Vicon, UK). pelvis more and to reduce the lumbar mo- Paired t-tests were performed to determine tion at the initial phase. This may be due to statistical significance at a p< 0.05 level. the defense mechanism against chronic RESULTS: No statistically significant differ- back pain and/or stabilization effects of the ences in rigidity were found between the spine by strenuous core muscle exercise. one and two-piece ALIF in the 360° setup (e.g., 3.5° ± 1.9° for the one-piece and 4.2° 101

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±1.8°for the two-piece ALIF in flex- el biomechanical model. ion/extension), while both configurations METHODS: A previously validated human significantly reduced the range of motion cadaveric model of degenerative compared to the intact condition (p< 0.05). spondylolisthesis for testing implants in Significantly less motion at the implant- shear was used. Lumbar FSUs (N=15) were endplate interface was found for the two- tested under a static 300 N axial compres- piece device (1.0° ± 0.6°) in comparison to sion force and a cyclic anterior shear force the one-piece ALIF (4.2° ± 1.7°) in flex- (5-250 N). Translation was tracked with a ion/extension. motion capture system. Four implants DISCUSSION: The two-piece ALIF significant- (Medtronic, Inc.) were instrumented with ly reduced the relative motion at the bone- strain gauges to determine the sheer force implant interface without compromising supported by the implant: Implant A Titani- stability. Theoretically, this can reduce the um, Implant B Oblong PEEK, Implant C risk of implant subsidence, improve fusion Round PEEK, and Implant D BalanCTM (PEEK and establish better sagittal balance. rod with a C-shape section and silicone in- sert). Each implant was affixed to each spec- imen, and they were tested in 3 conditions GP7 (intact, facet gap, disc lesion), with the lat- BIOMECHANICAL CHARACTERIZATION OF A ter 2 simulating a degenerative spine. NOVEL LOW-STIFFNESS POSTERIOR SPINAL RESULTS: Specimen condition and implant IMPLANT UNDER ANTERIOR SHEAR LOAD- type affected load-sharing and anterior ING IN A DEGENERATIVE SPINAL MODEL translation (p<0.0001). Load-sharing in- (1,2) Angela D. Melnyk, MASc, (2,3) Jason D. creased across all specimen conditions and Chak, MEng, (4) Vaneet Singh, MS, (1,5) decreased across the first 3 implants (Fig. Adrienne Kelly, MD, (1,2,3) Peter A. Cripton, mean ± SD). Implants D and B supported PhD, (1,2,5) Charles G. Fisher, MD, (1,2,5) similar shear forces for all specimen condi- Marcel F. Dvorak, MD, (1,2,3) Thomas R. tions (p>0.2). Translation tended to increase Oxland, PhD with the first three implants. However, im- 1 Department of Orthopaedics, University of plants D and B allowed similar translations British Columbia, Vancouver, BC, Canada, 2 for all specimen conditions (p>0.3). International Collaboration on Repair Dis- coveries (ICORD), University of British Co- lumbia, Vancouver, BC, Canada, 3 Depart- ment of Mechanical Engineering, University of British Columbia, Vancouver, BC, Canada, 4 Medtronic Inc., Memphis, TN, USA, 5 Divi- sion of Spine, University of British Columbia, Vancouver, BC, Canada

INTRODUCTION: Dynamic implants have been developed to address potential adja- cent level effects due to rigid instrumenta- tion. Prior to clinical use, implants should be rigorously tested ex vivo. The objective of our study was to determine how implant DISCUSSION: We tested a novel dynamic type and specimen condition affects implant implant (Implant D) and compared the re- load-sharing and specimen translation un- sults to those for three implants ranging der an applied anterior shear force in a nov- from high- to low-stiffness (implants A, B, 102

GENERAL POSTERS and C). Implant D behaved similarly to im- significance level of 0.05. plant B in both load-sharing and translation RESULTS: For FE, no statistically significant despite having a different design and stiff- change in motion was observed following ness. Complex implant design and speci- sequential unilateral facet resection com- men-implant interaction necessitate pre- pared to intact state. In LB, only the com- clinical testing of novel implants. plete unilateral facet resection (100%) re- sulted in a significant increase in motion of 8% (p = 0.005). In AR, there was a significant GP8 increase in motion following 75% (18.5%, p EFFECTS OF SEQUENTIAL UNILATERAL = 0.03) and 100% (33.8%, p < 0.001) facet FACETECTOMY ON CERVICAL SPINAL resection, respectively. STABILITY CONCLUSION: Unilateral facet resection Mageswaran P., Tolhurst S., Colbrunn R., does not significantly increase FE motion. Bonner T., Techy F., McLain R. However, significantly greater cervical spine 1 Spine Research Lab, Dept. of Center for mobility in LB and AR occurs following uni- Spine Health, Cleveland Clinic, Cleveland, lateral facet resection of 75% or more. We OH, USA; 2 Illinois Bone and Joint Institute, conclude that unilateral facet resections are Dept. of Orthopedic Surgery, University of not as destabilizing as are bilateral Illinois, Chicago, IL, USA facetectomies with laminectomy. Unilateral facet resection less than 75% did not gener- INTRODUCTION: Classical biomechanical ate instability in any plane of motion. studies have concluded that instability of the cervical spine occurs after a complete laminectomy and resection of more than GP9 50% of the bilateral capsule or facet joints DOES HEAD WEIGHT AFFECT CERVICAL at one cervical level. No study has ever SPINE STABILITY? AN IN VITRO ROBOTIC evaluated the effects of unilateral sequen- BIOMECHANICAL STUDY tial facet resection without laminectomy. Mageswaran P., Tolhurst S., Colbrunn R., This study is the first to assess spinal stabil- Bonner T., Techy F., McLain R. ity after unilateral sequential facet resec- 1 Spine Research Lab, Dept. of Center for tion. Spine Health, Cleveland Clinic, Cleveland, METHODS: Human cadaveric C2-T1 speci- OH, USA; 2 Illinois Bone and Joint Institute, mens (n = 7) were tested intact, and then Dept. of Orthopedic Surgery, University of underwent a sequential right unilateral Illinois, Chicago, IL, USA facetectomy at the C6 – C7 level. The width of the facet joint was measured and se- INTRODUCTION: Many biomechanical stud- quential resection was made as a percent- ies on cervical spine stability with extremely age of the facet width (25 %, 50 %, 75 % and strong clinical relevance were performed 100 %). The following loading conditions without accounting for the head weight. A were applied using a robotic spine testing biomechanical study of a constant vertical system: Applied moments (2.0 Nm) with load (head weight loading) while simulating head weight load of 40N were used to simu- flexion-extension (FE), lateral bending (LB) late flexion-extension (FE), lateral bending and axial rotation (AR) may improve the in (LB), and axial rotation (AR). Vertebral mo- vivo applicability of biomechanical test re- tion was measured using an optoelectronic sults. This study hopes to provide insight system. Mean relative range of motion into the effect of head weight on cervical (ROM) was compared among groups using spine motion and stability. repeated measures analysis of variance at a METHODS: Flexibility tests were conducted 103

GENERAL POSTERS on seven human cadaveric specimens, C2– MD, PhD T1, using a robotic spine testing system. The 1) Department of Orthopaedics, University system was used to test two conditions: of Tokushima, Tokushima, Japan, 2) De- intact and destabilized (Complete Unilateral partment of Anatomy, Sapporo Medical C6 – C7 Facetectomy). Continuous applied University School of Medicine, Sap-poro, moment, ± 2 Nm was used to simulate FE, Japan 3) Department of Orthopaedics, Sap- LB and AR with and without a constant head poro Medical University School of Medi-cine, weight of 40N. The head weight was applied Sapporo, Hokkaido, Japan 4) Department of in the direction of gravity. The test was re- Orthopaedic Surgery, Emory University peated again following complete unilateral School of Medicine, Atlanta, Georgia, USA facetectomy. Mean overall range of motion (ROM) of C2 – T1 was compared among INTRODUCTION: The pedicle diameters at groups using repeated measures analysis of the thoracolumbar levels in elderly patients variance at a significance level of 0.05. and the pedicle diameters at the thoracic RESULTS: We found a significant reduction levels in scoliosis patients are sometimes in motion with the application of a head very small. The question arises: Do pedicle weight (12.1% decrease, p = 0.02) in AR for screws that are inserted and breach the the intact condition. A similar reduction was pedicle wall provide stronger purchase as observed in the destabilized condition compared to pedicle screws of smaller di- (16.1% decrease, p = 0.05). There was a sig- ameter that are placed intra cortex in the nificant decrease in LB motion when head pedicle. The purpose of our study was to weight load was applied in the intact state answer this question using cadaveric thora- (12.4%, p = 0.01), with a larger reduction in columbar vertebrae. motion for the destabilized condition METHODS: Twelve thoracolumbar verte- (21.6%, p < 0.001). Intact FE motion was not brae (T6-L2) were harvested from eight significantly affected by the addition of male fresh cadaveric spines (mean age 85.3 head weight (p = 0.66). However, FE motion years). Pedicle screws were inserted in each decreased significantly with head weight in of the pedicles. On one pedicle the screw to the destabilized state (6.7% decrease, p = be inserted was chosen so as to be oversize 0.01). in the pedicle, and on the other pedicle the CONCLUSION: Application of a constant screw to be inserted was chosen so as to fit head weight load with flexibility testing re- the pedicle intra cortex. The pedicle diame- duces the overall ROM of the cervical spine. ter “a” and the screw diameter “b” were The magnitude of the effect is larger follow- measured, and the breached percentage of ing complete unilateral facetectomy. oversized screw “(b-a) x 100/a” was calcu- lated (Figure 1). Biomechanical testing: An adaptor was attached to the protruding end GP10 of each pedicle screw and then, using a ma- DO PEDICLE SCREWS THAT HAVE terials testing machine (Shimadzu Corpora- BREACHED THE PEDICLE WALL PROVIDE tion, Kyoto Japan), each pedicle was tested STRONGER PURCHASE AS COMPARED TO as follows: 1) toggling was applied in a SMALLER PEDICLE SCREWS PLACED INTRA cephalocaudad direction for 500 cycles at CORTEX? 0.3 Hz at ±50 N; 2) the screws were then 1) Kosaku Higashino, MD, PhD, 1) Yuichiro pulled out by applying a tensile force down Goda, MD, 2) Suzuki Daisuke, PhD, 3) Ta- the long axis of the screw: displacement kuma Kobayashi, MD, 1) Tetsuya Matsuura, rate of 20.0 cm/min. MD, PhD, 2) Mineko Fujimiya, MD, PhD, 4) RESULTS: The mean pullout strength for the William C. Hutton, DSc, 1) Natsuo Yasui, 104

GENERAL POSTERS oversized pedicle screws was 684.9±352.5 N determine the biomechanical effects of sin- and for the intra cortex pedicle screws was gle level disc degeneration on the adjacent 640.5±301.1 N; the difference was not sig- segments. Four different grades of disc de- nificance (p<0.05). There was significant generation (Thompsons Grades 2 to 5) were positive correlation between extent of modeled at L5/S1 level and their compara- breach and pullout force. In other words the tive effect on adjacent disc biomechanical oversized pedicle screws within 12.4% characteristics were studied under all the might be stronger than intra cortex pedicle three physiological moment loading condi- screws (Figure 1). tions. RESULTS: At adjacent L4/5 segment: Grade 5 disc at L5/S1 produced least increase in motions of 3% under flexion and largest under extension (125%), while under tor- sion and lateral bending it produced 18% increase in motions. When the increase in motions in all the three principal directions were combined, grade 4 and grade 5 at L5/S1 produced an increase nearly twice and seven times respectively as those pro- duced when L5/S1 had grade 3 disc. As the degenerative grade at L5/S1 increased from DISCUSSION: Pedicle screws that breach the 2 to 5, total facet forces increased from 77 pedicle wall do not provide stronger pur- N to 162 N under extension and 145 N to chase as compared to smaller pedicle 230 N under torsion. Annular stresses also screws that are placed intra cortex? increased with a sharp increase in stress value as the L5/S1 disc grade changed from 4 to 5. GP11 CONCLUSIONS: Largest increase in motion, BIOMECHANICAL EFFECT OF THE PRO- facet forces as well annular stresses at the GRESSION OF DISC DEGENERATION AT adjacent discs in the lumbar spine was seen L5/S1 ON ADJACENT DISCS IN A LUMBAR with grade 5 disc at L5/S1. Grade 3 and 4 SPINE did not produce substantial increase in ad- Raghu N Natarajan, Gunnar BJ Andersson jacent disc motions as well as annular Department of Orthopedic Surgery, Rush stresses leading to the conclusion that sin- University Medical Center, Chicago, IL, USA gle level disc degeneration induces ASDD only when the deceased disc is degenerated INTRODUCTION: When lumbar disc degen- to the highest grade. eration occurs at one level, whether treated or not, degeneration frequently develops at mobile segments above or below the de- GP12 generated segments referred to adjacent INVESTIGATION OF EQUIVALENT STRESS segment disc disease (ASDD). Aim of the OF ADJACENT VERTEBRAE AFTER BALLOON current study is to understand how progres- KYPHOPLASTY BY A CT-BASED FINITE sive degeneration at L5/S1 affects the bio- ELEMENT METHOD mechanics of the adjacent segments. Nahoko Iwakura1, Yusuke Matsuura2, METHODS: A refined poro-elastic non-linear Masahiro Shiba1, Keiji Wada1, Yasuaki 3D finite element model of a lumbar spine Murata1, Yoshiharu Kato1 and hybrid method of analyses were used to 1.Department of Orthopaedic Surgery, 105

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Tokyo Women's Medical University, Tokyo, change in equivalent stress of adjacent ver- Japan. 2.Department of Orthopaedic tebrae. This result suggests that the inci- Surgery, Graduate School of Medicine, Chiba dence of adjacent fractures after BKP has no University, Chiba, Japan relationship to stiffness of the treated ver- tebra. INTRODUCTION: Balloon kyphoplasty (BKP) is a minimally invasive surgical procedure for treatment of painful vertebral compres- GP13 sion fractures. It has numerous benefits HISTOMORPHOMETRIC AND RADIO- including a simple procedure, early pain GRAPHIC CHANGES AFTER WALLIS IM- control and height restoration of the col- PLANTATION IN RATS lapsed vertebral body. Consequently, the M. Melloh (1), T. Barz (2), J. Lange (3), L.P. number of treatments using this procedure Staub (4), H.R. Merk (5), I. Klöting (6), N. has risen significantly. However, complica- Follak (7) tions such as new vertebral fractures have (1) Western Australian Institute for Medical been reported. The aim of this study was to Research (WAIMR), University of Western evaluate equivalent stress of adjacent ver- Australia, Nedlands, Australia (2) tebrae after BKP using the finite element Department of Orthopaedic Surgery, (FE) method. Asklepios Klinikum Uckermark, Schwedt/ METHODS: Six patients were enrolled in this Oder, Germany (3) Department of Trauma study. The mean age was 77.0 years and the and Reconstructive Surgery, University of duration of follow-up was 4.8 months. All Greifswald, Greifswald, Germany (4) patients underwent CT within 1 week of BKP NHMRC Clinical Trials Centre, University of treatment. Three-dimensional, four- Sydney, Sydney, Australia (5) Department of functional unit, FE models were constructed Orthopaedic Surgery, University of from the CT data using MECHANICAL FIND- Greifswald, Greifswald, Germany (6) ER software (cement model). In addition, a Department of Laboratory Animal Science, cancellous bone model was developed. The Medical Faculty, University of Greifswald, model was a cement model where the ce- Germany (7) Orthopaedic Clinic, Pfeiffersche ment data was replaced with the cancellous Stiftungen, Magdeburg, Germany data of adjacent vertebrae. The equivalent stress of cement and cancellous bone, and INTRODUCTION: Clinical effectiveness of the front half of the adjacent vertebral body the PEEK-non-fusion spine implant WallisTM of both groups, were analyzed and com- is well documented. However, there is a pared. lack of evidence on the long-term behavior RESULTS: The mean equivalent stress of of this implant on bone, in particular its in- cement was significantly larger compared fluence on structural changes of bone ele- with cancellous bone (1.8±0.7 and 0.6±0.4) ments of the lumbar spine. The aim of this (p < 0.05). The mean equivalent stress of study was to investigate histomorphometric adjacent vertebrae of the cement model and radiographic changes in the rat model and cancellous bone model was 2.9±1.1, after WallisTM implantation. and 3.1±1.0, respectively. There was no sig- METHODS: Twenty-four male rats aged nificant difference. eleven weeks underwent surgery for im- DISCUSSION: Cement was stiffer than plantation of WallisTM implants or for a cancellous bone, so replacing cement data sham procedure in three groups of eight with cancellous data decreased the stiffness animals each each: 1) implantation at level of the vertebrae. However, there was no L4-5; 2) implantation at level L5-6 and 3) sham surgery. Eleven weeks postoperatively 106

GENERAL POSTERS resorption at the implant-bone interface al-rotation (AR). The specimens were first was measured via X-ray, bone mineral den- tested in their intact state, and then tested sity of vertebral bodies was analyzed using after each of the following sequential surgi- osteodensitometry, and bone mineral con- cal decompressive procedures at T4 – 5 tent as well as resorption of the spinous consisting of 1) laminectomy; 2) unilateral processes were examined by facetectomy; 3) unilateral histomorphometry. costotransversectomy and subsequently 4) RESULTS: Resorption of the spinous pro- instrumented fusion from T3 - T7. Range of cesses at the site of the interspinous im- Motion (ROM) between T1 - T12 and T3 - T7 plant was found in all treated segments. were measured for each specimen using an There was no significant difference in either optoelectronic motion system. Statistical bone density of vertebral bodies or analysis between and within group compar- histomorphometric structure of the spinous isons was done using repeated measures processes between adjacent vertebral bod- analysis of variance (p < 0.05 was consid- ies, between treated and untreated seg- ered statistically significant). ments and between groups. RESULTS: We found that in all three planes DISCUSSION: These findings indicate that of motion, the sequential decompressive resorption of spinous processes, as a result procedures caused no statistically signifi- of implant loosening, inhibit the targeted cant change in motion between T3 - T7 and load redistribution through the PEEK-non- T1 - T12 when compared to intact. In com- fusion interspinous device in the lumbar paring between intact and fusion, our study spinal segment of the rat. This leads to re- found that fusion reduced intrinsic motion duced long-term stability of the implant in between T3 - T7 by 85.4% (p = 0.0003), the animal model. These results suggest 92.8% (p = 0.0046) and 91% (p = 0.0004) for that PEEK-non-fusion interspinous devices axial rotation, flexion-extension and lateral like the WallisTM implants may have time- bending respectively. We also found that limited effects and should only be used for ROM between T1 - T12 also decreased un- specified indications. der fusion by 22% (p = 0.0013), 21% (p = 0.0020) and 28.2% (p = 0.0004) for axial rotation, flexion-extension and lateral bend- GP14 ing compared to intact. BIOMECHANICAL ANALYSIS OF THE THO- CONCLUSION: Thoracic spine stability was RACIC SPINE FOLLOWING DECOMPRESSIVE not significantly affected by sequential de- PROCEDURES compression procedures in thoracic seg- Healy AT, Lubelski D,Mageswaran P, Mroz T ments at the level of the true ribs in all 1 Spine Research Lab, Dept. of Center for three planes of motion. Placement of poste- Spine Health, Cleveland Clinic, Cleveland, rior instrumented fusion increased study OH, USA; segment rigidity at intrinsic levels and also reduced overall ROM of the thoracic spine. INTRODUCTION: This study evaluated the effect of the rib cage on thoracic spine sta- bility following sequential decompressive surgeries and instrumented fusion. METHODS: Human cadaveric spines with intact rib cages, C7-L1 (n = 9). An industrial robot was used to apply a ± 5 Nm moment applied along the spine to simulate flexion- extension (FE), lateral bending (LB) and axi- 107

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enough (100mm) in clinical use. Further, the GP15 moving area was vertically long linear shape 3D-CT SIMULATION STUDY OF THE ILIAC in remaining eleven cases, which indicate SCREW FOR THE FIRM FIXATION that the screw tip can move to the cranial- Bungo Otsuki, PhD; Shunsuke Fujibayashi, to-caudal direction. These results show that PhD; Mitsuru Takemoto, PhD; Masanori the single iliac screw is not enough for firm Izeki, M.D.; Syuichi Matsuda, PhD fixation even if the screw diameter and di- Department of Orthopaedic Surgery, rection are appropriate especially in the Graduate School of Medicine, Kyoto case of osteoporosis. Dual iliac screw will University, Kyoto, Japan resolve this problem when two screws with enough diameters are set at the cranial and INTRODUCTION: Distal fixation in thoracol- caudal end respectively. umbar spine surgery is crucial. Iliac screw technique has been reported with good clinical results; however, several studies GP16 showed high rates of iliac screw loosening. IS THERE AN ASSOCIATION BETWEEN AB- In the osteoporotic bone, adequate pur- DOMINAL MUSCLES AND DEGENERATIVE chase with a screw will be acquired only by SPONDYLOLISTHESIS? the contact to the cortex, and the use of Tcherveniakov P, Fraser R, Freeman BJC, longer and larger-diameter screw has been Jones CF recommended. The shape of the ilium is University of Adelaide, Adelaide, Australia complex, and the ideal direction or size of Adelaide Centre for Spinal Research, SA the screw has not been fully clarified. In this Pathology, Adelaide, Australia study, the contact between iliac screw and the cortex of the ilium was analyzed by us- INTRODUCTION: The pathogenesis of de- ing 3D-CT simulation. generative spondylolisthesis is not well un- METHODS: Twelve adult pelvic CT data derstood, with many etiological factors were analyzed using originally written soft- identified. The aims of this study were to ware. Screw was placed from the posterior investigate the contributions of abdominal superior iliac spine (PSIS) to the anterior muscle and aponeurosis morphology to L4-5 inferior iliac spine. In this study, we as- and L5-S1 vertebral slip and to devise mod- sumed that the insertion point at PSIS was els for the prediction of vertebral slip. fixed, and the screw tip could move freely METHODS: Axial abdomino-pelvic comput- under the condition that whole screw was ed tomography scans from 200 subjects located inside the cancellous bone of the were examined. Those with spondylolysis ilium. First, maximum screw diameter was were excluded (n=14), and spondylolisthesis decided in each screw length (50-120 mm) was expressed as a continuous measure in by changing the direction of the screw the remaining subjects. Muscle parameters three-dimensionally. Second, we investigat- (abdominal and paraspinal muscle area and ed whether or not screw with a maximum density, aponeurosis width) and bony pa- size can move in the ilium, and calculated rameters (vertebral slip, lumbar index, disc the area where the tip of the screw can index, facet joint angle) were measured for move (moving area). each vertebral or intervertebral level. Mul- RESULTS AND DISCUSSION: The moving tiple linear regression analyses were per- area became small as length of the screw formed to form six hypothesis-driven and became long in all cases. However, moving predictive models for percent vertebral slip. area did not disappear except one case RESULTS: Increasing lateral abdominal mus- when screw length is thought to be long cle (LAM) area (p=0.01) and decreasing rec- 108

GENERAL POSTERS tus abdominis muscle (RAM) area (p=0.02) INTRODUCTION: Invasion of back muscle were significant predictors of vertebral slip after spinal surgery often causes continuous at the L5-S1 level. Measures of aponeurosis pain, yet the pathological-mechanisms be- width did not contribute to L5-S1 vertebral hind continuous muscle pain remain un- slip. Neither muscle morphology or clear. The aim of the current study was to aponeurosis width parameters were signifi- compare in rats the behavior of the sensory cant predictors of slip at the L4-5 level. nervous system, and to investigate histolog- More sagittal facet joint orientation and de- ical changes and inflammatory cytokines in creasing lumbar index were also significant injured muscle. METHODS: In this study, we predictors of vertebral slip at both levels in used the right gastrocnemius contusion all models. model via a drop-mass technique because a DISCUSSION: In addition to previously iden- back muscle injury model would be difficult tified osseous factors such as facet angle for evaluating pain behavior. Exp.1: Pain and lumbar index, this retrospective imag- behavior was measured using CatWalk at ing study shows that abdominal muscle area twelve hours, 1, 2, 3 days, and 1, 2, 3 weeks may be associated with vertebral slip at the after muscle contusion. the bilateral gas- L5-S1 level. The reduction in RAM area may trocnemius was resected. Samples were H-E represent increased musculoaponeurotic stained and TNF-α, IL-6, and NGF levels laxity, which predisposes to vertebral slip by were quantified by ELISA. Exp.2: To detect lowering intra-abdominal pressure. The as- DRG neurons innervating the gastrocnemi- sociation with increased LAM area may be us, fluorogold (FG) was applied to the sur- the result of a compensatory response to faces of bilateral gastrocnemius 1 week be- vertebral slip, which increases intra- fore muscle contusion. DRGs from L4 to L6 abdominal pressure to brace an unstable levels were resected at 1, 2, and 3 weeks spine. after contusion, then immunostained for CGRP (pain-related neuropeptide). The ratio of CGRP and FG double-labeled DRG neu- GP17 rons among all FG-labeled neurons was cal- MUSCLE INJURY IN RATS INDUCES UP- culated. REGULATION OF INFLAMMATORY CYTO- RESULTS: Pain behavior: The swing speed of KINES IN MUSCLE AND PAIN-RELATED right hind paw was significantly lower than NEUROPEPTIDES IN DORSAL ROOT GAN- that of left hind paw through 1 day. Histolo- GLIA INNERVATING MUSCLE. -THE PATHO- gy: At 3 weeks, accumulation of granulated LOGICAL-MECHANISM OF CONTINUOUS tissue and myofibrillogenesis for repaired MUSCLE PAIN- tissue was observed. Inflammatory cyto- Sakuma, Yoshihiro1; Miyagi, Masayuki1; kines: Up-regulation of TNF-α, IL-6 and NGF Ohtori, Seiji1; Inoue, Gen2; Yamauchi, levels in the right side of right side com- Kazuyo1; Orita, Sumihisa1; Kamoda, pared to the left side was observed up to 2 Hiroto1; Ishikawa, Tetsuhiro1; Arai, Gen1; days but became less marked subsequently. Suzuki, Miyako1; Oikawa, Yasuhiro1; Kubo- DRG: The expression of CGRP was signifi- ta, Go1; Inage, Kazuhide1; Sainoh, Takeshi1; cantly higher in the right side than in the Sato, Jun1; Nakata, Yukio1; Takahashi, left side until two weeks. DISCUSSION: In Kazuhisa1 this model, pain response and increase in Dept. of Orthopaedic Surgery, Graduate inflammatory cytokines recovered immedi- School of Medicine, Chiba University, Japan1 ately, but pain-related neuropeptides re- Dept. of Orthopaedic Surgery, Kitasato Uni- mained up-regulated for 2 weeks. These versity, School of Medicine2 differences may explain the pathological-

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GENERAL POSTERS mechanism of continuous muscle pain. RESULTS: Media from CPC/MG132 and CPC/CNT/MG132 both showed potent in- hibitory effect on TNF-induced NF-kB- GP18 mediated IL-8 gene expression. After 5-day CARBON NANOTUBE-REINFORCED CALCI- TNFa treatment, with MG132 present in the UM PHOSPHATE CEMENT FOR DRUG DE- medium, the number of TRAP positive cells LIVERY IN MULTIPLE MYELOMA BONE DIS- decreased significantly. EASE TREATMENT DISCUSSION: The results have demonstrat- Boren Lin 1,3, Huan Zhou 2, Sarit Bhaduri ed that our cement was effectively able to 2,4, Douglas Leaman 1, Vijay Goel 3, Anand carry MG132. Inhibition of osteoclast differ- Agarwal 3 entiation by the CPC/CNT/MG132 medium 1. Department of Biological Sciences, the in a 5-day experiment confirmed the sus- University of Toledo, 2. Department of tained release of the drug from this combi- Mechanical, Industrial and Manufacturing nation. Together with its salient weight Engineering, the University of Toledo, 3. bearing and bioactive properties, our data Departments of Boengineering and suggest that the CPC/CNT is a promising Orthopaedic Surgery, the University of filler material for bone augmentation in Toledo, 4. Department of Surgery multiple myeloma related vertebral lesion (Dentistry), the University of Toledo or fracture.

INTRODUCTION: Current approaches in treating multiple myeloma fracture or lesion GP19 focus on developing osteoconductive frac- BIOMECHANICAL CONTRIBUTION OF ture stabilizing fillers capable of carrying TRANSVERSE CONNECTORS IN THE therapeutic agents to promote bone regen- SETTING OF A THORACIC PEDICLE eration, which cannot be achieved by con- SUBTRACTION OSTEOTOMY ventional PMMA methods. Robert W. Tracey, MD; Haines Paik, MD; METHODS: We have developed a biocom- Ronald A. Lehman, Jr., MD; Daniel G. Kang, patible carbon nanotubes (CNT) reinforced MD; John P. Cody, MD; Mario J. Cardoso, calcium phosphate-based cement (CPC) that MD; Anton E. Dmitriev, PhD exhibits desirable mechanical and handling Walter Reed National Military Medical properties. This novel composite was capa- Center, Bethesda, MD ble in carrying an inhibitor against NF-kB activated osteoclast differentiation. NF-kB INTRODUCTION: Little data is available to inhibitor MG132 was incorporated into the guide longitudinal construct planning after a CPC or CPC/CNT during the setting process, pedicle subtraction osteotomy (PSO) in the and the cement was submerged in culture thoracic spine. Previous studies have sug- medium for 24 hours. This MG132- gested transverse connectors (TC) may en- containing medium was harvested and add- hance torsional rigidity. However, the bio- ed to ACHN indicator cells or preosteoclast mechanical effect of augmentation with one RAW 267.4. NF-kB activation in ACHN cells or two TC after PSO has not been previously was detected by real-time RT-PCR analysis evaluated. of NF-kB-induced IL-8 after 4 hours of TNFa METHODS: 7 fresh-frozen human cadaveric treatment, and cell viability was assessed by thoracic spines (T3-T11) were prepared and crystal violet staining after 12 hours. Inhibi- intact range of motion (ROM) testing was tion of RAW 264.7 differentiation was inves- performed with non-destructive loading (±6 tigated after 5-day TNFa treatment by stain- Nm) in a six-degree-of-freedom spine simu- ing for TRAP positive osteoclast-like cells. lator. The specimens were instrumented 110

GENERAL POSTERS from T4-T10 with bilateral 5.5-mm pedicle screws and 5.5-mm contoured rods, and a INTRODUCTION: When a residual mismatch PSO performed at T7. ROM was subse- occurs between the rod and pedicle screw quently analyzed in the unaugmented con- head, a rod persuasion device has been struct, with 1 TC (T8-T9) and then 2 TC (T5- found to have deleterious consequences on T6 and T9-T10). ROM was analyzed in axial pedicle screw pull-out strength (POS) in the rotation, flexion-extension, and lateral thoracic spine. We investigated the ability bending loading planes over T4-T10 and at of complete facet osteotomies in the tho- the PSO level (T6-T8). racic and lumbar spine to counteract the RESULTS: After PSO and instrumentation detrimental effect on POS caused by the rod with a thoracic pedicle screw-rod construct, reduction technique. T4-T10 ROM was significantly reduced in all METHODS: Fifteen (n=15) thoracic and nine planes of motion from the intact condition (n=9) lumbar three-level, fresh-frozen hu- (p<0.05). Augmentation with either 1 or 2 man cadaveric specimens were prepared. TC did not significantly increase construct Thoracic Ponte osteotomies and lumbar stability in flexion-extension and lateral facetectomies were performed and instru- bending compared to the unaugmented mented. The right side rod was intentional- construct (p>0.05). In contrast, during axial ly contoured with a 5 mm residual gap and rotation, T4-T10 ROM was reduced by 43% was then reduced using a rod-reduction following addition of 2 TC (p<0.05), and was device. On the left side (paired control), a also reduced by 26% following 1 TC rod with no residual rod-screw mismatch (p>0.05), but did not reach statistical signifi- was placed. To simulate screw depth ad- cance. Focal segmental stability (T6-T8) at justment as an alternative to rod reduction, the PSO level had similar improvement in a screw from the bottom level of each axial rotation stability following the addition three-segment specimen was backed out of transverse connectors, with a 48% de- one complete revolution. Inline biomechan- crease in axial rotation after 2 TC (p<0.05), ical testing was performed and pullout and addition of 1 TC decreased axial ROM strength (POS) measured in Newtons (N). by 29%, but again did not reach statistical RESULTS: After rod reduction, pedicle significance (p>0.05). screws had significantly decreased POS DISCUSSION: Two TC significantly improved compared to the control group (thoracic: torsional rigidity but no differences in stabil- 40% decrease; 419±426 N versus 708±462 ity for all planes of motion were observed N, p=0.002 and lumbar: 36% decrease; with the use of one TC. 961±352N versus 613±563N, normalized p=0.048 ), and remained statistically signifi- cant after adjusting for BMD. Eleven (73%) GP20 thoracic and two (22%) lumbar pedicle THE BIOMECHANICAL CONSEQUENCES OF screws had visible pull-out/failure during ROD REDUCTION FOLLOWING THORACIC the reduction attempt. In both the thoracic PONTE OSTEOTOMY AND LUMBAR and lumbar specimens, no significant differ- FACETECTOMY ence was detected in POS between the Robert W. Tracey, MD; Daniel G. Kang, MD; backed-out screw and paired control Adam J. Bevevino, MD; Ronald A. Lehman, (824±402N versus 790±364N, p=0.41, tho- Jr., MD; John P. Cody, MD; Rachel E. Gaume, racic; 790±390N versus 635±374N, p=0.16, BS; J. Paul Happel, BS; Melvin D. Helgeson, lumbar). MD; Anton E. Dmitriev, PhD DISCUSSION: Despite facetectomies to im- Walter Reed National Military Medical prove flexibility of the spine, the rod reduc- Center, Bethesda, MD 111

GENERAL POSTERS tion device still significantly decreased pedi- IT was significantly increased (50%) in 2 cle screw pullout strength; typically result- (3.23±0.65 in-lbs) compared to 1 (2.15±0.56 ing in outright failure of the screw-bone in-lbs, p=0.0005). The peak screw IT was interface. also significantly increased (19%) in 2 (8.99±2.27 in-lbs) compared to 1 (7.52±2.96 in-lbs, p=0.02). An increased rate of optimal GP21 pedicle screw size selection was found in 2 TAPPING INSERTIONAL TORQUE PREDICTS with 9 of 15 (60%) pedicle screws compared BETTER PEDICLE SCREW FIXATION AND to 1 with 4 of 15 (26.7%) pedicle screws OPTIMAL SCREW SIZE SELECTION within 1 mm of the measured pedicle width. Robert W. Tracey, MD; Melvin D. Helgeson, A moderate correlation existed for tapping MD; Daniel G. Kang, MD; Ronald A. Lehman, IT with both screw IT (r=0.54) and pedicle Jr., MD; John P. Cody, MD; Anton E. screw POS (r=0.55). Dmitriev, PhD DISCUSSION: Tapping IT directly correlates Walter Reed National Military Medical with pedicle screw IT, pedicle screw pullout Center, Bethesda, MD strength, and optimal pedicle screw size. Tapping IT provides a reliable method to

INTRODUCTION: Several studies have eval- intra-operatively judge fixation strength. uated pedicle screw insertional torque (IT) and its direct correlation with pullout GP22 strength. The objective of this study is to A NOVEL LOAD SHARING LUMBAR investigate tapping insertional torque and INTERBODY FUSION DEVICE (INTERPLATE®) its ability to predict pedicle screw pullout PROVIDES BETTER STABILITY COMPARED strength and optimal screw size. TO THE PEDICLE SCREW SYSTEM. METHODS: 20 osteoporotic (mean BMD Palepu V+1, Kodigudla M+1, Aakash A+1, 0.60±0.07 g/cm2) human cadaveric thoracic Dhanvin D+1 , Goel VK+1, Moran J+2 vertebral levels were used. 5 specimens +1Engineering Center for Orthopaedic Re- were used for a pilot study, as no estab- search Excellence (E-CORE), Departments of lished values for optimal tapping IT existed. Bioengineering and Orthopaedic Surgery, Optimal tap size was selected as the tap University of Toledo, Toledo, OH 43606, +2 diameter 1 mm smaller than the optimal RSB Spine LLC, Cleveland, OH 44114 screw size. During optimal tap size insertion, all peak tapping IT values were found to be INTRODUCTION: Fusion with rigid instru- between 2 and 3 in-lbs. Thus, the threshold mentation resolves issues related to tapping IT value for optimal pedicle screw pseudoarthrosis. However, excessive rigidity and tap size was determined to be 2.5 in-lbs may lead to stress shielding and graft and a comparison tapping IT value of 1.5 in- resorption. To mitigate this, dynamic de- lbs was selected. Next, 15 specimens were signs have been evaluated in the past, but instrumented using a paired comparison they had varied clinical outcomes. An opti- between the two threshold tapping IT val- mal load sharing must exist between unre- ues (Group 1: 1.5 in-lbs; Group 2: 2.5 in-lbs). strained motion and rigid fixation. A novel Pedicle screws were in-line tested and load integrated plate-cage system was devel- to failure was measured in Newtons(N). oped that has dynamic features to enable RESULTS: The pedicle screw pullout load sharing with the graft. The purpose of strength was significantly increased (23%) in this study is to compare the stability of this 2 (877.9±235.2 N) compared to 1 system to the standard pedicle screw sys- (712.3±223.1 N, p=0.017). The peak tapping tem (PSS+C) . 112

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METHODS: Six ligamentous FSUs (3 L23 & 3 PSS+C. This aspect may enhance the load L45) were used. Pure moments were ap- sharing with the graft compared to pedicle plied in steps up to 10 Nm to simulate phys- screw rigid fixation. iological rotations in all planes. The proce- dure was repeated with a follower load of 400N in flexion and extension. Motion was GP23 recorded using the Optotrak System. After INITIAL RESULTS OF A FIVE-YEAR IN VIVO testing intact, anterior discectomy was per- LONGITUDINAL STUDY ON LUMBAR SEG- formed and cage of appropriate size was MENTAL AXIAL MOTION AND LOW BACK inserted close to posterior wall and PAIN InterPlate (IP+C) was implanted and tested Oshita Y, Espinoza Orías AA, Andersson GBJ, for ROM (Fig1a-c). The IP+C was removed An HS, Inoue N. and PSS+C was implanted without changing Department of Orthopaedic Surgery, Rush the cage position and tested again. A statis- University Medical Center, Chicago, Illinois tical paired-t analysis was performed for 60612 significant differences between the two groups. INTRODUCTION: Spinal instability, mani- RESULTS: Without preload, IP+C and PSS+C fested usually in torsion, is related to low significantly (P<0.05) reduced ROM in all back pain pathogenesis and disc degenera- rotations compared to intact. With preload, tion. Axial torsion is also known to be the both systems significantly reduced the mo- motion that is most susceptible to changes tion in extension compared to intact. In flex- brought on by disc degeneration (DD). This ion, only PSS+C significantly reduced the five-year longitudinal study aims to evaluate motion (Fig 1d). The increase in ROM for these in a cohort of controls and low-back IP+C compared to PSS+C was significant in pain subjects. bending and flexion. The increase in ROM MATERIALS: Supine and 50° rotated-torso for IP+C with preload in both extension and images of the lumbar spine of 83 volunteers flexion was significant when compared to (aged 22-59) were acquired at the beginning PSS+C. and after five years in this IRB-approved study. For the follow-up images, 23 subjects were available. The CT data was converted to point cloud 3D models to analyze the segmental axial rotation angular ranges of motion. T2-weighted MRIs were also ac- quired to grade the discs. Differences be- tween genders and symptoms were sought with unpaired t-tests. ANOVA was used to find significant associations between age and spinal level. Data is presented as mean±SEM. Significance was set at p<0.05.

DISCUSSION: IP+C provided significant seg- ment stability compared to intact which is essential to promote the fusion process. However, it is more flexible compared to 113

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INTRODUCTION: Epidemiological studies have reported increased incidence of annu- lar lesions in lumbar discs with increasing disc degeneration severity. It is hypothe- sized that disc failure location will shift from inner annulus layers in healthy disc to the peripheral annulus in degenerated discs. METHODS: A previously validated 3D, non- linear poro-elastic finite element model of

L4-L5 lumbar motion segment was modified RESULTS: Fig. 1 shows an increase in the to represent Thompson grade III and IV disc rotational ROM for controls after five years degeneration. Damage accumulation in (p=0.0172), while the symptomatic group healthy and degenerated discs was simulat- showed a decreasing trend (p=0.0869). Age ed by incorporating continuum damage me- did not influence changes in the rotational chanics formulation. Models were subjected ROM (p>0.43). Disc grade scores in females to cyclic compression and flexion. Failure increased in five years (p=0.0054), but for location and number of load cycles to fail- males they did not (p=0.66). Younger sub- ure were compared for different grades of jects (ages 20-30) saw a significant increase disc degeneration. in disc degeneration grade (p=0.0018), RESULTS: The number of load cycles to fail- while the older subjects (ages 40-50) main- ure decreased considerably with increasing tained theirs (p=0.80). Spinal level did not severity of disc degeneration. The numbers show influence on disc grade either: upper of load cycles to failure predicted for grade levels (L1-L4: p=0.14) and lower (L4-S1: III and IV degeneration discs under cyclic p=0.27. compression decreased by 53% and 93% DISCUSSION: This preliminary report shows respectively when compared with the cor- changes in spine parameters in a five year responding result in the healthy disc. In period related to torsional kinematics. No- healthy and grade III degeneration discs, tably, the increase in rotational ROM for the damage initiated in the inner posterior an- control group is evidence of increasing in- nulus and progressed radially towards the stability. However the symptomatic group periphery with increasing number of load exhibited a trend towards stabilization after cycles. In grade IV degeneration disc, dam- five years. Data also shows an increase in age initiated at the posterior outer periph- disc grade scores in the younger subjects ery of the annulus and propagated circum- that stabilize in the older group. ferentially. CONCLUSIONS: The current finite element models predicted the incidence of radial GP24 fissures in healthy and mildly degenerated FAILURE UNDER CYCLIC LOADING IN A discs while peripheral rim lesions were sim- LUMBAR DISC SHIFTS FROM INNER ANNU- ulated in moderately degenerated disc. This LUS LAYERS TO PERIPHERAL ANNULUS may be because in a healthy disc most of WITH INCREASING DISC DEGENERATION. the load is shared by nucleus that exerts Qasim, M., Natarajan, R.N., An, H., pressure at the inner annulus creating high- Andersson, G.B.J. er stresses. On the other hand, in a degen- University of Illinois at Chicago, IL, US Rush erated disc the load gets transferred to an- University Medical Center, Chicago, IL, US nulus creating higher stresses at the outer annulus. Results were consistent with the

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GENERAL POSTERS experimental and clinical observations in and moderate or weak positive correlation terms of the region of failure. between FH versus disc height, posterior wall height and disc grade. There was al- most no significance between FH and SLA GP25 (except L1/2), and height (except L1/2). Of IN VIVO CHARACTERIZATION OF THE 3D note, there was a moderate negative corre- LUMBAR FORAMEN GEOMETRY lation between FW and age. There were no Senoo I, Espinoza Orías AA, Park DK, differences between FW and disc height or Andersson GBJ, An HS, Inoue N segmental lordotic angle. Department of Orthopaedic Surgery, Rush DISCUSSION: The present study provided University Medical Center, Chicago, Illinois 3D foramen geometries of an asymptomatic 60612 cohort measured in vivo. Although data is limited to bony geometry, it could be used INTRODUCTION: There are many spinal as base line data for diagnosis of foraminal treatment options that require accurate stenosis and planning of treatment modali- knowledge of the lumbar foramen bounda- ty. ry. Alas, its definition is elusive due to the persistent use of planar methods to deter- mine the dimensions of a true 3D contour. GP26 This study aims to introduce innovative 3D CHANGES IN NUCLEUS PULPOSUS MRI CT-based analysis methods for the lumbar SIGNAL INHOMOGENEITY SHOW DISC foramen. DEGENERATION PROGRESS METHODS: This IRB-approved study ob- Yang S-H; Espinoza Orías AA; Pan C-C; Senoo tained CT scans in supine position of 59 I; Andersson GBJ; An HS; Inoue N healthy volunteers (31M/28F) that were Department of Orthopaedic Surgery, Rush used to create the 3D lumbar vertebral sur- University Medical Center, Chicago, Illinois face models. A floating spherical coordinate 60612 system was moved along the nerve root path inside each foramen using an algo- INTRODUCTION: MRI can monitor clinically rithm that calculated the distance from this the quality of the intervertebral disc center to the closest foramen elements through changes in the Nucleus Pulposus’ (facet joints, disc, pedicles). Its outcomes (NP) signal intensity. We propose that the were: foramen height (FH, distance be- location of the NP centroid weighted by tween any two points furthest apart from signal intensity could be a parameter to each other) and the foramen width (FW, define the signal homogeneity of a region of distance between any two points closest interest in MR data. together). These two parameters were cor- METHODS: T2-weighted sequences from a related with the vertebral posterior wall 1.5T MR unit provided mid-sagittal cuts height, segmental lordotic angle, disc height from 65 asymptomatic volunteers and MR disc grade (Pfirrmann’s). ANOVA (31M/34F, 22-59 y.o.) used in this IRB- and Pearson’s correlation were used for approved study. Three spine surgeons grad- statistical analyses. Significance level was ed 288 lumbar IVDs with a clearly identifia- set at p<0.05. ble NP boundary (Grade I: n=47, Grade II: RESULTS: Both FH and FW decreased with n=173, Grade III: n=68). A custom written age. FH and FW in the lower lumbar levels script was used to define the boundary, were significantly smaller than in the upper geometric and weighted centroids of each levels. In L5/S, there was moderate or weak NP. The weighted centroid was located in- negative correlation between FH and ages, side the region of the contour that had 115

GENERAL POSTERS highest homogeneous MR NP signal, but did not necessarily coincide with the geometric GP27 centroid. The distances between them in THE EFFECT OF DIFFERENCE IN HAM- the plane of the sagittal MR slice were cal- STRINGS FLEXIBILITY ON LUMBO-PELVIC culated and compared with ANOVA. Statis- RHYTHM tical significance set at p<0.05. Matsunaga,N.＊1 Okubo,Y.＊2 RESULTS: In 85.8% of NPs, the weighted Kaneoka,K.＊3 center was located posterior to the geomet- ＊1 Graduate School of Sport Sciences, ric center. The distance on the longitudinal Waseda University, ＊2 School of physical axis in Grade II discs was significantly larger Therapy, Faculty of Health and Medical than that in Grade I discs (p=0.035, Fig.1). Care, Saitama Medical University, ＊3 The distance on the axis perpendicular to Faculty of Sport Sciences, Waseda University the longitudinal axis in Grade III discs was significantly larger than that in Grade I and INTRODUCTION: The purpose of this study Grade II discs (p<0.01). was to investigate effect of difference in DISCUSSION: In the majority of NPs, the hamstrings flexibility on lumbo-pelvic weighted centers were located posterior to rhythm. the geometric centers. Grade II inter- METHODS: Thirteen young rhythmic gym- centroid distances were larger than in nasts (RG group) and 10 healthy women Grade I discs. This may suggest progressive (control group) participated in this study. signal intensity decrease in the anterior part After the markers were attached to the par- of NP during early stages of disc degenera- ticular points, the sagittal movements of tion. With advancing degeneration, the de- lumbar spine and pelvis during forward crease of signal intensity reached the poste- bending were collected by a digital camera rior part of the disc and the weighted cen- at a frequency of 30 Hz. Lumbar angle (LA) ters moved toward the geometric centers. and pelvic tilting angle (PTA) were defined This study showed the feasibility of the in- as the angle of Th12-L3 to L3-S1, and the ter-centroid distance as a NP homogeneity angle of the horizontal to anterior superior indicator. iliac spine-posterior superior iliac spine lines, respectively. The lumbar to hip ratio (L/H ratio) was calculated from LA and PTA. To normalize, we divided total time of for- ward bending into every 20%. Moreover, finger floor distance (FFD) was measured to investigate hamstrings flexibility. Group differences were assessed using independ- ent t-tests for each movement variables. RESULTS: The FFD of RG group and control group were -23.4±2.6 cm and -14.0±8.1 cm, that show a significant difference between the groups (p<0.001). In RG group, the av- erage of LA and PTA during total forward bending were 28.5±10.6°and 93.3±9.7°, respectively. Additionally, in control, the values were 43.3±8.7°and 65.2±9.2°, re- spectively. The above comparisons of LA and PTA between two groups shows signifi-

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GENERAL POSTERS cant differences (p=0.002, p<0.001). The related psychosocial factors are significant L/H ratio during total forward bending is in the onset of disabling back pain. Although summarized in Figure 1 the ergonomic effects on low back load while lifting have been investigated and are widely accepted in the workplace, few stud- ies have investigated the effect of psycho- social factors on low back load while lifting. The aim of this study was to determine the effect of mental processing on low back load during lifting. METHODS: Thirteen healthy subjects lifted a box from the ground in four different lift- ing tasks in randomized order: (1) squat

posture, with the back and hips flexed and There were significant differences between knees extended; (2) stoop posture, with the the groups in 0-20%, 20-40% and 40-60% of back and hips extended and knees flexed; forward bending (p=0.001, p=0.015). (3) squat posture with mental processing DISCUSSION: In RG group, L/H ratio was using arithmetic tasks; and (4) stoop pos- small. It suggests that flexible hamstrings ture with mental processing using arithme- which causes large pelvis anteversion has tic tasks. A 3D motion analysis system and lumbar spine less flexed. four force plates were used to record kine- Conclusion: RG group performed forward matic and kinetic data. Dynamic tri-axial low bending by large anteversion of pelvis and back joint moments and low back compres- small flexion of lumbar spine. Flexible ham- sion force were calculated as index parame- strings decrease the load of spine during ters of low back load under these experi- forward bending. mental conditions.

RESULTS: Mental processing significantly GP28 increased peak low back compression force EFFECT OF MENTAL STRESS ON LOW BACK and low back extension moment, but not LOAD WHILE LIFTING AN OBJECT lateral flexion or rotation moment, while Junji KATSUHIRA, Ph.D.1, Ko MATSUDAIRA, lifting in both lifting postures. Also, mental M.D, Ph.D.2, Kazuyuki IWAKIRI, Ph.D.3, processing decreased forward pelvic tilt in Hitoshi MARUYAMA, Ph.D.1 the stoop posture and increased trunk 1Department of Health Science, Interna- bending angles in the squat posture. tional University of Health and Welfare, DISCUSSION: Mental stress during lifting 2600-1 Kitakanemaru, Otawara, Tochigi tasks appears to affect both trunk and pelvis 324-8501, Japan, 2Clinical Research Center angles in the sagittal plane for squat and for Occupational Musculoskeletal Disorders, stoop postures, resulting in increased low Kanto Rosai Hospital, 1-1 Kizukisumiyoshi- back load. The present findings might help cho, Nakahara-ku, Kawasaki, Kanagawa to explain the effect of not only the ergo- 211-8510, Japan, 3National Institute of Oc- nomic demands of lifting tasks but also the cupational Safety and Health, Nagao 6-21-1, psychosocial factors responsible for the on- Tama-ku, Kawasaki, Kanagawa 214-8585, set of disabling back pain. Japan

INTRODUCTION: In addition to ergonomic factors such as frequent lifting, work-

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tension, lateral bending, and torsional mo- GP29 ments. BIOMECHANICAL ANALYSIS OF FUSION SEGMENT RIGIDITY UPON STRESS AT BOTH THE FUSION AND ADJACENT SEGMENTS - A COMPARISON BETWEEN UNILATERAL AND BILATERAL PEDICLE SCREW FIXATION Ho-Joong Kim, MDa, Kyoung-Tak Kang, MSb, Joon-Hee Park, MDc, Jin S. Yeom, MDa, Bong-Soon Chang, MDc, Choon-Ki Lee, MDc a Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital b Department of Mechanical Engineering, Yonsei University, c Department of Anesthesiology and Pain Medicine, Kangdong Sacred Heart Hospital, Hallym University Medical College, d Department of RESULTS: Under four moments, the unilat- Orthopaedic Surgery, Seoul National eral fixation leads to a reduction in the ROM University College of Medicine and Seoul increase at the adjacent segment after fu- National University Hospital sion, compared to bilateral fixation. At the fusion segment, larger motions were noted

INTRODUCTION: The biomehcanical stabil- at the fusion segment in the UF-HL and UF- ity of unilateral pedicle screw fixation relat- TL models under four moments, compared ed to the extent of decompression remains with the bilateral fixation models. The UF-TL unknown. The purpose of this study was to model demonstrated a vulnerability to tor- investigate the effects of unilateral pedicle sional moments at the fusion segment, with screw fixation on the fusion segment and an increase in remaining motion at the fu- the superior adjacent segment after one sion segment. Four models showed in- segment lumbar fusion using validated fi- creased maximal von Mises stress on the AF nite element (FE) models. at the adjacent segments under the four METHODS: Four L3-4 fusion models were moments, and unilateral fixation models led simulated according to the extent of de- to a prominent reduction in increased AF compression and the method of pedicle stress at the adjacent segment under the screws fixation in L3-4 lumbar fusion. These four moments models included hemi-laminectomy with DISCUSSION: The use of unilateral pedicle bilateral pedicle screw fixation in the L3-4 screw fixation is only warranted in limited segment (BF-HL model), total laminectomy decompression procedures such as hemi- with bilateral pedicle screw fixation (BF-TL laminectomies. However, reduced stiffness model), hemi-laminectomy with unilateral in fusion segment would have a beneficial pedicle screw fixation (UF-HL model), and effect on stress of adjacent segment. total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each sce- nario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, ex- 118

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GP30 IN VIVO RESPONSE TO A PARASPINOUS TENSION BAND DEVICE WITH TITANIUM COIL. AN OVINE IMPLANTATION STUDY E J Ehrhart, DVM, PhD, Dipl ACVP [1], Louie Fielding, MS [2], Amy Lyons Santoni, MS [3], Brandon G Santoni, PhD [3,4], Christian M Puttlitz, PhD [3], Dana R Ruehlman, DVM [1], Howard B Seim III, DVM, Dipl ACVS [1] A Simon Turner, BVSc, MS, Dipl ACVS, DVSc [1] [1] College of Veterinary Medicine and Biomedical Science, Colorado State RESULTS: All animals were healthy until University, Fort Collins, CO [2] Simpirica euthanasia. Gross examination revealed Spine, San Carlos, CA [3] Orthopaedic fibrous encapsulation of the PTB contiguous Bioengineering Research Laboratory, with midline ligamentous structures. Histo- Department of Mechanical Engineering, pathology with nondecalcified sections Colorado State University, Fort Collins, CO identified fibrovascular tissue had infiltrated [4] Foundation for Orthopaedic Research the coils. Minimal inflammation was associ- and Education, Tampa, FL ated with the coils. The strap was associat- ed with slightly higher yet mild inflammato- INTRODUCTION: Posterior lumbar dynamic ry scores. Bone remodeling indicated adap- stabilization devices have been proposed as tation to the PTB, trending toward bone an alternative to fusion. Dynamic compo- formation by the SPs. No reaction in distant nents and fixation elements may elicit a tissues or device debris was found; only biological response, affecting patient health minor fraying of the cut end of the straps. or implant performance. Coil stiffness increased approximately 33% METHODS: Eight sheep were implanted at 3 mo and 57% at 6 mo. Through the first with two paraspinous tension bands (PTB; 50% of elongation, stiffness was largely un- L1/2, L4/5) under IACUC approval. Each PTB affected, with most of the increase beyond comprised two titanium coil springs secured 50% elongation. to the spinous processes (SPs) with DISCUSSION: These results demonstrate UHMWPE straps. Four sheep were sacri- feasibility of the PTB as an alternative to ficed each at 3 and 6 months. PTB compo- spinal fusion. Inflammation was mild, with nents, local and distant tissues were exam- negligible inflammation associated with the ined macroscopically, and then evaluated coils and the response to the straps compa- histologically for qualitative changes and rable to that reported for sutures. The coils graded for inflammatory response, device remained functional, with increased stiff- findings and bone remodelling with a scor- ness beyond 50% elongation as load was ing system based on ISO standards. One coil transferred to adherent tissue. from each PTB underwent tensile testing to evaluate the functional impact of adherent tissue.

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angular instability between positions were GP31 13.9%, 8.5% and 13°, respectively. A signifi- INSTABILITY OF POSTERIOR VERTEBRAL cant correlation was identified between WALL CAUSES CANAL ENCROACHMENT IN change in ratio of occupation by bony frag- THE ELDERLY WITH VERTEBRAL ments and change in posterior vertebral PSEUDOARTHROSIS body height ratio (p=0.001). Tetsuo Hayashi, Takeshi Maeda, Eiji Mori, CONCLUSIONS: Our study demonstrated Takayoshi Ueta, Itaru Yugue, Osamu that collapse of the non-united posterior Kawano, Tsuneaki Takao, Hiroaki Sakai, vertebral wall and intracanal protrusion of Muneaki Masuda, Yuichiro Morishita, vertebral fragments would occur simulta- Keiichiro Shiba neously with axial loading, causing SCE. CT Department of Orthopedic Surgery, Japan taken in semi-sitting position appears quite Labour Health and Welfare Organization, useful to evaluate the amount of SCE by an Spinal Injuries Center, Fukuoka unstable posterior wall.

INTRODUCTION: The purpose of this study was to elucidate effects of loading associat- GP32 ed with SCE in patients with insufficient DEVELOPMENT OF A NOVEL PERCUTANE- bone union following vertebral fractures in OUS GUIDE WIRE (S-WIRE™) FOR PERCU- the elderly using computed tomography TANEOUS PEDICLE SCREW INSERTION –ITS (CT) myelography in two different positions. EFFICACY AND SAFETY– METHODS: Seventeen patients (mean age, Ishii K.1, Ishihara S3., Kaneko Y.4, Iwanami 77.4 years) with various degrees of neuro- A.1, Hikata T.1, Hosogane N.1, Watanabe logical deficit due to insufficient bone union K.2, Nakamura M.1, Toyama Y.1, at both vertebral body and posterior verte- Matsumoto M.1 bral wall were prospectively examined in 1Dept. of Orthopaedic Surgery, 2Advanced this study. CT myelography was performed Therapy for spine and spinal cord diseases, in both semi-sitting and supine positions. School of Medicine, Keio University, Tokyo, Kyphotic angle, rate of dural compression, Japan 3Dept. of Orthopedic Surgery, Nerima ratio of occupation by bony fragments and General Hospital, Tokyo, Japan 4Dept. of posterior vertebral body height ratio were Orthopedic Surgery, Kawasaki Municipal measured and compared between posi- Kawasaki Hospital, Kanagawa, Japan tions. RESULTS: Ratio of occupation by bony INTRODUCTION: In minimally invasive spi- fragments was significantly higher in the nal fusion surgery such as MIS-TLIF, the semi-sitting position (47.9%) than in the placement of percutaneous pedicle screw supine position (33.9%, p<0.001). Similarly, (PPS) is necessary, but several intraopera- posterior vertebral body height ratio was tive complications have been reported. One significantly lower in the semi-sitting posi- of the serious complications is the great tion (67.8%) than in the supine position vessel and bowel injuries due to the anteri- (76.3%), indicating a significant loss of ver- or migration and penetration of the guide tebral height in the semi-sitting position wire through the anterior cortex of the ver- (p<0.001). Rate of dural compression was tebral body. We have established a novel likewise significantly higher in the semi- percutaneous guide wire (S-wire™) in MIS- sitting position (48.6%) than in the supine TLIF procedure. Our aim was to investigate position (33.3%; p<0.001). Change in ratio the biomechanical characteristics of S- of occupation by bony fragments, change in wire™ in cadaveric spines by comparing posterior vertebral body height ratio and conventional wire, and evaluate the efficacy 120

GENERAL POSTERS and safety of S-wire™ in the clinical trial. Seoul National University Hospital METHODS: S-wire™ consists of a hollow and braided wire which extends at the one side INTRODUCTION: It is unknown whether of the tips. Fresh cadaveric lumbar spines osteotomies at the base of the spinous pro- from L1 to L5 (N=3) were used for biome- cesses might increase the risk of spinal in- chanical comparison between S-wire™ and stability despite preservation of the supra- a conventional wire. The push-out (1 cm spinous and inter-spinous ligaments. There- migration) and penetration forces were fore, the aim of this study was to evaluate measured in two wires. and compare the biomechanical behavior of RESULTS: A braided part of S-wire™ was the lumbar spine after posterior decom- moderately bent or unraveled when the pression with spinous process osteotomies axial force was applied, resulting in the in- (SPO) technique or conventional laminec- creased resistance against anterior migra- tomy (CL) technique using finite element tion. The mean push-out force in S-wires™ model. and conventional wires were 15.5±1.9N and METHODS: Three validated lumbar FE mod- 5.7±0.8N (P<0.0001), respectively. The els (L2-5) which represented intact spine mean penetration forces in S-wires™ and and two decompression models using SPO conventional wires were 69.1±4.2N and and CL technique were developed. Decom- 37.1± 4.8N （P<0.0005）, respectively. In pression procedures were simulated at the the clinical trial of a total number of 212 S- L3-4 segment in the SPO and CL mod- wires™, neither penetration of the anterior els.Under 400 N pre-compressive loading, wall nor breakage of wire was observed. 7.5 Nm moments simulated flexion, exten- Interestingly, 181 of 212 S-wires™ （85%） sion, lateral bending, and torsion were im- revealed increase of pull-out force after the posed. In each model, the ranges of motion, placement. the maximal von Mises stress of the annulus DISCUSSION: S-wire™ could prevent the fibrosus, and the intradiscal pressures at the anterior migration and the penetration of index segment (L3-4) and adjacent seg- the anterior wall of the vertebral body and ments (L2-3 and L4-5) were analyzed. Facet it is safe and useful device for not only MIS- contact forces were also compared among TLIF but balloon kyphoplasty. three models under the extension and tor- sion moments. RESULTS: Compared to the intact model, GP33 the CL and SPO models had increased range of motion and annulus stress at both the FINITE ELEMENT ANALYSIS FOR COMPARI- index segment (L3-4) and the adjacent seg- SON OF SUPRASPINOUS OSTEOTOMIES ments under flexion and torsion. The SPO TECHNIQUE WITH CONVENTIONAL LAMI- model demonstrated a reduced range NECTOMY ofmotion and annulus stress than the CL Ho-Joong Kim, MDa, Kyoung-Tak Kang, model. The both of CL and SPO models had MSb, Choon-Ki Lee, MDc, Bong-Soon Chang, the increase of the facet contact force at MDc, Jin S. Yeom, MDa the L3-4 segment under the torsion mo- a Spine Center and Department of Ortho- ment, compared to that of intact model. In paedic Surgery, Seoul National University contrast, under the extension moment, College of Medicine and Seoul National Uni- three models demonstrated the similar fac- versity Bundang Hospital b Department of et contact force even at the L3-4 model. Mechanical Engineering, Yonsei University c Department of Orthopaedic Surgery, Seoul National University College of Medicine and

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extension (FE). IDP was recorded and IDP slope/intercept were calculated based on a moment-IDP curve. Disc height was calcu- lated via CT scan and correlated with IDP (Pearson). RESULTS: C45 and C56 IDP measured in the neutral position was significantly increased with application of FL, but the IDP slope with increasing FE rotation was not. C5-6 tended to have a higher IDP in the neutral

position than C45 but a lower IDP slope as a DISCUSSION: The spinous process osteoto- result in FE rotation. IDP and disc height my technique for decompression led to bet- showed no correlation in the neutral posi- ter postoperative stability under flexion and tion, however a significant correlation was torsion than the conventional laminectomy. observed for flexion with no compression This suggests that the continuity of PLC has (.709, *p=.015) and for flexion (.666, importance for the stability of lumbar spine *p=.025) and extension (.629, *p=.038) with even after decompression surgery. application of FL.

GP34 CORRELATION BETWEEN INTRADISCAL PRESSURE AND DISC HEIGHT: EFFECT OF FOLLOWER LOAD AND ROTATION Kevin M. Bell, MS; Yiguo Yan, MD; Tiffany Dugan, MD; James D. Kang, MD Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, USA

INTRODUCTION: The relationship between in vivo and in vitro intradiscal pressure (IDP) remains unclear. This study sought to ex- plore this relationship in an in vitro cervical DISCUSSION: The effects of adding FL com- spine model by simulating the only known pression approximates the effect of the pa- in vivo study (Hattori, 1981). The current tient going from the supine to seated posi- study combined simulated muscle loading tion. However, data showed a higher in- (Follower Load, FL) with a robotic/UFS test- crease in IDP with flexion than extension, ing system to more closely (Pospiech, 1999) whereas Hattori’s study showed the oppo- replicate Hattori’s in vivo methodology. Fi- site effect on average, although this was not nally, in an attempt to bridge the gap be- consistent and depended on degeneration tween in vivo and in vitro the relationship grade. The high significant correlation be- between disc height (as calculated by CT) tween IDP slope and disc height may give and IDP was explored. insight into the mechanics of IDD and is of METHODS: FL (100N) was applied to N=12 great interest to researchers and clinicians. human (C37) cervical cadaveric specimen and the robot was then controlled to a pure moment target of 2.0 Nm for flexion and

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conus in the neutral (anatomic) position, GP35 the medullar cone displaced caudally in the IN VIVO MRI MEASUREMENT OF SPINAL spinal canal by 5.2 ± 1.5 mm with bilateral CORD DISPLACEMENT IN THE THORACOL- SLR (p=0.000). This displacement was also UMBAR REGION: PART 2 - COMPARISON statistically significant when compared with BETWEEN UNILATERAL AND BILATERAL the right SLR (p=0.000) and left SLR STRAIGHT LEG RAISE TESTS. (p=0.000). The ICCs were as follows: bilat- Marinko Rade 1, Mervi Könönen 2, Ritva eral SLR = 0.994, right SLR = 0.997, left SLR= Vanninen 2, Michael Shacklock 3, Markku 0.996, unilateral SLR (right and left SLR Kankaanpää 4, Olavi Airaksinen 1 compared) = 0.997. Number of required 1. Department of Physical and Rehabilita- subjects to get statistically significant results tion Medicine, Kuopio University Hospital, (p<0.05) is 3 for Bilateral SLR. Kuopio, Finland 2. Department of Radiology, CONCLUSIONS: The results showed that Kuopio University Hospital, Kuopio, Finland. the distal displacement of the medullar 3. Neurodynamic Solutions, Adelaide, Aus- cone was significantly greater (almost dou- tralia 4. Department of Physical and Reha- ble) with the bilateral compared to the uni- bilitation Medicine, Tampere University lateral SLR. We hypothesize that this great- Hospital, Tampere, Finland er movement may be because more force was transmitted to the cord through a larg- INTRODUCTION: Following on from our er number nerve roots with the bilateral previous study (Rade et al 2012) we further than unilateral SLR. measured spinal cord displacement during the passive bilateral SLR in asymptomatic subjects and compared these data with GP36 those of the unilateral. The corollary is then THREE DIMENSIONAL ASSESSMENT OF to develop a better understanding of the LUMBAR FACET JOINT TROPISM IN local mechanical responses and possible ASYMPTOMATIC AND LOW BACK PAIN clinical implications. SUBJECTS METHODS: Sixteen asymptomatic male vol- Huh J-S, Espinoza Orías AA, Otsuka Y, Simon unteers were scanned with 1.5T magnetic P, An HS, Andersson GBJ, Inoue N resonance scanner (Siemens Avanto, Erlan- Department of Orthopaedic Surgery, Rush gen, Germany) using T2 weighted turbo spin University Medical Center, Chicago, Illinois echo fat saturation sequence (TR 3880ms, 60612 TE 80ms, 10 slices, slice thickness 3mm, gap 0.3mm, FOV 400mm2, pixel size INTRODUCTION: Facet joint (FJ) orientation 1.3mm*0.9mm). Coronal slices were aligned and tropism are important parameters to with spinal cord. analyze FJ pathogenic contributions to vari- Displacement of the conus relative to the ous types of spinal diseases. However, lim- adjacent vertebral body during bilateral SLR ited data on orientation data and lack of a was quantified and compared with data on proper tropism definition make this topic the right SLR, left SLR and the neutral (ana- controversial. This study aims to describe tomic) position. Each movement was per- relationships between lumbar FJ 3D orienta- formed twice in order to provide intraclass tion, tropism, age, gender, level, and pres- correlation coefficients (ICC). Four practi- ence of chronic low back pain (LBP) and to tioners performed the maneuvers in a ran- evaluate possible cutoff values to define dom sequence in order to avoid possible tropism. series effects. METHODS: IRB-approved in vivo 3D orienta- RESULTS: Compared to the position of the tion measurements of lumbar FJs were per- 123

GENERAL POSTERS formed on 92 volunteers (58 asymptomat- INTRODUCTION: Etiology of Modic changes ic/34 chronic LBP subjects) using CT-based is not well understood.1 We hypothesize 3D facet joint surface models. Each facet that Modic changes are a direct conse- joint surface was represented by its normal quence of changes in biomechanical envi- vector, which was subsequently plotted on ronment due to disc herniation and thus a unit sphere. Differences in symmetry be- obey Wolff’s law of bone remodeling. tween left and right orientation vectors METHODS: Strain energy density theory of (tropism angle) were calculated between adaptive remodeling was implemented in each unit vector and its corresponding mir- our experimentally validated 3D finite ele- ror image. Angle differences were evaluated ment model of lumbar spine (L3-L5). The with unpaired t tests. Gender, age and level algorithm was executed for flexion (10Nm), effects were analyzed by a one-way ANOVA extension (10Nm), and compression (400N) with Fischer post hoc test, and significance after posterolateral disc herniation at L4-L5 set at p<0.05. Cutoff values attempted were IVD (nucleus pulposus-NP volume removed the mean and one standard deviation of - 2cm3; annulus fibrosus (AF) incised - angle difference, 5 and 10 degrees, and 44mm2). were analyzed by a chi-square test. RESULTS: In L5, the average apparent densi- RESULTS: The orientations of both superior ties decreased by 55% beneath the herniat- and inferior facets changed gradually from ed region due to no load transmission and sagittal to coronal orientation from L1 to L5. hence decrease in strain energy density More coronal orientation of L1 superior (SED) of that region, Figure 1. facets and more horizontal orientation of L5 Average apparent density increased by inferior facets revealed transitional features 101%, in the regions beneath the unaffect- of spine. The mean tropism angle was 7.65°. ed NP due to increase in SED. Likewise, ap- The mean angle difference of symptomatic parent density of L4 showed an increase of group was significantly larger than that of 129% in the region above the unaffected asymptomatic group. The cutoff values over NP. mean angle difference showed significantly DISCUSSION: Decreases in the density more tropism in symptomatic group than around herniated region are similar to loss asymptomatic group, the others did not. of trabecular bone and bone marrow deple- CONCLUSION: Our results of more tropism tion observed clinically as Modic changes.1 in symptomatic group based on a three- Our data concur with previous studies dimensional orientation model supports the which state that Modic changes may be due hypothesis of causative role of tropism to to changes in biomechanical environment of LBP. the surrounding bone.2, 3 Bone resorption occurred near the affected areas in the ver- tebra below the herniated IVD, with in- GP37 creases in bone densities in other areas, MODIC CHANGES FOLLOW BONE REMOD- both in agreement with literature.2 ELING PRINCIPLES Agarwal A; Kaul V; Goel VK; Agarwal AK Engineering Center for Orthopaedic Re- search Excellence (E-CORE), Departments of Bioengineering and Orthopaedic Surgery, University of Toledo, Toledo, OH 43606, Cor- responding author: [email protected]

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sion (10Nm), and compression (400N) after posterolateral disc herniation at L4-L5 IVD were predicted. The volume of nucleus pulposus (NP) removed was 2cm3 and area of annulus fibrosus (AF) incised was 44mm2. RESULTS: Regional endplate thickness changed substantially after disc herniation, Figure 1. However, the mean value was close to the initial value of endplate thick- ness (0.5mm) assigned in the model.

REFERENCES: 1. Rahme, R. et al. AJNR2008 2. Moore, R.J. et al. Spine1996 3. Malinin, T. et al. Spine2007 DISCUSSION: Change in morphology is at- GP38 tributed to the Wolff’s law of bone remod- CHANGES IN ENDPLATE THICKNESS AFTER eling. It is quite evident from the contour DISC HERNIATION – A BIOMECHANICAL that the posterolateral (left) region of the PERSPECTIVE vertebral endplate became thinner and the Agarwal A; Goel VK; Agarwal AK remaining region became thicker. Central Engineering Center for Orthopaedic Re- regions of endplate (associated with NP) search Excellence (E-CORE), Departments of were more affected than the peripheral Bioengineering and Orthopaedic Surgery, regions (associated with AF). Changes in University of Toledo, Toledo, OH 43606, Cor- endplate morphology are very critical as it responding author: [email protected] could change the nutrient permeability of the endplates affecting the IVD, starting a

INTRODUCTION: Morphological features of vicious cycle of degeneration. endplates play a major role in intervertebral disc (IVD) health, but the opposite could GP39 also be true with changes in IVD affecting EFFECT OF AN INTERSPINOUS IMPLANT ON the morphological features of endplates. IN VIVO DYNAMIC LUMBAR SPINE STIFF- We hypothesize that changes in biomechan- NESS AND BIPLANAR INTERSEGMENTAL ical environment due to disc herniation will MOTION change the thickness of the endplates at the Marek Szpalski, MD; Laurent G. Fabeck, MD; index level. Robert Gunzburg, MD, PhD; Christopher J. METHODS: Strain energy density theory of Colloca, DC; Jeb McAviney, DC; Mostafa adaptive remodeling was implemented in Afifi, PhD; Robert J. Moore, PhD; Brian J. our experimentally validated 3D finite ele- Freeman, MD ment model of lumbar spine (L3-L5).1 The Department of Orthopedics, Centre model response for flexion (10Nm), exten- Hospitalier Molière Longchamp, Brussels,

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Belgium; Departments of Orthopaedics and 6 Hz (p=0.002) and 12 Hz (p=0.011) testing. Traumatology, Université Libre de Bruxelles, Significant decreases in DV accelerations at Brussels, Belgium; Department of L3-L4 were also found for 12 Hz testing Orthopaedic Surgery, Edith Cavell Clinic, (p=0.024). In the AX plane, significant 2- to Brussels, Belgium; PhD Kinesiology Program, 6-fold reductions in intersegmental acceler- School of Nutrition and Health Promotion, ations were found for 2 Hz testing (p=0.026, Arizona State University, Tempe, Arizona, p=0.001) in animals with an interspinous U.S.A; Sydney Scoliosis Clinic, Sydney, implant. Australia; Faculty of Kinesiology, University DISCUSSION: This experimental model pro- of Calgary, Alberta, Canada; Adelaide vides novel evidence that an interspinous Centre for Spinal Research, Adelaide, device with tension band provides increased Australia; School of Medicine, Faculty of segmental and intersegmental lumbar sta- Health Sciences, University of Adelaide, bility in the DV and AX planes and further Australia confirms the frequency dependence upon stiffness testing. These results may be use- INTRODUCTION: This study examined the ful when considering non-fusion devices for effect of an interspinous implant on lumbar patients with symptomatic lumbar instabil- spine stiffness and intersegmental accelera- ity. tions in the dorsoventral (DV) and axial (AX) planes in an in vivo ovine model. METHODS: Dynamic lumbar spine stiffness GP40 and intersegmental accelerations were T2 VALUES OF HUMAN LUMBAR DISCS: quantified in eight anesthetized adolescent TEMPLATE-BASED SEGMENTATION AND Merino wethers 68.4 kg (s.d.=4.5 kg). Two, VARIATIONS WITH AGE, SEX AND LEVEL 6, and 12 Hz oscillatory loads were random- WC Bae, +T Yamaguchi, R Pichika, ME Lenz, ly applied to the L3 spinous process in the T Fujiwara, GM Bydder, K Mausda prone and oblique positions using a previ- University of California, San Diego, San ously validated technique. In each position, Diego, CA, USA. + Doshisha University, measurements were obtained with the Kyoto, Japan lumbar spine intact; and following insertion of an InSwing® interspinous device at L3-L4 INTRODUCTION: Quantitative MRI is useful secured by a tension band. DV stiffness for evaluation of disc degeneration. Howev- (N/mm) was calculated over 6 trials during er, segmentation of NP and AF can be diffi- 10 seconds of testing at each loading fre- cult, when the signal intensity from the NP quency in each position. L3-L4 accelera- is low and indistinct from the AF. Aim of this tions were derived from tri-axial accelerom- study was to describe a template-based eters mounted to steel pins rigidly affixed to technique to segment NP indirectly, and to the L3 and L4 spinous processes. Stiffness report age- and level-dependent changes in and accelerations for each position and T2 of human discs. condition were compared using one-way METHODS: Lumbar spines (L1 to L5) from ANOVA with repeated measures and post- cadavers (n=84, 58±10 yrs, 18F, 66M) were hoc analyses. obtained from tissue bank and imaged at RESULTS: Mean DV stiffness ranged from 3T. Spin echo T2 mapping was performed: 6.73 to 28.67 N/mm intact compared to mid-sagittal plane, FOV=16 to 20 cm, slice=3 12.39 to 40.32 N/mm for the interspinous mm, TR=2000 ms, TE=10 to 90 ms (8 TEs). implant condition. Significant increases in Discs (n=334) were Pfirrmann-graded DV lumbar spine stiffness were observed for (1=normal, 5=degenerate) and T2 values determined. Using grade 1 discs (n=11), 126

GENERAL POSTERS template of AF boundary and NP region of interest (A) was created, and applied to GP41 other discs using affine registration (B) to SHEAR STIFFNESS OF BABOON INTERVER- match target AF. Using this method, T2 val- TEBRAL DISC ASSESSED BY MR ues of NP and AF of each disc was deter- ELASTOGRAPHY mined. Ephraim I Ben-Abraham, Jun Chen, Ph.D., RESULTS: Grade 1 discs readily segmented Richard L Ehman, M.D. into NP and AF due to bimodal distribution Mayo Clinic, Rochester, Minnesota, United of T2 values (A), unlike higher grade discs. States T2 values of the NP varied with age (p<0.001) but not with sex (p=0.4) or level INTRODUCTION: There are many tech- (p=0.5). T2 values of the NP decreased at a niques to characterize disc degeneration rate of -1.1 ms/yr (intercept 136 ms), a sig- such as x-ray and MRI methods. However, nificant correlation (p<0.001, r2=0.22). This no techniques exist to directly assess the was stronger than that between Pfirrmann material properties of the intervertebral grade and age (r2=0.10). T2 values of the AF disc (IVD) within the intact spine. Magnetic did not vary with age (p=0.9), sex (p=0.54) resonance elastography (MRE) is a sensitive, or level (p=0.5). phase contrast-based imaging technique for non-invasively mapping the mechanical properties of tissues. The objective of this study is to determine if MRE is capable of detecting shear wave propagation and gen- erating a shear stiffness map for an axial cross-section of the IVD. METHODS: A fresh frozen lumbar spine segment (L3-L4) was tested with posterior elements removed to increase flexibility. Shear vibration at 1,000 Hz was applied to the upper vertebral body while the lower vertebral body was fixed using a custom-

built testing fixture. The disc specimen was DISCUSSION: A template-based method of imaged with a spin echo-based MRE se- NP segmentation was developed and used quence in a standard 1.5T GE full-body MRI to assess cadaveric discs. The novel tech- scanner with a 5-in diameter receive RF coil nique is useful when other methods of di- (TE/TR = 50/290 ms). rectly segmenting NP fail due to low image RESULTS: Propagating waves were seen in contrast, as is often the case for degenerat- an axial cross-section of the IVD in all three ing discs. Additional studies to compare motion-encoding directions. A representa- accuracy of this method to reference stand- tive filtered wave image showing the shear ards would be useful. Our findings of non- wave displacement pattern is shown (Fig. effect of gender and significant decrease in 1A). Distinct wave patterns can be seen in T2 of the NP with aging agree with past the annulus and nucleus pulposus, with the studies. Advances in knowledge include nucleus showing a much shorter wave- histogram of T2 values in discs, rate of length (“softer”). A shear stiffness map was change of T2 values with age. generated from the MRE data in the IVD

(Fig. 1B). Although the wavelength was too

long in the annular region to reliably ap-

proximate stiffness, the nucleus showed an 127

GENERAL POSTERS average shear stiffness of 79 ± 15 kPa. linkage robot capable of six-axis motion. Media (10% FBS) is pumped through the chamber (1.25 ml/min), and temperature and gas concentrations are controlled to 37 °C and 5/5% CO2/O2. FSUs are subjected to three cycles of FE using adaptive displace- ment control to determine the pure mo- ment path. FSUs are rotated through (1)

large amplitudes—moment-angle curves DISCUSSION: These results suggest MRE is enter the linear region and (2) small ampli- capable of detecting shear wave propaga- tudes—moment-angle curves remain within tion in the IVD, creating a stiffness map of the toe region. Following three cycles of the IVD, and can differentiate the nucleus preconditioning, FE kinematics are repeated and annulus regions. Based on these results, for 1 h at 0.33 °/s. Unloaded FSUs (L2-3) MRE could provide a valuable tool to study serve as controls. Outcome measures in- the mechanical properties of healthy and clude relative mRNA expression of catabolic degenerated discs, with the potential for (MMP-3 and ADAMTS-5), inflammatory investigating conservative treatments for (COX-2), and anabolic (Agg) genes alongside patients with low back pain. changes in mechanical outcomes—load re- laxation and hysteresis. GP42 RESULTS: Large amplitudes relative to small ones showed relative mRNA expression EX-VIVO RESPONSE OF SPINAL CARTILAGI- changes that were pro-inflammatory in NP NOUS TISSUES TO FLEXION-EXTENSION OF and FC, catabolic in FC, and anti-anabolic in RABBIT FUNCTIONAL SPINAL UNIT NP. Hysteresis changed over loading cycles Hartman RA, Bell KM, Yurube T, Vo NV, in the large amplitude but not the small Kang JD, Sowa GA amplitude FSUs. University of Pittsburgh, Department of DISCUSSION: Preliminary data suggest larg- Physical Medicine & Rehabilitation; De- er amplitudes of FE, which reflect physiolog- partment of Bioengineering; Department of ic motion extremes, promote inflammation Orthopaedic Surgery, Pittsburgh, PA, USA and matrix degradation in the NP and FC.

INTRODUCTION: Intervertebral disc (IVD) degeneration is characterized by degrada- GP43 tion of disc extracellular matrix and is fre- Empty quently coupled with facet cartilage (FC) degradation. Mechanical loading plays an important role in degeneration, yet flexion- GP44 extension (FE) has not been investigated STATIC AND DYNAMIC COMPRESSIVE and simultaneous cellular responses to me- CHARACTERIZATION OF LUMBAR INTER- chanical loading in IVD and FC remain un- VERTEBRAL DISCS OF THE ADULT NEW known. The goal of this study was to eluci- ZEALAND WHITE RABBIT FOLLOWING IN date the influence of repeated FE simulta- VIVO DEGENERATION OR EX VIVO ANNU- neously in IVD and FC using viable function- LAR PUNCTURE al spinal units (FSU) loaded ex vivo. †Taborek, Alex P; †Chen, Albert C; MATERIALS AND METHODS: Freshly har- †*Yamaguchi, Tomonori; †Nguyen, vested rabbit L4-5 FSUs are mounted within Quynnhoa T; *Inoue, Nozomu; †Sah, Robert a chamber that interfaces with a serial- L; †Masuda, Koichi.

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†University of California-San Diego, La Jolla, and dynamic biomechanical tests may give CA, *Doshisha University, Kyoto, Japan greater insight into the functional changes induced by anular injury. INTRODUCTION: In animal models, interver- tebral disc (IVD) degeneration, induced in vivo by anular puncture, involves mechani- cal, biochemical, geometric, and histologic changes. The effect of anular puncture on biomechanical properties depends on de- fect dimensions, but has not been studied in rabbits. The objectives of this study were to investigate the biomechanical consequenc- es of defect size made with 18-27G needles during ex vivo anular puncture and of de- generation induced in vivo by 18G anular puncture (equilibrium modulus and dynamic stiffness of lumbar IVDs) of the rabbit. METHODS: Adult rabbits, 9-15 months, 4.5- 5kg were used. Ex vivo study: Rabbits (n=10) were sacrificed and 40 bone-disc-bone units (BDB) were obtained (L1/2-L4/5). IVD thick- GP45 ness was determined (µCT and 3D models) IN VIVO THREE-DIMENSIONAL LUMBAR and anular puncture was performed (27, 22, KINEMATICS: DIFFERENCES BETWEEN 18G). In vivo study: Rabbits (n=8) were sub- STATIC AND DYNAMIC MEASUREMENTS jected to anular puncture (18G; L2/3 and William Anderst, Ameet Aiyangar, Liying L4/5) to induce IVD degeneration. After 1 Zheng, James Kang, Xudong Zhang month, 32 BDB segments were obtained. University of Pittsburgh Department of Or- Biomechanics: BDB samples were tested in thopaedic Surgery unconfined compression between porous platens (10 and 15% offset), allowed to INTRODUCTION: It is unclear how well static stress-relax to equilibrium, then subjected radiographic measurements represent lum- to dynamic oscillations of 0.5% amplitude at bar kinematics during dynamic movement. 1 Hz. Equilibrium modulus and dynamic The purpose of this study was to compare in stiffness were determined. vivo lumbar kinematics when assessed un- RESULTS: Ex vivo puncture with an 18G der static and dynamic conditions. needle, but not smaller needles, caused a METHODS: Three healthy subjects (25 decrease in dynamic IVD compressive prop- ±1yrs) consented to participate in this IRB- erties without affecting IVD thickness approved study. Three-dimensional lumbar (p<0.05). In contrast, in vivo puncture led kinematics were determined using a biplane to decreases in both static and dynamic X-ray system and a volumetric bone-model- compressive properties (p<0.05) and a re- based tracking process that has been vali- duction in IVD thickness (p<0.01). (Fig.1A, B) dated in vivo to have sub-millimeter accura- DISCUSSION: Anular puncture with an 18G cy. Each subject performed a two-handed needle had distinct effects on IVD ex vivo straight-legged lifting task with three and in vivo, indicating that softening is due weights (10, 20, 30 lbs.) while biplane radi- to both direct mechanical perturbation and ographs were collected at 30 images per response to injury in vivo. Using both static second. Biplane radiographs were also col-

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GENERAL POSTERS lected with the subjects holding the weights stationary at approximately 45° and 60° of GP46 trunk flexion. Intervertebral flexion- OPTICAL COHERENCE TOMOGRAPHIC extension (FE) and disc compression- ELASTOGRAPHY MEASURES INHOMOGE- distraction were compared at each verte- NEOUS STRAIN IN ANNULUS FIBROSUS bral level from L2 to S1 at the instants LOADED IN SHEAR where the total L2/S1 angle determined Sang Kuy Han, Chao-Wei Chen, Chia-Chu from the dynamic trial most closely Chou, Yu Chen and Adam Hsieh matched the total L2/S1 angle at each static Fischell Department of Bioengineering, position (Figure 1). University of Maryland, College Park, MD, United States; Department of Orthopaedics, University of Maryland, Baltimore, MD, United States

INTRODUCTION: Shear stress is considered to be an important contributor health of the annulus fibrosus (AF). AF in shear mechanics has been studied, but structural interactions between lamellar and inter-lamellar/cross-

bridge networks are not well understood. RESULTS: Intervertebral FE range of motion We utilized optical coherence tomography averaged 10.0±4.1°, 11.3±2.0°, 13.8±1.6°, (OCT), which can capture AF mesostructural and 14.5±3.2° for the L2/L3, L3/L4, L4/L5 features, to obtain elastographic strain dis- and L5/S1 motion segments, respectively. tributions during shear loading. Static versus dynamic intervertebral FE dif- METHODS: Fresh-frozen porcine lumbar AF ferences averaged 1.0±0.5°, and these dif- tissues (N=4) were subjected to shear ferences were not affected by weight, mo- strains of 20% and 40%. A swept-source tion segment or trunk flexion angle. Static OCT system was paired with a materials versus dynamic differences in disc strain testing system to visualize a 2 x 2 x 1.8 mm3 averaged 6.6±5.2% in the anterior annulus volume within AF samples loaded in shear and 15.4±14.1% in the posterior annulus, (Fig. 1a-b). Using optical flow analysis, shear and these differences were more pro- strain distributions were computed (Fig 1c- nounced in more flexed positions. e). Images were then segmented to differ- DISCUSSION: The results suggest that while entiate lamellar and inter-lamellar/cross- lumbar kinematics measured in static posi- bridge strain. tions may represent dynamic kinematics sufficiently for clinical use, the small angular differences substantially affect estimates of lumbar disc deformation. Data should be collected during dynamic motion when at- tempting to evaluate lumbar disc stress and strain.

RESULTS: Local AF shear strains in inter- lamellar/cross-bridge network were 4.0% +/- 1.2, 6.6% +/- 2.5 for 20 and 40% applied shear strain, respectively. Lamellar shear strains (8.0% +/- 3.3, 12.3% +/- 2.6 at 20 and 130

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40% respectively) were significantly higher (anterior PMMA augmentation from cranial than those measured in the inter- to caudal endplate) and directed lamellar/cross-bridge structures. vertebroplasty (VP). DISCUSSION: To our knowledge, this is the METHODS: 32 specimens were harvested first study to quantify strain distributions from 6 cadavers (T5-S1, age 74±14, BMD between the lamellar and inter- 0.7±0.2). Each consisted of one full vertebra lamellar/cross-bridge compartments of the and 2 adjacent hemi-vertebrae (physiologic AF. This was achievable due to the load transmission/sharing). Lytic lesions mesoscale imaging capabilities of OCT. with peripedicular cortical disruption were Based on our results, it can be concluded created and filled with adipose tissue to that the two compartments behave distinct- simulate tumor bulk. Specimens were ran- ly during AF shear. Their differential me- domly distributed between 3 groups: lesion chanics might play important roles in tissue alone (control), standard VP, and directed damage and cell regulation. Figure 1. (a) peripedicular augmentation using a target- Custom-designed shear testing system with ed system into the lytic lesion. Specimens OCT scanner. (b) Schematic illustration of then underwent unconstrained compres- tissue loading. (c) OCT images of mesoscale sion using a bilateral cable system passing structures before (red) and after (green) through the approximate center of rotation applying shear load. L=lamellar. of the vertebral body. IL=Interlamellar. CB=Cross-bridge. (d) Dis- RESULTS: Height reduction was significantly placement vectors (arrows) obtained from higher in the anterior body (p=0.003). Mean optical flow analyses. (e) Strain map for the height loss was least for the group with di- corresponding area shown in (d). rected VP (Table 1). The use of directed VP demonstrated the least increase in kypho- sis. Average injected cement volume for the GP47 directed VP was 49% less than the standard DIRECTED VERTEBROPLASTIC CEMENT IN- VP (p<0.0005). The injected cement to ver- JECTION AT LYTIC METASTATIC LESION RE- tebral body volume ratio was lower for di- STORES STRENGTH WITH MINIMUM CE- rected than for standard VP. Data demon- MENT VOLUME strated that cement augmentation signifi- +1Eeric Truumees, +2Ata M. Kiapour, cantly increased normalized failure stress in +2Vijay K. Goel, +2Constantine K. lumbar specimens (p=0.04). Demetropoulos +1Seton Spine and Scoliosis Center, Austin, TX; +2Engineering Center for Orthopaedic Research Excellence (ECORE), Departments of Orthopaedics and Bioengineering, Univer- sity of Toledo, Toledo, OH DISCUSSION: Data suggest that an optimum INTRODUCTION: Metastatic disease in the threshold cement injection volume may thoracolumbar spine represents a large and exist, at which vertebral body strength is growing problem, which can lead to pain, improved with minimum cement volume. pathologic fracture and neurologic com- Findings suggest that fixation by directed VP promise. Over the last two decades, the can achieve similar augmentation to stand- utilization of PMMA for percutaneous ver- ard VP with an anterior fill, while requiring tebral stabilization has increased. This study roughly half the PMMA cement injection was conducted to examine and compare the volume. biomechanical effectiveness of the standard 131

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ferase and bradykinin receptor B1 at the

GP48 protein level. GENOME-WIDE PAIN-, NERVE- AND DISCUSSION: Since the degenerating hu- NEUROTROPHIN-RELATED GENE EXPRES- man disc is primarily an avascular tissue site SION IN THE DEGENERATING HUMAN AN- into which disc cells have contributed high NULUS levels of proinflammatory cytokines, these Helen E. Gruber, Gretchen L. Hoelscher, Jane substances are not cleared from the tissue A. Ingram, Edward N. Hanley and remain there over time. We hypothe- Department of Orthopaedic Surgery, Caroli- size that as nerves grow into the human nas Medical Center, Charlotte, NC USA annulus, they encounter a proinflammatory cytokine-rich milieu which may sensitize INRODUCTION: In spite of its high clinical nociceptors and exacerbate pain produc- relevance, the relationship between disc tion. degeneration and low back pain is still poor- ly understood. Genome-wide gene expres- sion studies utilizing ontology searches pro- GP49 vide an efficient methodology for identifica- MATRIX METALLOPROTEINASE-12, MAC- tion of clinically relevant genes. ROPHAGE METALLOELASTASE, IS CONSTI- METHODS: Ontology searches were used in TUTIVELY EXPRESSED AND PRODUCED IN a genome-wide analysis of pain-, nerve-, THE HUMAN INTERVERTEBRAL DISC IN VI- and neurotrophin-related gene expression VO patterns in specimens of human disc tissue. Helen E. Gruber, Gretchen L. Hoelscher, Jane Control, non-herniated clinical and herniat- A. Ingram, Natalia Zinchenko , Synthia ed clinical specimens of human annulus Bethea and Edward N. Hanley, Jr. tissue was studied following IRB approval. Department of Orthopaedic Surgery, Caroli- Analyses were performed on more generat- nas Medical Center, Charlotte, N.C. USA ed (Thompson grade IV and V) discs vs. less degenerated discs (grades I-III), on surgically INTRODUCTION: Matrix metalloproteinase- operated discs vs. control discs, and on her- 12 (MMP-12), also known as macrophage niated vs. control discs; immunohistochem- metalloelastase, degrades elastin and other istry was also performed. extracellular matrix (ECM) components in- RESULTS: Analyses of more degenerated vs. cluding type IV collagen, fibronectin, less degenerated discs identified significant laminin, gelatin, vitronectin, chondroitin upregulation of well-recognized pain- sulfates and fibrinogen. To date, no study related genes (bradykinin receptor B1, calci- has assessed the presence or gene expres- tonin gene-related peptide and catechol-0- sion of MMP-12 in the intervertebral disc. methyltransferase). Nerve growth factor The objective of this study was to determine was significantly upregulated in surgical vs. if MMP-12 is present in the degenerating control and in herniated vs. control discs. human annulus utilizing immunohistochem- All three analyses also found significant istry and microarray analyses. changes in numerous proinflammatory cy- METHODS: IRB approval was obtained for tokine- and chemokine-related genes. this study. Since MMP-12 also has known Nerve, neurotrophin and pain-ontology relationships to cytokine and chemokines, searches identified many signal- we examined human intervertebral disc ing/functional genes with known disc im- tissue expression of MMP-12 using microar- portance. Immunohistochemistry con- ray analysis in discs from 23 subjects; firmed the presence of calcitonin gene- immunohistochemical localization studies related peptide, catechol-0-methyltrans- were performed in 18 specimens. 132

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RESULTS: Molecular studies showed that by nucleus pulposus cells, comparison anal- MMP-12 exhibited a 1.45 fold significant ysis were performed between the test down regulation in more degenerated discs group and the control. compared to healthier discs (p = 0.006). RESULTS: NP cells could be effectively trans- Immunohistochemistry showed localization fected by rAAV2, positive hTERT mRNA and of MMP-12 in disc cells, but not disc extra- protein expression could be detected at cellular matrix (ECM). 5,10,15,30 and 60days post transfection. No DISCUSSION: MMP-12 is involved with positive hTERT mRNA and protein expres- elastin degradation; the elastic extension sion was detected at the control group. The property of the intervertebral disc is an im- hTERT gene expression reached a peak at portant biologic function. From cartilage 10days post transfection and dropped slow- literature we know that MMP-12 can be ly with increasing culturing time. RAAV2- mediated by local cytokines via a number of hTERT transfection effectively upregulated pathways. Here we have shown novel doc- the proteoglycan and type Ⅱcollagen ex- umentation of the expression and produc- pression which was significantly higher than tion of MMP-12 by cells of the human disc. the control. As to the expression of type Ⅰ Since MMP-12 has been implicated in the collagen, however, no significant difference breakdown of numerous ECM components, was detected between the test and control. including elastin, in other cells and tissues, CONCLUSION: RAAV2-hTERT could effec- and since MMP-12 has additional roles in- tively transfect NP cells and upregulate the volving proinflammatory cytokines in other proliferative capacity and extracellular ma- tissues, we look forward to future research trix expression of NP cells cultured in vitro. which will better elucidate the role of MMP- This hTERT activated NP cell has the poten- 12 in disc health and disease. tial to be used in the biological therapy for degenerative disc disease. GP50 FEASIBILITY OF NP CELL ACTIVITY GP51 UPREGULATION BY HTERT GENE TRANS- INJECTION OF BUPIVACAINE INTO DISC FECTION SPACE TO DETECT PAINFUL NONUNION Di-Ke RUAN, MD; Hong-Kui XIN, MD; Chao AFTER ALIF SURGERY IN PATIENTS WITH ZHANG, MD; Deli WANG; Zhiyuan SHI, MD; DISCOGENIC LOW BACK PAIN. Tao GU, MD;Chao-Feng WANG; Jianhong Kimura S, Ohtori S, Inoue G, Orita S, WU,MD; Yan ZHANG, MD; Qin HE, MD Yamauchi K, Eguchi Y, Aoki Y, Ishikawa T, Department of Orthopedic Surgery The Navy Miyagi M, Kamoda H, Suzuki M, Sakuma Y, General Hospital,Beijing, P R. China Kubota G, Oikawa Y, Inage K, Sainoh T, Sato J, Toyone T, Takahashi K. OBJECTIVE: To investigate the NP cells activ- Dept. Orthop. Surg., Chiba University, Chiba, ity and phenotype preservation after Japan rAAV2-hTERT transfection. METHODS: Nucleus pulposus cells were INTRODUCTION: Bupivacaine is commonly transfected with rAAV2-hTERT at multiplici- used for the treatment of back pain and the ties of infection of 1×105 genomes per cell. diagnosis of its origin. Nonunion is some- The expression of hTERT mRNA and protein times observed after spinal fusion surgery; were assessed by RT-PCR and Western-blot however, whether the nonunion causes at 5,10,15,30 and 60 days post-transfection; pain is controversial. In the current study, Real-time PCR and Elisa were used to test we aimed to detect painful nonunion by proteoglycan and type Ⅱcollagen secreted injecting bupivacaine into the disc space of 133

GENERAL POSTERS patients with nonunion after ALIF surgery Disorders, Budapest, Hungary, 5Istituto for discogenic low back pain. Ortopedico Galeazzi, Milano, Italy METHODS: From 52 patients with low back pain, we selected 42 who showed disc de- INTRODUCTION: Impaired endplate perme- generation at only one level (L4–L5 or L5– ability due to degeneration and calcification S1) on magnetic resonance imaging and is considered to be a key contributor to in- were diagnosed by pain provocation on dis- tervertebral disc (IVD) degeneration. An up- cography and pain relief by discoblock (the regulation of metalloproteinases and in- injection of bupivacaine). They underwent flammatory cytokines has been observed in ALIF surgery. If the patients showed low degenerated IVDs. We hypothesize that the back pain and nonunion 2 years after sur- cartilaginous endplate (CEP) contributes to gery, we injected bupivacaine into the non- the regulation of disc matrix degradation via union disc space. Patients showing pain re- molecular interactions with the disc tissue. lief after injection of bupivacaine under- METHODS: To identify these possible mo- went additional posterior fixation using lecular interactions we analyzed in a bioas- pedicle screws. These patients were fol- say conditioned media of cartilaginous end- lowed up 2 years after the revision surgery. plates (CEP-CM) from disc degeneration RESULTS: Of the 42 patient subjects, 7 patients (n=4) with regard to their influence showed nonunion. Four of these did not on matrix turnover and inflammatory fac- show low back pain; however, 3 showed tors on nucleus pulposus cells (in alginate moderate or severe low back pain. These 3 beads) of the same patient. The CEP-CM patients showed pain reduction after injec- was further analyzed by protein array for tion of bupivacaine into their nonunion disc inflammatory cytokines. Further CEP sam- space and underwent additional posterior ples underwent histological (n=15), ultra fixation. They showed bony union and pain structural (n=8) and cell biological analysis relief 2 years after the revision surgery. (n=5) to determine alterations of tissue DISCUSSION: Injection of bupivacaine into structure and differentiation potential of the nonunion disc space after ALIF surgery CEP cells. for discogenic low back pain is useful for RESULTS: NP-cells exposed to their donor- diagnosis of the origin of pain. corresponding CEP-CM exhibited dose- dependent up-regulation of inflammation- factors (IL 1β, - IL6, IL-8 – up to 400-fold), GP52 matrix metalloproteinases (MMP3, MMP13 MOLECULAR INTERACTIONS BETWEEN – up to 1000-fold) and a slight decrease in HUMAN CARTILAGINOUS ENDPLATES AND matrix protein expression. Pro- NUCLEUS PULPOSUS CELLS: A PRELIMI- inflammatory cytokines were identified in NARY INVESTIGATION the CEP-CM. The occurrence of apoptotic Cornelia Neidlinger-Wilke1, Antje Mietsch1, cells and degraded matrix fragments as well Fabio Galbusera1, Claus Carstens2, as the differentiation capacity of CEP- Christoph Brochhausen3, Aron Lazary4, derived cells varied strongly between do- Marco Brayda-Bruno5, Anita Ignatius1, nors. Hans-Joachim Wilke1 DISCUSSION: Our results indicate interac- 1Institute of Orthopaedic Research and tions between the CEP and the NP tissue via Biomechanics, Centre of Musculoskeletal molecular factors that may up-regulate ma- Research, University of Ulm, 89081 Ulm, trix degrading enzymes and inflammatory 2Galenus-Klinik Stuttgart, 3REPAIR-lab, cytokines and thereby influence the patho- Institute of Pathology, University of Mainz, physiology of disc degeneration. Ongoing Germany, 4National Center for Spinal 134

GENERAL POSTERS investigations are necessary to further iden- cells incorporated 6.3 + 0.6 pmoles 35S- tify the regulative role of potential molecu- sulfate/฀g DNA, about a three-fold lower lar factors that are responsible for these than that seen in untreated non-senescent degenerative alterations. hNP cells. Compared to non-senescent hNP ACKNOWLEDGEMENT: Funded in part by cells, senescent hNP cells greatly up- FP7-EU-Project Genodisc (HEALTH-F2-2008- regulated mRNA expression of MMP-1 201626) (27X), MMP-3 (12X), IL-6 (6X) and IL-8 (9X), the protein products of which were also found in dramatically elevated levels in cul- GP53 ture conditioned media. SENESCENT DISC CELLS EXHIBIT SEVERELY PERTURBED MATRIX HOMEOSTASIS Ngo, Kevin; Nasto, Luigi; Sowa, Gwendolyn; Kang, James; Vo, Nam Department of Orthopaedic Surgery, University of Pittsburgh

INTRODUCTION: Age-related disc matrix proteoglycan (PG) loss is primarily a cell- driven process due to a combination of re- duced PG synthesis and increased PG proteolytic breakdown. However, the disc DISCUSSION: Strong oxidant-induced disc cell population(s) with perturbed PG home- senescent cells exhibited greatly perturbed ostasis has not been identified. The link be- matrix homeostasis, showing decreased tween aging and senescent cells was noted capacity for new PG synthesis as well as in human discs, but it is still not known if enhanced expression and secretion of key senescent disc cells differ in matrix homeo- inflammatory cytokines and matrix stasis from their non-senescent counter- metalloproteinases, the latter may have parts. Hence the goal of this study is to de- profound catabolic effects on neighboring termine PG homeostatic characteristics of cells and the extracellular matrix. senescent disc cells.

METHODS: Culture of human nucleus pulposus (hNP) cells isolated from surgical GP54 specimens were induced to enter senes- PROLYL HYDROXYLASE 3 (PHD3) cence by treating with 0.5mM H2O2 for 2 MODULATES CATABOLIC EFFECTS OF hours followed by culturing the cells for 4 TUMOR NECROSIS FACTOR ALPHA ON days in fresh media (F-12, 10% FBS, 1% PS); CELLS OF THE NUCLEUS PULPOSUS the same procedure was repeated twice to THROUGH CO-ACTIVATION OF NUCLEAR induce complete senescence. Cellular se- FACTOR KAPPA B/P65 SIGNALING nescence (SA β-gal), PG synthesis (35S- Fujita, Nobuyuki (1,2); Gogate, Shilpa (1); sulfate incorporation), mRNA expression Chiba, Kazuhiro (3); Matsumoto, Morio (4); (qRT-PCR) and protein levels (ELISA) of se- Toyama, Yoshiaki (4), Shapiro, Irving (1); lected catabolic factors in the culture condi- Risbud, Makarand (1) tioned media were determined. 1 Department of Orthopaedic Surgery and RESULTS: Most (>90%) of the hNP cells Graduate Program in Cell and were stained positive for SA β-gal following Developmental Biology, Thomas Jefferson H2O2 treatment, confirming induction of University, Philadelphia, USA 2 Department senescence. H2O2–induced senescent hNP 135

GENERAL POSTERS of Orthopaedic Surgery, International syndecan4, MMP13 and COX2, at the same University of Health and Welfare, Shioya time there is restoration of aggrecan and hospital, Tochigi, Japan 3 Department of collagen type II expression. Orthopaedic Surgery, Kitasato University DISCUSSION: The experiments described in Kitasato Institute Hospital, Tokyo, Japan 4 this investigation demonstrated for the first Department of Orthopaedic Surgery, Keio time that in NP cells, expression of PHD3 University School of Medicine, Tokyo, Japan was controlled by the inflammatory cyto- kines TNF-α and IL-1β. Our studies also e- r INTRODUCTION: We have recently shown vealed that NF-κB controlled cytokine e- d that prolyl-4-hydroxylases (PHD) 1, 2 and 3 pendent PHD3 expression. A second major are expressed in the nucleus pulposus (NP). observation was that PHD3 promoted cyto- However, the regulation and function of kine-induced NF-κB/p65 signaling activity. PHDs under inflammatory conditions that These findings lend strong support to the characterize degenerative disc disease is not hypothesis that PHD3 is part of regulatory yet known. The first objective of the study is circuit, with NF-κB enhancing the impact of to determine if expression of PHDs is regu- the inflammatory cytokines, a critical step in lated by TNF-α and IL-1β through NF-κb sig- the pathogenesis of the degenerative disc naling in the NP cells. The second objective disease. is to determine if PHDs are involved in regu- lation of NF-κB signaling. RESULTS: Real-time RT-PCR and Western GP55 blot analysis clearly show that TNF-α and IL- VERTEBRAL CARTILAGE ENDPLATE LE- 1β induces PHD3 expression (Fig. 1). SIONS: A MORPHOLOGICAL STUDY TO EVALUATE THE EFFECTS OF OSTEOPOROSIS AND DISC DEGENERATION IN RATS Ying Ding, Jie Jiang, Jian Zhou, Xiuhua Wu, Zhiping Huang, -Jianting Chen, Qingan Zhu Department of Spine Surgery, Nanfang Hos- pital, Southern Medical University, Guang- zhou, China

INTRODUCTION: Osteoporosis (OP) may

Lentiviral delivery of Sh-P65 and Sh-IKKβ coexist with disc degeneration (DD) in pa- confirms that cytokine dependent PHD3 tients, but their compound effect on the expression is NF-κB dependent. Next, we cartilage endplate lesion remains unknown. investigated if PHD3 participates in TNF-α- This study was to evaluate compounding dependent signaling and target gene ex- effect of OP and DD on cartilage endplate pression. Loss of function studies clearly lesions at 12, 18 and 24 weeks after surger- indicate that PHD3 serves as a co-activator ies combined ovariectomy (OVX) with cervi- of NF-κB signaling activity in NP cells. Final- cal muscle section (CMS) in rats. ly, to examine the role of PHD3 in control- METHODS: 52 SD female rats were assigned ling TNF-α dependent target gene expres- randomly into the CMS and OVX, the CMS, sion, we transduced NP cells with lentivirus OVX and Sham groups (n=14, 14, 14, 10). expressing ShPHD3. We observed that when The C6/C7 segment and tibia were harvest- PHD3 is silenced there is a significant de- ed at 12, 18 and 24 weeks after surgery. crease in TNF-α-induced expression of cata- Specimens were scanned using micro CT bolic markers that include ADAMTS5, and then stained. OP was evaluated by structural indices of the C6 body and the 136

GENERAL POSTERS tibial metaphyseal region. After the lesion was identified on axial CT images, ratio of GP56 the lesion area to the whole endplate area EXPRESSION OF THE TISSUE RENIN- was calculated. Intervertebral disc height ANGIOTENSIN SYSTEM IN RAT AND BOVINE (IDH) was measured, and DD was graded for INTERVERTEBRAL DISCS each sample. Koji Akeda, Ryo Morimoto, Ryu Iida, Koichiro RESULTS: OP occurred at 12 weeks after Murata, Akihiro Sudo OVX as structural indices was dropped sig- Department of Orthopaedic Surgery, Mie nificantly, and became severe afterwards. University Graduate School of Medicine Maximum lesion was on the ventral carti- lage endplates at 12 weeks after CMS sur- INTRODUCTION: The renin-angiotensin sys- gery, and was severe in the compound tem (RAS) plays a vital role in regulating the group (28%, P<0.05) and the caudal end- physiology of the cardiovascular system. plate (P>0.05). The lesion was shrunk and Recent studies have shown that locally pro- calcified in situ at 18 and 24 week. The CMS duced angiotensin II (Ang II), the “tissue surgery resulted in a significant decrease of renin-angiotensin system (tRAS), contribut- IDH, while the OVX added surgery led to IDH ed to inflammation and fibrosis in many decreasing significantly at 24 weeks organs. We have previously reported that (P=0.043). DD scores were higher following tRAS was expressed by rat intervertebral CMS or OVX surgery. DD score correlated to disc (IVD) cells. In this study, we compared the lesion at 12, 18 and 24 weeks (P<0.01), (1) the expression of tRAS by bovine (a and IDH at 18 and 24 weeks (P<0.01) re- chondrodystrophoid animal) and rat IVD spectively. cells, and (2) examined the biological role of tRAS by rat IVD cells using Ang II peptide. METHODS: tRAS expression by rat and bo- vine IVD cells was examined using real-time polymerase chain reaction (PCR) (rat) and immunohistochemistry (rat and bovine). Rat annulus fibrosus (AF) cells in monolayer culture were used to examine the biological role of tRAS in vitro. The effect of Ang II peptide on extracellular matrix metabolism was assessed by real-time PCR. RESULTS: mRNA of tRAS components, in- cluding angiotensin converting enzyme (Ang DISCUSSION: Our results suggested that II), Ang II receptor type 1, Ang II receptor disc degeneration induced cartilage end- type 2, and Cathepsin D (a renin-like en- plate lesion while osteoporosis appeared to zyme), were clearly confirmed by real-time deteriorate the lesion more to the degener- PCR analysis. In AF and nucleus pulposus ating discs. The lesion may be related to (NP) cells from rat and bovine in monolayer cartilage endplate wearing at the early culture, immunohistochemical analysis stage and calcification in situ later. The le- showed that the expression of each tRAS sion and IDH were associated with the DD component was clearly observed. In rat IVD levels. The results imply that osteoporosis tissues, immunoreactivity to each antibody may accelerate the disc degeneration at for tRAS components was also observed. specific time. Proliferation of rat AF cells was mildly stimulated by Ang II peptide. Ang II peptide also had a minor stimulatory effect on the 137

GENERAL POSTERS expression of extracellular matrix compo- conjoint analysis by Gene Ontology (GO) nents, growth factors and catabolic pro- terms and Kyoto Encyclopedia of Genes and teins. Genomes (KEGG) pathways based on the DISCUSSION: Our results demonstrate that human accession id, using MAS platform. the tRAS components necessary to activate RESULTS: Forty eight Micro-RNAs were tRAS have been found in normal rat and highlighted in comparing among equine bovine IVD cells. To elucidate the associa- boneprotein extract, rhBMP-2 and autograft tion between tRAS and the process of IVD at different time points, which regulated degeneration, the expression and function over 100 genes in bone regeneration. Ac- of tRAS in the human degenerated IVD companying with the down-regulations of should be examined in a future study. miR-129, 140, 133, etc, the genes related to inflammatory were up-regulation, ALIF us- ing equine bone protein extract in particu- GP57 lar. The genes related to bone formation SIGNATURE MIRNA EXPRESSION PROFILE were increased following the decreased of OF SPINAL FUSION USING EQUINE BONE miR-19, 29, 218, etc. PROTEIN EXTRACT, RHBMP-2 AND DISCUSSION: The rhBMP-2 recruits progeni- AUTOGRAFT DURING THE PROCESS OF tor cells, proliferationand differentiation ANTERIOR LUMBAR INTERBODY FUSION and then leads to preferable membranous Zhou Zhiyu, Dafu Chen, Dai Xuejun, ossification and bone remodeling. Con- Manman Gao, Zou Xuenong versely, equine bone protein extract results Department of Spine Surgery/Orthopedic in endochondral ficationossi via Research Institute The First Affiliated upregulation of cartilage-related genes. hospital of Sun Yat-sen University MicroRNAs participate the bone regenera- tion after the transplantation of equine INTRODUCTION: Using microarray technol- bone protein extract, rhBMP-2 and ogy and data analysis, we examined the autograft. gene-expression profiles after implantation of equine boneprotein extract, rhBMP-2 and autograft and found the different molecular GP58 mechanisms underlying the diverse patterns CANINE NOTOCHORDAL CELL-SECRETED of histological ossification. However, the FACTORS PROTECT MURINE AND HUMAN mechanisms of the epigenetic adjustment NUCLEUS PULPOSUS CELLS FROM have not yet been delineated in detail. APOPTOSIS BY INHIBITION OF ACTIVATED METHODS: Eighteen pigs underwent a 3- CASPASES -9, AND -3/7 level ALIF procedure at L3-4, L4-5, and L5-6 A. Mehrkens 1, 2, R. Hilario 1, S. Kim 1, M. Z. in the present study using equine bone pro- Karim 1, M. G. Fehlings 1, M. W. Erwin 1 tein extract, rhBMP-2 and autograft, respec- 1 Toronto Western Research Institute, tively. The fused vertebral bodies of 6 ani- University of Toronto, Toronto, Canada 2 mals at each time-point were observed for Department of Orthopaedic Surgery - Spine 2, 4, or 8 weeks post-operatively. The pool- Unit, Basel University Hospital, Basel, ing RNA from each tissue sample analyzed Switzerland by CapitalBio Corporation for miRNA micro- array and Porcine Genome Array INTRODUCTION: Effective therapies that (Affymetrix) experiments. Hierarchical clus- may stop or reverse disc degeneration re- tering with average linkage was carried out main elusive. A minimally invasive method by Cluster 3.0. The differentially expressed through which nucleus pulposus cell viabil- genes and Micro-RNAs were performed ity could be achieved would revolutionize 138

GENERAL POSTERS the treatment of degenerative disc disease. IL-1ß+FasL- and Etoposide- mediated apop- We have investigated if non tosis via suppression of activated caspase-9 chondrodystrophic (NCD) canine disc (IVD)- and caspase-3/7, CDCM demonstrated an derived notochordal cell conditioned medi- inhibitory effect on IL-1ß+FasL mediated um (NCCM) and chondrodystrophic (CD) apoptosis via caspase-3/7 (Fig1A). canine IVD-derived conditioned medium In human NP cells, NCCM inhibits (CDCM) are able to protect murine and hu- Etoposide- mediated apoptosis via suppres- man NP cells from apoptosis. sion of activated caspase-8, caspase-9 and METHODS: We developed NCCM and CDCM mainly caspase-3/7. CDCM demonstrated from hypoxic culture of freshly isolated NPs an inhibitory effect on Etoposide- mediated from NCD and CD canines respectively. We apoptosis via suppression of activated obtained murine NP cells from 9 different caspase-8, caspase-9 and mainly caspase- C57BL/6 mice and human NP cells from 4 3/7, though not as effective as NCCM patients who underwent surgery for discec- (Fig1B). tomy. Cells were cultured with aDMEM/F- DISCUSSION: Soluble factors secreted by 12 (control media), NCCM or CDCM under the NCD IVD NP strongly protect murine and hypoxic conditions (3.5% O2) and treated human NP cells from induced apoptosis via with IL-1ß+FasL or Etoposide. All media suppression of activated Caspase -9 and -3/- were supplemented with 2% fetal bovine 7. A better understanding and harnessing of serum. We then determined the expression the restorative powers of the notochordal of specific apoptotic pathways in the murine cell could lead to novel cellular and molecu- and human NP cells by recording caspase-8, lar strategies for treatment of DDD and -9 and -3/7 activity. GP59 ABILITY OF T2 MAPPING AND T1 RHO MAPPING TO EVALUATE LUMBAR INTERVERTEBRAL DISC DEGENERATION AND GLYCOSAMINOGLYCAN CONTENT OF THE NUCLEUS PULPOSUS Oikawa, Yasuhiro1; Watanabe, Atsuya2; Kamoda, Hiroto1; Ishikawa, Tetsuhiro1; Miyagi, Masayuki1; Sakuma Yoshihiro1; Inoue, Gen1; Yamauchi, Kazuyo1; Orita Sumihisa1; Suzuki, Miyako1; Kubota, Go1; Inage, Kazuhide1; Sainoh, Takeshi1; Sato, Jun1; Ohzone, Humio3; Obata, Takayuki4; Okubo, Toshiyuki3; Toyone, Tomoaki3; Ohtori, Seiji1; Takahashi, Kazuhisa1 1: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba Univer- sity. 2: Department of Orthopaedic Surgery, Teikyou University Chiba Medical Center, Japan. 3: Department of Orthopaedic Radi- ology, Teikyou University Chiba Medical Center,Japna. 4: National Institute of Radio- RESULTS: In murine NP cells, NCCM inhibits logical Sciences, Japan.

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INTRODUCTION: T2 mapping and T1ρ map- potential to detect degeneration and evalu- ping by MRI are non-invasive quantification ate repair and regeneration. tools to measure intervertebral disc (IVD) degeneration. MRI T2 relaxation time is a quantitative parameter that is sensitive to GP60 change in collagen and water content, and THE MECHANISM OF THE INFLAMMATORY T1ρ relaxation time reflects water and sul- RESPONSES IN THE INTERVERTEBRAL DISC fated glycosaminoglycan (GAG) content in HERNIATION EXPLORED BY CO-CULTURE the nucleus pulposus of IVDs. The purpose MODEL IN VITRO of this study was: (1) to evaluate degenera- Yamamoto Junya1, Maeno Koichiro1, Taka- tive IVDs quantitatively with T2 mapping da Toru1, Kakutani Kenichiro1, Yurube Ta- and T1ρ mapping, (2) to analyze water and kashi1, Zhang Zhongying1, Hirata Hiroaki1, GAG content histologically, and (3) to in- Kurakawa Takuto1, Shingo Miyazaki1, Sakai spect the efficacy of a quantitative imaging Daisuke2, Mochida Joji2, Doita Minoru3, of the degenerated IVDs. Kurosaka Masahiro1, Nishida Kotaro1 METHODS: Eight-week-old New Zealand 1. Dept of Orthopaedics, Kobe University, White rabbits were used in this study. IVDs Kobe, Japan. 2. Dept of Orthopaedics, Tokai were punctured 10, 5, 1 or 0 (control) times University, Kanagawa, Japan. 3. Dept of with an 18-gauge needle at each level. MRI Orthopaedics, Takatsuki General Hospital, was performed 4 weeks and 8 weeks after Takatsuki, Japan. injury and water and GAG content of the nucleus pulposus were calculated. INTRODUCTION: We have clarified that Fas RESULTS: GAG content in the nucleus de- ligand (FasL) is expressed on human NP cells creased in all the puncture groups com- and that the interaction between NP cells pared with the control group. Conversely, and macrophages causes the inflammatory there was no strong correlation of GAG con- responses which are considered to cause tent and the number of punctures or dura- pains in the intervertebral disc herniation. A tion after injury. Water content was lower Disintegrin And Metalloproteinase in the puncture groups than in the control (ADAM)10 is reported to regulate FasL cell group, and lower in the 8 weeks group than surface expression. Therefore, we assumed the 4 week group. T1ρ mapping showed that FasL and ADAM10 participate the in- stronger correlation of GAG and water con- flammatory responses in the intervertebral tent than T2 mapping. GAG and water con- disc herniation. To validate this assumption, tent decrease with the progression of IVD We explored the function of FasL and degeneration in the puncture groups. ADAM10 using co-culture model in vitro. DISCUSSION AND CONCLUSIONS: Previous METHODS: FasL over-expression and studies reported that the degeneration of ADAM10 knock-down were induced by IVDs correlates with the number of punc- transferring FasL plasmid and ADAM10 tures. This study shows that GAG and water shRNA plasmid respectively into human NP content tended to decrease in early stage of cell line using the electroporation method. IVD degeneration and that T1ρ mapping Human NP cell line and macrophage (GM- evaluated the degenerating IVDs more ac- CSF) cell line were co-cultured on the differ- curately than T2 mapping. GAG and water ent surfaces of microporous membrane. content were lower in IVDs punctured once After 12- and 24-hour co-culture, each cell than in the control. Therefore, T2 relaxation was collected respectively. The mRNA- and T1ρ times can detect early stages of IVD quantification of pro-inflammatory cyto- degeneration. Quantitative MRI has the kines (IL-1β, TNF-α, and IL-6) and ADAM10

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GENERAL POSTERS were estimated with the real-time RT-PCR. blebs in response to stimulus or stress. MPs And the qualitative analysis of proteins of consist of membrane and cytoplasmic sub- those was detected by the Western Blot- components along with a number of pro- ting. teins and extracellular RNA characteristics RESULTS: The production of all pro- of their parental cells. Emerging evidence inflammatory cytokines and ADAM10 in- suggest that MPs are biologic information creased significantly in the case of co- messengers with important roles in both in culture, differing from the cases of inde- pathological and non-pathological process- pendent culture respectively. This tendency es. Because the interaction between endo- was more remarkable in the case of co- thelial MPs and disc cells are likely to occur culture with FasL over-expression. On the during neovascularization, the objective of other hand, ADAM10 knock-down induced this study is to evaluate the influence of the to decrease both the expression of FasL and endothelial MPs on disc cells metabolism. the production of pro-inflammatory cyto- METHODS: Endothelial microparticles kines. (EMPs) were isolated as described (J Cell DISCUSSION: It has been reported that the Physiol. 2012 227:534-49) from the culture reverse signaling in the TNF family contrib- media of a microvascular endothelial cell utes to the production of pro-inflammatory line grown on monolayer culture for two cytokines. In our results, it seems reasona- weeks. 15 μl of 14mg/ml EMPs (totalo- pr ble to conclude that FasL has great possibil- tein) were added to each well of the 6-well ity to regulate the production of pro- plate of human annulus fibrous (hAF) cell inflammatory cytokines and that ADAM10 cultures, and the cultures were incubated regulates the FasL reverse signaling and for 3 days. Gene expression of MMP-1, participates the inflammatory responses in MMP-2, MMP-3, MMP-13, and aggrecan the intervertebral disc herniation. were determined by qRTPCR. RESULTS: Increased gene expression of MMP-1, MMP-2, MMP-3 and MMP-13 were GP61 observed in EMP-treated hAF cells com- CATABOLIC EFFECTS OF ENDOTHELIAL pared to untreated hAF cells. In contrast, CELL-DERIVED MICROPARTICLES ON IN- aggrecan gene expression decreased in TERVERTEBRAL DISC CELLS EMP-treated hAF cells compared to un- Pedro Henrique Isoldi Pohl, Hong Joo Moon, treated hAF cells. Thomas Lozito, Thais Cuperman, Kevin Ngo, DISCUSSION: Endothelial cell microparticles Takashi Yurube, Gwendolyn Sowa, Rocky promote catabolic metabolism in disc cells. Tuan, James D Kang, Nam Vo If confirmed in vivo, this could represent a Department of Orthopaedic Surgery, new mechanism by which disc extracellular University of Pittsburgh Medical Center, PA, matrix is degraded during the degenerative USA., The Ferguson Lab for Orthopaedic and process. Spine Research, Center for Cellular and Molecular Engineering GP62 INTRODUCTION: Neo-vascularization, a THE NOTOCHORDAL CELL VIABILITY AF- prominent feature of injured and degener- FECTED BY DYNAMIC MECHANICAL LOAD- ated discs, requires the invasion of endothe- ING VIA ALPHA5/BETA1 INTEGRINS IN RAT lial cells, the primary producer of IVDS microparticles (MPs). MPs, also known as Kurakawa T. 1, Kakutani K. 1, Morita Y. 2,, microvesicles or exosomes, are 0.1 to 1 μm Takada T. 1, Maeno K. 1, Yurube T. 1, particles shed from cell plasma membrane Yamamoto J. 1, Hirata H. 1, Miyazaki S. 1, 141

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Doita M. 3, Kurosaka M. 1, Nishida K. 1 nificantly decreased with NC disappearance. 1. Dept of Orthopaedic Surgery, Kobe mRNA expressions of aggrecan and collagen University Graduate School of Medicine, type 2 were up-regulated in Group TL com- Kobe, Japan., 2. Dept of Biomedical pared to Group L (P<0.05), whereas signifi- Engineering, Doshisha University, Kyoto, cant up-regulation of MMPs and α5/β1 Japan., 3. Dept of Orthopaedic Surgery, integrins in Group L was not seen in Group Takatsuki General Hospital, Osaka, Japan. TL. DISCUSSION: Our results suggested that the INTRODUCTION: It is essential to clarify the loss of NCs due to dynamic mechanical load- notochordal cell (NC) viability to elucidate ing was affected by α5β1 integrin expres- intervertebral disc (IVD) degeneration, but it sions in rat IVDs. remains unclear. The α5β1 integrin is a transmembrane protein that mediates bio- logic interactions between cells and extra- GP63 cellular matrix. The aim of this study was to A QUANTITATIVE PROTEOMIC ANALYSIS assess the NC viability affected by dynamic OF THE NON-CHONDRODYSTROPHIC AND mechanical loading via α5β1 integrins in rat CHONDRODYSTROPHIC CANINE NUCLEUS IVDs. PULPOSUS METHODS: Consecutive two en-bloc coc- L. DeSouza 1, M. Z. Karim 2, O. Masui 1, S. cygeal IVDs were dissected from 24 male SD Maedler 1, A. Mehrkens 3, S. Kim 2, R. rats. Discs were assigned to following condi- Hilario 2, W. M. Erwin 4, 5,* tions and cultured for 6 days using an organ 1Chemistry, York University, 2Genetics , culture system, Group T; with an inhibitory 3Orthoapedic surgery, 4Orthoapedic and peptide treatment against α5β1 integrin neurological surgery, 5Genetics and Devel- (GRGDSP), Group L; with mechanical loading opment, University Health Network, Toronto (1.3MPa, 1Hz at initial state), Group TL; Western Hospital, Toronto, Canada both with treatment and loading, Group C; without any treatment or loading. Cell via- INTRODUCTION: The morphology of the bility analysis was examined using calcein intervertebral disc (IVD) nucleus pulposus green staining. Histomorphology was as- (NP) varies dramatically between the sessed by Masuda’s degeneration scale. notochordal cell-rich non- Immunopositivity of a NC marker (galectin- chondrodystrophic (NCD) and the 3) and α5/β1 integrins were evaluated by notochordal cell poor chondrodystrophic the percentage of positive cells. mRNA ex- (CD) canine as does their respective suscep- pressions of aggrecan, collagen type-1/-2, tibility to degenerative disc disease (DDD). MMP-3/-13, and α5/β1 integrins were cal- Here we used iTRAQ quantitative proteomic culated by real-time RT-PCR. analysis to determine the differential pro- RESULTS: Cell viability of Group L (65.9%) tein/peptide ‘fingerprint’ of the NCD and CD and Group TL (77.9%) was decreased than canine NP. Group C (91.6%) in the nucleus pulposus METHODS: NPs obtained from the IVDs of 8 (NP) (P<0.05). Degenerative changes were (4 NCD and 4 CD) dogs were mechanically mainly seen in the NP. Histological grade of homogenized/centrifuged and identical ali- Group TL was lower than Group L. quots of soluble proteins from the superna- Immunopositivity of galectin-3 was de- tant were then analyzed using 4-plex iTRAQ creased in Group L (3.6%) and TL (30.1%) analysis. Proteins/peptides separated on a compared to Group C (81.7%) (P<0.05). The nano-LC column and the eluting peptides % positive cells of α5/β1 integrins were sig- were analyzed a minimum of two times each on either a QStar Elite or the 5600 Tri- 142

GENERAL POSTERS ple TOF instrument and the subsequent MS data were then analyzed using ProteinPilot INTRODUCTION: Low back pain (LBP), which software. Proteins demonstrating consistent is caused by the sensory nerve innervating a differential expression in either the NCD or degenerated intervertebral disc(IVD), can be CD samples greater than two-fold relative to induced by several inflammatory peptides. the reference pool were selected for further However, there is little clinical information investigation. on the effects of some inflammatory RESULTS: Dramatic differences in the ex- peptide inhibitors on LBP. Recent studies pression of a number of important extracel- have shown that the capsaicin receptor lular matrix-related proteins within the NPs TRPV1 responds to acidity, pH fluctuation, of these two canine sub-species were de- and temperature and is related to tected. Significant differences in protein inflammation and pain. We aimed to expression were: Fibronectin, decorin, determine the therapeutic significance of biglycan, cartilage intermediate layer pro- TRPV1 in cases of LBP by tein (CILP), cartilage oligomeric protein immunohistochemical evaluation of its (COMP), fibromodulin, biglycan, and iso- levels in the sensory nerve innervating form B of proteoglycan-4 (lubricin) all of injured rat IVDs. which were dramatically under expressed in METHODS: 8w-old female rats were used in the NCD canine NP as compared to the CD this study. In the disc-injury group, L5/6 canine NP. discs were injured 10 times with a 24G CONCLUSIONS: We have determined that needle; simultaneously, the neurotracer the small leucine rich proteoglycans (SLRPs) Fluoro-gold(FG) was injected into the L5/6 or interstitial proteoglycans such as decorin, IVD (injured group,N=5;sham group,N=5). biglycan as well as fibromodulin were far The L5/6 IVD and the dorsal root more abundant in the CD NP homogenate ganglion(DRGs) from L1 to L6 were resected ascompared to the NCD canine. Degenera- at 7days after surgery. The expression levels tive changes underway in the CD as com- of TRPV1 and induction levels of the pared to the NCD NP animal may make this calcitonin gene-related peptide(CGRP) in the an ideal biological entity with which to DRGs were evaluated using immunohisto- study the biology of DDD. chemistry. Then, the rate of TRPV1- immunoreactive(IR) DRG cells among FG- labeled DRG cells and the rate of CGRP-IR GP64 DRG cells among FG-labeled DRG cells in LUMBAR INTERVERTEBRAL DISC INJURY IN both groups were compared statistically. RATS INDUCES UPREGULATION OF TRPV1 RESULTS: The rate of TRPV1-IR cells was EXPRESSION IN THE SENSORY NERVE IN- significantly higher in the injured group NERVATING THE DISCS 1) 2) (42.5%) than in the sham group (29.5%) Yusuke Shibata , Miyako Suzuki , Yoshihiro (p<0.05). Similarly, the rate of CGRP-IR cells Sakuma2), Yasuhiro Oikawa2), Masayuki 2) 2) was higher in the injured group (45.0%) Miyagi , Tetsuhiro Ishikawa , Kazuhide than in the sham group (20.1%) (p<0.05). Inage2) , Go Kubota2), Takeshi Sainoh2), Jun 2) 2) 2) And, the rate of TRPV1-IR cells and CGRP-IR Sato , Sumihisa Orita , Kazuyo Yamauchi , cells were practically equal in both groups. Hiroto Kamoda2), Seiji Ohtori2), Gen Inoue3), 2 DISCUSSION: Disc injury in rats increased Kazuhisa Takahashi the levels of TRPV1 and CGRP in DRGs. It 1) School of Medicine, Chiba University 2) was reported degenerative IVDs condition Department of Orthopaedic surgery, Chiba related to inflammatory mediators such as University 3)Department of Orthopaedic acidity and pH fluctuation. These results surgery, Kitasato University 143

GENERAL POSTERS suggest inflammatory mediators induce TRPV1 and CGRP. Subsequently, the rate of TRPV1 expression in degenerative IVDs. TRPV1-immunoreactive(IR) DRG cells among Thus, TRPV1 may serve as a new target for the FG-labeled DRG cells and the rate of the treatment of degenerative discogenic CGRP-IR DRG cells among the FG-labeled LBP. DRG cells were compared in each groups. RESULTS: FG-labeled cells from C5/6IVD were bilaterally distributed from C2 to C8

GP65 DRG. The rate of TRPV1-IR cells among the CERVICAL INTERVERTEBRAL DISC INJURY FG-labeled cells was significantly higher in PRODUCES UP-REGULATION OF TRPV1 the disc-injured group(55.3%) than in the AND NEUROPEPTIDES IN SENSORY DISC- sham group(23.2%)(p<0.05). Similarly, the INNERVATING NERVES IN RATS 1) 2) rate of CGRP-IR cells among the FG-labeled Takahito Arai , Miyako Suzuki , Yoshihiro cells was significantly higher in the disc- Sakuma2), Yasuhiro Oikawa2), Tetsuhiro Ishi- 2) 2) injured group (59.4%) than in the sham kawa , Masayuki Miyagi , Hiroto group(31.0%)(p<0.05). Kamoda2), Kazuhide Inage2), Go Kubo- 2) 2) 2) DISCUSSION: These results showed that the ta , Takeshi Sainoh , Jun Sato , Seiji innervated sensory nerves from C5/6IVD Ohtori2), Gen Inoue3),Kazuyo Yamau- 2) 2) 2 were distributed from DRGs C2 to C8 and chi , Sumihisa Orita ,Kazuhisa Takahashi might induce discogenic cervical pain over a 1) School of Medicine, Chiba University wide area. Furthermore, disc injury in rats 2)Dept of Orthopaedic surgery, Chiba increased TRPV1 and neuropeptides in University 3) Dept of Orthopaedic surgery, DRGs. These results suggest that these Kitasato University inflammatory mediators from degenerative IVDs relate to the mechanism of INTRODUCTION: Cervical intervertebral degenerated discogenic cervical pain, and discs induce obscure neck and interscapular TRPV1 may play the role of a new target of pain. However, the detailed mechanism of one’s therapy discogenic cervical pain is unknown. It was recently reported that TRPV1-a capsaicin receptor-that senses acid, pH fluctuation, GP66 and temperature change in human LONGITUDINAL EVALUATION OF SCHMORL intervertebral disc(IVD), is related to NODES, MODIC CHANGES AND RELATED inflammatory pain. The goal of this study LOW BACK PAIN was to evaluate by immunohisto- Ryuhei Kawamura, Hideki Murakami, chemistry(IHC), the up-regulation of TRPV1 Takafumi Horii, Akira Izumi, Yoshitaka calcitonin gene-related peptide(CGRP) as Konari, Toshio Wada the inflammatory neurotransmitter inner- Dept. of Orthop. Surg, Towadahigashi Hos- vated sensory nerve in rat cervical pital intervertebral injured disc. METHODS: We used 8w-old male SDrats. In INTRODUCTION: The association of MRI the disc-injured group, C5/6 discs were findings such as Schmorl nodes (SNs) and injured 10 times with a 24G needle; Modic changes (MCs) with low back pain is simultaneously, the neurotracer Fluoro- somewhat controversial. Furthermore the gold(FG) was injected into the C5/6 association between SNs and MCs is not IVD(disc-injured groupN=5,sham groupN=5). well known. Therefore we investigated the Dorsal root ganglion(DRGs) from the C1 to association among SN, MCs and low back C8 levels were resected 7days after surgery. pain. Using IHC, we evaluated the DRGs with MATERIALS AND METHODS: SNs and MCs 144

GENERAL POSTERS on lumbar MRI were observed in total 135 patients between 2004-2005. Another MRI GP67 was taken on those same patients again DISCOGENIC DIFFERENTIATION OF HUMAN more than 24 months later. We retrospec- BONE MARROW MESENCHYMAL STEM tively reviewed their medical records and CELL USING ADENOVIRAL-HYPOXIA INDUC- MRI to have low back pain and changes in IBLE FRACTOR-1Α size of SNs and type of MCs at the initial KANG, YOUNG MI *,+; KIM, HO JUNG 2; LEE, examination and final follow-up. BYUNG HO +; PARK, JIN-O +; LEE, HWAN MO RESULTS: At the initial examination, SNs +; MOON, SEONG HWAN*,+ were observed in 335 vertebrae out of total *BK21 Medical science Graduated School, 675 vertebrae. In these vertebrae, MCs type College of Medicine, Yonsei University, I were observed in 74 vertebrae (25.1%), Seoul, Korea +Department of Orthopaedic type II were observed in 35 vertebrae Surgery, College of Medicine, Yonsei (11.9%), type III were 11 vertebrae (3.7%). University, Seoul, Korea At the final follow-up, vertebrae increasing size of SNs were observed in 69 vertebrae INTRODUCTION: Recently, various ap- (37.7%), and those decreasing size of SNs proaches to biological repair and regenera- were observed in 71 vertebrae (38.8%). In tion of the intervetebral disc cell function the 69 vertebrae increasing size of SNs, are under investigation, including gene nonexistent MCs were 37 (53.6%), MCs type therapy, growth factor injection, cell thera- I were 27 (39.1%), MCs type II were 27 py and cell-based tissue engineering. In this (39.1%) and no MCs type III at the initial study, we investigate mesenchymal stem examination. In the 71 vertebrae decreasing cells (MSC) isolated from human bone mar- size of SNs, nonexistent MCs were 23 row can be induced into IVD cells using var- (32.4%), MCs type I were 31 (43.7%), MCs ious oxygen concentration and adenovirus- type II were 12 (16.9%) and MCs type III hypoxic inducible factor 1 alpha construct were 5 (7.0%) at the initial examination. Ten (Ad-HIF-1a). patients were diagnosed that their low back MATERIAL AND METHODS: The bone mar- pain were caused from SNs. All of their SNs row MSCs (BMSCs) were obtained from pa- were observed at the upper lumbar and tients’ iliac crest during surgery for lumbar associated with MCs type I. spinal stenosis. BMSCs were cultured in se- DISCUSSION: It was revealed that longitudi- quential change in oxygen tension and with nal changes in size of SNs and type of MCs transduction of Ad-HIF-1a. Controls were in lumbar spine were not uncommon. Alt- cultures with normal oxygen tension and hough association among SNs, MCs and low Ad-GFP. RT-PCR was performed to detect back pain was still unclear, all patients who expressions of aggrecan, type II collagen, were diagnosed as SNs related low back HIF-1α and GLUT-1 at the mRNA, western pain had MCs type I. These MCs type I might blot was used for proteoglycan synthesis. be reflected bony edematous of vertebral RESULTS: BMSCs with Ad-HIF-1฀showed body caused by SNs. increased expression of aggrecan, GLUT-1 and type II collagen mRNA at 24 and 48 hours in normoxic condition compared to control. Then same cultures switched to hypoxic condition (6%) and cultured for 48 hour more. BMSCs withAd-HIF-1฀, initially under normoxic(48hr) then hypoxic condi- tion(48hr) demonstrated more enhanced expression of aggrecan, GLUT-1 and type II 145

GENERAL POSTERS collagen mRNA at 96 hours compared to similar actions. cultures with normoxic condition continu- METHODS: Isolated cells from human IVD ously. In proteolgylcan synthesis, BMSCs were stimulated with IL-1 with or without with Ad-HIF-1฀and sequential change in PGE1 or PGE2 in the presence or absence of oxygen tension (normoxic then hypoxic) a selective COX-2 inhibitor (NS398). The exhibited increased synthesis of proteogly- expressions of MMP-1 and NGF were quan- can compared to controls. tified by realtime-PCR. NGF production was DISCUSSION AND CONCLUSION: Making measured by ELISA. MMP-1 production was cellular environment simulating hypoxic determined by Western blotting. condition by transducingAd-HIF-1฀renders RESULTS: IL-1 strongly induced both NGF more discogenic phenotypical expression. and MMP-1 expressions in human IVD cells. Moreover BMSCs with Ad-HIF-1฀and initial These expressions were enhanced when the normoxic then hypoxic condition provides cells were stimulated in the presence of optimal phenotypical expression and matrix NS398 at the concentrations at which PGE2 synthesis. Hence meticulous modification of release was substantially inhibited. The oxygen related gene and oxygen tension in over-inductions of MMP-1 and NGF were BMSCs might open new arena for disc engi- reversed when PGE1 as well as PGE2 was neering. supplemented to the culture. DISCUSSION: Our previous findings revealed that PGE2 has suppressive roles for both GP68 MMP-1 and NGF expression, thereby inhibi- A NOVEL PHARMACOLOGICAL ACTION OF tion of COX-2 activity may have limited effi- PROSTAGLANDIN E1 FOR INTERVERTEBRAL cacy since it cancels the suppressive action DISC DEGENERATION AND INNERVATION. of PGE2. Although PGE1 is widely used and Yasunobu Sawaji, Wuqikun Alimasi, Kenji reliefs LBP, its pharmacological action has Endo, Hidekazu Suzuki, Hidetoshi Tanaka been unknown except for peripheral vasodi- and Kengo Yamamoto lation. Our findings that PGE1 inhibited Department of Orthopedic Surgery, Tokyo MMP-1 and NGF expressions suggest that Medical University PGE1 could prevent IVD from degeneration and innervation. This would be a novel INTRODUCTION: Degeneration of interver- pharmacological action of PGE1 for the tebral disc (IVD) and following innervation treatment of patients with LBP. are considered to be one of the mecha- nisms of developing chronic low back pain (LBP). Since the extracellular matrix in IVD GP69 mainly consists of type I and II collagen, ma- ELEVATED LEVELS OF INFLAMMATORY trix metalloproteinase (MMP)-1 is thought MARKERS FOLLOWING EXPOSURE TO to play an important role for degeneration REPETITIVE LIFTING AND MENTAL LOAD BY of the tissue. Nerve growth factor (NGF) SUBJECTS WITH DIFFERENT PERSONALITY expressed by IVD is known to stimulate pe- TRAITS ripheral nerves to penetrate into the de- Riley E. Splittstoesser, William S. Marras, generated tissue. Our previous work Thomas M. Best demonstrated that PGE2 inhibits MMP-1 The Ohio State University Biodynamics La- and NGF expression in a negative feedback boratories, The Ohio State University fashion in human IVD cells stimulated with Biodynamics Laboratories, The Ohio State interleukin (IL)-1. These observations University Department of Family Medicine prompted us to examine whether PGE1, which is clinically used in Japan, also has INTRODUCTION: Recent research indicates 146

GENERAL POSTERS an inflammatory response to occupational work. This creates potential for repeated loading of lumbar spine tissues. Mental inflammatory exposure before previous stress has been shown to alter inflammato- inflammation has resolved. Further, the ry responses and slow wound healing. In- inflammatory response appears to be influ- flammation is the basic process the body ence by mental load, subject personality uses to respond to cellular injury or infec- and a mismatch between personality pref- tion so the presence and modification of an erences and job task demands. The pres- inflammatory response to occupational ence and modification of this finammatory tasks is of concern as it may impact the de- injury process has implications for workers velopment of occupationally related low who regularly perform repetitive lifting. badck pain. METHODS: Two groups of 10 subjects grouped by preference for sensor or intuitor personality traits performed two, two hour GP70 bouts of repetitive 6.8kg lifting combined TNF-ALPHA INDUCED WNT SIGNAL IN with a high or low mental workload task INTERVERTEBRAL DISC CELLS. separated by one week. Spinal loading was Katsuya Yokoyama, Akihiko Hiyama, assessed using an EMG-assisted subject- Fumiyuki Arai, Tadasi Nukaga, Daisuke spedcific biomechanical model and immune Sakai, Joji Mochida markers (WBC counts, Creatine Kinase (CK), Department of Orthopaedic Surgery, Substance P (SP), TNFα, IL-1, IL-6, IL-8, IL-10, Surgical Science Tokai University School of cortisol) were collected before and 0, 2 and Medicine 20 hours after exposure.

RESULTS: CK, WBC percentages, TNFα, IL-6 INTRODUCTION: Low back pain has been and IL-8 changed over time. SP levels and associated with intervertebral disc (IVD) WBC percentages differed between sen- degeneration. We previously reported that sor/intuitor preferences. Cortisol levels dif- Wnt/β-catenin (hereafter called Wnt) signal fered between mental load conditions. A plays an essential role in the control of cell significant interaction was found between proliferation and cell senescence in IVD sensor/intuitor preference and mental load cells. (Hiyama et al. Arthritis and Rheum for CK (figure) and SP levels. 2010). However, little is known about how upstream stimuli regulate Wnt signal in IVD cells. Elevated levels of pro-inflammatory cytokines have been reported to be present in degenerate discs including tumor necro- sis factor alpha (TNF-alpha). Therefore, the major objective of the investigation in this study was to examine whether TNF-alpha regulates the Wnt signal by IVD cells. METHODS: Nucleus pulposus (NP) cells were isolated from 11-week-old Sprague- DISCUSSION: The results suggest a well- Dawley (SD) rat lumber discs (n=20). The regulated inflammatory response follows expression of beta catenin messenger RNA moderate occupational lifting exposure. (mRNA) and protein in rat NP cells after the Inflammatory markers had not returned to treatment of TNF-alpha was assessed by baseline 20 hours after exposure – corre- using several transfection experiments, real- sponding to when a worker would return to time PCR, western blot and immunofluores-

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GENERAL POSTERS cence analyses. iology. The IVD cells, notochordal cells (NC) RESULTS: Rat NP cells exhibited increased and chondrocyte-like cells (CHC) can, ac- beta-catenin mRNA (1.5-fold) and protein cording to previous studies, affect nerve upon stimulation with TNF-alpha compared tissue, but the detailed mechanisms of such to control cells. In addition, T-cell-specific effects are incompletely known. The aim of transcription factor (TCF) promoter activity the present study was to investigate the (TOPflash) was found to increase the follow- morphology of spinal nerve tissue exposed ing stimulation with TNF-alpha (10ng to the two disc cell populations and sub- /ml).We analyzed the role of TNF-alpha in jected to mechanical displacement and nu- the regulation of aggrecan and col2. We cleus pulposus (NP) application. assessed the effects of TNF-alpha on METHODS: A total of 61 Sprague Dawley aggrecan and col2 reporter activity. The rats were used in this study. L4 spinal cells were cultured for 48 hours after trans- nerves were exposed to NC (25,000 cells), fection, and the reporter activity was meas- CHC (25,000 cells), NP (3 mg), mechanical ured thereafter. The transfected cells were displacement + application of NP or F12 treated with or without a TNF-alpha, and diluent. Sham and naïve rats were used as the reporter activity was measured. The control animals. Seven days after surgery aggrecan and col2 reporter activity was the L4 spinal nerve with its DRG were har- suppressed in a TNF-alpha treatment. vested and prepared for blinded DISCUSSION: The present study demon- neuropathological analysis using light mi- strates for the first time that in nucleus croscopy. pulposus, TNF-alpha regulate Wnt signal, RESULTS: The rats subjected to displace- which plays a key role in pathogenesis of ment + application of NP of the spinal nerve degenerative disc disease by promoting showed more extensive nerve tissue dam- aggrecan and col2 degradation. age as compared to all the groups without mechanical deformation of the spinal nerve. DISCUSSION: Light microscopic examination GP71 was performed to evaluate the possible THE EFFECTS OF NOTOCHORDAL CELLS AND influence of the deposition of two relevant CHONDROCYTE-LIKE CELLS ON THE cell types derived from IVD as well as NP, MORPHOLOGY OF SPINAL NERVE TISSUE: F12 diluent and mechanical displacement, AN EXPERIMENTAL STUDY IN RATS on the morphology of spinal nerve tissue. Larsson K (1), Örndal C (2), Nordborg C (2), The results indicate that application of NC, Sasaki N (3), Runesson E (1), Brisby H (1), CHC or NP, per se, did not structurally affect Rydevik B(1) neural tissue compared to spinal nerves 1 Department of Orthopaedics, Institute of which had been mechanically displaced and Clinical Sciences, 2 Department of subjected to application of NP. These ob- Pathology, Institute of Biomedicine, servations support the concept that spinal University of Gothenburg, Gothenburg, nerve involvement in association with disc Sweden. 3 Department of Orthopaedic herniation is based on a combination of Surgery, Fukushima Medical University, mechanical spinal nerve deformation and Fukushima, Japan biological effects mediated via nucleus pulposus. INTRODUCTION: Lumbar disc herniation and sciatica are common conditions in which interactions between intervertebral discs (IVD) and neural tissue are considered to be involved in the underlying pathophys- 148

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reaction) and by confocal imaging (Laser- GP72 MAI-TAIDeepSee microscope). SIMILAR PATTERNS OF CELLS MIGRATING RESULTS: Fe+ cells with elongated migrato- FROM NICHES IN THE INTERVERTEBRAL ry phenotype were detected within annulus DISC REGION AND IN THE KNEE JOINT RE- fibrosus (AF) in all injected animals (all time GION DETECTED BY IN SITU LABELLING AN points)(>1200 µm from the injection site). EXPERIMENTAL STUDY IN THE NEW Most Fe+ cells were observed in outer AF, in ZEALAND WHITE RABBIT a few animals Fe+ cells were seen in middle *Henriksson HB,**Lindahl A,**Skioldebrand part of AF. In the KJ, Fe+ cells were detected E,***Tängemo C,****Mattsson J and in 56% of the animals in the AC. Results *Brisby H were supported by confocal imaging anal- *Inst. of Clinical Sciences, Dept. of Ortho- yses. paedics, Sahlgrenska University Hospital, DISCUSSION: Detection of labeled cells in Gothenburg University, Sweden **Inst. of cartilaginous tissues, after in situ labeling of Biomedicine Dept. of Clinical Chemistry and local cells in niche areas, indicates that cells Transfusion Medicine, Sahlgrenska Universi- migrate from niches toward/into cartilagi- ty Hospital, Gothenburg, Sweden*** Centre nous tissues. The similar pattern of cellular for Cellular Imaging, The Sahlgrenska Acad- migration within IVD and KJ areas suggest emy, University of Gothenburg, Sweden similar mechanisms of growth/regeneration ****Inst. of Biomedicine Dept. of microbiol- in different types of cartilaginous tissues. ogy and immunology, Sahlgrenska Universi- Knowledge of cellular migration patterns ty Hospital, Gothenburg, Sweden and potential possibilities to stimulate these cells is of interest from clinical tissue engi- INTRODUCTION: Regeneration of the inter- neering perspective. vertebral disc (IVD) and articular cartilage (AC) is sparsely described. Recently, poten- tial stem cell niches were described lateral GP73 to the epiphyseal plate in different mammal DO INTERVERTEBRAL DISCS DEGENERATE IVDs (rat, pig, rabbit,) and in knee joints, BEFORE OR AFTER HERNIATION? (KJ)(rabbit,) and cellular migration in the Polly Lama, Christine LeMaitre*, Laura IVD region reported. The aim of the present Spooner, J Ben St Joseph, Patricia Dolan, Ian study was to examine the direction of cellu- J Harding**, Michael A Adams lar migration from niches by in situ labeling Centre for Comparative and Clinical toward/ within the IVD and compare to AC Anatomy, University of Bristol, Bristol U.K, of the KJ. *Sheffield Hallam University, Sheffield, U.K., METHODS: 12 rabbits were used in this in ** Frenchay Hospital, Bristol, U.K. situ labelling study. Two different types of cell tracers; 10 µl iron-nanoparticles INTRODUCTION: Herniated disc tissue re- (Endorem® ,BraunMedical, Germany) or the moved at surgery usually appears degener- fluorochrome compound (CDFA, Invitrogen, ated, and MRI often reveals degeneration in USA) were injected under anaesthesia, us- adjacent discs and vertebrae. This has fos- ing image intensifier into niche areas of tered the belief (which has medicolegal sig- IVDs(two lumbar levels) and KJ(proximal nificance) that a disc must degenerate be- tibia). Negative controls were naive IVDs fore it can herniate. We hypothesise that and tibia from the same animals. Animals degenerative changes in herniated disc tis- were sacrificed after 2-3 and 5-6 weeks. sue differ from those found in discs that Labelled cells were visualized by the ferric- have degenerated in-situ, and are con- iron-staining-method (Preussian-blue- sistent with being consequences rather than 149

GENERAL POSTERS causes of herniation. University of Pennsylvania METHODS: 21 surgically-removed herniated (extruded) discs were compared with 11 INTRODUCTION: Inflammation plays a cen- age-matched discs that had reached a simi- tral role in the progression of disc degenera- lar Pfirrman grade of degeneration without tion. We recently demonstrated in vitro that herniating. Histology was used to grade de- IL-1ra delivered from poly(lactic co-glycolic generative features separately in three tis- acid) (PLGA) microspheres could attenuate sue types: nucleus, inner annulus, and outer the degradative effects of IL-1β for up to 20 annulus. Immunofluorescence, using laser- days. The objectives of this in vivo study scanning confocal microscopy and 30µm were: 1) to investigate whether PLGA mi- frozen sections, was used to quantify crospheres could be retained in the NP, and nerves, blood vessels, and cells positive for 2) to test whether IL-1ra delivered from matrix-degrading enzymes (MMPs). Mann- those microspheres could effectively inhibit Whitney U tests were used to compare IL-1β induced glycosaminoglycan loss using ‘herniated’ and ‘degenerated’ tissues. a rat caudal disc model. RESULTS: Herniated tissues had significant- METHODS: PLGA microspheres were fabri- ly greater fissuring, greater proteoglycan cated using the water-oil-water double loss, greater infiltration by inflammatory emulsion technique. For retention studies, cells, greater neovascularisation as indicat- microspheres were labeled with coumarin-6 ed by CD31, greater innervation as indicated to facilitate post-mortem localization, and by PGP 9.5 and Substance P, and greater injected into the caudal discs of 6 rats, eu- expression of MMPs 1 and 3. Differences thanized at 1, 7, 14, 28 and 56 days. Micro- were most marked in the outer annulus, spheres were located using fluorescent mi- less in the inner annulus, and not significant croscopy. To see if microspheres could ef- in the nucleus. fectively inhibit IL-1β in vivo, 4 discs for DISCUSSION: Herniated annulus tissue is each of 4 rats were allocated to: intact; sa- disrupted and therefore able to swell, lose line; IL-1β; or - IL1β+IL-1ra microspheres. proteoglycans and allow invasion by in- Rats were sacrificed at 7 days and NP GAG flammatory cells, blood vessels and nerves. content was measured. These events could explain most observed RESULTS: Release kinetics demonstrated differences between ‘herniated’ and ‘de- that these microspheres could deliver a sus- generated’ annulus. Results for nucleus tis- tained dose of IL-1ra for up to 35 days. Fluo- sues suggest that disc herniation (in our rescently labeled microspheres were visible patients) did not occur because of acceler- in the disc at all time points except 56 days. ated nucleus degeneration. Results there- The GAG content of discs injected with IL-1β fore support our hypothesis, and warn alone was significantly lower than that of against assuming that degenerative changes the intact controls and the microsphere must precede (or cause) disc herniation. treatment group. For discs injected with both IL-1β and IL-1ra microspheres, GAG content was not different from intact con- GP74 trols. IN VIVO RETENTION AND BIOACTIVITY OF DISCUSSION: Local sustained delivery of IL-1RA MICROSPHERES IN THE RAT CAUDAL therapeutics for disc degeneration is im- INTERVERTEBRAL DISC portant as the avascular nature of the disc Deborah J. Gorth, John T. Martin, Dawn M. limits the efficacy of systemic delivery, and Elliott, George R. Dodge, Neil R. Malhotra, repeated injections are impractical and may Robert L. Mauck, Lachlan J. Smith induce damage. In this study we demon- Department of Orthoapedic Surgery, 150

GENERAL POSTERS strated that IL-1ra delivered from micro- cleft of nucleus pulposus, and pore space of spheres prevents IL-1β induced GAG loss in lamella complex and cleft in annulus vivo, and that microspheres are retained in fibrosus. There was no correlation between the disc space for 4 weeks. CD68 positive cells in high-power field and Pfirrman MRI grading scale. M1/M2 ratio was 95.5/4.5. GP75 DISCUSSION: Non-herniated degenerative M1 MACROPHAGE EXISTS IN THE NON- disc consists of macrophages which express HERNIATED DEGENERATIVE DISC. CD68 and CD14. Almost of these macro- T. Takada, K. Maeno, K. Kakutani, T. Yurube, phages are M1 macrophages. These mac- J. Yamamoto, H. Hirata, T. Kurakawa, S. rophages are thought to be derived from Miyazaki, M. Kurosaka, K. Nishida extra disc. M1 macrophages induce inflam- Department of Orthopedic Surgery Kobe matory reaction and foreign body elimina- University Graduate School of Medicine tion. M1 macrophages in non-herniated disc can play important role in the etiology of INTRODUCTION: In herniated disc disease, disc degeneration and discogenic pain. intervertebral disc and macrophages inter- action play important role not only disc ab- sorption but also inflammatory reaction and GP76 pain. In non-herniated degenerative disc, PATHOGENESIS OF OSSIFICATION OF CD68-positive cells exist. Macrophage is LIGAMENTUM FLAVUM classified M1 macrophage (inflammation Naresh-Babu J, Neelima Govada inducing) and M2 macrophage (anti- in- Mallika Spine Centre and Osmania Medical flammatory). But CD68-positive cell’s deri- College, Hyderabad, INDIA vation (chondrocyte phenotype change or infiltrating from extra disc) and class in non- INTRODUCTION: Ossification of ligamentum herniated degenerative disc are not still flavum (OLF) is a rare disorder. Present clarified. In this study, we clarified the exist- study aims at histopathological analysis of ence of macrophages and their classifica- OLF with special emphasis on the altera- tion. tions in the elastin fibers, collagen, matrix, MATERIALS AND METHODS: 33 non- cellularity, chodrocyte proliferation and herniated degenerative disc specimen slices osteoid metaplasia. were stained with anti CD68, CD14 and METHODS: The study involves iNOS monoclonal antibody using histopathologic examination of surgically immunohistochemical methods. The CD68 harvested ligamentum flavum (LF) speci- positive macrophages were counted in 10 mens from 10 OLF, five with degenerative consecutive high-power (×400) fields, and spinal stenosis and five normal LF as con- expressed as cells per high-power field. We trols. The specimens were studied with compared correlation between Pfirrman Hematoxylin and Eosin (H&E), Verhoff’s van MRI grading scale and CD68-positive cells Gieson (VvG), Toluidine blue (TB), Masons per high-power field using Mann-Whitney’s trichrome (MT) and Alcian Blue (AB). All U test. Under CD14 (M1 and M2 commonly specimens were analysed qualitatively for observed antigen) and iNOS (M1 specific 1.elastic fiber orientation, integrity and loss, antigen) multistaining procedure, we evalu- 2) Collagen bundles 3) Fibrosis 4) Chondroid ated M1/M2 ratio in each samples. metaplasia 5) Chondrocyte proliferation and RESULTS: Among 33 specimens, 32 speci- 6) Osteoid metaplasia. The quantitative mens showed CD68 positive cells. CD68 pos- analysis was done using SCION image analy- itive cell were frequently observed in the sis software. 151

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Switzerland

INTRODUCTION: New cells/hydrogel based treatments for intervertebral disc (IVD) re- generation need to be tested on animal models before clinical translation. Ovine IVD represents a good model but doesn’t allow

the injection of a significant volume into RESULTS: All ten OLF specimens showed intact IVD. The objective of the study was to extensive loss of elastic fibers associated compare different methods to create a cavi- with cartilage matrix formation. There were ty into ovine nucleus pulposus (NP) by en- many areas of irregularly oriented elastic zymatic digestion (E), mechanical discecto- fibers, areas of ossification and in between my (M) and a combination of both (E+M), as there was a transitional area of cartilage a model to study IVD regeneration strate- matrix with chondrocytes progressing to- gies with intact anulus fibrosus (AF). wards ossification. METHODS: Ovine lumbar functional spinal Elastic fiber occupying ratio was 60.96%, units (FSU) were used. The transpedicular 40.25% and 22.66%; no of Chondrocytes per approach via the endplate route (2mm tun- mm2 was 37.56, 93.35 and 117.68; area of nel) was performed to access the NP with chondroid matrix (%) was 11.34, 32.37 and AF intact. FSUs were treated through M 73.56 and the area of osteoid matrix (%) (Arthroscopic shaver), E (Tryp- was 0, 9.37 and 33.43 respectively for nor- sin/Collagenase) and E+M. The cavity was mal controls, degenerative group and OLF macro- and micro-scopically evaluated. The group. The areas of cartilage matrix were degradation of GAG (gel chromatography) more on the dorsal side compared to the around the cavity (inner AF) was assessed. dural side of LF. In contrast, cartilage matrix The cavity volume was quantified through osteogenesis was more in dural than dorsal µCT after injection of Agarose gel/Contrast surface of LF. agent. CONCLUSIONS: In OLF, loss of elastic fibers RESULTS: The cavity has been successfully was associated with proliferation of colla- created using all methods. The M group gen fibers, fibrosis, chondrogenesis and showed high reproducibility, low GAG deg- osteogenesis. The pathological process initi- radation and no endplate thinning com- ates in the dorsal surface with chondroid pared to other groups. The histology analy- metaplasia gradually elevating the mature sis demonstrated NP matrix degradation in cartilage matrix towards the dural surface E groups while the proteoglycan content was still homogenous in the M. The per- centage of the cavity volume normalized to GP77 the total IVD volume was 5.2% ± 1.6 in E, 5% A NOVEL NUCLEOTOMY MODEL WITH ±1.4 in E+M and 4,2% ± 0.1in M. INTACT ANULUS FIBROSUS TO TEST DISCUSSION: M represents the best method INTERVERTEBRAL DISC REGENERATION to create a reproducible and less destruc- STRATEGIES tive cavity in the NP. Indeed, E-based meth- Vadalà G. 1, Russo F. 1, Patappa G. 2, ods perform better in terms of cavity vol- Peroglio M. 2, Grad S. 2, Stadelmann V. 2, ume but the GAG of the surrounding tissue Alini M. 2, Denaro V. 1 may be affected. While a lesion of the end- 1 University Campus Bio-Medico, Rome, plate might lead to further IVD degenera- Italy 2 AO Research Institute, Davos, tion, this approach is minimal invasive

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(2mm) and can be easily sealed using bone through the pedicle and the endplate both cylinder, cements or scaffolds. The biome- in ovine and human spine (Fig-A/B), without chanical characterization and in vivo evalua- affecting the spinal canal and the neural tion are on going. foramina (Fig-C). The BS was delivered into the IVD (Fig-D). Nucleotomy was successful- ly performed and the cavity filled with the GP78 gel. NP was removed from the disc by the THE TRANSPEDICULAR APPROACH AS NEW transpedicular approach and filled with the ROUTE FOR INTERVERTEBAL DISC gel (Fig-E). REGENERATION DISCUSSION: The transpedicular approach Vadalà G. 1, Russo F. 1, Patappa G. 2, represents a new route to the NP for IVD Schiuma D. 2, Peroglio M. 2, Grad S. 2, regeneration, whilst maintaining the AF Benneker L. 3, Alini M. 2, Denaro V. 1 intact. The injection of BS into the NP, 1 University Campus Bio-Medico, Rome, demonstrated the feasibility of a drug/cell Italy, 2 AO Research Institute, Davos, Swit- therapy to treat early disc degeneration zerland, 3 Bern University Hospital, Bern, (IDD) through this approach. The tunnel Switzerland. might be also used to perform nucleoplasty in moderate or severe stages of IDD allow- INTRODUCTION: Present delivery ap- ing the delivery of a hydrogel/cells con- proaches of therapeutic agents (growth struct. factors/cells/hydrogels) within the interver- tebral disc (IVD) need to be through injec- tion, via the anulus fibrosus (AF). However, it has been demonstrated that even a small needle puncture of the AF leads to further degeneration and disc herniation [1]. The aim of the study is to describe a novel transpedicular approach to deliver thera- peutic agents into IVDs of ovine and human cadaveric spinal segments. METHODS : Lumbar ovine and human func- tional spinal units (FSUs) were used. Under fluoroscopy, a 2 mm K-wire has been intro- duced in the caudal vertebra of FSU. The K- wire was inserted through the pedicle and the inferior endplate to the nucleus pulposus (NP). µCT (HR-pQCT) was per- formed to assess the right position of the K- wire in the pedicle. Discography and nucleotomy have been performed using barium sulfate (BS) through a 16G cannula and arthroscopic shaver (2mm), respective- [1] Carragee, Spine 2009 ly. Nucleoplasty was performed delivering agarose gel/BS and evaluated through µCT. The bonny tunnel was sealed with a porous polyurethane scaffold. RESULTS: Fluoroscopy and µCT images showed that the NP could be approached 153

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AGEs discs exhibited mechanical changes GP79 consistent with degeneration, & treating THE ROLE OF ADVANCED GLYCATION END- these discs with AGE-breakers reverted PRODUCTS IN THE DEGENERATION OF THE them to a healthy state. Both NP & AF cells INTERVERTEBRAL DISC exhibited increases in RAGE and inflamma- +Tang, SY(1); Morse, LJ(2); Chen, L(2); tory cytokine expression with dose- Sharan, AD(3) dependently with AGEs. 1 Orthopaedic Surgery, Washington University in St Louis, St Louis MO, 2 Orthopaedic Surgery, Univ Calif San Francisco, San Francisco, CA, 3 Orthopaedic Surgery, Albert Einstein College of Medicine, Bronx, NY

INTRODUCTION: Intervertebral Disc (IVD) degeneration occurs with cellular & matrix changes that result in altered mechanical & cellular behavior. Advanced glycation endproducts (AGEs), the result of sugar- protein binding IVD tissue during degenation, but its role remains unknown. DISCUSSION: AGEs accounted for a signifi- AGEs may play a significant role in IVD de- cant decline in NP viscoelasticity & AF stiff- generation by modifying tissue material ening. Removal of AGEs restored the me- behavior & inducing inflammation in IVD chanical properties in these discs. Primary cells. IVD cells increase inflammatory cytokines METHODS: Cadaver lumbar discs (11 do- when exposed to AGEs. Taken together, nors, 56 discs) of varying Thompson grades these results demonstrate the prominent were split into the annulus (AF) & nucleus role that AGEs plays in IVD degeneration (NP) tissues and then divided into 3 groups: and a possible therapy for IVD degenera- control; elevated AGEs (in vitro induction); tion. & AGEs-breaker group. Each sample was microindentated to quantify the elastic & viscoelastic behavior, & then assayed for proteoglycans (PG), AGEs, collagen, & wa- ter. To determine the effects of AGEs on IVD cell inflammation cascade, primary AF & NP cells were extracted from the bovine caudal discs, cultured to confluency, & then exposed to either (BSA)-AGEs, BSA, or con- trol media for 3 days. The gene expression of RAGE, IL-1, IL-6, NFκB, & TNFα were x-e amined by PCR. RESULTS: NP exhibited reduced PG, water content, & AGEs content in degeneration, while the AF had reduced PG & water con- tent, but significant increases in collagen & AGEs. AF stiffened with degeneration, while the NP declined in viscoelasticity. The high 154

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Zoki Pharma, Japan) for 48hrs. Expression GP80 levels of cytokines (IL-1β, IL-6, TNF-α), en- EFFECT OF THE NON-PROTEIN BIOACTIVE zymes (TS4, TS5, MMP3) and pain markers COMPOUND, NEUROTROPIN® ON (NGF, VEGF and COX-2) were analyzed. INTERLEUKIN-1Β-INDUCED EXPRESSION LEVELS OF CYTOKINES, MATRIX ENZYMES AND PAIN MARKERS IN HUMAN INTERVERTEBRAL DISC EXPLANT CULTURES *Pichika, Rajeswari; *§Yamaguchi, Tomon- ori; *Fujiwara, Tatsuhiko; †Bae, Won C, *Lenz, Mary E; δNaiki, Mitsuru; *Masuda, Koichi *Orthopaedic Surgery, †Radiology, Universi- ty of California at San Diego, CA, United States. §Biomidical Engineering, Doshisha University, Kyoto, Japan. δNippon Zoki Pharm, Osaka, Japan.

INTRODUCTION: Disc degeneration increas- es innervation, causing low back pain. Ani- mal model studies showed that pain corre- lates with increased nerve growth factor (NGF) expression. Disc injury initiates proinflammatory cytokine production re- sulting in hyperalgesia. Cytokines that are mediators of pain (IL-1β/tumor necrosis factor-α (TNF-α)) are localized in degener- ated discs. Treatment of chronic pain with RESULTS: NTP addition to IL-1β-stimulated NSAIDs, Opioids and anti-depressants has a cultures significantly down-regulated ex- number of side effects. Neurotropin® (NTP), pression of IL-1β, TNF-α, IL-6, COX-2, TS4 a non-protein extract from inflamed skin of and TS5 in a dose-dependent manner (Fig- rabbits inoculated with vaccinia virus, is ure). For MMP3, NGF and VEGF, higher dos- used to treat pain. NTP, shown to suppress es of NTP (100and200mNU/ml) suppressed TNF-α and cyclooxygenase-2 (COX-2) ex- mRNA expression. pression, stimulates proteoglycan synthesis DISCUSSION: NTP significantly suppressed by human and bovine intervertebral disc the IL-1β-induced expression of cytokines, (IVD) cells. The purpose of this study was to MMP3, TS4, TS5, NGF and COX2 by NP and determine if NTP suppresses the expression AF explant cultures, suggesting that NTP of cytokines, matrix enzymes and pain may be anti-inflammatory and have benefi- markers induced by IL-1β in human IVD ex- cial effects on pain and IVD homeostasis. plant cultures. Further studies may prove the usefulness of METHODS: Anulus fibrosus (AF) and nucleus intradiscal injections of NTP as a valid ther- pulposus (NP), dissected from human ca- apeutic approach. daveric IVDs (grades 2-3; n=3, age: 53.3±8), were cultured as explants in triplicate in DMEM/F12+0.1%ITS for 24 hours then treated: 1)Control 2)IL-1β (5ng/ml) 3) - IL 1β+NTP (10, 100 and 200mNU/ml, Nippon 155

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6, TNF-α), enzymes (ADAMTS4/5, MMP3) GP81 and pain markers (NGF and PTGS2) were CLONIDINE, AN ALPHA-2 ADRENERGIC AG- measured. ONIST DECREASES CYTOKINE, MATRIX DEGRADATION AND ASSOCIATED PAIN MARKER EXPRESSION IN HUMAN INTER- VERTEBRAL DISC EXPLANT CULTURES *Pichika, Rajeswari; *§Yamaguchi, Tomonori; *Fujiwara, Tatsuhiko; *Lenz, Mary E; †Bae, Won C; ‡Penta, Kalyani; ‡Binette, Francois; ‡McKay, William F; *Masuda, Koichi. *Orthopaedic Surgery, University of California-San Diego, CA, United States. §Biomedical Engineering, Doshisha University, Kyoto, Japan. †Radiology, University of California-San Diego, La Jolla, CA, United States. ‡Medtronic Spinal and Biologics, TN, United States.

INTRODUCTION: Treatment of chronic low back pain (LBP) in disc degenerative disease RESULTS: IL-1β significantly increased total is often limited to pain alleviation and/or NO and PGE2 release and the mRNA expres- invasive surgical intervention. Opioids pre- sion levels of cytokines, matrix enzymes and scribed to relieve pain are associated with pain markers (p<0.05). Clonidine dose- undesirable side effects. Clonidine has been dependently decreased the IL-1-induced used as a spinal analgesic in humans to treat release of nitrate and PGE2 into the media chronic LBP. Clonidine provides neurological and decreased expression levels of all blockade in patients with LBP by a mecha- markers tested (p<0.05). nism resulting from axonal membrane stabi- DISCUSSION: We demonstrated the sup- lization, an α2/α1-agonist effect on neu- pressive effects of clonidine on NO and rons, or a combination of these two effects. PGE2 production and mRNA expression of The aims of the present study were to de- various cytokines, matrix-degrading en- termine the direct effects of clonidine on zymes and pain markers under IL-1 stimu- disc tissues, specifically in suppressing the lated conditions in human IVD tissues. Our expression of cytokines, matrix-degrading data suggest that clonidine is not simply an enzymes, and pain markers (cyclooxygen- α2/α1-agonist, but may be involved in mul- ase-2, nerve growth factor) by human inter- tiple mechanisms in the pain generation vertebral disc (IVD) explant cultures. associated with degenerative disc disease. METHODS: Anulus fibrosus (AF) and nucleus pulposus (NP) tissues dissected from human cadaveric IVDs (n=5, age 64.2+10) were cul- tured as explant cultures for 24h (DMEM/F12+ITS) then treated: 1)control 2) IL-1β (10ng/ml) 3)clonidine hydrochloride (10, 100, 1000umol/ml) 4)clonidine+IL-1 for 48hrs. Nitrite (NO) and PGE2 media levels and mRNA expression of cytokines (IL-1β, IL- 156

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(each p<0.05) roughness than the central or GP82 the posterior regions. ENDPLATE ROUGHNESS IN HUMAN LUMBAR SPINES: VARIATIONS WITH AGE, LEVEL AND REGION WC Bae, J He, I Shieh, +T Yamaguchi, +N Inoue, K Masuda University of California, San Diego, San Diego, CA, USA. + Doshisha University, Kyoto, Japan. DISCUSSION: Higher roughness in aged samples is similar to previously reported INTRODUCTION: The cartilaginous end- results in human and animal endplates, and plates (CEP) form interfaces between the may contribute to disc degeneration in aged intervertebral disc (IVD) and vertebral body. population. Regional variation in roughness Calcification of the CEP, which increases was independent of aging and may reflect surface roughness and clogs open pores, intrinsic structure. This study is limited sinc may hinder solute transport and lead to disc roughness is an indirect measure of calcifi- degeneration. The goal of the study was to cation, and it is unclear if increased rough- determine variations in micro-CT measure ness values reflects altered transport. of endplate roughness with age, level, and region. GP83 METHODS: Nine cadaveric lumbar spines were obtained and divided into two groups INTERVERTEBRAL DISC REPAIR USING based on age: <60 yr (51±3 yr, 3M, 2F) and NEONATAL HUMAN DERMAL FIBROBLASTS >60 yr (70±6 yr, M). Cylindrical disc-bone IN THE RABBIT MODEL cores (n=173) were harvested from anteri- *Chee, Ana; *Shi, Peng; ΔCha, Thomas; or, central, posterior and lateral regions of †Kao, Ting-Hsien; #Yang, Shu-Hua; *Zhang, L2 inferior (L2i), L3 superior (L3s), L4i, and Yejia; *An, Howard S. L5s. Cores were imaged using micro CT at 9 *Dept of Orthopaedics, Rush University µm. Using Matlab, images were thresholded Medical Center, Chicago, IL, United States; and coordinates of endplate surface were ΔMassachusetts General Hospital, Boston, determined. Baseline contour was then sub- MA, United States; †Taichung Veterans tracted to determine local surface rough- General Hospital, Taichung, Taiwan, ness. Effects of age, level, and region on Republic of China; # National Taiwan surface roughness were determined using University Hospital and National Taiwan 3-way ANOVA with posthoc test. University College of Medicine, Taipei, RESULTS: Endplate roughness varied with Taiwan, Republic of China. age group (p<0.05) and region (p<0.001), but not with level (p=0.3). Roughness was INTRODUCTION: Transplanting cells to re- higher (A) in aged samples (73±41 µm) than populate the intervertebral disc (IVD) and to younger samples (59±35 µm). Level-wise, provide growth signals to resident cells may roughness varied from 56 to 71 µm (B), but be effective in reversing disc degeneration. no differences were found. Region-wise, Human dermal fibroblasts from the pa- lateral region had the lowest roughness tient’s skin tissue or from a donor tissue (49±30 µm), followed by anterior (49±30 may be a promising cell source. The purpose µm), central (80±39 µm), and posterior of these studies is to determine the effects (91±36 µm) regions (C). Both the lateral and of neonatal human dermal fibroblast cell anterior regions had significantly lower (nHDF) therapy on the progression of IVD 157

GENERAL POSTERS degeneration. Markova, ‡D. Greg Anderson, MD, METHOD: New Zealand white rabbits (n=16) †Gabriella Cs-Szabo, PhD, #Sherrill L. received an annular puncture using an 18- Adams, PhD, *Howard S. An, M.D. guage needle to induced disc degeneration. *Department of Orthopedic Surgery, nHDFs (Invitrogen) were labeled with infra- †Biochemistry, and ΔPhysical Medicine and red dye. Four weeks after injury, rabbit IVDs Rehabilitation, Rush University Medical Cen- were treated with nHDFs (n=8), or saline ter, Chicago, IL; #Department of Biochemis- (n=8). At two (n=2 per group) and eight try, School of Dentistry, University of Penn- weeks post-treatment (n=6 per group), an- sylvania, Philadelphia, PA; ‡Department of imals were sacrificed. X-ray, T2 weighted Orthopedic Surgery, Thomas Jefferson Uni- magnetic resonance imaging (MRI) and in- versity, Philadelphia, PA. frared images were obtained. IVDs were isolated for histological, biochemical and INTRODUCTION: The mechanism of RNA analyses. discogenic back pain is not well understood. RESULTS: The infrared images showed that A better understanding of the underlying nHDFs were retained in the IVD at both 2 pathophysiology for discogenic axial back and 8 weeks after transplantation. There pain is needed to facilitate the development was a 10% increase in the disc height index of targeted therapies for this prevalent dis- after 8 weeks of treatment with nHDFs ease. We hypothesize that certain cyto- when compared to 4 weeks after injury kines, specifically interleukin (IL)-8, in inter- (p≤0.05) while there was no significant dif- vertebral disc (IVD) tissues from patients ference in the saline group. In the RNA with discogenic back pain differ from those analysis at 8 weeks after treatment, the in non-painful disc tissues and that IL-8 can collagen type II/collagen type I ratio, a be expressed by IVD cells. marker for disc repair, was 1.63 in the IVDs METHODS: IVD tissues from patients who treated with nHDFs and 1.0 in those treated underwent surgery for discogenic pain con- with saline. There was no significant differ- firmed with discography (painful discs) or ence in the biochemical measures, MRI indi- spinal deformity reconstruction (control ces and histological scores between the two discs) were collected and paired according groups. However, NP cellularity in the histo- to MRI grade. Using cytokine array analysis, logical grading in the nHDF treated discs cytokine levels in the painful and control were higher than the saline treated discs discs were compared. To determine if cyto- (p≤0.05). kines can be expressed by IVD cells, cells DISCUSSION: After 8 weeks of treatment, were isolated from surgical and donor nu- nHDFs were retained in the IVD, there was cleus pulposus (NP) and annulus fibrosus some disc height recovery, NP cellularity (AF) tissues and stimulated with IL-1β (10 increased, and the ratio of Collagen type II ng/mL) or TNF-α (10 ng/mL) for 24 hours. IL- and I gene expression was favorable sug- 8 gene expression was analyzed using real- gesting that nHDF is a promising cell thera- time PCR and IL-8 protein levels in the su- py option for disc degeneration. pernatant were analyzed using enzyme- linked immunosorbent assays. RESULTS: Among the 42 cytokines studied, GP84 there was a trend for IL-8 levels to be ele- INTERVERTEBRAL DISC CELLS PRODUCE vated in patients with discogenic back pain INTERLEUKIN-8 (IL-8) IN RESPONSE TO (p= 0.19). IL-8 gene expression was INFLAMMATORY STIMULI upregulated in both NP and AF cells that *†ΔYejia Zhang, M.D., Ph.D.,*Ana Chee, were stimulated with either IL-1β or TNF-α. PhD, *Peng Shi, DDS, PhD, ‡Dessislava 158

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High levels of IL-8 protein were detected in analysis was performed. the supernatant of cells after stimulation. RESULTS: NP cells were more sensitive to DISCUSSION: We have shown, for the first TNF than AF cells (p<0.005). NP cells had a time, that IL-8 is present in painful IVDs, higher density of TNF receptor (TNFR) than thus providing a physiological basis for pain AF cells. TNF treatment resulted in signifi- generation.We have shown that cultured cantly elevated levels of pNF-κB compared IVD cells produce massive amounts of IL-8 in to the control (p<0.01), which was down- response to inflammatory stimuli (e.g., TNF- regulated by BGN. TNF significantly up- α and IL-1β). regulated the expression of MMP-1, MMP- 13, NGF and IL-8 (p<0.05); TNF+BGN treat- ment resulted in the down-regulation of GP85 these mRNA species compared to TNF alone BIGLYCAN DOWN-REGULATES TNF-ALPHA- (p< 0.05). INDUCED PROTEASE AND CYTOKINE GENE DISCUSSION: The difference in sensitivity of EXPRESSION IN HUMAN INTERVERTEBRAL NP and AF cells to TNF is partly due to dif- DISC CELLS ferences in cell-surface TNFR. TNF can ‡Samuel Buchanan, BS, ‡David Gerard, MS, upregulate NGF expression, promoting §‡†Yejia Zhang, MD, PhD, §Ana Chee, PhD, nerve ingrowth, and of IL-8, which may §Howard S. An, MD., §Gunnar Andersson stimulate invading nerve endings. BGN can and ‡§Gabriella Cs-Szabo, PhD counteract the effect of TNF-alpha by reduc- Departments of ‡Biochemistry §Orthopedic ing expression of MMPs, NGF and cytokines Surgery and †Physical Medicine and Reha- thus inhibiting pain generation. We propose bilitation, Rush University Medical Center, that BGN protects against TNF, leading to Chicago, IL. reduction of matrix degeneration and inhi- bition of pain generation through a poten- INTRODUCTION: Inflammatory mediators tial mechanism of stimulating the Erk path- like TNF-alpha (TNF) can trigger release of way or reducing TNFR on the cell surface cytokines and enzymes to the matrix. Blood vessels and nerves can grow into compro- mised tissue leading to pain. We found that GP86 the concentration of biglycan (BGN) is sig- THE SAFETY AND EFFICACY OF nificantly increased in IVDs of the elderly MESENCHYMAL STEM CELLS FOR PREVEN- who clinically rarely experience discogenic TION OR REGENERATION OF INTERVERTE- back pain. Our goal was to determine if BGN BRAL DISC DEGENERATION: A SYSTEMATIC could counteract the effect of TNF and play REVIEW a protective role in IVD degeneration and (1) Rita Lok-hay Yim, (1) Juliana Lee, (2) pain generation. Patrick Vavken, (1) Dino Samartzis METHODS: Annulus fibrosus (AF) and nu- (1) Department of Orthopaedics and Trau- cleus pulposus (NP) cells from 8 deceased matology, The University of Hong Kong, human donors were treated with TNF (1 Pokfulam, Hong Kong, SAR, China (2) De- and 10 ng/ml) in the absence or presence of partment of Orthopaedic Surgery, Harvard 2.2 μg/ml BGN. NF-κB signaling was deter- Medical School, Boston, USA mined by Western blots; gene expression of matrix metalloproteinases (MMP)-1, MMP- INTRODUCTION: Mesenchymal stem cells 13, interleukin (IL)-8, nerve growth factor (MSCs) have been used to halt the progres- (NGF), and GAPDH by real-time PCR, and sion or regenerate the disc with hopes to TNF receptor density by immunohistochem- prevent or treat discogenic back pain. How- istry. One-way ANOVA with Tukey post-hoc ever, the safety and efficacy of the use of 159

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MSCs for such treatment in animal and hu- man models at short and long term assess- GP87 ment (i.e. greater than 48 weeks) have not EFFECTS OF IL-1BETA ON AXONAL been systematically addressed. This study OUTGROWTH FROM ADULT RAT LUMBAR addressed a systematic review of compara- DORSAL ROOT GANGLIA USING A NOVEL tive controlled studies addressing the use of 3D CULTURE SYSTEM MSCs to that of no treatment/saline for the Hyunchul Kim 1, Sameer B. Shah 2, Adam H. treatment of disc degeneration. Hsieh 1,3 METHODS: Online databases were exten- 1 Fichell Department of Bioengineering, sively searched. Controlled trials in animal University of Maryland, College Park , USA 2 models and humans were eligible for inclu- Departments of Orthopaedic Surgery & sion. Trial design, MSC characteristics, injec- Bioengineering, University of California, San tion method, disc assessment, outcome Diego, USA 3 Department of Orthopaedics, intervals, and complication events were University of Maryland, Baltimore, USA assessed. Validity of each study was as- sessed addressing trial design. Two individ- INTRODUCTION: Increased innervation of uals independently addressed the afore- the intervertebral disc (IVD) by neurons mentioned. originating from dorsal root ganglia (DRG) RESULTS: Twenty-two animal studies were has been implicated in low back pain. As a included. No human comparative controlled first step toward improving our understand- trials were reported. All three types of MSCs ing of interactions between disc cells and (i.e. derived from bone marrow, synovial the DRG in the inflammatory environment and adipose tissue) showed successful inhi- of a degenerate disc, we developed a novel bition of disc degeneration progression. experimental system to measure axonal From three included studies, bone marrow outgrowth of adult rat lumbar DRG neurons derived MSC showed superior quality of disc into collagen hydrogels, and examined the repair when compared to other treatments, effects of IL-1β treatment. including TGF-β1, NP bilaminar co-culture METHODS: Lumbar DRGs were harvested and axial distraction regimen. However, from adult Sprague-Dawley rats, bisected to osteophyte development was reported in expose cell bodies, and seeded onto type I two studies as potential complication of collagen gels prepared in 24-well Transwell MSC transplantation. inserts. DRGs were then cultured with 0, 1, CONCLUSIONS: Based on animal models, and 10 ng/ml of IL-1β (n=3 per group) in the current evidence suggests that in the NGF-supplemented media. After 7 days, short-term MSC transplantation is safe and collagen constructs with DRGs were fixed effective in halting disc degeneration; how- and whole mount staining for neurofilament ever, additional and larger studies are was performed. Simple Neurite Tracer (Fi- needed to assess the long-term regenera- ji/ImageJ) was used to measure neurite tive effects and potential complications. lengths from confocal image stacks. Lengths Inconsistency in methodological design and of the ten longest neurites per DRG were outcome parameters prevent any robust compared among groups. conclusions. In addition, randomized con- trolled trials in humans are needed to as- sess the safety and efficacy of such therapy.

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Xi’an, China; 2 Department of Orthopaedics and Traumatology, University of 9 Hong Kong, Pokfulam, Hong Kong, SAR China

INTRODUCTIONS: As a main cellular com- ponent within the disc, nucleus pulposus (NP) cells play important roles in disc physi- ology. However, little is known on the bio- logic hallmarks of human NP cells. There- RESULTS: Robust neurite outgrowth into fore, the present study aimed to address collagen gels was observed in all groups. the features of human NP cells. Treatment by IL-1β significantly decreased METHODS: Human NP samples were col- (p<0.05) neurite outgrowth by 39% lected from normal donators, patients with (1ng/mL) and 38% (10ng/mL) compared scoliosis and disc degeneration as normal, with the NGF-only group. However, there disease control and degenerative NP, re- was no significant effect of IL-1β concentra- spectively. The NP samples were studied tion. using transmission electron microscopy and DISCUSSION: This study utilized a novel 3D TUNEL assay. Pre-digested NP samples were culture system to investigate factors gov- studied using flow cytometry with erning neuronal ingrowth. Advantages of PI/Annexin V staining. such a system include the use of physiologi- RESULTS: Both control and degenerative cally-relevant adult DRGs, maintenance of human NP consisted of mainly viable cells native DRG microenvironment for cell bod- with a variety of morphology. Both necrosis ies, and the presence of appropriate bio- and apoptosis were noted in human NP as physical cues for neurons invading a com- forms of cell death with increased apoptosis pliant collagen matrix. We found that adult in degenerative NP, which was further con- rat lumbar DRGs responded well, with NGF firmed by the TUNEL assay. Phagocytic NP promoting neurite outgrowth over separate cells had the hallmarks of both stationary NGF-free treatments. Similar to previous macrophages with lysosomes and NP cells studies, IL-1β significantly decreased the with the endoplasmic reticulum. Annulus lengths of growing axons. We are currently fibrosus cells have similar morphologic using this system to investigate the role of characteristics with NP cells in terms of cell disc cell interaction in these processes. nest, phagocytosis and intracellular organs. Moreover, NP cells with long processes ex- GP88 isted in degenerative and scoliotic NP rather than normal NP. When cultured in glucose- NOVEL INSIGHTS INTO THE HALLMARKS OF free medium, NP cells developed long and HUMAN NUCLEUS PULPOSUS CELLS WITH thin processes. PARTICULAR REFERENCE TO CELL DISCUSSION: Human degenerative NP con- VIABILITY, PHAGOCYTIC POTENTIAL AND sists of primarily viable cells. We present LONG PROCESS FORMATION direct and in vivo evidence that both human Yu-Fei Chen1, Yong-Zhao Zhang1, Hai-Qiang annulus fibrosus and NP cells have phago- Wang1, Zhi-Heng Liu1, Wei-Lin Zhang1, cytic potential. Moreover, NP cells with long Zhong-Yuan Wan1, Zhen Sun1, Shu Zhu1, processes exist in both scoliotic and degen- Dino Samartzis2, Chun-Mei Wang1, Zhuo- erative NP with lack of glucose as one of the Jing Luo1 possible underlying mechanisms. 1 Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, 161

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GP89 the two groups in low back pain while in motion and standing. However, the elderly EVALUATION OF NON-SPECIFIC LOW BACK group showed significantly lower VAS score PAIN USING A DETAILED VISUAL for low back pain while sitting compared to ANALOGUE SCALE FOR PATIENTS IN the young group. MOTION, STANDING AND SITTING: DISCUSSION: In this study, differences in CHARACTERIZING NON-SPECIFIC LOW characteristics of NSLBP between elderly BACK PAIN IN ELDERLY PATIENTS and young patients were successfully de- Yasuchika Aoki1, Shiro Sugiura2, Koichi tected by a detailed VAS scoring system. Nakagawa1, Arata Nakajima1, Hiroshi The detailed VAS revealed that elderly pa- Takahashi1, Seiji Ohtori3, Kazuhisa tients with NSLBP have significantly less Takahashi3, Satoru Nishikawa2 pain than the young group when sitting. 1Department of Orthopaedic Surgery, Toho This minor modification of the traditional University Sakura Medical Center, VAS may be useful for characterizing and 2Nishikawa Orthopedics Clinic, evaluating low back pain. 3Department of Orthopaedic Surgery, Grad- uate School of Medicine, Chiba University GP90 INTRODUCTION: This study aimed to evalu- LUMBAR SCOLIOSIS IN RHEUMATOID ate low back pain using a detailed visual ARTHRITIS -EPIDEMIOLOGIC RESEARCH analog scale (VAS) scoring system. Because WITH A DXA COHORT- of our clinical impression that elderly pa- Makino, Takahiro; Kaito, Takashi; Fujiwara, tients have low back pain while in motion Hiroyasu; Ishii, Takahiro; Yonenobu, Kazuo and standing, but less pain when sitting, we Department of Orthopaedic Surgery, investigated characteristics of non-specific National Hospital Organization Osaka low back pain (NSLBP) in elderly patients. Minami Medical Center METHODS: One hundred eighty-nine pa- tients with NSLBP were included. The pa- INTRODUCTION: The prevalence of lumbar tients were divided into an elderly group scoliosis in the normal adult population has (≥65 years-old; n=56) and a young group been reported, but that in patients with (<65 years-old, n=133). Low back pain was rheumatoid arthritis (RA) remains unclear. evaluated by (i) a traditional VAS scoring The aim of this study was to identify the system (0-10 cm), (ii) the Oswestry Disability prevalence of and risk factors for lumbar Index (ODI), and (iii) a new detailed VAS scoliosis in patients with RA using lumbar scoring system in which pain is inde- images obtained from dual-energy X-ray pendently evaluated in three different pos- absorptiometry (DXA). tural situations (in motion, standing, and METHODS: Subjects comprised 241 patients sitting). with RA who underwent annual DXA. Cobb RESULTS: Mean scores for the traditional angles of the lumbar spine were measured VAS and ODI for low back pain were 4.8 and by lumbar anteroposterior DXA and the 24.6 in the elderly group and 5.0 and 23.2 in prevalence of lumbar scoliosis (curvature the young group with no significant differ- ≥10°) was calculated. Correlations between ence found between the groups. Mean lumbar scoliosis and potential risk factors scores for the detailed VAS for low back (age, sex, duration of RA, T-score of lumbar pain (motion, standing, and sitting) were spine and hip, and severity of hand deformi- (3.8, 3.7, and 2.8) in the elderly group, (4.4, ty) were analyzed. 3.8, and 4.2) in the young group. The results RESULTS AND DISCUSSION: The prevalence showed no significant differences between of lumbar scoliosis in RA patients was 162

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32.0%. Mean Cobb angle was 7.1 ± 5.5º Avantic (2010 model). The images were among all subjects, compared to 13.6 ± 4.4º then downloaded, placed into a randomizer (range, 10-32º) among subjects with scolio- program, and evaluated by a group of spine sis. Subjects with scoliosis were significantly surgeons and neuroradiologists inde- older (67.8 years) than those without (61.6 pendently. The reviewers, who were blind- years, p<0.0001). T-score of the hip was ed to the fluoroscope the images were significantly smaller in subjects with scolio- from, ranked them from best to worst using sis (-1.79) than in those without (-1.26, a numeric system. In addition, the images p=0.0005). Multivariate logistic regression were rated according to a quality scale from analysis revealed age as the sole risk factor 1 to 5, with a 1 representing the best image for lumbar scoliotic changes in RA patients quality. The radiation exposure level for the (odds ratio, 1.069; 95% confidence interval, fluoroscopy units was also compared and 1.032-1.108; p=0.0002). The prevalence of was based on energy emission. lumbar scoliosis in RA patients was about RESULTS: According to the mean values for three- or four-times higher than rank the following order of best to worst prevalences from previous reports in DXA was observed: 1. GE OEC> 2. Philips 2010 > cohorts irrespective of RA. Increased age 3. Philips 2009 > 4. Siemans. The exact same represented an independent risk factor for order was found when examining the image lumbar scoliosis in patients with RA. quality ratings. When comparing the radia- tion exposure level difference it was ob- served that the OEC was the lowest, and GP91 there was a minimum 30% decrease in en- COMPARISON OF IMAGE QUALITY AND ergy emission from the OEC versus the oth- RADIATION EXPOSURE FROM C-ARM er C-arms studied. FLUOROSCOPES WHEN USED FOR DISCUSSION: This is the first time the spine IMAGING THE SPINE image quality and radiation exposure of 1Mark L Prasarn MD, 2Ellen Coyne MS, commonly used C-arm machines has been 2Michael Schreck MD, 2Glenn R Rechtine compared. The OEC was ranked the best, MD produced the best quality images, and had 1University of Texas, 2University of the least amount of radiation. Rochester “Glenn Rechtine, M.D., Associate Chief of Staff, Department of Veterans Affairs, INTRODUCTION: There are no previous Bay Pines VA Healthcare System, Bay Pines, published studies comparing mobile C-arm Florida.” Adjunct Professor, Departments machines commonly used in clinical practice of Surgery and Orthopaedic Sur- for imaging the spine. We sought to com- gery, University of South Florida and De- pare the fluoroscopic images produced by 4 partment of Orthopaedic Surgery, University different fluoroscopes for image quality and of Rochester.“This material is the result of radiation exposure when used for imaging work supported with resources and the use the spine. of facilities at the Bay Pines VA Healthcare METHODS: Anterior-posterior and lateral System.” images of the cervical, thoracic, and lumbar “The contents of this paper do not repre- spine were taken of a cadaver placed supine sent the views of the Department of Veter- on a radiolucent table. The fluoroscopy ans Affairs or the United States Govern- units used for the study included: 1. GE OEC ment.” 9900 Elite (2010 model), 2. Philips BV Pulsera (2009 model), 3. Philips BV Pulsera (2010 model), and 4. Siemens Arcadis 163

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DISCUSSION: Bone scan was more sensitive GP92 than STIR in detecting changes associated STIR MRI AND SPECT BONE SCAN IN THE with painful osteoporotic fractures. It is not EVALUATION OF PAINFUL OSTEOPOROTIC clear to us why STIR MRI has superceded VERTEBRAL FRACTURES bone scan in the assessment of these frac- L H Lee, T B Beckingsale, A Manoj-Thomas, P tures. We are not aware of any literature L Sanderson that suggests that MRI has a better positive Dept of Spinal Orthopaedic Surgery, Royal predictive value than a bone scan. By just Victoria Infirmary, Newcastle upon Tyne, UK relying on MRI 40% of fractures may be de- nied treatment. INTRODUCTION: STIR MRI is the currently 1) Maynard AS et al. AJNR 2000 21(10) preferred invstigation of choice in assessing 1807-12. suitability of vertebral body fractures for vertebroplasty. The Short T1 Inversion Re- covery (STIR) offers high sensitivity for the GP93 presence of oedema. Bone scan was tradi- DEVELOPMENT OF A COMPUTER-BASED tionally used in assessing suitability of oste- CLINICAL DECISION SUPPORT TOOL FOR oporotic fractures for veretebroplasty and SELECTING APPROPRIATE REHABILITATION has been shown to have a 93% positive pre- INTERVENTIONS FOR INJURED WORKERS dictive value (1). No such figures exist for Douglas P. Gross, PhD 1,2, Jing Zhang, MSc STIR MRI. Our aim was to assess the rela- Student 3, Ivan Steenstra, Ph.D. 4, Susan tionship of the STIR MRI and Spect bone Barnsley, MSc. 2, Calvin Haws, BSc. O.T. 2, scan in these fractures. Tyler Amell, Ph.D 5, Greg McIntosh, MSc. 6, METHOD: A prospective analysis of 36 con- Juliette Cooper, Ph.D. 7, Osmar Zaiane, secutive patients with painful osteoporotic Ph.D. 3 thoracolumbar fractures. Each patient had a 1 ) Department of Physical Therapy, Univer- MRI and a radionuclide spect bone scan. sity of Alberta, Canada , 2) Workers’ Com- The MRI's and bone scans were assessed for pensation Board-Alberta Millard Health, high signal and increased uptake respective- Edmonton, Canada 3) Department of Com- ly in the vertebral body by an independent puting Science, University of Alberta 4) In- radiologist. stitute for Work and Health, Toronto, Cana- RESULTS: 24 female and 12 males with 53 da 5) Centric Health, Calgary, Canada 6) CBI thoracolumbar fractures were assessed. Health, Toronto, Canada 7) University of There were 33 thoracic fractures and 20 Manitoba, Winnipeg, Manitoba, Canada lumbar fractures. The mean age was 65 years (range 20-91). Bone scan showed in- INTRODUCTION: Selecting the interventions creased radionuclide uptake in 41 fractures. that will lead to successful outcomes re- Of these, only 24 (58.5%) demonstrated mains a challenging task. The purpose of high signal change in the STIR images. In the our project was to develop a classification 12 normal bone scans, 10 (83.3%) also algorithm and accompanying computer- showed no STIR high signal. Only 2 (16.7%) based clinical decision support tool to help of the normal bone scans showed a high categorize injured workers toward optimal STIR sequence signal. STIR sequence images rehabilitation interventions based on were normal in 27 fractures. Of these 17 unique worker characteristics. (63%) had increased uptake on bone scan. METHODS: Population-based historical co- When there was a high signal on STIR se- hort design. Data were extracted from a quences, 24/26 (92.3%) of bone scans Canadian provincial workers’ compensation showed increased uptake. database on all claimants undergoing work 164

GENERAL POSTERS assessment between December 2009 and 2 Workers' Compensation Board of Alberta, January 2011. Data were available on: 1) Edmonton, Canada numerous personal, clinical, occupational, 3 Asante Rehab Consulting, Calgary, Canada and social variables; 2) type of rehabilitation 4 School of Public Health, University of undertaken; and 3) outcomes following re- Alberta, Edmonton, Canada habilitation (receiving time loss benefits or undergoing repeat programs). Machine INTRODUCTION: Functional capacity evalu- learning, concerned with the design of algo- ations (FCE) are commonly used to identify rithms to discriminate between classes work abilities and to inform decisions about based on empirical data, was the founda- return-to-work (RTW). FCE is time- tion of our approach to build a classification consuming and expensive compared with system with multiple independent and de- self-report functional assessment. We stud- pendent variables. ied whether use of FCE leads to better re- RESULTS: The population included 8,611 turn-to-work outcomes. unique claimants. Subjects were predomi- METHODS: We conducted a cluster ran- nantly employed (85%) males (64%) with domized controlled trial at a rehabilitation diagnoses of sprain/strain (44%). Baseline facility. Data were collected on all claimants clinician classification accuracy was high undergoing RTW assessment at the facility (ROC = 0.86) for selecting programs that since November 2011. Twenty-six clinicians lead to successful RTW. Classification per- at the facility are trained and experienced in formance for machine learning techniques performing the WorkWell FCE protocol. outperformed the clinician baseline (ROC = These clinicians were randomized into two 0.94). The final classifiers were multifactori- groups, with 14 selected to conduct a struc- al and included the variables: injury dura- tured functional interview instead of FCE. tion, occupation, job attachment status, Outcomes included recommendation fol- work status, modified work availability, pain lowing assessment (RTW or other) and func- intensity rating, self-rated occupational dis- tional work ability level determined (seden- ability, and 9 items from the SF-36 Health tary, light, medium, heavy or very heavy Survey. level). DISCUSSIONS: The use of machine learning RESULTS: Therapist groups were compara- classification techniques appears to have ble in terms of discipline, sex, and years of resulted in classification performance better experience. To date, 339 claimants have than clinician decision-making. The final been assessed of whom 163 were tested algorithm has been integrated into a com- with FCE and 176 were tested with struc- puter-based clinical decision support tool tured interview. Claimants were predomi- that requires additional validation in a clini- nantly job attached (79%) males (65%) with cal sample. sub-acute or chronic musculoskeletal condi- tions. Groups were similar with the excep- tion of a higher proportion of males in the GP94 interview group (70% versus 60%). No sta- DOES PERFORMANCE-BASED FUNCTIONAL tistically significant difference was observed CAPACITY EVALUATION ENHANCE RETURN between groups in assessment outcome TO WORK ASSESSMENT? (52% RTW in interview group versus 47% for Gross DP1,2, Asante AK2, Miciak M1, Battié FCE, p=0.38). However, a statistically signifi- MC1, Carroll LJ4, Sun A2, Welch J2, Mikalsky cant difference was observed on functional M2, Huellstrung R2, Niemeläinen R2 work ability levels (58% sed/light for the 1 Department of Physical Therapy, interview group versus 41% for FCE, University of Alberta, Edmonton, Canada 165

GENERAL POSTERS p<0.001). tosterone replacement (n = 909) were sig- CONCLUSIONS: Performance testing ap- nificantly older than those who did not, and pears to lead to higher functional work abil- had greater comorbidity, depression, smok- ity levels, but no difference in RTW recom- ing, and use of sedative-hypnotic medica- mendations. Whether determinations using tions. In logistic regressions, long-term opi- the two methods lead to different RTW out- oid use was associated with greater use of comes remains to be determined. Data col- medications for erectile dysfunction or tes- lection is ongoing and claimants will be con- tosterone replacement, compared to pa- tacted over the following year to determine tients with no opioid use (OR 1.45, 95% CI RTW status. 1.12, 1.87, p<0.01). Age, comorbidity, de- pression, and use of sedative-hypnotics were also independently associated with GP95 use of medications for erectile dysfunction PRESCRIPTION OPIOIDS FOR BACK PAIN or testosterone replacement. Patients pre- AND USE OF MEDICATIONS FOR ERECTILE scribed daily opioid doses of 120 mg mor- DYSFUNCTION phine-equivalent or more had greater use of Richard A. Deyo MD, MPH, David H.M. medication for erectile dysfunction or tes- Smith, RPh, PhD, Eric S. Johnson, PhD, Carrie tosterone replacement than patients with- J. Tillotson MPH, Marilee Donovan RN, PhD, out opioid use (OR 1.58, 95% CI 1.03, 2.43), , Xiuhai Yang MS, Amanda Petrik MS, Ben- even with adjustment for duration of opioid jamin J. Morasco PhD, Steven K. Dobscha, therapy. MD DISCUSSION: Opioid dose and duration, as Oregon Health and Science University; Kai- well as age, comorbidity, depression, and ser Permanente Center for Health Research; use of sedative-hypnotics were associated and the Portland VA Medical Center, Port- with evidence of erectile dysfunction. These land, OR findings may be important in the process of decision-making for long-term opioid use.

INTRODUCTION: Men with chronic pain may experience erectile dysfunction related GP96 to depression, smoking, age, or opioid- NOCTURNAL PAIN AND/OR PAIN IN related hypogonadism. The prevalence of RECUMBENCY OF CAUDA EQUINA TUMOR this problem in back pain populations and Masahiko Watanabe, Daisuke Sakai , the relative importance of several risk fac- Toshihiro Nagai, Akihiko Hiyama, Masato tors are unknown. We sought to examine Sato, Joji Mochida associations between use of medication for Dept of Orthopaedic Surgery, Surgi-cal Sci- erectile dysfunction or testosterone re- ence, Tokai University School of Medi-cine placement and use of opioid therapy, pa- tient age, depression, and smoking status INTRODUCTION: Nocturnal pain relieved by METHODS: This was a cross-sectional analy- walking and/or pain in recumbency (n-pain) sis of electronic pharmacy and medical rec- is a specific clinical feature of a cauda ords for men with back pain in a large group equina tumor. However, the mechanism model HMO during 2004. Relevant prescrip- responsible for the pain generation is un- tions were considered for six months before known. Previous reports postulated that n- and after the index visit. pain is caused by stretching of the cauda RESULTS: There were 11,327 men with a equina with a change in body posture, diagnosis of back pain. Men who received whereas another report suggested that in- medications for erectile dysfunction or tes- creasing pressure of CSF exerts downward 166

GENERAL POSTERS pressure on the nerve roots. To identify the mechanism responsible for n-pain, we re- GP97 viewed the patients with a cauda equina PREVALENCE AND CHARACTERISTICS OF tumor. DISK LEAKS METHODS: Our series included 35 patients Conor O'Neill, M.D. (24 men, 11 women, mean age 53.1 years). University of California San Francisco, De- We classified the patients into 2 groups: 10 partment of Orthopedics, San Francisco, CA patients who experienced n-pain and 25 patients who had no history of n-pain. Data INTRODUCTION: A variety of biologics and on the duration of symptoms, maximum pharmaceuticals are under investigation for occupation ratio in the subarachnoid space treatment of discogenic pain. Most of these on MRI, and CSF blockage were investigated treatments are administered by intra-discal retrospectively. Multivariate logistic analysis injection. Leakage of these substances out was performed to identify the factors corre- of the disc could lead to two undesirable lated with pain, including CSF blockage and outcomes- a toxic effect on neural struc- occupation ratio > 70%. tures in the epidural space and insufficient RESULTS: Age did not differ significantly dose delivered to the disc. The aim of this between the 2 groups, but the proportion study was to quantify the risk of disk leak- of women was significantly higher in the age. pain group (p < 0.05). The mean duration MATERIALS AND METHODS: The records of from the initial symptoms to surgery was all patients undergoing discography in a 4.0 months in the pain group, which was specialty spine practice over a five year pe- significantly shorter than the 15.5 months in riod were reviewed. Each discogram was the nonpain group (p < 0.01). The mean done under pressure monitoring and the occupation ratio was 75.3% in the pain pressure and volume that leaks (if present) group, which was significantly higher than occurred at were recorded. the 55.7% in the nonpain group (p < 0.01). RESULTS: A total of 1759 discs were inject- Eight of 10 patients in the pain group and 8 ed. The prevalence of discs that leaked was of 25 in the nonpain group showed blockage 6.9%. The mean volume that a disc leaked of CSF (p < 0.05). The occupation ratio re- at was 2.01 cc and the mean pressure 32 mained significant, even after adjusting for psi. blockage of CSF. DISCUSSION: Discography is the only test DISCUSSION: All patients in the pain group that can determine whether a disc will leak exhibited a mobile tumor. It is difficult to on injection. The downside of a discogram is understand how an unfixed tumor can that disc puncture can initiate/worsen disc stretch the cauda equina during a change in degeneration, which may interfere with the body posture. We postulate that a mobile success of subsequent intra-discal treat- and large tumor causes n-pain by obstruct- ments. These data demonstrate 1) the ing CSF by acting in a ball–valve manner to prevalence of leaky discs in patients under- increase the CSF pressure. going discography for investigation of spinal pain is low (6.9%) and 2) among discs that do leak the average volume that can be in- jected is relatively high (2.01 cc). This data may allow discography to be eliminated prior to intra-discal treatments, depending on the pharmacology/toxicity of the inject- ed substance.

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GP98 GP99 INTERSPINOUS LIGAMENT LIDOCAINE AND PAINVISION APPARATUS IS EFFECTIVE FOR STEROID INJECTIONS FOR THE MANAGE- ASSESSING LOW BACK PAIN. MENT OF BAASTRUP’S DISEASE Ohtori S (1), Kawaguchi H (2), Takebayashi T Norimoto M, Ohtori S, Inoue G, Orita S, (3), Inoue G (1), Orita S (1), Yamauchi K (1), Yamauchi K, Eguchi Y, Aoki Y, Ishikawa T, Eguchi Y (1), Aoki Y (1), Ishikawa T (1), Miyagi M, Kamoda H, Suzuki M, Sakuma Y, Miyagi M (1), Kamoda H (1), Suzuki M (1), Kubota G, Oikawa Y, Inage K, Sainoh T, Sato Sakuma Y (1), Kubota G (1), Oikawa Y (1), J, Toyone T, Takahashi K. Inage K (1), Sainoh T (1), Sato J (1), Toyone T Dept. Orthop. Surg., Chiba University, Chiba, (1), Takahashi K (1). Konno S (4). Japan 1, Dept. Orthop. Surg., Chiba Univ., Chiba, Japan. 2, Dept. Orthop. Surg., Tokyo Univ., INTRODUCTION: Baastrup’s disease is asso- Tokyo, Japan. 3, Dept. Orthop. Surg., ciated with axial low back pain. Baastrup’s Sapporo Med. Univ., Sapporo, Japan. 4, disease has been more recently described Dept. Orthop. Surg., Fukushima Med. Univ., as the “kissing spinous processes” disease. Fukushima, Japan. Several authors have reported methods for the diagnosis and treatment of the disease. INTRODUCTION: Tools developed to assess However, there has been only one report of low back pain and its effect on quality of life patients receiving interspinous ligament are mostly dependent on subjective evalua- injections of agents for the treatment of tion by patients in self-reported question- Baastrup’s disease. naires. It is therefore difficult to compare MATERIALS AND METHODS: Seventeen scores between patients at different times. patients showed severe low back pain be- A newly developed device, PainVision PS- tween spinous processes at L3–L4 or L4–L5. 2100 (Nipro, Osaka, Japan), has been used X-ray imaging, CT, and MRI revealed kissing to assess the perception of pain in a quanti- spinous processes, consolidation of spinous tative manner. In the current study, we process, or inflammation of an interspinous aimed to evaluate the efficacy of PainVision ligament. Pain relief after lidocaine and for assessing low back pain. dexamethasone administration into METHODS: We assessed 89 patients with interspinous ligament as therapy for low low back pain. The numeric rating scale back pain was examined and followed up. (NRS) score, McGill Pain Questionnaire RESULTS: Low back pain scores significantly (MPQ) score, and degree of pain calculated improved immediately after injection of the using PainVision were measured twice at 4- agents into interspinous ligaments. At final week intervals in each patient. An electrode follow-up (1.4 year), low back pain scores was patched on the forearm surface of the significantly improved compared with be- patients, and both the current for percep- fore treatment. tion threshold and current at which the pa- CONCLUSION: Findings from the current tient reported the same intensity as their study indicate that lidocaine and dexame- low back pain were measured. The degree thasone administration into interspinous of pain was calculated automatically (de- ligament in patients diagnosed with gree of pain = 100 x (current producing pain Baastrup’s disease is effective for manage- comparable with low back pain ‒ current at ment of the pain associated with this dis- perception threshold/current at perception ease. threshold)). Correlations between NRS and MPQ scores and the degree of pain were determined using Spearman’s rank correla- 168

GENERAL POSTERS tion test. compared, and the relationship between RESULTS: There was a strong correlation the efficacy and the degree of slipping also between the NRS and MPQ scores at each evaluated. time point (rs = 0.60, P < 0.0001). The de- RESULTS: In all 75 cases, the mean number gree of pain also showed moderate correla- of NRI treatments was 2.8 (range 1 to 6) and tion with NRS and MPQ scores at each time there was no relationship between treat- point (rs = 0.40, P < 0.03). Change in the ment frequency and efficacy. For total cas- degree of pain over 4 weeks showed a es, efficacy was: excellent, 40 cases (53%); moderate correlation with changes in NRS good, 21 (28%); and poor, 14 (19%), 11 of and in MPQ scores (rs = 0.40, P < 0.01). which required surgical treatment. For the DISCUSSION: PainVision is as useful to as- CS group efficacy was: excellent, 29 cases sess low back pain as self-reported ques- (57%); good, 17 (33%), and poor, 5 (10%). tionnaires. For the DS group efficacy was: excellent, 11 cases (46%); good, 4 (17%); and poor, 9 (37%). The rate of poor outcome in the DS GP100 group was significantly higher than in the CS THE EFFICACY OF SPINAL NERVE ROOT group (P < 0.05) and all 9 cases of poor out- INFILTRATION FOR LUMBAR SPINAL CANAL come showed more than 15% slip or disc STENOSIS WITH UNILATERAL RADICULAR ROM by more than 10°. SYMPTOMS DISCUSSION: NRI was extremely effective Tanno, Takaaki 1; Ataka, Hiromi 1; for radicular symptoms caused by LCS, Miyashita, Tomohiro 2 compatible with findings of previously pub- 1 Matsudo Orthopaedic Hospital, Spine lished studies. However, efficacy in the DS Center, Chiba, Japan; 2 Matsudo City group was significantly low and dependent Hospital, Spine Center, Chiba, Japan on the degree of slipping. Therefore, the current study helps us to provide useful OBJECTIVE: To investigate the efficacy of informed consent for patients requiring NRI. spinal nerve root infiltration (NRI) for uni- lateral radicular symptoms caused by lum- bar spinal canal stenosis (LCS). GP101 METHODS: Seventy-five consecutive cases THE TREATMENT OF NOCTURNAL LEG of LCS with unilateral radicular symptoms CRAMPS BY MEDIAL BRANCH BLOCKADE OF treated by NRI were reviewed. Fifty-one THE DEEP PERONEAL NERVE FOLLOWING patients had LCS without degenerative LUMBAR SURGERY. spondylolisthesis at the stenotic level (CS Imura T, Inoue G, Nakazawa T, Ueno M, Saito group) and 24 had LCS with W, Adachi K, Uchida K, Takahira N, Takaso spondylolisthesis (DS group). NRI was re- M; peated upon patient request and number of Department of Orthopaedic Surgery, Kitasato treatments noted. The efficacy of NRI was University, School of Medicine Kanagawa, investigated for at least 3 months after final Japan NRI. The efficacy of NRI was classified into three grades as follows: excellent, pain scale INTRODUCTION: Patients with lumbar dis- 0–2 (10 being the degree of symptoms be- ease sometimes complain of leg cramps, fore NRI) or no need for medication; good, even after successful lumbar spinal surgery. pain scale 3–6 or less need for medication; Effectiveness of physiological or pharmaco- and poor, pain scale 7–10 or continuing logical treatment for leg cramps has been need for medication. Furthermore, the effi- reported. However, the use of peripheral cacy of NRI in the DS and CS groups was nerve blocks has not been recognized as an 169

GENERAL POSTERS effective treatment. So, we evaluated the bar segment. In the literature, there are effectiveness of the block as a treatment for many reports on low back pain and Modic nocturnal leg cramps sustained after lumbar type 1 change. However, there are only few surgery. reports of the Modic type 1 among athletes. METHODS: Forty-three postoperative pa- The purpose of this paper is to review 8 tients underwent blockade of the medial cases showing Modic type 1 among high- branch of the deep peroneal nerve with 5.0 class athletes. ml of lidocaine (1% solution without epi- METHODS: MRI was taken for athletes hav- nephrine), and we investigated the frequen- ing chronic backache. T1-wt, T2-wt and cy and degree of relief every 2 weeks until 6 STIR images were taken to understand the months after the blockade. Correlation of the type of Modic changes. The dynamic radio- effectiveness and another factors including graphs were also taken to understand the patients’ profile were also evaluated. instability. Intradiscal steroid injection was RESULTS: Compared with baseline before the conducted to treat their low back pain due block, the frequency of nocturnal leg cramps to the inflammation. Location of Modic was reduced to less than a quarter in 60% of change, clinical outcome and time course of the patients, and reduced to less than half in Modic type was evaluated. 77%. The reduction of frequency of cramps RESULTS: Total 8 athletes were diagnosed was sustained for 16.8±9.1 weeks in patients as Modic type 1 for their pain cause. All who had their nocturnal cramps reduced to cases showed asymmetrical presentation. less than half (n=32). The subjective severity For 2 wrestlers, the changes are only in the of each cramp was reduced in 64% of pa- anterior aspect. For 4 right-handed golfers, tients. Patients with bilateral leg cramps the change is seen at the right lateral corner demonstrated less effectiveness with the of the endplate. For 1 baseball player, the blockade. No adverse side effects were ob- site is at the right anterior corner. For re- served during the study in all patients. maining 1 hammer thrower, it is at the right DISCUSSION: Our findings demonstrate that corner. Any of them did not have the lum- blockade of the medial nerve branch of the bar instability on the dynamic radiographs. peroneal nerve is an effective treatment for All but one received intradiscal therapy at nocturnal leg cramps sustained after lumbar least once, and the chronic backache disap- spinal surgery, which is easy to perform with peared. After the treatment, with decreas- low risk, and long lasting. ing their low back pain the type was changed to type 2 or type 3, suggesting fat- ty marrow or sclerosis. GP102 DISCUSSION AND CONCLUSION: Among ASYMMETRIC MODIC TYPE 1 CHANGE AND high-class athletes, Modic change would ITS INTRADISCAL TREATMENT AMONG appear without spinal instability and the HIGH-CLASS ATHLETES WITH LOW BACK change is appeared asymmetrically at the PAIN. performance-specific location. Yasuhiro Kitagawa, Koichi Sairyo, Akira Dezawa. Department of Orthopedic Surgery, Teikyo University Mizonokuchi Hospital, Kawasaki, Japan

INTRODUCTION: Modic type 1 is reported to be related to the backache and it may be related to the micro-instability of the lum- 170

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hough correlation between JOA score and PI GP103 was not found, subjects with greater PI MULTI-DETECTOR CT-BASED ANALYSIS OF tended to show lower JOA score. PELVIC INCIDENCE OF PATIENTS WITH LUMBAR SPONDYLOLYSIS Yoichiro Takata, Toshinori Sakai, Kosaku GP104 Higashino, Shinsuke Kato, Koichi Sairyo MULTIMODAL ASSESSMENTS OF EFFICACY Dept. of Orthopedic surgery, The university OF PHYSICAL THERAPY FOR PATIENTS of Tokushima WITH NEUROGENIC CLAUDICATION DUE TO LUMBAR SPINAL STENOSIS INTRODUCTION: Lumbar spondylolysis is a Minetama, Masakazu*;Miyake, Takahiro*; stress fracture of pars interarticularis and Moriki, Takashi*; Sakon, Nana*; Kinoshita, hyperlordosis of lumbar spine is thought to Yasumasa*; Kadosaka, Yasunori*; be a risk factor of spondylolysis or Matsuoka, Toshiko*; Nakao, Shinichi*; spondylolisthesis. Pelvic incidence (PI) is an Fukui, Daisuke†; and Kawakami, Mamoru* anatomical factor that is not influenced by *Spine Care Center, Wakayama Medical individual position. Higher PI is associated University Kihoku hospital. with higher lumbar lordosis (LL). †Department of Orthopaedic Surgery, MATERIALS AND METHODS: We analyzed Wakayama Rosai hospital. 115 subjects (78 men and 37 women) with lumbar spondylolysis and 170 age- and sex- INTRODUCTION: It has been reported that matched control subjects (110 men and 60 preoperative depression status affects the women) without spondylolysis. PI was postoperative outcome significantly in pa- measured from multi-detector computed tients with lumbar spinal stenosis (LSS) tomographic (CT) images using 3- treated with surgery. However, responders dimentional reconstruction. Originally modi- of physical therapy for patients with LSS are fied Japanese Orthopedic Association (JOA) still unknown. The purposes of this prospec- score, which focused on symptoms and an tive study were to examine the efficacy of extent of difficulty in activity of daily living, physical therapy using multimodal assess- was obtained from each control subject. ments and to evaluate which patients with RESULTS: PI was significantly higher in sub- LSS were responders or not. jects with spondylolysis (51.5° ± 8.7°) com- METHODS: Patients presenting with symp- pared with the control subjects (47. 6° ± toms of neurogenic claudication caused by 9.2°) (p < 0.01). In the male subjects, signifi- LSS (confirmed by MRI or CT) were enrolled. cantly higher PI was obtained in subjects Patients were treated with manual therapy, with spondylolysis (p < 0.01). In the female stretching and strengthening exercises, and subjects, there was no significant difference body-weight-supported treadmill walking between subjects with and without once a week for 6 weeks. Clinical outcomes spondylolysis. PI of control subjects did not were measured using the Zurich Claudica- correlate with modified JOA score (r = -0.18, tion Questionnaire (ZCQ); a visual analog p < 0.05) scale of low back pain, leg pain, and leg DISCUSSION: These findings suggest that numbness; the Japanese Orthopaedic Asso- higher PI contributes to the biomechanical ciation Back Pain Evaluation Questionnaire; mechanisms of the development of lumbar the Pain Catastrophizing Scale; the Pain spondylolysis, especially in male subjects. Anxiety Symptoms Scale; the Hospital Anxi- Based on the gender difference of the pelvic ety and Depression Scale; the Self-Rating morphology, female subjects with Questionnaire for Depression (SRQ-D); and spondylolysis may have other factors. Alt- a Biodex isokinetic dynamometer. Accord- 171

GENERAL POSTERS ing to Stucki’s criteria for the satisfaction or traumatic spinal cord injury (SCI). How- scores of the ZCQ subscales, patients were ever, there are no comparative study on divided into the effective group (Group I) neuroprotective effect of MEH and MSH and the ineffective group (Group II). The following SCI. If hypothermia is to be con- characteristics of those patients with LSS sidered as one modality for treating SCI, who can obtain satisfactory results with our further studies on the advantages and dis- physical therapy programs were clarified. advantages of hypothermia will be manda- RESULTS: Groups I and II had 22 and 12 pa- tory. This study was designed to compare tients, respectively. There were no differ- neuroprotective effect of hypothermia be- ences in the demographic data and MRI tween MEH and MSH following SCI. findings between the two groups. At base- METHODS: A spinal cord contusion was line, however, there was a significant differ- produced in all 32 rats, and these rats were ence in the SRQ-D (Group I, 7.1 points vs. randomly divided into 4 groups, 8 rats each Group II, 10.8 points). group; (1) the control group (spinal cord contusion only), (2) the methylprednisolone (MP) group, (3) the MEH group (28 for 48 hours), (4) the MSH group (32 for 48 hours). The functional recovery ℃was as- sessed using BBB scale and anti℃-apoptotic and anti-inflammatory effect were assessed. RESULTS: The BBB scales in both the hypo- thermia groups were significantly higher than that of the control group at 6 weeks.

DISCUSSION: Depressive symptoms inter- The numbers of TUNEL-positive cells and fere with the ability of patients to obtain an OX-42 positive cells were significantly lower optimal physical therapy outcome. Our re- in both the MEH and the MSH groups com- sults suggest that assessments of depres- pared to that of the control group. The p38 sion are needed to improve the clinical out- MAPK expression of the treated groups was comes of physical therapy for patients with significantly lower than that of the control LSS. group. The expression of caspase-8 and caspase-9 significantly decreased in the treated groups compared with that of the GP105 control group. However, in terms of NEUROPROTECTIVE EFFECT OF HYPO- caspase-3, only the MSH group has shown THERMIA FOLLOWING SPINAL CORD INJU- to be significantly lower than that of the RY IN RATS- COMPARATIVE STUDY BE- control group. TWEEN EPIDURAL AND SYSTEMIC HYPO- CONCLUSION: This study presented that THERMIA-. both systemic and epidural hypothermia Ha, Kee-Yong, Kim, Young-Hoon demonstrated neuroprotective effects fol- Department of Orthopedic Surgery, Seoul St. lowing spinal cord injury. Systemic hypo- Mary’s Hospital, College of Medicine, The thermia showed more neuroprotective ef- Catholic University of Korea fect by anti-apoptotic and anti- inflammatory effects. INTRODUCTION: Experimental moderate epidural hypothermia (MEH) or moderate systemic hypothermia (MSH) has been at- tempted for neuroprotection after ischemic

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high ORs for progressive collapse. These GP106 findings should be considered when treating RISK FACTORS AFFECTING PROGRESSIVE patients with acute OSF. And more atten- COLLAPSE OF ACUTE OSTEOPOROTIC tion should be paid to patients with OSF and SPINAL FRACTURE. these risk factors during conservative man- Ha, Kee-Yong, Kim, Young-Hoon agement. Department of Orthopedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea. GP107 CLASSIFICATION FOR FORAMINAL STENO- INTRODUCTION: This study was designed to SIS ON A SAGITTAL MRI investigate the clinical and radiological risk Yasuaki Murata, M.D., Ph.D., Kohichi factors related to progressive collapse of Kanaya, M.D., Ph.D., Hiroyoshi Wada, M.D., acute osteoporotic spinal fractures (OSF). Ph.D., Keiji Wada, M.D., Ph.D., Masahiro METHODS: In total, 100 patients with acute Shiba, M.D., Satoshi Hatta, M.D., Ken Kato, OSF were prospectively enrolled at a single M.D., Yoshiharu Kato, M.D., Ph.D.. institute. Five pathological fractures were Dept. of Orthop. Surg., Tokyo Women's excluded. Twelve patients dropped out of Medical University the study because of conversion to surgical treatment during follow-up. Eight patients INTRODUCTION: Foraminal stenosis of the were excluded as follow-up losses. Thus, 75 lumbar spine can cause lower limb pain. patients were analyzed. Clinical data and However, it requires endeavor to diagnose radiological data were recorded and ana- foraminal stenosis on MRI, because the lyzed. As a definition of progressive OSF, compression to the spinal nerve is some- height loss ≥ 15%, kyphotic angle ≥ 10° and times invisible on 2-dimensional images. the occurrence of an intravertebral cleft The purpose of the present study was to sign at the 6 month follow-up compared to classify the shapes of foramen on the sagit- the initial values were adopted. Correlation tal MRI, and to apply the classification for analysis and multiple logistic regression the diagnosis. analyses were performed to elucidate the METHODS: Patients who underwent lumbar related clinical or radiological factors for spine surgery were investigated by electro- progressive OSF. myography, nerve-conduction studies, neu- RESULTS: The occurrence of intravertebral rological findings, and spinal nerve infiltra- cleft was not related to any significant dif- tion to detect foraminal stenosis (n = 203). ferences in the clinical results, and was only The shapes of the 2030 foramen were clas- related to the fracture level in the regres- sified into 4 groups; the foraminal space sion analysis. A ≥ 15% increase in height loss below the caudal edge of the vertebra is and a ≥ 10° increase in kyphotic angle were remained (type 1); the space is totally occu- related to worse clinical results. Mid-portion pied with disc below the caudal edge of the type fractures and involvement of the pos- vertebra (type 2); the space is occupied with terior wall were significant risk factors with disc above the cranial edge of the disc (type relatively high odds ratios for progressive 3); and the space is filled with the disc (type OSF under these criteria. 4). The relation between the types and CONCLUSION: During the 6-month follow- foraminal stenosis was studied. up of conservative treatment for acute OSF, RESULTS: On the sagittal MRI, 1927 fora- mid-portion type fracture, involvement of men were classified into type 1, 58 into type the posterior wall and the thoracolumbar 2, 40 into type 3, and 5 into type 4. Patients area were predictive factors with relatively who were diagnosed as foraminal stenosis 173

GENERAL POSTERS were 2 (0.1%) in type 1, 9 (16%) in type 2, between the S and C groups. Univariate 11 (28%) in type 3, and 5 (100%) in type 4. analyses were performed using the χ2 test On the L5/S foramen, 7 of the 19 foramen for categorical variables and the Mann- (37%) were diagnosed as stenosis in type 2, Whitney U test for continuous variables. and 6 of 12 (50%) in type 3. L5/S foraminal The odds ratios for significant variables and stenosis of type 2 tended to trigger radicu- the 95% confidence intervals were calculat- lopathy compared with the others (p < ed by multivariate logistic regression analy- 0.05). sis. DISCUSSION: Electromyography, nerve- conduction studies, neurological findings, and spinal nerve infiltration were per- formed to detect foraminal stenosis. These methods are useful but not suitable for the screening. Our results showed that 36% of patients in type 3 or 4 had foraminal steno- sis symptoms. Furthermore, 65% had symp- toms in type 3 or 4 at the L5/S. Sagittal MRI can be a convenient examination to pick foraminal stenosis.

GP108 IMPACT OF MUSCULAR TIGHTNESS ON RESULTS: The positive ratios of the TM and LUMBAR SPONDYLOLYSIS IN ADOLESCENT OB in the S group (TM:81.3%, OB:83.3%) ATHLETES were significantly higher than those in the C Naoki Ishigaki and Takato Aihara group (TM:58.3%, OB:20.8%). The HBD in Dept. of Physical Therapy and Orthopedic the S group (mean, 5.4cm) were significant- surgery, Funabashi Orthopedic Hospital, ly lager than that in the C group (mean, Funabashi-city, Japan 2.4cm). However, there were no significant differences between S and C groups con- INTRODUCTION: There have been few stud- cerning the SLA and HROM. Multivariate ies concerning the muscular tightness in logistic regression analysis showed that OB lumbar spondylolysis (LS) in adolescent ath- (P=0.001, odds ratio=12.9) and HBD letes. The purpose of this study was to in- (P=0.038, odds ratio=1.29) were the im- vestigate the impact of muscular tightness portant factors of LS. on LS in adolescent athletes. DISCUSSION: The results indicated that the METHODS: Approval of this hospital’s ethics high positive ratio of OB and large HBD committee and informed consent to inclu- were significantly associated with the LS in sion in this study from 83 adolescent ath- adolescent athletes. It has been reported letes were obtained. Forty-six adolescent that lumbar lordosis and pelvic tilt, which athletes with LS according to plain radio- were caused by TFL and RF tightnesses, graphs or MRI (S group) and 37 adolescent were risk factors of LS. These findings sug- athletes without previous low back pain (C gest that TFL and RF tightnesses may be a group) were included in this study. The flex- cause of LS in adolescent athletes. ibilities of the legs were evaluated as fol- lows: (Fig.). The positive ratios of the TM and OB, the mean values of the right and left HBDs, SLAs, and HROMs were compared 174

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ture. Also, a total of 13 HSCs (26.5%) includ- GP109 ing extraosseous region were found. In the A STUDY ON PATHOGENESIS OF LUMBAR past, Sairyo, et al. reported the SPONDYLOLYSIS USING MRI FINDINGS extraosseous HSC and it causes radiculopa- Sakai T.1, Goda Y. 1, Takata. 1, Higashino K. thy, indicating hematoma in the vicinity of 1, Katoh S. 1, Sairyo K. 2 the fracture site. From the results of this 1Dept. Orthopaedic Surgery, Tokushima study, spondylolysis is thought as an un- University, Tokushima, Japan 2Dept. Ortho- common stress fracture. paedic Surgery, Teikyo University, Kawasaki, Japan GP110 INTRODUCTION/AIM: Spondylolysis is PAINVISION APPARATUS IS EFFECTIVE FOR thought as a stress fracture of the pars ASSESSING LEG PAIN AND NUMBNESS interarticularis (pars). However, there are ORIGINATED FROM LUMBAR DISEASE. still a lot of unknown factors affecting on its Furusawa S (1), Hashikawa T (1), Terakado pathogenesis. In this study, to elucidate it, A (1), Orita S (2), Takahashi K (2), Ohtori S we evaluated MRI in patients with very ear- (2) ly- and early-stage spondylolysis and ana- 1, Kitachiba Orthop. Surg. Mihama Clin., lyzed the localization of the signal changes. Chiba, Japan. 2, Dept. Orthop. Surg., Chiba METHODS: A total of 28 patients (5 women Univ., Chiba, Japan. and 25 men) with very early- or early-stage lumbar spondylolysis were included in this INTRODUCTION: Tools developed to assess study. Mean age was 14.1 (10 to 17) years. low back / leg pain and its effect on quality We analyzed the localizations of MRI high of life are mostly dependent on subjective signal change (HSC) around pedicle adjacent evaluation by patients in self-reported ques- to the pars using both sagittal and axial tionnaires. It is therefore difficult to com- views of T2- and STIR-weighted images. We pare scores between patients at different divided the localizations of HSC into the times. A newly developed device, PainVision following three zones (Zone1: pedicle- PS-2100 (Nipro, Osaka, Japan), has been interarticuaris, Zone 2: interarticularis- used to assess the perception of pain and spinous process, Zone 3: extraosseous). numbness in a quantitative manner. In the RESULTS AND DISCUSSION: HSCs were de- current study, we aimed to evaluate the tected bilaterally in 18 vertebrae and 13 efficacy of PainVision for assessing leg pain vertebrae. A total of 49 HSCs were ana- and numbness originated from lumbar dis- lyzed. Thirty-one HSCs (63.3%) were found ease. in only Zone 1, five HSCs (10.2%) were METHODS: We assessed 39 patients with found in Zone 1 & 2, and seven HSCs leg pain and numbness originated from (14.3%) were found in Zone 1 & 3. Six HSCs lumbar spinal stenosis. The numeric rating (12.2%) were found in Zone 1 & 2& 3. scale (NRS) score, Roland-Morris Disability Basically, MRI bone marrow changes on Questionnarie (RDQ) score, and degree of stress fracture of long bone shows signal pain and numbness calculated using changes in both proximal and distal sites PainVision were measured twice at 4-week across the fracture site, and sometimes in intervals in each patient. An electrode was extraosseous region. In this study, more patched on the forearm surface of the pa- than half HSCs (63.3%) were localized in tients, and both the current for perception only one side across the fracture site (pars). threshold and current at which the patient This result suggests that lumbar reported the same intensity as their leg pain spondylolysis is not a common stress frac- and numbnsess were measured. The degree 175

GENERAL POSTERS of pain and numbness was calculated auto- sociodemographics, all patients completed matically (degree of pain and numbness = a Tampa Scale for Kinesiophobia (TSK). All 100 x (current producing pain and numb- patients had mechanical LBP with no neu- ness comparable with leg pain and numb- rology, as determined by the Saskatchewan ness ‒ current at perception thresh- Spine Pathway triage methodology. old/current at perception threshold)). Cor- RESULTS: The mean age of the cohort was relations between NRS and RDQ scores and 39.9 years (SD=11.3, range=18-69) with the degree of pain and numbness were de- 63.7% males. The median symptom dura- termined using Spearman’s rank correlation tion was 173 days (29% acute, 71% chronic). test. The average overall TSK score was 40.8 RESULTS: There was a strong correlation (SD=9.03, range 6-70). There were no base- between the NRS and RDQ scores at each line statistically significant differences in TSK time point (rs = 0.40, P < 0.05). The degree scores based on dominant pain location, of pain and numbness also showed moder- medication use, constancy, work status, ate correlation with NRS and RDQ scores at presence of sleeping difficulties, symptom each time point (rs = 0.40, P < 0.05). Change duration, smoking status, legal consultation in the degree of pain and numbness over 4 or pain classification. Males had significantly weeks showed a moderate correlation with higher scores than females (41.9 v 38.6) changes in NRS and in RDQ scores (rs = 0.50, (p=0.001). There was no correlation be- P < 0.01). tween TSK scores and age or baseline func- DISCUSSION: PainVision is as useful to as- tion. For clinical outcomes, there was no sess pain and numbness originated from correlation between TSK scores and number lumbar spinal stenosis as self-reported of days in treatment, change in numerical questionnaires. pain rating or functional improvement. There were no statistically significant differ- ences in TSK scores based on global pain GP111 rating or return to work status. LACK OF VALUE IN SCREENING FOR FEAR DISCUSSION: The presence of pain-related OF MOVEMENT VIA THE TAMPA SCALE FOR fear, as measured by the Tampa Scale for KINESIOPHOBIA Kinesiophobia (TSK) was not associated with Greg McIntosh MSc, Chris Gregg MHealSc, higher disability, poorer function or more Hamilton Hall MD, Chris Hoffman MD, Tom pain in this sample. In addition, baseline Carter BSc PT characteristics were similar regardless of CBI Health Group Research Department, TSK score. The lack of differences by TSK Toronto, Canada; The Back Institute, Wel- score revealed that screening for fear of lington, New Zealand movement was not worth the effort and provided little clinical benefit. INTRODUCTION: The purpose of this study was to assess the role of baseline screening for fear of movement and pain-related fear - Tampa Scale for Kinesiophobia (TSK) - in a cohort of low back pain (LBP) patients com- pleting active exercise-based treatment. METHODS: This was a prospective study of LBP cases (n=416) treated at four spine care rehabilitation clinics in New Zealand be- tween January 2008 and October 2012. In addition to baseline data on pain, function, 176

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lumbar spondylosis (70%), fracture (15%), GP112 lumbar disc herniation (LDH 6%), hemato- EFFICACY OF DIFFUSION-WEIGHTED IMAG- logical malignancies (3.4%, multiple myelo- ING (DWI) BASED ON MRI TO EVALUATE ma 1.9%, malignant lymphoma 1.3%, leu- HEMATOLOGICAL MALIGNANCIES IN LUM- kemia 0.2%), metastatic spinal tumor (3%), BAR SPINE. and infectious spondylitis (2.6%). Fracture, Masaomi Yamashita, MD, PhD*, Kazuhiko metastatic spinal tumor, and infection could Kikuchi+, Koki Abe, MD*, Keishi Yamashita, be diagnosed by C-MRI. However, hemato- MD*, Akiyoshi Yamaoka, MD*, Seiji Ohtori, logical malignancies were not diagnosed by MD, PhD**, Kazuhisa Takahashi, MD, C-MRI. The mean value of ADC in bone mar- PhD** row in hematological malignancies (Mean: *Department of Orthopedic Surgery, 1.86×10-4 mm2/s) was significantly higher Funabashi Central Hospital, Chiba, Japan than those of spondylosis and LDH (Mean: +Department of Radiology, Funabashi Cen- 1.31×10-4 mm2/s) (p<0.05). tral Hospital **Department of Orthopedic DISCUSSION: In LBP patients, 3.4% patients Surgery, Graduate School of Medicine, Chiba were hematological malignancies in current University study. Only C-MRI did not clarify hematolog- ical malignancies, however, DWI may have INTRODUCTION: Patients with hematologi- the potential of diagnostic capacity in he- cal malignancies such as multiple myeloma, matological malignancies. lymphoma, and leukemia, undergo the re- placement of spinal hemopoietic bone mar- row. Plain radiography and conventional GP113 MRI (C-MRI), including T1- and T2-weighted PHARMACOLOGICAL ANXIOLYSIS WITH imaging, have been used to estimate patho- PROMETHAZINE AS AN ADJUNCTIVE logic lesion of low back pain (LBP). However, THERAPY FOR ACUTE LOW BACK PAIN IN diagnosis of hematological malignancies is THE ADULT EMERGENCY DEPARTMENT difficult in use of C-MRI. Diffusion-weighted Eyal Behrbalk, The Spine Unit - Queen's imaging (DWI) based on MRI can provide a Medical Centre, Nottingham, United non-invasive method that reveals the mi- Kindoms. Ofir Uri, Royal National crostructure of tissues on the basis of its Orthopaedic Hospital NHS Trust Brockley ability to monitor the random movements Hill, Stanmore, Middlesex. Bronek of water molecules. DWI has been widely Maximilian Boszczyk, The Spine Unit- used clinically in the evaluation of malig- Queen’s Medical Centre, Nottingham, nancy for diagnosis of diseases. The aim of United Kindoms Ruth M Parks,University of this study is to evaluate the potential of Nottingham, Medical School, Queen's DWI in hematological malignancies in lum- Medical Centre.United Kindoms Pinchas bar spine. Halpern, The Tel-Aviv Sourasky Medical METHODS: 1437 patients with LBP form July Centre, Israel 1 .2009 to June 30. 2012 were examined and underwent plain radiography, C-MRI, INTRODUCTION: Low back pain (LBP) is a DWI-MRI of the lumbar spine, and blood common and disabling problem presenting examination. We measured the apparent to the emergency department (ED); analge- diffusion coefficient (ADC) of bone marrow sia is an important step in immediate man- in vertebral bodies using 1.5-T MRI, and agement. It has been proven that non- compared ADC in bone marrow with final pharmacological methods of anxiety relief diagnosis of lumbar spine. can be beneficial. A prospective randomised RESULT: In 1437 patients, diagnosis were double-blind study carried out to determine 177

GENERAL POSTERS whether combination treatment of pro- Outcomes & Process Evaluation Research methazine and morphine was superior to (iHope International) 4) Department of morphine alone, for severe acute LBP. Epidemiology and HealthCare Research, METHODS: All patients admitted to the ED Graduate School of Medicine and Public with simple acute LBP were candidates for Health, Kyoto University; the study. Patients included met the follow- ing criteria: LBP< 3weeks duration, pain INTRODUCTION: Lumbar spinal stenosis >65mm on a 100mm visual analogue scale, (LSS) has various symptoms and they age between 18-65, American Society of change with activities of daily living and Anesthesiologists (ASA) grade 1 or 2, systol- posture. We have developed and validated ic blood pressure >90 mmHg, no known a self-administered symptom scale for LSS hypersensitivity to the medications, able to (Spine 37, 2012). The aim of this study was provide informed consent. Pregnant wom- to a) verify a criterion validity using a lum- en, LBP after traumatic event, history of bar extension test and a gait-loading test as malignancy, neurological deficiencies or objective indexes, and b) responsiveness of atypical pain were excluded. 59 patients the LSS symptom scale. concluded the study and assessed for pain METHODS: One hundred and sixty seven and anxiety reduction as well as satisfaction patients with a diagnosis of LSS completed of treatment received. questionnaires including the LSS symptoms RESULTS: Neither treatment regime proved scale before and after a medical therapy. A superior in the relief of pain. patients re- lumbar extension test and a gait-loading ceiving promethazine and morphine, were test were performed to evaluate standing more likely to require a longer duration of and walking capacities. Subjects were divid- stay in the ED (p=0.0427). They were also ed into three groups according to these more likely to experience adverse events; tests, low; less than mean-1/2 standard de- however, these findings were not statistical- viation (SD), middle; between low and high ly significant. Patients satisfaction and am- groups, high; greater than mean+1/2SD. The bulation status were similar for both responsiveness to medication effects was groups. analyzed with an interval of 8 weeks. ANO- DISCUSSION: We do not recommend rou- VA was used to test differences in the LSS tine administration of promethazine for symptom scale scores among groups. anxiety and pain reduction in the treatment RESULTS: In the lumbar extension test, a of acute LBP in the ED. Non- mean standing capacity was 164.6±109 s. pharmacological methods of anxiety relief The LSS symptom scale score was signifi- may still be helpful. cantly higher in accordance with a shorter standing time (p<0.01). In the gait-loading test, the mean walking distance was GP114 213.0±154m. The LSS scale scores in the low A VALIDATION STUDY OF A SYMPTOM group was higher than that of the middle SCALE FOR LUMBAR SPINAL STENOSIS and high groups (p<0.01). The changes of Miho Sekiguchi 1), Takafumi Wakita 2), Koji LSS scale scores were higher in accordance Otani 1), Yoshihiro Onishi 3), Shunichi with improvement of symptoms by the two Fukuhara 4), Shin-ichi Kikuchi 1), Shin-ichi tests, both before and after medication. Konno 1) DISCUSSION: The results suggested that the 1) Department of Orthopaedic Surgery, LSS symptom scale is a reliable and valid Fukushima Medical University School of instrument with good responsiveness to Medicine; 2) Department of Sociology, non-surgical therapeutics. This scale may be Kansai University; 3) Institute for Health 178

GENERAL POSTERS useful to evaluate patient’s progress of to favour ZA at 1 month. The improvements symptoms, to establish standards for indica- in ODI were of similar magnitude. At base- tion of treatment, and to assess treatment line, the treatment groups reported no dif- effectiveness. ferences in non-steroidal anti-inflammatory drug use, whereas at 12 months, only 20% of patients in the ZA group used these drugs GP115 compared to 60% in the placebo group EFFICACY OF ZOLEDRONIC ACID FOR (p=0.022). No significant differences were CHRONIC LOW BACK PAIN ASSOCIATED observed in RAND-36 or sick leaves. Flu-like WITH MODIC CHANGES IN MRI: A symptoms emerged in 90% of patients in RANDOMIZED CONTROLLED TRIAL the ZA group, compared to 15% in the pla- Koivisto K, Kyllönen E, Haapea M, Niinimäki cebo group. Only one serious adverse ef- J, Sundqvist K, Pehkonen T, Seitsalo S, fect, sinusitis requiring hospitalization, oc- Paldanius P, Tervonen O, Karppinen J curred in the ZA group. Department of Physical and Rehabilitation DISCUSSION: The tendency for improve- Medicine, Oulu University Hospital, Oulu, ment was greater in the ZA group. Although Finland the results are encouraging, larger studies are required to prove the efficacy of ZA. INTRODUCTION: Modic changes (MC) are (ClinicalTrial.gov identifier NCT01330238) associated with low back pain (LBP) but no effective treatments are available. The aim of this randomized, placebo-controlled, GP116 double-blinded trial was to evaluate the MINIMAL CLINICAL IMPORTANT IM- efficacy of Zoledronic acid (ZA) for the PROVEMENT (MCII) AND PATIENT AC- chronic LBP of patients with MC in magnetic CEPTABLE SYMPTOM STATE (PAAS) VAL- resonance imaging (MRI). UES OF THE DALLAS PAIN QUESTIONNAIRE METHODS: Inclusion criteria were LBP for at (DPQ) IN PATIENTS WITH LOW BACK PAIN least three months, an LBP intensity ≥of M Marty (1) S. Genevay (2) ; D. S. 6/10 on 10-cm VAS or an Oswestry Disabil- Courvoisier (3); V. Foltz (4); G. Mahieu (5); C. ity Index (ODI) of≥ 30%, and MC in MRI. Desmoulin (6); A. Gierasimowicz Fontana Exclusion criteria included e.g. renal im- (7); M. Norberg (8); P. de Goumoëns (8); C. pairment, and willingness to retire early. Cedraschi (9); S. Rozenberg (4); Section Patients were randomized into single intra- Rachis de la Société Française de venous infusion of ZA 5 mg in 100 ml saline Rhumatologie (n=20), or saline (n=20) groups. The primary (1) Service de Rhumatologie, C.H.U. Henri outcome was LBP intensity and secondary Mondor, Créteil France ; (1) Rhumatologie, outcomes disability (ODI), health-related Hôpitaux Universitaires de Genève, Genève, quality of life (RAND-36), lumbar flexibility, Suisse; (3) Epidémiologie Clinique, Hôpitaux sick leaves and pain medication use. The Universitaire de Genève, Genève, Suisse; (4) treatment differences at 1 and 12 months Service de Rhumatologie, C.H.U Pitié- were analysed using ANCOVA with adjust- Salpêtrière, Paris, France; (5) Unité du Dos, ments for age and gender. C.H. de Dinant, Dinant, Belgique; (6) Bat B; RESULTS: At baseline, the treatment groups Sart-Tilman, Isepk, Liège, Belgique; (7) had no significant differences. Both the Clinique de Médecine Physique et treatment difference in intensity of LBP Réadaptation, CHU Brugmann, Bruxelles, (1.3, 95% CI -0.2 to 2.8; p=0.097) and pro- Belgique; (8) Appareil Locomoteur, CHUV, portion of patients with 20% improvement Lausanne, Suisse; (9) Réhabilitation (ZA 55% vs. placebo 25%; p=0.105) tended Médicale, Hôpitaux Universitaire de Genève, 179

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Genève, Suisse. studies to help clinicians interpreting clinical results. INTRODUCTION: The DPQ has demonstrat- ed its validity in patients with chronic low back pain (CLBP). Norms for clinically signifi- G117 cant differences are missing. This work QUANTITATIVE EVALUATION OF INJURED aimed to estimate Minimal Clinical Im- NERVE WITH DIFFUSION TENSOR IMAGING portant Improvement (MCII) and Patient Oikawa, Yasuhiro1; Eguchi, Yawara1; Acceptable Symptom State (PASS) values of Ohtori, Seiji1; Inoue, Gen3; Yamauchi, DPQ. Kazuyo1; Orita, Sumihisa1; Kamoda, METHOD: 168 patients with no specific LBP Hiroto1; Ishikawa, Tetsuhiro1; Miyagi, Ma- lasting for at least 4 weeks were evaluated sayuki1; Suzuki, Miyako1; Sakuma, Yoshihi- at baseline and 6 months later after a non ro1; Kubota, Go1; Inage, Kazuhide1; Sainoh, standardized treatment. Question for MCII Takeshi1; Sato, Jun1; Watanabe, Atsuya2; addressed patient-reported response to Takahashi, Kazuhisa1 treatment at FU on a 5-point Likert scale, 1 Department of Orthopaedic Surgery, and PASS a yes/no answer concerning satis- Graduate School of Medicine, Chiba Univer- faction with present state. MCII was com- sity, Japan 2 Department of Orthopaedic puted as the difference in mean DPQ scores Surgery, Teikyou University Chiba Medical between patients reporting treatment as Center, Japan 3 Department of Orthopaedic effective vs. patients reporting treatment as Surgery, Kitasato University, School of Medi- not effective, and PASS was computed as cine, Japan the 3rd quantile of the DPQ score among patients who report being satisfied with INTRODUCTION: Conventional imaging mo- their present state. dalities are useful for the morphological RESULTS: Mean (SD) intensity of back pain evaluation of spinal nerves, but not for the (0-10 VAS) and Roland Morris Disability quantitative evaluation of nerve damage. Questionnaire scores were 5.5 (2.0) and Diffusion tensor imaging (DTI) is a possible 12.9 (5.0) at baseline, 3.7 (2.6) and 7.5 (6.5) new diagnostic tool for lumbar spinal de- at FU, respectively. generative disease. Using DTI, a lower frac- tional anisotropy (FA) value is observed in DPQ component Baseline M6 MCII PASS symptomatic nerves than in asymptomatic (0-100) nerves. The purpose of this study was to Daily activity 60.5 40.6 22.2 29.4 evaluate the efficacy of DTI in the quantita- Work leisure 57.8 37.2 23.1 23.1 tive evaluation of injured nerves. Social interest 34.1 24.5 2.0 20.0 METHODS: Twelve patients with single- Anxiety depression 42.5 29.4 9.5 21.3 sided radiculopathy who had undergone DTI Total 48.7 32.4 14.2 23.9 using 3.0T magnetic resonance imaging (MRI) and surgical treatment were included. The PASS total score threshold (23.9) cor- The FA values of lumbar nerve roots were rectly classified 84.1% of the patients who calculated from FA maps in both injured and declared being unsatisfied with their pre- intact nerves. Minimum and mean FA values sent state. were investigated, and the differences be- DISCUSSION: These values give information tween injured and intact nerves were also of paramount importance for clinicians to investigated. Neurological severity was as- interpret change over time of the DPQ sessed using the Japanese Orthopaedic As- measure. Authors should be encouraged to sociation (JOA) and visual analog scale (VAS) report the MCII and PASS in RCT and cohort pain scores. 180

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RESULTS: In injured nerves, e.g., those spondylolysis and compared with those with compressed by disc herniation, lower FA no spondylolysis. values were found at the injured portion. METHODS: We have previously reported The mean FA of injured nerves was 0.220; the incidence of lumbar spondylolysis in the the mean difference between injured and general population in japan based on intact nerves was 0.097. The mean and min- multidetector computed tomography scans imum FA values were not directly correlated from 2000 subjects (Sakai T, et al. Spine, with JOA and VAS scores; however, pre- and 2009). Among those, 107 subjects (37 postoperative VAS scores were higher in women and 70 men) with L5 single-level patients with larger differences in intact and spondylolysis were evaluated as injured FA values. spondylolysis group (Sp (+)). Mean age was CONCLUSIONS: Lower FA values were ob- 64.1(22 to 88) years. The gender- and age- tained at the compressed portion in injured matched control group (Sp (-)) was chosen nerves, and the difference between the FA randomly from the other subjects with no values of the intact and injured nerves spondylolysis. Four changes (narrowing, tended to correlate with neurological sever- sclerosis, osteophyte, bone cyst) of degen- ity. This means that although it is difficult to erative changes of facet joints (L4/5, L5/S) evaluate an injury using only its FA value, it adjacent to the pars defects. may be possible to utilize the difference RESULTS AND DISCUSSION: In a total of 214 between the injured nerve and an intact L4/5 facet joints, the following results were nerve. DTI is a possible new diagnostic tool found (Sp (+): Sp (-)): narrowing (210: 187), for degenerated lumbar disease as it is ca- sclerosis (200: 137), osteophyte (116: 82), pable of both detecting lesions and quanti- and bone cyst (52:3). In a total of 214 L5/S tatively evaluating nerve damage. facet, narrowing (210: 181), sclerosis (194: 145), osteophyte (65: 40), and bone cyst (16: 2) were found (Figure 1). Totally, de- GP118 generative changes of facet joints with lum- DEGENERATIVE CHANGES OF FACET JOINTS bar spondylolysis were more severe than IN ADULTS WITH LUMBAR SPONDYLOLYSIS those of control, statistical significantly Goda Y. 1, Sakai T. 1, Harada T. 2, Takao S. (p<0.05). Unfortunately, the reasons of this 2, Harada M. 2, Takata Y. 1, Higashino K. 1, result were not clarified in this study. But, Katoh S. 1, Yasui N. 1, Sairyo K. 3 there are many candidate reasons of the 1Department of Orthopaedic surgery, results in this study. Particularly, alignment, Tokushima University, Tokushima, Japan slip grade, morphological changes as facet 2Department of Radiology, Tokushima tropism, facet orientation, should be inves- University, Tokushima, Japan 3Department tigated in the next step. of Orthopaedic Surgery, Teikyo University, Kawasaki, Japan GP119 INTRODUCTION: Lumbar spondylolysis PROTEOMIC ANALYSIS OF LIGAMENTUM (spondylolysis) is a bony defect of pars FLAVUM FROM LUMBAR SPINAL CANAL interarticularis. Once bony discontinuity of STENOSIS bilateral laminae occurred, it is called a “ Goda Y. 1, Sato N. 1, Taniguchi T. 2, Takata floating lamina.” In such a situation, biome- Y. 1, Kosaka H. 1, Sakai T. 1, Higashino K. 1, chanical stresses on adjacent facet joints Sairyo K. 3, Katoh S. 1, Taniguchi H. 2, Yasui are thought to be decreased. In this study, N. 1 we evaluated multi-detector CT to analyze 1Department of Orthopaedic surgery, degenerative changes of facet joints with Tokushima University, Tokushima, Japan 181

GENERAL POSTERS

2Division of Disease Proteomics, Institute for gens were identified (Figure 1). Since elas- Enzyme Research, Tokushima University, tin contributes to the elasticity (softness) of Tokushima, Japan 3Department of the tissue, the decrease of elastin in Orthopaedic Surgery, Teikyo University, ligamentum flavum with hypertrophy af- Kawasaki, Japan fects not only the thickness of the tissue, but also the softness of that. These results INTRODUCTION/AIM: Lumbar spinal canal may explain, at least in part, the cause of stenosis (LCS) is a common lumbar spinal the LCS. disorder in aged population. Hypertrophy of ligamentum flavum is one of main factors of LCS but its pathomechanism has not been clarified yet. In many diseases, proteomic analysis has been applied to understanding of their pathogenesis. Although proteomic analysis of ligamentum flavum was difficult due to the intrinsic insolubility of the tissue, Sato et al. succeeded in solubilization of ligamentum flavum. The purpose of this study is to analyze proteomic changes in components of the hypertrophic ligamentum flavum in the LCS patients. METHODS: All samples of the ligamentum flavum were obtained from patients with GP120 LSC or lumbar disc herniation (LDH) at the time of operation, and divided them into SPINO-PELVIC SAGITTAL ALIGNMENT IN the two groups. LCS group includes 3 male ELDERLY PATIENTS WITH ISTHMIC patients at the age of 80 (A), 74 (B), and 59 SPONDYLOLISTHESIS (C) years. LDH group includes 17 year-old Hidekazu Suzuki*, Kenji Endo*, Hirosuke male (D) and 22 (E), 30 (F) year-old female Nishimura*, Hidetoshi,Tanaka*, Shinsuke patients. All samples were axially cut into 1- Sakai**, Kengo Yamamoto* * Department of Orthopedic Surgery, Tokyo μm slices with cryotome. They were treat- ed with CNBr under N2 gas and digested Medical University ** Department of with various enzymes. LC/MS/MS analysis Orthopedic Surgery, Tokyo Medical has been performed. Analysis on protein Unversity Ibaraki Medical Center database were performed using the Mascot software. INTRODUCTION: The risk for progression of RESULTS AND DISCUSSION: In the LCS isthmic spondylolisthesis appears to be group, the contents of elastin were (A)14%, greatest during the adolescent growth spurt (B)38%, (C)50%, and the contents of colla- and subsequently decreased to the mini- gen were (A)77%, (B)56%, (C)40%. In the mum after adolescence. However, some of LDH group, the contents of elastin were the patients have an onset of radiculopathy (D)57%, (E)66%, (F)57%, and the contents of at an old age. Spinal sagittal alignment plays collagen were (D)35%, (E)18%, (F)33%. The an important role in the development of contents of elastin in LCS group were lower spondylolysis and spondylolisthesis. How- than those in LDH group and the contents of ever, there are few studies about spinal collagen in LCS group were higher than sagittal alignment of elderly patients with those in LDH group. Various types of colla- isthmic spondylolisthesis (IS). The purpose of this study is to evaluate spino-pelvic 182

GENERAL POSTERS alignment of the patients with isthmic 1) Department of Orthopaedic surgery, spondylolisthesis developing radiculopathy Osaka City University graduate school of at old age. medicine 2) Department of Orthopaedic METHODS: We analyzed 21 patients with surgery, Spine center of Shiraniwa Hospital isthmic spondylolisthesis developing radicu- lopathy at the age of 55 years or older INTRODUCTION: It is difficult to differenti- (mean age 67), 28 patients with lumbar spi- ate fresh osteoporotic vertebral fractures nal stenosis (LSS) without slippage (mean (OVF) from old fractures. MRI is a potential- age 67), 38 patients with degenerative ly useful tool; however, there is no detailed spondylolisthesis (DS) (mean age 64) and 88 report describing the changes found post- asymptomatic volunteers (Vo) (mean age fracture. Here, we report intensity changes 36). The following parameters were meas- in MRI findings after a fracture and whether ured on the lateral whole-spine standing it is possible to differentiate fresh from old radiographs: lumbar lordotic angle (LLA), fractures. lumbosacral lordotic angle (L1S1), sacral METHODS: We examined 150 vertebrae in slope (SS), pelvic tilting angle (PA) and pelvic 147 patients. All patients had apparent pain lordosis (PRS1). onset and were evaluated using X-ray and RESULTS: The measurements of spino-pelvic MRI within 2 weeks of onset and reevaluat- parameters were as follows: IS, LLA 24.2, ed after 6 months. The anterior body height L1S1 44.4, PA 20.6, SS 36.6, PRS1 32.9, Vo, ratio was calculated from the X-ray as the 36.1, 42.9, 19.5, 34.4, 36.4, DS, 27.2, 40.7, anterior body height of the fractured verte- 28, 29.2, 32.7, LSS 19.0, 31.2, 25.6, 26.9, bral body divided by the height of the adja- 36.3 (degree), respectively. IS patients had cent intact vertebral body. The cutoff value small PRS1 and decreased lumbar lordosis, of the fresh fracture was determined by but lumbosacral hyperlordosis and pelvic ROC curve analysis. Based on the T1- anteversion. weighted MRI, the intensity change of the DISCUSSION: IS patients have small pelvic posterior wall of the fractured vertebra was conpensatory ability because of a defect in evaluated and classified as normal signal the pars interarticularis. Lumbar intensity or low signal intensity. hypolordosis with aging and pelvic anteversion set up lumbosacral hyperlordosis for postural compensation, resulting in onset of radiculopathy at old age. In surgical treatments for elderly IS patients with lumbosacral hyperlordosis, it must be considered to perform a sufficient decompression surgery. RESULTS: The anterior body height ratio declined from 83.9% at initial visit to 63.8% at 6 months. When the ratio >75% was de- GP121 fined as a fresh fracture, sensitivity was THE DIFFERENTIAL IMAGING FINDINGS 82%, specificity was 68.7%, and positive BETWEEN FRESH AND OLD OSTEOPOROTIC predictive value (PPV) was 72.4%. With MRI, VERTEBRAL FRACTURES 126 vertebrae (84%) showed a low signal Kentaro Yamada 1), Hiroaki Nakmura 1), change at the posterior wall of the fractured Shinji Takahashi 1), Hidetomi Terai 1), vertebra in the fresh stage, which decreased Hiromitsu Toyoda 1), Sho Dohzono 1), to 62 vertebrae (42.7%) after 6 months Tomiya Matsumoto 1), Masatoshi Hoshino (Figure). When the low signal change at the 2), Tadao Tsujio 2) 183

GENERAL POSTERS posterior wall of the vertebral body was a few animal models which enable quantita- defined as a fresh fracture, sensitivity was tive evaluation of infection in the paraspinal 84%, specificity was 58.7%, and PPV was soft tissues. We have established a noninva- 67%. With a combination of the above find- sive quantitative mouse model of paraspinal ings, the specificity improved to 88% and muscle infection using bioluminescence PPV improved to 85.1% respectively. imaging (BLI). DISCUSSION: Almost half of the vertebral METHODS: Bioluminescent strains of MRSA bodies with a low-intensity change at the were inoculated into the paraspinal muscle posterior wall at the fresh stage had nor- of BALB/c adult mice (N = 6). Photon inten- malized in 6 months. The specificity and PPV sity (PI = pho- in diagnosing a fresh OVF can be improved tons/sec/cm2/st by combining an X-ray and the signal change eradian) of the of the posterior wall by MRI. bacteria and background were then se- GP122 quentially ESTABLISHMENT OF A NEW PARASPINAL measured using INFECTION MOUSE MODEL EVALUATED BLI over 4 NONINVASIVELY AND QUANTITATIVELY weeks. Serolog- USING BIO-IMAGING ical and histo- Kenji Yoshioka1, Ken Ishii1, Tetsuya logical analyses Kuramoto1, Haruki Funao1, Shigenori were also performed. Nagai2,3, Hiroko Ishihama1, Aya Sasaki4, RESULTS: Bacterial signal was detected in Yasunori Okada4, Kazuhiro Chiba1, Shigeo the paraspinal muscle immediately after the Koyasu2, Yoshiaki Toyama1, Morio inoculation of MRSA. Mean PI of the bacte- Matsumoto1 ria plateaued at approximately 7days (2.16 x 1 Department of Orthopaedic Surgery, 10⁴ PI) and could be stably measured over School of Medicine, Keio University, 4weeks. Serum levels of interleukin-6 and C- Shinjuku, Tokyo, JAPAN 2 Department of reactive protein were significantly higher at Microbiology and Immunology, School of 7days in the infection model mice than the Medicine, Keio University, Shinjuku, Tokyo, control mice. Histological analysis revealed JAPAN 3 Core Research for Evolutional that the muscle necrosis and cumulated Science and Technology (CREST), Japan neutrophils with bacterial colonies were Science and Technology Agency (JST), Tokyo, observed in the paraspinal muscle at 7days. Japan 4 Department of Pathology, School of DISCUSSION: We have successfully visual- Medicine, Keio University, Shinjuku, Tokyo, ized and quantified the bacterial growth in JAPAN the mouse paraspinal muscles using BLI, which enabled us to monitor the infectious INTRODUCTION: The infections in the spine process in the live mice over a long period and paraspinal regions cause progressive of time. The paraspinal muscle has strong inflammation and destruction of bony struc- fascia and can keep down spreading of the tures, often resulting in prolonged pain and infectious lesion minimally. Our model can neurological symptoms. Treatment of the be used for investigation of pathophysiology infection especially caused by multi- of infections in the spine and paraspinal antibiotic resistant bacteria such as MRSA regions and assessing the effect of novel remains a challenging problem, and basic antibiotics and antibacterial implants. researches providing solutions for the prob- lem are necessary. However, there are only 184

GENERAL POSTERS

the OFA of the DS and LSS groups had no GP123 significant difference at any of the levels. FACET ORIENTATION IN PATIENTS WITH The AFA and OFA in the DS and LSS groups LUMBAR DEGENERATIVE were smaller than those in the LBP group at SPONDYLOLISTHESIS all levels. From the L2 to L4 levels, the LA of Miyamoto H, Hidekazu Suzuki*, Kenji Endo*, the DS and LSS groups had a tendency to be Wuqikun Alimasi*, Hirosuke Nishimura*, larger than LBP group. At the L5 level, how- Hidetoshi,Tanaka*, Shinsuke Sakai**, Kengo ever, the LA was similar among all groups. Yamamoto* DISCUSSION: Patients with DS had more * Department of Orthopedic Surgery, Tokyo sagittally oriented facet joints in the axial Medical University ** Department of plane than the two other groups at the slip- Orthopedic Surgery, Tokyo Medical page level. However, facet orientation was Unversity Ibaraki Medical Center not horizontal in the DS group compared with the LCS group on the oblique and lat- INTRODUCTION: Several reports have indi- eral planes. The sagittal orientation of facet cated a correlation between lumbar degen- joints is more likely due to a secondary re- erative spondylolisthesis (DS) and increased modeling of the joint orientation rather sagittal orientation of the facet joints. than a pre-existing morphologic feature. Sagittalization of lumbar facet joints is a major cause of DS, however, the majority of studies of lumbar facets were analyzed in GP124 the axial plane. We analyzed the spinal EMPIRIC ANTIBIOTIC THERAPY FOR morphological character by examining both PYROGENIC SPONDYLITIS the axial and sagittal views in DS patients Sei Terayama, Takashi Yamazaki, Keiji and compared these parameters to patients Hayakawa, Hiroshi Nakamura with lumbar spinal stenosis (LSS, without Department of Orthopaedic Surgery, slippage) and low back pain (LBP, without Japanese Red Cross Musashino Hospital slippage nor neurological symptoms). METHODS: We analyzed 119 patients divid- INTRODUCTION: It is common practice to ed into 3 groups based on the clinical and use first-generation cephalosporins (CEZ) imaging findings: 42 patients with DS, 39 empirically for pyogenic spondylitis before with LSS, and 38 with LBP. The following infectious organisms are isolated. Infectious parameters were measured from L2-3 to L5- organisms causing pyrogenic spondylitis are S1 levels: axial facet angle (AFA) in an axial commonly staphylococci and streptococci. orientation, oblique facet angle (OFA) and The objective of this study is to review in- lamina angle (LA) in sagittal orientations. fectious organisms causing pyogenic spon- dylitis and to clarify what kind of antibiotics we should use empirically. METHODS: We retrospectively reviewed cases of pyogenic spondylitis in 117 patients who were treated in our hospital from 1997 to 2011, including 75 men and 42 women with a mean age of 66.5 years (range 32 to 88 years). RESULTS: The AFA of the DS group was sig- RESULTS AND DISCUSSION: Conditions in- nificantly smaller than that of the LSS and cluding diabetes mellitus, cancer, steroid LBP groups at the slippage level. However, use, hemodialysis, liver cirrhosis, and others compromised 62 patients (53%). Organisms 185

GENERAL POSTERS were isolated from 70 patients (42 com- promised and 28 uncompromised patients), GP125 included Staphylococcus aureus, Methicillin- THORACOLUMBAR VERTEBRAL ENDPLATE resistant Staphylococcus aureus (MRSA), LESIONS IN YOUNG GYMNASTS streptococci, Staphylococcus epidermidis, Urushibara Makoto, Aihara Takato, and Pseudomonas aeruginosa and others. Hatakeyama Kenji Organisms in 22 of 70 cases (31%) had no Funabashi orthopedic hospital sensitivity for CEZ. In uncompromised hosts, 6 of 28 cases(21%) had no sensitibity for INTRODUCTION: An increased frequency of CEZ. On the othrer hand, in compromised radiologic abnormalities in the thoracolum- hosts, 16 of 42 cases(38%) had no sensitivity bar spine has been reported among young for CEZ, including MRSA in 10 cases, Pseu- gymnasts. The purpose of this study is to domonas aeruginosa in 3 cases, and others evaluate the incidence of thoracolumbar in the remaining 3 cases. 6 cases required vertebral endplate lesions in young gym- broad spectrum antibiotics and 10 needed nasts. anti-MRSA drugs. Antibiotic-resistant organ- METHODS: We examined the thoracolum- isms were more commonly isolated from bar spine of 126 young gymnasts aged 6-19 compromised patients (Figure). years (mean age, 15.4years) and 103 control subjects (23 baseball, 18 soccer, 11 athlet- ics, 8 basketball, 8 volleyball, 8 tennis, and 27 other sports players) aged 10–18 years (mean age, 14.9 years). All subjects suffered from low back pain. We investigated the incidence of radiological abnormalities of vertebral endplate lesions in them. We di- vided the involved site into two regions, the Thoracolumbar Junction of the Spine “TL group” defined as T11 to L2 and the Lower Lumbar region “LL group” defined as L3 to In patients with negative cultures, CEZ was S1. The incidences of these abnormalities used empirically in 16 cases in uncompro- were then compared between the TL group mised patients and broad spectrum antibi- and LL group. The incidences of these ab- otics were needed in 1 case (6%). CEZ was normalities were then compared between used empirically in 8 cases in compromised the gymnasts and control subjects, and be- patients and broad spectrum antibiotics tween the TL group and LL group. were needed in 2 cases (25%). RESULTS: Vertebral endplate lesions were This study suggests that broad spectrum seen in 38 lesions of 26 (20.1%) gymnasts antibiotics and anti-MRSA drugs should be and 2 lesions of 2 (1.9%) control subjects. used empirically for pyogenic spondylitis in They occurred significantly more often in compromised patients before isolating the gymnasts than in the control subjects. causative organism The locations of the lesions were more fre-

quent in the TL group (26 lesions) than in

the LL group (12 lesions) among the gym-

nasts. No difference was found in the loca-

tion of the lesions in the control subjects.

DISCUSSION: The young gymnasts demon-

strated a higher rate of vertebral endplate

lesions and occurred more often in the 186

GENERAL POSTERS

thoracolumbar from 2004 to 2012. There were 33 males junction. There is a and 28 females, with a mean age of 72 possibility that deep years old (range, 32 to 91 years old). The flexion of the trunk following data were recorded the causative under high velocity organism, complications, echocardiographic exerts great pres- studies, and outcome. sure on the spine, RESULTS: The causative organism was iso- especially on the lated in 45 patients (73.7%). MSSA was pre- anterior part of the sent in 14 cases, MRSA in 12 cases, and vertebrae of the E.coli in 4 cases. 26 patients (42.6%) had thoracolumbar complications, such as IE, meningitis, pseu- junction. domembranous colitis, and drug rashes. Blood cultures were performed for 88.5% of (Figure) 18y.o male patients, and the positive detection rate gymnast. Lateral was 61.1%. Transthoracic echocardiography lumbar radiography sho-wed deformation of was performed in 42.6% of all patients. IE vertebral endplate of L1 and kyphosis at the was diagnosed in 4 patients (6.6%). All of same level. their blood cultures were positive. Cardiac

surgery was required for 3 patients, and GP126 refractory bacteremia occurred in 1 patient. DIAGNOSIS OF INFECTIVE ENDOCARDITIS DISCUSSION: Some studies reported the WITH PYOGENIC SPONDYLITIS prevalence of IE in patients with PS to range 1Masatugu Tukamoto, 1Tadatsugu from 9.3% to 43.3%. In this study, the Morimoto, 1Tomohito Yoshihara, 1Hajime prevalence of IE was 6.6%, which was lower Kugisaki, 2Itaru Furuichi, 1Motoki Sonohata, than in other studies. The reasons might be 1Masaaki Mawatari a lack of recognition of IE at our institution. 1. Department of Orthopedic Surgery, Echocardiography was performed for only Faculty of Medicine, Saga University, Saga, 43% of patients, so the search for IE may Japan. 2. Department of Orthopedic have been insufficient. In patients with PS, Surgery, Ureshino Medical Center, Saga, the possibility of complications of IE should Japan be kept in mind, and patients should be evaluated by echocardiography and blood

INTRODUCTION: It is known that the patho- cultures. genesis of pyogenic spondylitis (PS) is main- ly hematogenous and that infective endo- GP127 carditis (IE) can cause persistent bactere- AGONISTIC SWIMMING IN ADOLESCENCE: mia. In recently a few reports has been rec- RISK FACTOR FOR SCOLIOSIS AND LOW ognized that IE may be the source of PS BACK PAIN? RESULTS OF A CROSS- more frequently than has been believed. SECTIONAL STUDY However, the incidence of IE in PS patients, Fabio Zaina*, Barbara Bonzanini°, Barbara and the outcome of these patients are still Colli°, Stefano Negrini# uncertain. The purpose of the present study *ISICO, Milan, Italy – °Università Cattolica was to investigate the incidence, the diag- del Sacro Cuore, Milan, Italy. # Brescia Uni- nostic methods, and the outcome for IE in versity, Italy patients with PS. METHODS: We retrospectively reviewed 61 INTRODUCTION: Swimming is widely prac- cases of PS diagnosed at our institution ticed by adolescent in many countries, and 187

GENERAL POSTERS has been considered for a long time a safe hyperkyphosis is quite new. Swimming is sport and even a scoliosis treatment. Re- generally considered a complete sport and a cently this opinion has changed, but data treatment option but this is contradicted by are still scant. our data. No causal effect can be deter- AIM: Verify prevalence of postural changes, mined with this study design, but a correla- spinal deformities and LBP in adolescent tion exists. agonistic swimmers compared to normal CONCLUSION: Swimmers showed more LBP, controls. scoliosis and hyperkyphosis than controls. METHODS: 112 adolescents (62 girls) com- These findings should change completely pared to 217 scholars (106 girls) of the same the perception of swimming. age range (12.5 and 12.1 respectively). We proposed a validated questionnaire to col- lect data on LBP. We collected a series of GP128 already validated measurements: IS SPINO PELVIC ALIGNMENT ASSOCIATED • plumbline distances from kyphosis apex WITH OSTEONECROSIS AFTER THORACOL- of the C7 and L3 vertebrae UMBAR VERTEBRAL COMPRESSION FRAC- • ATR (Angle of Trunk Rotation) according TURE? to Bunnell. Takashi Onishi, Masahiro Kanayama, According to previous studies, we consid- Tomoyuki Hashimoto, Keiichi Shigenobu, ered these normal references: Fumihiro Oha, Akira Iwata, Masaru Tanaka • ATR: 5° Spine Center, Hakodate Central General • C7: 15-55 mm Hospital • L3: 30-60 mm INTRODUCTION: This study aims to examine Statistics: ANOVA;฀฀2 test; Kruskall Wallis test. which spino-pelvic parameters are associat- RESULTS: LBP: Compared to control, female ed with vertebral osteonecrosis after osteo- swimmers had a higher prevalence (69% vs porotic vertebral compression fracture 53%, p<0.05), and 49% of them had to re- (VCF). duce their recreational activity compared to METHODS: Forty six patients who under- 29% of control (p<0.05). 30% of female went conservative treatment for a single- swimmers had a medical visit for back pain level thoracolumbar VCF (T10 to L3) were vs 21%. In the male group the differences reviewed retrospectively. Pelvic incidence were not significant. (PI), anterior deviation of C7 plumb line We found more spinal deformities in (C7PL) to the sacrum, distance of C7PL to swimmers: the fractured vertebra, kyphotic wedge an- • ATR: 5.3°±2.7 (female swimmers) vs gle and mid-vertebral body height of frac- 4.5°±1.9, p<0.05. tured vertebra were measured on initial • ATR >5°: Males (swimmers vs school) standing whole spine radiograph. As an out- 58% vs 44%, p<0.05; females 56% vs come measure, presence or absence of ver- 51%, p<0.05 tebral osteonecrosis was evaluated • C7: Males (swimmers vs school) radiographically at the final follow-up. 41.4±12.6 vs 33.6±11.0 p<0.05. Mean follow-up period was 18 months. Females 36.0±16.7 vs 27.7±12.3. RESULTS: Multiple logistic regression analy- • L3 > 60: 16% vs 8% (female swimmers sis demonstrated that mid-vertebral body vs schoolgirls). height of fractured vertebra (p=0.04, odds DISCUSSION: The correlation between ratio=1.263) and distance of C7PL to the swimming and LBP, scoliosis and fractured vertebra (p=0.08, odds ra- tio=1.031) were associated with osteone- 188

GENERAL POSTERS crosis after VCF. Relative risk for osteone- at the level of spondylolisthesis and those at crosis increased 1.6 times by 3 mm, 2.5 the adjacent levels for each patient. Statisti- times by 5 mm, 8.2 times by 10 mm loss of cal analyses were performed with SPSS ver- mid-vertebral body height of fractured ver- sion 20. tebra, and 2.4 times by 3cm, 4.3 times by RESULTS: Mean T2 values of facet joint at 5cm and 19.5 times by 10cm anterior devia- the level of spondylolisthesis was tion of C7PL to the fracture site. Anterior 88.7±9.9msec on the right and deviation of C7PL to the sacrum (p=0.27), 89.3±8.5msec on the left. Mean T2 values of pelvic incidence (p=0.49), vertebral wedge facet joint at the cranial adjacent level angle (p=0.50) were not significant risk fac- was76.3±7.4msec on the right and tors. 77.7±9.0msec on the left. There was signifi- DISCUSSION: It was suggested that the larg- cant difference. Mean T2 values of facet er anterior deviation of gravity center, the joint at the caudal adjacent level was larger flexion moment to the fractured site, 81.3±10.5msec on the right and which led to the impairment of bone heal- 82.5±11.2msec on the left. There was also ing. significant difference. DISCUSSION: It has been reported that T2 mapping reflects water content and colla- GP129 gen structure and indicates early degenera- EVALUATION ON THE DEGENERATION OF tion of cartilage in such as large joint. In this FACET JOINT IN LUMBAR SPINE USING T2 study, T2 values of facet joint at the level of MAPPING spondylolisthesis were increased as com- Daisuke Yamabe, Murakami Hideki, Yoshida pared with those at the adjacent levels with Satoshi, Takayuki Kikuchi, Ken Yama-zaki, significant difference. This result suggest Tadashi Shimamura that T2 mapping has an efficacy for evalua- Department of Orthopaedic Surgery, School tion of cartilage degeneration in small joint of Medicine,Iwate Medical University and particularly helpful to diagnose an early stage of osteoarthritis in facet joint. INTRODUCTION: Degenerative changes of lumbar facet joints seem to be associated with low back pain. The radiological evalua- GP130 tion of degenerative change of cartilage has CHARACTERISTICS OF LOW BACK PAIN IN been based on plain radiography, CT and ADOLESCENT PATIENTS WITH EARLY-STAGE MRI. In recent years, T2 mapping is one SPONDYLOLYSIS EVALUATED BY A DE- promising candidate for clinical quantitative TAILED VISUAL ANALOG SCALE imaging of cartilage in knee joint. Therefore Shirou Sugiura1, Satoru Nishikawa1, Tetsuo we assessed that T2 mapping of lumbar Shiga1, Takeshi Toyooka1, Kazumi Otsuki1, facet joints yield a same feasibility. Emi Aikawa1, Kazuhisa Kitou1, Yuka MATERIALS AND METHODS: Twenty pa- Takata1, Toru Ishizaki1, Yasuchika Ao- tients with grade I degenerative ki2 spondylolisthesis (9 men and 11 women; 1Nishikawa Orthopaedic Clinic 2Department mean age 69.2 years) were examined by of Orthopaedic Surgery, Toho University axial T2 mapping. The facet joint at the level Sakura Medical Center of spondylolisthesis (L2-3; 1, L3-4; 5, L4-5; 11 patients), and adjacent cranial and cau- INTRODUCTION: Early-stage spondylolysis dal level were sliced and the regions of in- (ESS) is one of the common causes of acute terest (ROIs) were selected manually. T2 low back pain (LBP) in adolescent patients. values were compared between facet joints Although accurate diagnosis of ESS is im- 189

GENERAL POSTERS portant to provide appropriate treatment, ESS is difficult to differentiate, using pain GP131 characteristics, from other low back disor- DOES THE RESPONSE TO PHYSICAL ders without the use of magnetic resonance THERAPY FOR CHRONIC NON-SPECIFIC imaging (MRI). The purpose of this study LOW BACK PAIN VARY ACCORDING TO was to elucidate the characteristics of LBP in AGE? patients with ESS. Shirou Sugiura1, Satoru Nishikawa1, Kazumi METHODS: Adolescent patients (n=79) with Otsuki1, Takeshi Toyooka1, Keita Nakamu- acute LBP were included (<1 month after ra1, Hiroyuki Obara1, Tetsuo Shiga1, Takato onset). All patients were evaluated by plain Oyama1, Chikako Sakaida1, Yasuchika Ao- radiography and MRI; patients who showed ki2 obvious pathological finding other than ESS 1Nishikawa Orthopaedic Clinic 2Department (e.g., disc herniation, infection, etc.) were of Orthopaedic Surgery, Toho University excluded. LBP was evaluated by a traditional Sakura Medical Center VAS scoring system, the Oswestry Disability Index (ODI), and a detailed VAS scoring sys- INTRODUCTION: There are few studies de- tem in which pain is independently evaluat- scribing differences in response to physical ed in 3 different postural situations (in mo- therapy for non-specific chronic low back tion, standing, and sitting). pain (CLBP) between elderly and adult pa- RESULTS: Of 79 patients, 42 had ESS (ESS tients. This study aimed to examine the re- group: mean age: 14.4 years-old; 34 male/8 sponse to physical therapy in elderly and females) and 37 had no pathological find- younger adult patients with CLBP, and to ings that explained the LBP origin (non- elucidate differences in response between specific LBP group (NS-LBP): mean age: 14.6 these two populations. years-old; 21 males/16 females). ODI and METHODS: Patients (n=47) with CLBP (>3 traditional VAS scores were 16.5, 4.9 in the months) without lower-extremity symptoms ESS group, and 26.3, 6.4 in the NS-LBP were divided into the elderly group≥65 ( group, respectively. Both scores were signif- yrs-old; n=18; mean age: 73.8 yrs; 8 icantly higher in the NS-LBP group. The re- males/10 females) and the younger group sults of the detailed VAS revealed that the (<65 yrs-old; n=29; mean age: 45.2 yrs; 13 ESS group showed significantly greater pain males/16 females) and received physical intensity while in motion, than in standing therapy for at least 3 months. Evaluation of and sitting (4.2, 2.0, and 1.9, respectively), the patients’ low back pain (visual analog whereas the NS-LBP group showed similar scale: VAS), disability (Oswestry Disability pain intensity in the three situations (5.4, Index: ODI), and quadriceps muscle strength 3.9, and 5.1, respectively). (Weight Bearing Index: WBI) were per- DISCUSSION: The present study revealed formed before treatment and at 1-, and 3- LBP characteristics capable of distinguishing months follow-up. ESS from the LBP of other low back disor- RESULTS: VAS scores before treatment and ders. Because early diagnosis is essential for at 1-, and 3-months follow-up were 4.0, 3.0, the treatment of spondylolysis, MRI exami- 2.7 in the elderly group, and 4.6, 3.3, 2.1 in nation is recommended for those patients the younger group, respectively. At 1-month who have severe pain in motion, but less follow-up, the elderly group did not show a pain while standing and sitting. significant decrease in VAS, while the younger group showed a significant de- crease. At 3-months follow-up, the elderly group showed a non-significant tendency (p=0.087) towards less pain compared with 190

GENERAL POSTERS before treatment, and the younger group were selected manually. T2 values were showed a further significant decrease in VAS compared between each facet joints before compared with the 1-month follow-up. The certain lumbar spinal motions (flexion, ex- elderly group did not show significant im- tension and rotation) and those immediate- provement in ODI and WBI even at 3- ly after those motions. months follow-up, while the younger group RESULTS: In men, mean T2 values of facet showed significant improvement at the 1- joints before and after lumbar motion were month follow-up. 57.1±6.2 and 49.0±2.2msec at the L1-2, DISCUSSIONS: This study showed that el- 59.1±4.3 and 49.8±4.4msec at the L2-3, derly patients with CLBP require a longer 59.7±5.6 and 51.1±6.5msec at the L3-4, time to respond to physical therapy than 62.8±6.1 and 50.9±5.3msec at the L4-5, and younger patients. In elderly patients, alt- 57.2±7.9 and 49.1±6.6msec at the L5-S1. In hough physical therapy for 3 months did not women, mean T2 values of facet joints be- significantly improve disability and muscle fore and after lumbar motion were strength, low back pain tended to improve, 54.3±11.8 and 42.8±5.7msec at the L1-2, although the response was less and slower 59.3±11.3 and 47.4±6.5msec at the L2-3, than in younger patients. 61.4±10.0 and 53.8±4.8msec at the L3-4, 62.5±7.0 and 50.2±6.8msec at the L4-5, and 62.9±6.3 and 52.6±6.1msec at the L5-S1. At GP132 the all levels, there were significant differ- T2 MAPPING EVALUATION OF LUMBAR ences (p<0.05) between T2 values before FACET JOINTS BEFORE AND AFTER SPINAL and after lumbar motion. MOTIONS DISCUSSION: T2 values of facet joints after Takayuki kikuchi, Hideki Murakami, Satoshi lumbar motion was significant lower than Yoshida, Daisuke Yamabe, Ken Yamazaki, those before lumbar motion at the all levels. Tadashi Simamura These results suggest that water contents in Department of Orthopaedic Surgery, School cartilage of lumbar facet joints increased of Medicine, Iwate Medical University, after lumbar motion. It is possible that ex- Iwate, Japan tracellular matrix enhanced taking of water inward to oppose compression and shear INTRODUCTION: Joint cartilage has ability force during lumbar motion. of releasing and taking water that compose extracellular matrix by mechanical stress such as compression and shear force. In GP133 recent years, T2 mapping is one promising CORONAL ALIGNMENT OF THE LUMBAR candidate for clinical quantitative imaging SPINE AND PELVIS IN PATIENTS WITH AN of cartilage, because T2 mapping reflects ANKYLOSED HIP water contents and collagen structure. The YOSHIHARA T, Morimoto T, Kugisaki H, purpose of this study is to reveal the chang- Tsukamoto M, Shiraki M, Kitajima M, es of water contents in the cartilage of lum- Sonohata M, Mawatari M bar facet joint before and after lumbar spi- Department of Orthopaedic Surgery, Faculty nal motions using T2 mapping. of Medicine Saga University, Saga city, METHODS: Twenty healthy volunteers (10 Japan, men and 10 women; mean age 19.3 years) were examined by axial T2 mapping. The INTRODUCTION: A fixed deformity at the facet joint at the center of intervertebral hip joint may cause pelvic obliquity, with a level of L1-2, L2-3, L3-4, L4-5 and L5-S1 were secondary lumbar scoliosis. However, there sliced and the regions of interest (ROIs) have been few reports on the influence of 191

GENERAL POSTERS the fixed position at the hip on the coronal alignment of the spine. The present investi- GP134 gation examined the coronal alignment of EARLY STAGE MRI FAT SUPPRESSION the spine and pelvis in patients with an IMAGE PREDICT THE PROGNOSIS OF ACUTE ankylosed hip (AS) OSTEOPOROTIC VERTEBRAL COMPRESSION METHODS: The subjects included 19 male FRACTURE TREATED BY HARD-CORSET and 32 female patients (45-80 years of age) TREATMENT treated by THA due to unilateral AS after Nobuyuki Suzuki, Muneyoshi Fukuoka, Jun spontaneous (n = 24) or surgical (n =28) Mizutani, Seiji Otsuka, Takanobu Otsuka fusion of the hip joint. Patients with bilat- Department of Orthopaedic Surgery, eral AS and a previous history of THA or Nagoya City University Graduate School of BHA or spine surgery were excluded from Medical Sciences the study. Regarding coronal spinopelvic alignment, the following parameters were INTRODUCTION: The vertebral body frac- measured: the lumbar scoliosis (LS; L1-L5 ture is the most frequent type of osteopo- Cobb angle), pelvic tilt (PT) and ankylosed rotic vertebral fractures (OVFs). We report- hip angle (AHA). The PT and AHA were de- ed more than 4/5 patients were suffering fined as the angle between the inter- long-lasting pain over the year. From the teardrop line and the horizontal line, and view of the fracture treatment, that is too the long axis of the femur of the AH side. high rate of unsuccessfulness. The purpose The variable was calculated a formula with of this study was to identify the pattern of the abduction side regarded as a positive the MR image that can predict a risk for angle and adduction side as a negative an- delayed union or sever collapse of OVFs. gle. For each parameter, correlations be- METHODS: All the patients over 40 years tween parameters were evaluated by a re- who visited our department and were diag- gression analysis. P< 0.05 was considered to nosed having fresh OVF were enrolled in be significant. this study. Plain X-ray, CT and MR images RESULTS: The average angles of the LS, PT were underwent within one week from the and AHA were 7.8°, 7.2°, and 12°, respec- first visit and also at 3weeks and 3months. tively. The correlation coefficients between The treatment was in all cases conservative the AHA and LS, AHA and PT, and PT and LS using hard corset. The occurrence of pseu- were 0.65, 0.55, and 0.72, respectively do-arthritis and degree of collapse were (P<0.01). evaluated by using CT at three months. DISCUSSION: Our study provides evidence RESULTS: A total of 20 patients were en- to suggest that, in patients with AH, the rolled in this study. Mean age was 79.4 . abduction position is positively correlated Fracture level was 3 for T12, 7 for L1, 3 for with the downward PT and the convexity of L2, 2 for L5, and 1 for T8, T9, T11, L3, and the LS toward the AH side. On the other L4. All of the cases showed the tendency hand, the adduction position positively cor- that the area of low intensity in the fat sup- related with the results on the opposite pression image collapsed. Six of them col- side. These results are in good agreement lapsed more than half of the vertebral with the clinical impression that an inade- height and became pseudo-arthritis. Four of quate position in patients with AH could those six had low intensity in fat suppres- cause compensatory pelvic tilt and lumbar sion image more than half of the vertebral scoliosis in order to maintain proper body area, and two of those had spot low intensi- balance. ty in fat suppression image almost all verte- bral area. Two collapsed less than half of the vertebra, but became pseudo-arthritis, 192

GENERAL POSTERS which showed low intensity line in fat sup- (EQ5D), Zurich Claudication Questionnaire pression. (ZCQ), Hospital Anxiety and Depression DISCUSSION: This study showed the low Scale (HADS), and Pain DETECT (a diagnostic intensity area of the fat suppression will tool for neuropathic pain). collapse. So the low area of the fat suppres- RESULTS: At 1 year, 170 (72%) patients sion image can predict how much the ver- were followed-up. 37 patients had opera- tebra will collapse afterwards. Furthermore tive treatment (22: decompression alone, if more than half of the vertebral area is 15: decompression and fusion) and 133 had low, the vertebra will be lead to pseudo- non-operative treatment. Patients treated arthritis. So we can apply the vertebro- or with surgery had severe symptoms and kyphoplasy in early stage to such patients lower ADL scores than non-operative group. who have large fat suppression low area to Both operative treatment and non- prevent pseudo-arthritis or further collapse. operative treatment improved EQ5D, ZCQ Symptom and Function score, but operative cohort significantly improved in all these GP135 measurements. The improvement of HADS EPIDEMIOLOGY OF LUMBAR SPINAL was not statistically different between two STENOSIS -MULTICENTER COHORT STUDY- groups. The total score for PainDETECT was Hara N 1), Takeshita K 1), Takebayashi T 2), significantly improved in operative cohort. Ida K 2), Yamashita T 2), Sato K 3), Nagata K Patients who had operative treatment had 3) higher ZCQ satisfaction score than non- 1Dept. of Orthopaedic Surgery, University of operative group. Tokyo, Tokyo, Japan, 2 Dept. of Orthopaedic DISCUSSION: It would appear from this Surgery, Sapporo Medical University School study that both operative treatment and of Medicine, Sapporo, Japan , 3 Dept. of non-operative treatment improved the Orthopedic Surgery, Kurume University, symptoms and the QOL in patients with LSS Kurume, Japan at 1-year follow-up. However, operative treatment significantly improved the symp- INTRODUCTION: Epidemiological evidence toms and the QOL, and patients had higher of lumbar spinal stenosis (LSS) is not enough satisfaction for operative treatment. because its definition has not been clearly established. The objective of this prospec- tive multicenter cohort study was to deter- GP136 mine the degree of severity and define the THE SPINAL STENOSIS PEDOMETER AND disease state of LSS using common outcome NUTRITION LIFESTYLE INTERVENTION measures. (SSPANLI) PILOT METHODS: Patients who visited the hospi- Tomkins-Lane CC, Lafave LZ, Parnell J, tals located in 3 regions in Japan who were Rempel J, Rogerson M, Wilson P, Hu R, diagnosed with LSS were prospectively en- Moriartey S. rolled in this study. LSS was defined accord- Mount Royal University ing to the North American Spine Society guidelines. Patients who had already been INTRODUCTION: Owing to age and mobility treated for LSS were excluded. A total of limitations, people with lumbar spinal ste- 238 patients (127 males) with a mean age of nosis (LSS) are at risk for sedentary behavior 71.5y were enrolled. Assessments were and obesity. Obesity is one of the most im- made at baseline and 1-year follow-up portant determinants of quality of life based on an LSS diagnostic support tool, the (QOL), and is linked to inferior outcomes of degree of stenosis from MRI, EuroQol LSS surgery. Therefore, weight management 193

GENERAL POSTERS in LSS is critical. BMI is the strongest predic- tor of function in LSS, suggesting that GP137 weight loss may promote physical activity STAPHYLOCOCCUS DECOLONIZATION IN and provide a unique treatment option for ELECTIVE SPINE SURGERY IS EFFECTIVE increasing function. Currently there is a lack Chen, Antonia F.; Farber, Nicholas J.; of research on weight loss in LSS. We pro- Zammerilla, Lauren L.; Nowicki, Andrea L.; pose a lifestyle modification approach of Kang, James D.; Lee, Joon Y.; Donaldson, physical activity and nutrition education, William F. delivered through an online platform. University of Pittsburgh Medical Center METHODS: The e-health platform was de- veloped. We recruited 10 overweight or INTRODUCTION: Surgical site infections obese individuals with LSS. Baseline and (SSIs) may be prevented by screening and follow-up testing included dual energy x-ray decolonizing Staphylococcus (MSSA/MRSA) absorptiometry, blood draw, 3-day food in elective spine patients. record, 7-day accelerometry, questionnaire, METHODS: A prospective study was con- and walking test. Intervention: During Week ducted from 4/2012-10/2012 evaluating 1, participants received a pedometer, a per- 135 consecutive elective spine patients. sonalized consultation with a Dietitian, and Eleven patients cancelled, and 12 swabs an Exercise Physiologist. For 12 weeks par- were not repeated on the day of surgery, ticipants logged on to the website to access leaving 112 patients (26 primary cervical, 59 personal step goals, walking maps, nutrition primary lumbar, 3 revision cervical, and 24 videos, and a discussion board. Follow-up, revision lumbar). Patients were screened for including structured interviews, occurred at nasal MRSA/MSSA colonization 2-6 weeks Week 13. prior to surgery. Those who were positive RESULTS: Nine participants had a mean age underwent decolonization using intranasal of 67.5±6.7 yrs (60% female). A significant mupirocin twice a day and chlorhexidine decrease was observed in fat mass, and body wash daily 5 days before surgery. Pa- symptom severity (Swiss Symptom Scale) tients were reswabbed on the day of sur- (p<0.05). Non-significant improvements gery to determine if the decolonization pro- were observed for waist circumference, tocol was effective. Statistical analysis was pain, ODI, and obesity bio-markers. 70% lost performed using chi-squared and McNemar weight, 50% increased walking capacity, and tests. 60% increased QOL. The mean increase in RESULTS: For pre-operative nasal swabs, 27 steps was 15%. patients (23.9%) were positive for MSSA DISCUSSION: The SSPANLI intervention was colonization and 2 patients (1.8%) were shown to be feasible, attractive to partici- positive for MRSA colonization. On the day pants, and effective. This intervention pro- of surgery, 4 patients (3.5%) were positive vides people with LSS the opportunity to for MSSA and 0 patients were positive for participate in their own health manage- MRSA. The reduction in MSSA colonization ment, potentially improving access to care, was significant (p<0.001), and there were and outcomes of surgery. Efficacy is being no patients with MRSA on the day of sur- assessed in a randomized trial. gery. Patients undergoing primary (p=0.06), lumbar (p=0.30) and no fusion (p=0.05) sur- gery were more likely to be positive for MSSA prior to surgery, with no difference between groups for MRSA. On the day of surgery, all 4 patients positive for MSSA were primary lumbar patients, with 2 fusion 194

GENERAL POSTERS and 2 laminectomy cases. During the study T2-weighted MRI was used to measure CSA period, 2 primary lumbar patients devel- and fat infiltration of the paraspinal muscle oped SSIs (MRSA and Streptococcus), both at the intervertebral disc level from L1 to L5. of which were successfully treated with I&D To quantify the depth of the groove be- and IV antibiotics. Neither patient was posi- tween the paraspinal muscles, our own im- tive on either MRSA/MSSA screening prior age indicator, the T-back value, equal to the to or on the day of surgery. length of the bulge of the muscle to the DISCUSSION: Our study demonstrates that attachment of the spinous process, was also MRSA/MSSA decolonization in elective measured. We then determined the rate of spine cases is effective. Ongoing studies are occurrence of T-back values 0 with age evaluating whether screening will reduce and evaluated the imaging features of postoperative infections. them. ≦ RESULTS: Of the 704 patients, 45 male (13%) and 80 female (22%) had T-back val- GP138 ues 0, and their mean age was 68 years. A NEW PREDICTIVE INDEX FOR BACK The occurrence of T-back values 0 in- MUSCLE DEGENERATION AND SAGITTAL creased≦ markedly in individuals over 60 ALIGNMENT ASSOCIATED WITH AGING years of age. Their mean lumbar lordosis≦ 1 Kazushi Takayama, 1 Teruo Kita, 2 Fumiaki was 19.5 degrees. CSA of the paraspinal Kanematsu, 2 Toshiya Yasunami, 1 Shigehiro muscle decreased and fat infiltration in- Ikeda, 1 Yoshinori Kyo, 1 Hideki Sakanaka, 1 creased to a greater extent in elderly pa- Yoshiki Yamano tients than in patients with good sagittal 1 Dept. of Orthopaedic Surgery, Seikeikai balance. Patients with T-back value 0 in- Hospital, Osaka, Japan; 2 Dept. of cluded young patients who exhibited de- Orthopaedic Surgery, Saiseikai Nakatsu creased lumbar lordosis without degener≦ a- Hospital, Osaka, Japan tive changes and elderly patients with de- generative changes such as disc narrowing, INTRODUCTION: It is widely accepted that vertebral fractures, and focal kyphosis. maintaining both lumbar lordosis and paraspinal muscle function is important in the prevention of low back pain. Our study focused on the groove between the left and right lumbar paraspinal muscles to obtain a simple index for evaluating back muscle degeneration. We have already reported that the cross-sectional area (CSA) of a paraspinal muscle tends to decrease with age. Our new index, referred to as the T- back value, strongly correlated with CSA. The aim of this study was to determine the rate of occurrence of T-back values 0 and to evaluate the imaging features in patients showing these T-back values. ≦ METHODS: A total of 704 patients who un- derwent an MRI of the lumbar spine at our hospital during 2010 were included in this study. Sagittal T2-weighted MRI was used to measure lumbar lordosis (L1-S1 angle). Axial 195

GENERAL POSTERS

lack of self-motivation, lack of support from GP139 colleagues, and inadequate time to exer- EFFECT OF WORKSITE EXERCISE ON BACK cise. AND CORE MUSCULAR ENDURANCE IN DISCUSSION: A supervised worksite exercise FIREFIGHTERS training program is safe and effective in John M. Mayer; William S. Quillen; Simon improving back and core muscular endur- Dagenais ance in firefighters. Future exercise pro- School of Physical Therapy & Rehabilitation grams in research or implementation set- Sciences, Morsani College of Medicine, tings aimed at preventing low back pain in University of South Florida firefighters should address barriers and fa- cilitators to improve participation and out- INTRODUCTION: Achieving an optimal level comes. of physical fitness is important for workers, such as firefighters, who are exposed to physically-demanding environments and at risk for low back pain. The purpose of this GP140 study was to: 1) assess the efficacy of a RELATIONSHIPS BETWEEN LOW BACK worksite exercise program on the develop- PAIN-RELATED CEREBRAL SUBSTRATES ment of back and core muscular endurance AND SURROUNDING NEURAL NETWORKS, in firefighters; and 2) explore barriers and AND PSYCHOPHYSICAL CHARACTERIZA- facilitators to participation in the exercise TION IN CHRONIC LOW BACK PAIN PA- program. TIENTS. - A FUNCTIONAL MAGNETIC RESO- METHODS: An RCT was conducted with ca- NANCE IMAGING STUDY - reer firefighters (n = 96) from a municipal Yohei Matsuo1, Jiro Kurata2, Katsuhiro fire department. Participants were random- Yoshida1, Miho Sekiguchi1, Takuya ized by fire station to exercise (n = 54) (su- Nikaido1, Shin-ichi Kikuchi1, Shin-ichi pervised work-site core stability and pro- Konno1 gressive resistance exercise for the back 1. Department of Orthopaedic Surgery, extensors, 2X/week, 24 weeks) or control (n Fukushima Medical University School of = 42). All participants continued their usual Medicine 2. Department of Anesthesiology, fitness routines. Back and core muscular Tokyo Medical & Dental University endurance was assessed by standard fitness tests before and after the intervention. Fo- BACKGROUND: Functional magnetic reso- cus groups were held with participants, us- nance image (fMRI) is used to investigate ing open-ended questions to identify barri- brain activation in patients with chronic ers and facilitators to participation in the pain. It is reported that there are brain are- exercise program. as, which presents deactivation in common RESULTS: At 24 weeks, adjusted isometric by various tasks or sensory and cognitive back and core muscular endurance times activities in recent years. This area is called were 12% (p = 0.021) and 21% (p < 0.001) default mode network (DMN). greater, respectively, for the exercise group The aim of the present study was to investi- compared with control. Related side effects gate the relationships between LBP-related were generally usual responses to exercise, cerebral substrates included DMN, and psy- minor, self-limiting, and did not disrupt job chophysical characterization in chronic low performance. Key facilitators to exercise back pain (cLBP) patients. were group cohesiveness, competitiveness, METHODS: Nine cLBP patients and 8 interest in exercise, financial incentives, and healthy subjects (HS) were enrolled in this perceived health benefits. Key barriers were study. Three 30-second blocks of pressure 196

GENERAL POSTERS stimulus were applied with 30 seconds of that the low back pain (LBP) in the American intervening rest conditions during the imag- male professional golfer is caused by the ing (3.0 Tesla MRI scanner). Short-form restricted internal rotation of the left hip McGill Pain Questionnaire (MPQ) Japanese joint. To the best of our knowledge, there version was used to evaluated sensory and have been no studies concerning the female affect of pain. Blood oxygenation level- professional golfer (FPG). The purpose of dependent (BOLD) signal was analysed using this study was to determine the relation BrainVoyager QX○R software. The correla- between the LBP and rotation range of mo- tion with the BOLD signal of the area ob- tion of the hip joint in the FPG. tained by subtraction analysis and MPQ METHODS: Thirty-two right-handed FPGs in score was examined. our country (mean age, 31.6 years, mean RESULTS: In the HS group, the right insular height, 162.5 cm, and mean weight, 62.1 cortex and prefrontal cortex (PFC), the left kg), who participated in our periodical phys- anterior cingulate cortex (ACC) and posteri- ical check-up, were examined. Twenty of or cingulate cortex were activated by a them had previous or present LBP (LBP stimulus, while the bilateral DMN were de- group: LG) and 12 of them had been no LBP activated. In the cLBP group, the bilateral (NLBP group: NG). We measured the inter- DMN and left supplemental motor area nal rotation angles (IRA) and external rota- were deactivated. The BOLD amplitude of tion angles (ERA) of the bilateral hip joints the right DMN deactivation in the cLBP which were 90°flexed. All angles were group was smaller than in the HS group. In compared between LG and NG, and be- the subtraction analysis, at the PFC and tween the right and left sides by Mann- ACC, the BOLD amplitude was activated in Whitney U test. A P value ＜0.05 was con- the HS group, while deactivated in the cLBP sidered statistically significant. group. The correlation coefficient of the RESULTS: The left IRA was significantly %BOLD signal and MPQ scores were smaller in LG than in NG (Fig.). R2=0.53 and R2=0.32, respectively, at the There were no significant differences be- PFC and ACC. tween LG and NG concerning the right IRA, CONCLUSION: The results suggested that the left ERA, and the right ERA. The left IRA right DMN in the cLBP patients occur dys- was significantly smaller than the right IRA function. In addition, hypofunction of the in LG (Fig.). However, there were no signifi- PFC and ACC which are both considered as cant differences between the right and left the cerebral terminal of the descending pain sides in regard to the IRA in NG, the ERA in inhibitory system might be induced in the LG, and the ERA in NG. cLBP patien

GP141 RELATION BETWEEN THE LOW BACK PAIN AND ROTATION RANGE OF MOTION OF THE HIP JOINT IN THE FEMALE PROFES- SIONAL GOLFER Tomofumi Ezure and Takato Aihara Dept. of Physical Therapy and Orthopedic Surgery, Funabashi Orthopedic Hospital, Funabashi-city, Japan

INTRODUCTION: There has been reported 197

GENERAL POSTERS

Gumiro, Bundang-gu, Sungnam, 463-707, Republic of Korea, + Department of Mechanical Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, Republic of Korea, ++ Kangdong Sacred Heart Hospital, Hallym University Medical College, ** Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul, 110-744, Republic of Korea

INTRODUCTION: In spite of the similarity in definition between JHM and spinal instabil- ity, there have been few studies clarifying the association between two entities. Fur- thermore, the clinical significance of the spinal instability in the young men with JHM still remains unknown. Therefore, the pur- pose of this study was to firstly, to evaluate spinal intervertebral mobility in patients DISCUSSION: From the results of this study, with joint hypermobility (JHM) and matched only the left IRA was restricted in right- controls without JHM, and secondly, to in- handed FPG who had previous or present vestigate the influence of JHM on back pain, LBP. We think that the restricted internal disability, and general health status in the rotation of the left hip joint prevents the young man with a retrospective case- weight shift to the finish position, then the control analysis of prospectively collected FPG compensates those by the lumbar ex- data. tension which can lead to LBP. These find- METHODS: The JHM group included 32 sub- ings suggest that it is important to pay at- jects who had Beighton scale of 4 or more tention to the IRA in FPG and the flexibility according to nine-degree Beighton scale. of the hip rotation is called for the preven- The age-matched 32 young men without tion of LBP. JHM were selectively included in the control group. In both groups, Oswestry Disability GP142 Index (ODI), Visual Analog Pain Scale (VAS) THE ASSOCIATION OF BENIGN JOINT for back pain, and Short Form-36 (SF-36) HYPERMOBILITY WITH SPINAL INSTABILITY was assessed. Radiological sagittal plane AND ITS CLINICAL IMPLICATION IN ACTIVE motions for each segment and whole lum- YOUNG MAN bar spine were calculated as the difference Ho-Joong Kim, MD*, Jin S. Yeom, MD*, between the Cobb angle measurements in Dong-Bong Lee, MD*, Joon-Hee Park, MD++, the flexion and extension plain radiographs. Kyoung-Tak Kang, MS+, Bong-Soon Chang, RESULTS: The JHM group showed signifi- MD**, Choon-Ki Lee, MD** cantly larger range of motion both at each * Spine Center and Department of matched segment and at whole lumbar Orthopaedic Surgery, Seoul National spine (L1-S1) than the control group. The University College of Medicine and Seoul JHM group had significant increased VAS for National University Bundang Hospital, 166 back pain and ODI score, compared to con-

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GENERAL POSTERS trol group. The SF-36 physical function, role physical, role emotional, and physical com- INTRODUCTION: The symptom severity of ponent summary in the JHM group were back pain/leg pain is not correlated with the significantly lower than in the control group. severity of degenerative changes and canal stenosis in lumbar spinal stenosis (LSS). Considering the individual pain sensitivity might play an important role in pain percep- tion, this discordance between the radiolog- ic findings and clinical symptom in the LSS might originate from the individual differ- ence of pain sensitivity. Therefore, the aim of this study was to determine the relation- DISCUSSION: In conclusion, the present ship among the clinical symptom, radiologic study shows that the young man with JHM findings, and the individual pain sensitivity has the symptomatic spinal instability corre- in the patients with degenerative LSS. lated to significant low back pain, disability METHODS: In 94 patients who had chronic and limited physical activity. Future study back pain and/or leg pain caused by degen- regarding spinal instability should be taken erative lumbar spinal stenosis, a medical into account this benign JHM. history, a physical examination, and com- pletion of a series of questionnaires, includ- GP143 ing pain sensitivity questionnaire (PSQ) [to- tal PSQ and PSQ-minor], Oswestry Disability THE INFLUENCE OF PAIN SENSITIVITY ON Index (ODI), Visual Analog Pain Scale (VAS) THE SYMPTOM SEVERITY IN PATIENTS for back pain, and Short Form-36 (SF-36) WITH LUMBAR SPINAL STENOSIS were recorded on the first visit. Radiologic Ho-Joong Kim, MD1, Bo-Gun Suh, MD1, analysis was performed using the MRI find- Dong-Bong Lee, MD1, Gun-Woo Lee, MD1, ings. The grading of canal stenosis was Dong-Whan Kim, MD1, Kyoung-Tak Kang, based on the method by Schizas, and the MS2, Bong-Soon Chang, MD3, Choon-Ki Lee, degree of disc degeneration was graded MD3, Joon-Hee Park, MD4, Jin S. Yeom, from T2-weighted images with the MD1 Pfirrmann classification. The correlations 1 Spine Center and Department of among variables were statistically analyzed. Orthopaedic Surgery, Seoul National RESULTS: VAS for leg and back pain was University College of Medicine and Seoul highly associated with the total PSQ and the National University Bundang Hospital, 166 PSQ-minor. Total PSQ and PSQ-minor were Gumiro, Bundang-gu, Sungnam, 463-707, also significantly associated with ODI. Republic of Korea, 2 Department of Among SF-36 scales, the PSQ minor had Mechanical Engineering, Yonsei University, significant correlations with SF-36 BP, RE, 134 Shinchon-dong, Seodaemun-gu, Seoul, and MCS after control of confounding varia- Republic of Korea, 3 Department of bles such as BMI, age, and the grade of ca- Orthopaedic Surgery, Seoul National nal stenosis/disc degeneration. Total PSQ University College of Medicine and Seoul was significantly associated with the SF-36 National University Hospital, 101 RP, BP, and RE. There was no significant Daehangno, Jongno-gu, Seoul, 110-744, association between the grade of canal ste- Republic of Korea, 4 Department of nosis/disc degneratin and symptom severi- Anesthesiology and Pain Medicine, ty. Kangdong Sared Heart Hospital, Hallym University College of Medicine 199

GENERAL POSTERS

ed by four different non-operative spine clinicians administering best evidence clini- cal practice guideline-based treatment that included chiropractor-administered lumbar spinal manipulative therapy. METHODS: Design: prospective nonrandom- ized trial. Inclusion: ages 19-59; Quebec Task Force categories 1 and 2; pain duration of 2-4 weeks. Exclusion: “red flag” condi- tions; contraindications to high velocity low amplitude (HVLA) spinal manipulation ther- apy (SMT). Treatment: standardized clinical practice guidelines-based care including

DISCUSSION: The current study suggests at 24 weeks (primary), and in SF-36 bodily that the pain sensitivity could be a deter- pain (BP) and physical functioning (PF) mining factor for symptom severity in the scores at 8, 16 and 24 weeks (secondary). degenerative spinal disease. RESULTS: In adjusted models, nearly signifi- cant overall differences between groups was detected on RDQ (P=0.10) and PF GP144 (P=0.16), but not BP (P=0.41) change scores at 24 weeks. Significant differences were VARIATIONS IN CLINICAL OUTCOME IN THE observed between groups on both RDQ CLINICAL PRACTIC GUIDELINE-BASED (P=0.02), and PF (P=0.008) change scores at TREATMENT OF PATIENTS WITH ACUTE 8 weeks, but not at 16 or 24 weeks. No sig- LOWER BACK PAIN: AN INTENTION TO nificant differences in BP change scores oc- TREAT ANALYSIS OF THE CHIROPRACTIC curred at any time points. Generally, im- HOSPITAL-BASED INTERVENTIONS provements on all outcomes occurred with- RESEARCH OUTCOMES (CHIRO) STUDY. in all patient groups over time. Paul B. Bishop, DC, MD, PhD*†, Jeffrey A. DISCUSSION: Early statistically and clinically Quon, DC, PhD, FCCS(C)*†‡, Brian Arthur, important differences in RDQ and PF change DC, MSc*† scores at 8 weeks are not maintained at 16 * International Collaboration on Repair Dis- and 24 weeks. Outcomes are almost univer- coveries (ICORD), University of British Co- sally positive over time irrespective of treat- lumbia (UBC), Vancouver, Canada; † Com- ing clinician. bined Neurosurgical and Orthopaedic Spine

Program, Division of Spine, Department of

Orthopaedics, UBC, Vancouver, Canada;

‡School of Population and Public Health,

UBC, Vancouver, Canada

INTRODUCTION: To conduct an intention- to-treat analysis of data on the consistency of outcomes between patient groups treat-

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Cord Disorders, Hokkaido University Gradu- GP145 ate School of Medicine, Sapporo, Japan (16) FACET JOINT TROPISM AND DEGENERA- Department of Orthopaedic Surgery, Osaka TIVE SPONDYLOLISTHESIS – A STUDY FROM University Graduate School of Medicine, THE AOSAP RESEARCH COLLABORATION 1 2 3 Suita, Japan (17) Department of Neurosur- Samartzis D, Rajasekaran S, Kawaguchi gery, College of Medicine, Hangang Sacred Y, 4 Acharya S, 5 Kawakami M, 6 Satoh S, 7 8 9 10 Heart Hospital, Hallym University, Seoul, Chen S, Park CK, Lee CS, Foocharoen T, South Korea (18) Department of Orthopae- 11 Nagashima H, 12 Kuh S, 13 Zheng Z, 14 Con- 15 16 17 1 dic and Traumatology, Faculty of Medicine dor R, Ito M, Iwasaki M, Jeong JH, Airlargga University, Dr Soetomo Teaching Luk KDK, 18 Prijambodo B, 19 Rege A, 20 Jahng 21 22 23 Hospital, Surabaya, Indonesia (19) Depart- TA, Luo Z, Tassanawipas W, Acharya ment of Orthopaedics, Deenanath N, 24 Pokharel R, 25 Shen Y, 26 Ito T, 27 28 29 30 Mangeshkar Hospital, Jehangir Hospital, Zhang Z, Aithala J, Kumar GV, Jabir Pune, India (20) Department of Neurosur- RA, 31 Basu S, 32 Li B, 33 Moudgil V, 1 Sham P, 34 gery, Seoul National University Bundang Williams R Hospital, Seongnam, South Korea (21) Spine (1) Department of Orthopaedics and Trau- Service, Department of Orthopaedic Sur- matology, University of Hong Kong, Hong gery, Xijing Hospital, the Fourth Military Kong, SAR China (2) Department of Ortho- Medical University, Xi'an, China (22) De- paedics, Ganga Hospital, Coimbatore, India partment of Orthopedics, (3) Department of Orthopaedic Surgery, Phramongkuthklao Army Hospital, Bangkok, University of Toyama, Toyama, Japan(4) Thailand (23) Dwaraka Institute of Spine Department of Orthopedics, Sir Gangaram Care, Bellary, India (24) Department of Or- Hospital, New Delhi, India (5) Department of thopedics & Trauma Surgery, Spine Unit, Orthopaedic Surgery, Wakayama Medical Tribhuvan University, Teaching Hospital, University, Kihoku Hospital, Ito-gun, Japan Kathmandu, Nepal (25) Department of Spine (6) Department of Spine Surgery, Eniwa Surgery, The Third Hospital of Hebei Medical Hospital, Hokkaido Japan (7) Orthopaedic University of China, Shijiazhuang, China (26) Department, Chang Gung Memorial Hospi- Department of Orthopaedic Surgery, Niigata tal, Taoyuan, Taiwan City General Hospital, Niigata, Japan (27) (8) Department of Neurosurgery, Seoul St. Department of Orthopaedic Surgery, Beijing Mary's Hospital, Catholic University of Ko- 361 Hospital (Aviation General Hospital), rea, Seoul, South Korea (9) Department of Beijing, China (28)Department of Orthope- Orthopedic Surgery, Samsung Medical Cen- dics, Kasturba Medical College, Manipal ter, Sungkyunkwan University School of University, Mani, Udupi, India (29) Depart- Medicine, Seoul, South Korea (10) Depart- ment of Neurosurgery, Fortis Hospital, Kol- ment of Orthopaedic Surgery, Khonkaen kata, India (30) Orthopaedic and Trauma- Regional Hospital, Khonkean, Thailand (11) tology Department, University of Indonesia / Department of Orthopedic Surgery, Faculty RS Ciptomangunkusumo, Jakarta, Indonesia of Medicine, Tottori University, Yonago, Ja- (31) Neurosciences Division, Park Clinic, Kol- pan (12) Department of Neurosurgery, kata, India (32) Department of Spine Sur- Gangnam Severance Hospital, Seoul, South gery, The Third Hospital of Hebei Medical Korea (13) Department of Spine Surgery, University of China, Shijiazhuang, China (33) The First Hospital Affiliated of Zhongshan Department of Orthopedic, Punjab Institute University, Guangzhou, China (14) Depart- of Medical Sciences Jalandhar, Jalandhar, ment of Orthopedics, Cebu Orthopaedic In- India (34) Department of Orthopaedics, stitute, Cebu, Philippines (15) Department of Princess Alexandra Hospital, Brisbane, Aus- Advanced Medicine for Spine and Spinal 201

GENERAL POSTERS tralia likelihood of dSpl. Our study broadens the understanding of FJ morphology and its role INTRODUCTION: Orientation of lumbar fac- in degenerative sagittal plane instability. et joints (FJ) may be associated with the pathogenesis of degenerative spondylolisthesis (dSpl). However, the role GP146 of FJ tropism (i.e. asymmetry between facet HIP FLEXION CONTRACTURE AND OUT- joint orientations at the same level) in dSpl COME OF CORRECTIVE SURGERY FOR is undetermined. This study addresses the ADULT SPINAL DEFORMITY WITH SAGITTAL role of FJ tropism in relation to dSpl. IMBALANCE METHODS: A multi-national, cross-sectional Atsunori Yuasa, PT, Masahiro Kanayama, study was performed in 34 institutions in MD, Tomoyuki Hashimoto, MD, Keiichi the Asia Pacific region. Lateral standing ra- Shigenobu, MD, Fumihro Oha, MD, Akira diographs and axial MRIs and/or CT scans Iwata, MD, Takashi Onishi, MD, Masaru were obtained for subjects with single level Tanaka, MD lumbar dSpl. Imaging was analyzed to assess Spine Center, Hakodate Central General lumbar levels with L4-5 dSpl (Group A) or Hospital, Hon-cho 33-2, Hakodate 040-8585, without dSpl (Group B). FJ tropism was de- Japan fined as a ≥ 7 degree angulation difference and also assessed on ROC curve analysis to INTRODUCTION: Hip flexion contracture identify critical values. Subject de- might be a potential risk for fixation failure mographics were also noted. and loss of correction in surgical treatment RESULTS: The study included 351 patients of sagittal imbalance. This study aimed to (36.9% males, 63.1% females) with a mean evaluate preoperative hip flexion contrac- age of 61.8 years. There were 267 patients ture and to investigate the effect of periop- (76.1%) in Group A and 84 individuals erative physical therapy on the outcomes of (23.9%) in Group B (control). A significant corrective surgery sagittal imbalance. difference was noted in FJ angulations be- METHODS: Fourteen patients who under- tween Group A (mean right: 57.5 degrees; went corrective surgery for adult spinal de- left: 55.4 degrees) and Group B (mean right: formity with sagittal imbalance were in- 48.4 degrees; left: 46.5 degrees) (p<0.001). cluded in this study. The mean age was 68 Based on FJ tropism of 7 degrees, there was years (54-78 years). Surgical procedures no statistically significant difference be- were posterior or transforaminal lumbar tween Groups. ROC analysis identified FJ interbody fusion (PLIF/TLIF) in eight pa- angulation difference of 15 degrees or tients, pedicle subtraction osteotomy (PSO) greater associated with dSpl. Based on age in five patients, and posterior vertebral col- and FJ angulation-adjusted multivariate umn resection (PVCR) in one patient. Hip analysis, FJ tropism with a critical value of range of motion (ROM) was measured pre- ≥15 degrees noted an odds ratio of 2.43 operatively in all patients. Improvement of (95% CI: 1.20 - 4.91; p=0.014) associated ROM was also assessed in patients with with dSpl. Slippage was noted with in- physical therapy intervention for hip con- creased FJ tropism, but the effects could not tracture. “Remaining sagittal imbalance” be discerned. was defined as more than 10 cm deviation DISCUSSION: Greater sagittal FJ orientation of C7 plumb line even after surgery. was associated with dSpl, as was joint tro- RESULTS: Ten patients achieved improve- pism. A critical value of 15 degrees FJ angle ment of sagittal balance (successful correc- difference produced a two-fold increased tion group), but sagittal imbalance re- mained in four patients (poor correction 202

GENERAL POSTERS group). Hip flexion contracture (hip exten- ders, and the study was approved by the sion < -5 degree) was observed in 7 of 14 internal review board. The muscle thick- patients. Hip extension ROM was -8 degrees nesses of external oblique (EO), internal in poor correction group, and was 1 degree oblique (IO), and transversus abdominis in successful correction group. Periopera- (TA) were measured using the ultrasonog- tive physical therapy was done in three pa- raphy (Fig.). The muscle thicknesses were tients; hip extension ROM was improved measured twice independently and aver- from -15 degrees to 8 degrees. C7 plumb aged. The observer A (OA) and observer B line deviation was improved from 14.8 cm (OB) remeasured the bilateral muscle thick- to 6.0 cm in the patients with physical ther- nesses of the four of the 13 subjects one apy intervention, but was worsen from 5.1 week later, and the intraobserver reliabili- cm to 13.2 cm in those without physical ties (IARs) of the two days’ measurements therapy. were determined by the intraclass correla- DISCUSSION: Hip flexion contracture was tion coefficient (ICC). Also, interobserver frequently observed in patients with adult reliability (IER) between OA and OB was spinal deformity and sagittal imbalance. calculated. Perioperative physical therapy improved hip RESULTS: IARs between the two days were extension ROM, and might have a favorable high in both observers and in all muscles effect on postoperative sagittal spinal bal- (OA: ICC=0.953 in EO, 0.919 in IO, and 0.970 ance. in TA, OB: ICC=0.830 in EO, 0.915 in IO, and 0.864 in TA). IERs between OA and OB were also high in all muscles (ICC=0.928 in EO, GP147 0.906 in IO, and 0.908 in TA). INTRAOBSERVER AND INTEROBSERVER DISCUSSION: From the results of this study, RELIABILITIES IN ULTRASONOGRAPHIC IAR and IER were high and evaluated to be MEASUREMENT OF THE LATERAL AB- “almost perfect” according to Ladis (’77, DOMINAL MUSCLE THICKNESS WITH USE Biometrics). We think this is because that OF THE BONE INDEX IN THE IMAGE we could reemerge accurately the lateral Hiroshi Mikami, Naoki Ishigaki, and Takato abdominal muscles using the bone index in Aihara* the image and using the probe which was Dept. of Physical therapy and *Orthopedic placed perpendicularly to the fasciae. The- surgery, Funabashi Orthopedic Hospital, se findings suggest that our new method Funabashi-city, Japan may be useful for the follow-up study of the same subject and for the comparison of the INTRODUCTION: There have been reported muscle thicknesses which were measured that the lateral abdominal muscle was im- by the other observers. portant to stabilize the spine. However, it has been difficult to measure accurately the muscle thickness without the index using the ultrasonography. The purpose of this study was to establish a new method to measure the lateral abdominal muscle thickness and to investigate the reliability of our method. METHODS: Informed consents to inclusion in this study were obtained from 13 healthy men (mean age, 24.5 years) who did not have any previous back nor lumbar disor- 203

GENERAL POSTERS

induction with TRPV1 as a capsaicin GP148 receptor. The percentages of TRPV1- THE EFFICACY OF LP-IDOPE AS A NEAR- immunoreactive (IR) DRG cells and CGRP-IR INFRARED PROBE IN THE MANAGEMENT DRG cells were statistically compared OF PAIN CAUSED BY SPINAL METASTASIS 1) 1) between the groups. Kazuyo Yamauchi , Kazuhide Inage , RESULTS: Tumor growth was inhibited in the Miyako Suzuki1), Yoshihiro Sakuma1), Yasuhi- 1) 1) region showing spinal metastasis after NIR ro Oikawa , Tetsuhiro Ishikawa , Masayuki irradiation. The percentage of CGRP- and Miyagi1), Hiroto Kamoda1), Go Kubota1), 1) 1) 1) TRPV1-IR DRG cells was lower in the NIR- Takeshi Saino , Jun Sato , Sumihisa Orita , irradiated group than in the non-NIR- Kazuhisa Takahishi1), Yutaka Tamura2), Seiji 1) irradiated. Ohtori DISCUSSION: Spinal metastasis is associated 1) Department of Orthopaedic surgery, with acid and pH fluctuation. We found that Chiba University 2)Department of the levels of TRPV1, a sensor of acid and pH Bioinformatics, Chiba University fluctuation, and CGRP, a nociceptive neurotransmitter, decrease after NIR INTRODUCTION: The cause of and irradiation. Therefore, LP-iDOPE, as an NIR mechanism underlying pain due to spinal probe, is effective in managing the pain metastasis, despite severe and refractory caused by spinal metastasis. therapy, is unclear. No standard therapy has yet been established for the management of pain due to spinal metastatic tumors. In a GP149 recent study, we have reported that HEALTH, SOCIAL AND ECONOMIC CONSE- liposomally formulated 1,2-dioleoyl-sn- QUENCES OF NECK INJURIES: A CON- glycero-3-phosphoethanolamine(LP-iDOPE) TROLLED NATIONAL STUDY EVALUATING along with indocyanine green as a near- SOCIETAL EFFECTS ON PATIENTS AND infrared(NIR) probe accumulates near fragile THEIR PARTNERS vascular tissue. LP-iDOPE accumulates near Tom Bendix (1), Poul Jennum (2), Jakob various tumors and inhibits tumor growth Kjellberg (3), Rikke Ibsen (4). after NIR irradiation. However, to our (1) Center for Rheumathology and spinal knowledge, no studies have reported Diseases, University of Copenhagen, whether it plays a role in relieving pain Glostrup Hospital, Denmark; (2) Danish caused by spinal metastasis. The aim of this Center for Sleep Medicine, Department of study was to determine the efficacy of LP- Clinical Neurophysiology, Center for Healthy iDOPE as an NIR probe for alleviating pain Aging, Faculty of Health Sciences, University due to spinal metastatic tumors. of Copenhagen, Glostrup Hospital, Copen- METHODS: Rat breast tumor cell-line cluster hagen, Denmark; (3) Danish Institute for transplanted at the L6 vertebral body was Health Services Research, Copenhagen, used as the spinal metastasis model. Seven Denmark; (4) itracks, Klosterport 4E, 4, Aar- days after surgery, the L6 vertebra was hus, Denmark. intravenously injected with LP-iDOPE and subjected to NIR irradiation. Then, in-vivo INTRODUCTION: Despite neck injuries fluorescence imaging of the L6 was cause significant socio-economic burdens, performed after 24, 48, and 168 h. Further, there is insufficient information about the the bilateral dorsal root gangliaon(DRGs) at time course, as well as the effect on their the L1–L6 levels were resected and partners. The aim was to estimate health- immunohistochemically evaluated using care costs of neck injuries, except fractures, calcitonin gene-related peptide(CGRP) in patients and their partners, both follow- 204

GENERAL POSTERS ing and preceeding the injury. METHODS: In a case-control study, using GP150 records from the Danish National Patient CT CLASSIFICATION OF VACUUM PHENOM- Registry 1998-2009, all patients with a diag- ENON FOR THE LUMBAR INTERVERTEBRAL nosis of neck injury and their partners were DISC identified and compared with randomly K. Nishida, K. Maeno, K. Kakutani, T. Taka- chosen controls matched for age, gender, da, J. Yamamoto, H Hirata, T. Kurakawa, S. geographic area and civil status. Direct costs Miyazaki, T Yurube, *T. Iguchi, M. Kurosaka included frequency of primary and hospital Dept. of Orthopaedic Surgery, Kobe Univer- sector contacts, procedures and medica- sity Graduate School of Medicine, Kobe, Ja- tion. Indirect costs included the effect on pan * Dept. of Orthopaedic Surgery, Hyogo labour supply. Social transfer payments Rehabilitation Center Hospital, Kobe, Japan were included to illustrate the effect on national accounts. INTRODUCTION: Vacuum phenomenon in RESULTS: The register contributed 94,224 the intervertebral disc has been well- patients, and 372,341 matched controls recognized phenomena in disc degeneration were identified. Approximately 47.5% were process. However, the clinical significance married or cohabiting in both groups. Neck as well as the comprehensive analysis has injury patients had significantly higher rates not been assessed. Our objective was to of health-related contacts, medication use clarify characteristics of vacuum phenome- and higher socio-economic costs than con- non in lumbar disc. trols. To a lesser extent, they also had lower METHODS: The study involved 120 lumbar employment rates, and those employed discs from 24 patients (mean 70.4 years) generally had lower incomes. Furthermore, with existence of vacuum phenomenon de- the patients had already presented negative tected by reconstructed sagittal CT images. social- and health-related status up to 11 Vacuum phenomenon was classified into 5 years before the first diagnosis, which be- grades: Grade 1, dot- like change in the nu- came more pronounced for those with the cleus pulposus (NP); Grade2, linear cleft in highest costs. The health effects on costs the NP; Grade 3, massive defect in the NP; were present regardless of age group and Grade 4, massive defect from the NP gender, and it was also seen for the pa- through annulus fibrosus (AF); and Grade 5, tients’ partners. linear cleft through the disc. Disc height was DISCUSSION/CONCLUSION: Neck injuries measured by CT. Segmental instability was are associated with major socio-economic evaluated by flexion/extension radiographs. consequences for patients, their partners Correlation of vacuum phenomenon grades and society. However, the increased ex- with MRI Pfirrmann degeneration grades penses during subsequent years cannot be and Modic change type was investigated. explained by the injury alone, because these RESULTS: Vacuum phenomenon was de- patients already had elevated expenses pri- tected in 49% of 120 discs (L1/2, 3%; L2/3, or to the injury. This indicates some selec- 6%; L3/4, 10%; L4/5, 17%; and L5/S, 13%), tion of increased vulnerability for both pa- which were classified into Grade 1, 6%; tients and their partners. Grade 2, 8%; Grade 3, 8%; Grade 4, 14%; and Grade 5, 13%. Disc height was signifi- cantly decreased in Grade 5. In comparison between vacuum phenomenon grades and Pfirrmann grades, while no disc with Pfirrmann Grade 1-2 was observed, and 77% of discs with Grade 4 vacuum were 205

GENERAL POSTERS identified as Pfirrmann Grade 4, and 100% of discs with Grade 5 vacuum were classi- RESULTS: The Table displays seven conduc- fied as Pfirrmann Grade 5. Type 2 Modic tion tests evaluated in this study and the change was observed in 73% of vacuum frequency of occurrence based on location Grade 5 discs. In functional radiographs, of dominant pain. There was a statistically 10% of segments with vacuum Grade 3 disc significant difference between conduction and 18% of segments with vacuum Grade 4 tests that were positive among those with disc showed translation over 3mm. back pain vs those with leg pain (p<0.05). DISCUSSION: Our grading system for vacu- DISCUSSION: Positive tests in those without um phenomenon facilitates classifying discs leg dominant pain or with the reproduction with advanced degeneration in MRI. Even in of LBP only are highly unlikely to be associ- Pfirrmann Grade 4-5 discs, vacuum Grade 3- ated with the current clinical problem. They 4 discs with massive defect from NP may represent a pre-existing neurological through AF may have the potential to in- deficit or, more frequently an error in exam- duce segmental instability. ination. True positive conduction tests oc- cur only in those with leg dominant pain; thus, the ‘positive back’ column is consid- GP151 ered false positives while the ‘positive leg’ TRUE POSITIVE CONDUCTION TESTS OCCUR column are the true positives. Clinicians RARELY IN CLINICAL PRACTICE need to cross reference test results with Greg McIntosh MSc, Hamilton Hall MD, Tom location of dominant pain to ensure accu- Carter BSc PT rate diagnoses and avoid false positives. CBI Health Group Research Department, Toronto, Canada GP152 INTRODUCTION: Conduction tests are a ANALYSIS OF THE S1 SACRAL FORAMINAL necessary component of the low back pain LOCATION USING A THREE-DIMENSIONAL (LBP) physical examination. This study com- CT RENDERING TECHNIQUE pares conduction test findings with location Yusuke Sato , Kotani Toshiaki,Tetsuharu of dominant pain to establish false positives Nemoto,Tsutomu Akazawa,Tsuyoshi Sa- from true positives. kuma, Mitsuhiro Kitamura1, kazuhisa METHODS: This was a prospective observa- Takahashi2, Shohei Minami1 tional cohort study of low back pain (LBP) 1. Dept. of Orthopaedic Surgery, Seirei Sa- cases (n=2196) treated non-operatively at kura Citizen Hospital, Chiba, Japan, 2. Dept. 40 spine care rehabilitation clinics across of Orthopaedic Surgery, Chiba University, four provinces between January 2008 and Chiba, Japan June 2010. All patients had mechanical LBP as determined by the Saskatchewan Spine INTRODUCTION: Nerve root blocks (NRBs) Pathway triage methodology. have been widely performed under fluoro- scopic guidance. Because of the lack of Level test #positive #positive total three-dimensional (3D) anatomical infor- (back) (leg) mation, an S1 NRB is more difficult than a L4 knee reflex 65 5 70 L4-5 ankle dorsiflexion 58 14 72 lumbar NRB. The purpose of the present L5 trendelenberg 14 0 14 study was to investigate the location of the L5 ext. hallicus longus 60 9 69 S1 foramen using a 3D computed tomo- S1 ankle reflex 82 5 87 graphic (3D CT) rendering technique, ray- S1 plantar flexion 57 12 69 S1 gluteus maximus 14 4 18 sum projection. METHODS: We retrospectively assessed 60 206

GENERAL POSTERS patients (30 female, 30 male; age 22‒84 years, average 54.4 years) with lumbar de- INTRODUCTION: Lumbar spinal stenosis generative disease. Spiral CT was performed (LSS) patients may experience neuropathic using a multi-detector CT scanner in the pain (NeP) that is refractory to existing an- axial plane. Images were networked to im- algesics. Pregabalin (PGB), a novel analgesic aging software Synapse Vincent developed for NeP management, suppress- V3.0.0003(Fujifilm Medical, Japan) for 3D es the secretion of pain-related mediators imaging. On axial CT imaging, we marked in the synapses by binding to α2δ subunits the center of the posterior sacral foramina of Ca2+ channels. PGB has already been (PS1). The marked point (PS1) was displayed reported to be effective for post- by 3D CT with ray-sum projection as a sub- therapeutic neuralgia and diabetic neuropa- stitute for fluoroscopic radiography. Ray- thy; however, its efficacy in LSS patients sum projection is a 3D rendering technique with NeP has not yet been evaluated. The in which the attenuation value of each voxel present study aimed to investigate whether is summed along a projection line. A ray- PGB has an effect on NeP management in sum image resembles a conventional radio- LSS patients. graph. The center of the L5 pedicle (PL5) MATERIALS AND METHODS: The subjects was also marked on a ray-sum image. The were LSS patients with NeP identified using distances between PS1 and PL5 were meas- a screening tool, Pain DETECT. Individuals ured in the vertical and lateral directions, who experienced leg pain(Visual Analog respectively. Scale [VAS] score > 30) and intermittent RESULTS: PS1 was located 39.3 ± 7.0 mm claudication(<300 m) refractory to NSAIDs caudally and 3.5 ± 3.7 mm laterally from for more than a month were included. They PL5. were administered PGB at a dose of 25 DISCUSSION: The present findings demon- mg/d, which was gradually increased to 150 strate the excellent feasibility of the 3D-CT mg/d for 6 wk according to their pain inten- rendering technique for assessing the 3D sities. VAS scores and Japan Orhthopaedic anatomy of the S1 foramen. Quantitative Association Back Pain Evaluation Question- analysis indicates that a fluoroscope should naire (JOABPEQ) responses were assessed be aimed 39.3 ± 7.0 mm caudal and 3.5 ± before and 1 mo after the PGB treatment 3.7 mm lateral from the center of the L5 was initiated. JOABPEQ is a novel, validated pedicle to perform an S1 NRB under fluoro- method for evaluating the degree of low scopic guidance. The present findings may back pain (LBP) based on the Roland-Morris be useful when performing an S1 NRB. Disability Questionnaires and Short Form 36 containing the following 5 subscores: pain- GP153 related disorders (PD), gait disturbance CLINICAL EVALUATION OF PREGABALIN (GD), lumbar spine dysfunction (LD), social FOR LUMBAR CANAL STENOSIS PATIENTS life disturbance (SD), and psychological dis- WITH PERIPHERAL NEUROPATHIC PAIN orders (PD). Sumihisa Orita, Gen Inoue, Kazuyo RESULTS: Fifty-seven LSS patients were as- Yamauchi, Hiroto Kamoda, Masayuki sessed (ave. 71.0 yo). The use of PGB signifi- Miyagi, Tetsuhiro Ishikawa, Miyako Suzuki, cantly decreased their VAS scores (P < 0.01). Yoshihiro Sakuma, Go Kubota, Yasuhiro With respect to JOABPEQ, PD(P < 0.01), Oikawa, Kazuhide Inage, Takeshi Sainoh, Jun LD(P = 0.031), GD(P = 0.028), and PD(P = Sato, Yukio Nakata, Kazuhisa Takahashi, 0.014) showed significant improvement Seiji Ohtori after PGB treatment. Complications such as Department of Orthopaedic Surgery, School dizziness or nausea were not observed dur- of Medicine, Chiba University, Chiba, Japan 207

GENERAL POSTERS ing the study. alent at L5-S1 (31.3%) and L4-L5 (24.3%). CONCLUSION: PGB can alleviate the pain Based on an adjusted multivariate model, and improve LBP-related factors such as PD, DBE (OR: 1.36; 95% CI: 1.15-1.60), females LD, GD, and PD in LSS patients with NeP (OR: 1.38; 95% CI: 1.17-1.64), obesity (OR: symptoms. 1.68; 95% CI: 1.25-2.24), and moder- ate/heavy workload (OR:1.74; 95% CI: 1.11- 2.74) were associated with sciatica. Subjects GP154 with sciatica reported worse SF-36 and ODI EPIDEMIOLOGY, DETERMINANTS, AND functional outcomes (p<0.05). FUNCTIONAL STATUS OF SCIATICA: A DISCUSSION: This is one of the largest LARGE-SCALE POPULATION-BASED STUDY population-based studies to assess de- IN CHINESE mographics, environmental/lifestyle, func- (1) Dino Samartzis, (2) Jaro Karppinen, (1) tional, and imaging factors in relation to the Keith DK Luk, (1) Kenneth MC Cheung development of self-reported sciatica. DBE, (1)Department of Orthopaedics and females, obesity, and moderate/heavy Traumtology, University of Hong Kong, workload were significant determinants Pokfulam, Hong Kong, SAR China (2) De- associated with sciatica. Decreased func- partment of Physical and Rehabilitation tional status was also more prevalent in Medicine, University of Oulu, Finland sciatica subjects.

INTRODUCTION: The prevalence, risk fac- tors, and outcomes of sciatica have been GP155 sporadically reported in the literature, CHANGES IN OBJECTIVELY MEASURED largely patient-based and mainly related to WALKING CAPACITY OVER A 2 YEAR PERI- Caucasians. The following study addressed OD IN INDIVIDUALS WITH LUMBAR SPINAL the epidemiology, determinants, and func- STENOSIS tional status of sciatica within a Chinese Christy C. Tomkins-Lane,* Michele C. Battie population. ** METHODS: A cross-sectional population- * Mount Royal University, Calgary, Canada based study of 2,597 Southern Chinese was ** University of Alberta, Edmonton, Canada performed assessing sagittal T2-weighted lumbar MRIs for the presence of radio- INTRODUCTION: Walking capacity is recog- graphic findings from L1-S1 (e.g. HIZ, Modic nized as a key outcome in people with lum- changes, Schmorl's nodes). A summated bar spinal stenosis (LSS). The majority of disc bulge/extrusion (DBE) score was ob- studies investigating walking in LSS have tained of all levels. Self-reported sciatica used inaccurate self-report tools. Little is during the past year was assessed. Subject known about long term changes in objec- demographics, environmental/lifestyle fac- tively measured walking. tors, and functional status (i.e. SF-36, ODI) OBJECTIVE: Assess changes in objectively were also assessed. measured walking capacity over 2 years in RESULTS: There were 60% females and 40% people with LSS. Methods: Of 49 subjects males (mean age: 42 years). The overall enrolled in a study of walking in LSS, we prevalence of sciatica was 39.4%, which were able to follow 26. All subjects had LSS increased with progression of each age cat- diagnosed by a spine surgeon, confirmed on egory (p=0.005). An elevated DBE score was imaging. At baseline and 2 yrs subjects found in subjects with reported sciatica completed a Self-Paced Walking Test, and a (mean: 0.80) compared to those without questionnaire. At follow-up they indicated (mean: 0.63) (p<0.001). DBE was most prev- treatments accessed over the 2 yr period. 208

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For analysis subjects were divided into sur- by the A118G polymorphism in the opioid gical, non-surgical treatment, and no treat- receptor Mu 1 gene is reported to affect ment groups. postoperative outcome. However, it is un- RESULTS: The 26 subjects had a mean base- clear whether this is true for lumbar spine line age of 68.4(9.2) and 65% were female; surgery. The purpose of this study was to 11 had surgery over the 2 year period, while prospectively evaluate whether preopera- 8 had some form of non-surgical treatment tive opioid sensitivity alters postoperative and 7 had no treatment of any kind. The outcome in patients undergoing lumbar only significant difference between groups spine surgery. for baseline walking was between the sur- METHODS: Subjects included 22 patients gery and no treatment groups. Over the 2 suffering from low back pain (LBP) and radi- yrs, the surgery group had a non-significant ated leg pain who were treated with opioids increase in capacity from 871m(867) to (fentanyl or tramadol) at our hospital from 1402(1009), the non-surgical treatment September 2009 to August 2012. Cases in- group had a significant decrease from cluded 4 lumber disc herniation and 18 1868m(907) to 960(783), and subjects who lumbar spinal stenosis patients who under- had no treatment showed no change went posterior lumbar discectomy and pos- (1463m(839) to 1301(974)). terior lumbar decompression accompanied DISCUSSION: Individuals who elected to by instrumented posterolateral fusion, re- have surgery had lower baseline walking spectively. We evaluated their LBP and leg capacity compared to those who had no pain improvement rate on the visual analog treatment. A significant decrease in walking scale (VAS) in response to opioids before was observed for the 8 subjects who had and after surgery. Patients were divided non- surgical intervention, yet despite a into two groups according to their response similar baseline capacity, the 7 subjects who to presurgical opioid administration: higher had no treatment showed relatively stable improvement rate on VAS (>50%; HR group) walking capacity over 2 years. Given the and lower improvement rate (<50%; LR observational nature of this study, we can group). Symptoms are indicated by a sub- make limited conclusions regarding compar- script “LBP” or “LEG” (leg pain). ison of treatments. However, these results RESULTS: For LBP, the HRLBP group showed may aid us in better understanding the na- 58.6% postsurgical improvement, while the ture of walking limitation in LSS. LRLBP group experienced 28.3% improve- ment; this difference was statistically signif- icant (P<0.05). For leg pain, the HRLEG GP156 group showed 64.3% postsurgical improve- OPIOID SENSITIVITY AFFECTS POSTOPERA- ment, while the LRLBP group experienced TIVE OUTCOME IN LUMBAR SPINE SUR- 32.7% improvement; this difference was not GERY statistically significant. Kazuhide Inage. Sumihisa Orita. Kazuyo DISCUSSION: Higher opioid sensitivity was Yamauchi. Miyako Suzuki. Yoshihiro Sa- indicative of significantly higher postsurgical kuma. Go Kubota. Yasuhiro Oikawa. Takeshi improvement in LBP, while no such associa- Sainoh. Jun Sato. Kazuhisa Takahashi. Seiji tion was observed for leg pain. The results Ohtori. of the present study suggest that the inten- Dept. of Orthopaedic Surgery, Graduate sity of LBP derived from lumbar disorders School of Medicine, Chiba University can be associated with altered opioid sensi- tivity. This implies that preoperative opioid

INTRODUCTION: Opioid sensitivity altered sensitivity can be a potential predictive fac-

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GENERAL POSTERS tor for postsurgical outcome. bilateral L1 to L6 DRGs and spinal cord. The CGRP expression in FG-labeled DRG neu- rons, Iba-1 (a marker of microglia) expres- GP157 sion in spinal dorsal horn were statistically CHARACTERISTICS OF PAIN-RELATED SEN- examined between the two groups using SORY INNERVATION ON OSTEOPOROTIC immunofluorescence. LUMBAR VERTEBRAE WITH RESULTS: The proportions of FG-labeled OVARIECTOMIZED RATS. CGRP immunoreactive (-ir) DRG neurons in Miyako Suzuki*1, Sumihisa Orita*1, Gen the OVX group were significantly elevated Inoue*2, Masayuki Miyagi*1, Tetsuhiro Ishi- compared with the control (p < 0.05). Fur- kawa*1, Hiroto Kamoda*1, Yawara thermore, the proportion of Iba-1-ir neu- Eguchi*1, Gen Arai*1 ,Kazuyo Yamauchi*1, rons in the dorsal horn of spinal cord were Yoshihiro Sakuma*1, Go Kubota*1, Yasuhiro also significantly increased in the OVX group Oikawa*1, Kazuhide Inage*1, Takeshi (p <0.05). Sainoh*1, Kazuhisa Takahashi*1, Seiji DISCUSSION: The result of the present Ohtori*1 study suggested that osteoporotic state *1 Department of Orthopaedic Surgery, might increase CGRP expression in DRG Graduate School of Medicine, Chiba neurons innervating L3 vertebrae and mi- University, Chiba, Japan *2 Department of croglial activation in spinal dorsal horn, im- Orthopaedic Surgery, Kitasato University plying that the central nervous system may School of Medicine be activated as well as peripheral in osteo- porosis rats. That should be lead to clarify INTRODUCTION: Osteoporotic patients the pathology of osteoporotic pain. without fractures sometimes experience chronic low back pain of unknown origin. We have previously reported that the ex- GP158 pression of calcitonin gene-related peptide SEVERE SCOLIOSIS DURING ADULTHOOD: (CGRP), a marker of inflammatory pain, is IS SURGERY THE ONLY POSSIBLE TREAT- increased in dorsal root ganglia (DRG) neu- MENT? rons innervating lumbar vertebrae of osteo- Fabio Zaina*, Alessandra Negrini*, Silvana porotic rats. However there is few evicence Parzini*, Michele Romano*, Salvatore what is happening in the osteoporotic spinal Atanasio*, Stefano Negrini+ dorsal horn where microglia is activated in a *ISICO, Milan,Italy; +Don Gnocchi Founda- state of chronic neuropathic pain. The pre- tion, Brescia University, Italy sent study aimed to examine the character- istics of pain-related sensory inervation in INTRODUCTION: Surgery is generally con- rat osteoporotic lumbar vertebrae in their sidered the only approach for worsening DRG and spinal dorsal horn. asult scoliosis. Nevertheless there are pa- MATERIALS AND METHODS: As an osteopo- tients who cannot undergo surgery for poor rosis group(OVX group), we used 21-weeks- general health condition or who are willing old female rats ovariectomized at 5 weeks not to be fused. An evidence based treat- (n=20). As the control group, sham- ment for these patients is necessary. In our operated rats without ovariectomy were facility we treat adult scoliosis patients with used (n=20). Fluoro-Gold (FG), retrograde specidic exercise to avoid/stop progression. neurotracer, was applied into the myeloid The aim of this study is to report our results of L3 to label DRG neuronal cells innervating in a cohort of patients the vertebra. Four weeks after the FG- METHODS: Population: Thirty one patients labeling, the animals were killed to resect (3 males) of 38 ± 11 years and 55 ± 14° Cobb 210

GENERAL POSTERS scoliosis, treated for 3 (range 1–18) years diffusion weighted imaging (DWI), which because of progression subjectively per- can be examined within a short time, in ad- ceived (17 patients), or objectively docu- dition to conventional MRI. The purpose of mented (14 patients: subgroup A, previous this study was to evaluate the usefulness observation of 10 years, range 1–27), have and the limit of DWI for lumbar diseases. been included. 6 patients (sub-group B) METHODS: One-hundred fifty two consecu- were observed also after stopping treat- tive patients, who were performed MRI and ment for 6 (3–10) years. Patients were DWI (1.5-T, b-value 400, imaging time treated according with a scoliosis specific 86seconds) in Jan 2012 for lumbar diseases exercise protocol (SEAS). were included. One spine surgeon and one RESULTS: Exercises caused a statistically radiological technician interpreted DWI and significant decrease of 3.6 ± 5° of scoliosis (- recorded the abnormality findings of nerve 3.2 ± 4.3° per year): 1 patient progressed, root as follows; swelling, stoppage and de- 45% improved; in sub-group A results were viation of the runway of nerve root. In addi- identical, after a previous worsening of 9.7 tion, the high intensity of tissues around ± 6.8° (+2.1 ± 4.3° per year); in sub-group B nerve was recorded. When both viewers’ stopping exercises caused a progression of findings coincided, they were defined to be 8.3 ± 3.8° (+1.4 ± 0.5° per year). The best DWI positive. Neurological symptoms and results were observed in patients exercising diagnosis were checked by a medical record since, even if some patients continued to and MRI, so that its sensitivity and specifici- decrease their curve during the years. ty were evaluated. CONCLUSION: SEAS exercises revert the RESULTS: One-hundred forty four patients progression of adult scoliosis, and a pro- were able to be interpreted (84 men and 60 spective study is already under way. The women). Mean age was 56 (range: 14 to different results according to length of 84). There were 56 lumbar disc herniation treatment could be due to a plateau of cor- patients (lateral type 5 patients), spinal ca- rection or to an increase of quality of the nal stenosis 25, spondylolisthesis 20, com- protocol applied (SEAS changes continuous- pression fracture 13, foraminal stenosis 5, ly according to new nowledge in the litera- spondylolysis 5, and normal findings were ture). These results question the immediate 20 patients. 100 patients had unilateral or need for surgery when facing progression of bilateral sciatica. DWI positive were 33 pa- deformity in adulthood. tients. The sensitivity of DWI positive to sciatica was 36% and specificity was 20%, therefore it was not useful. However, as to GP159 lateral disc herniation and foraminal lesions, A STUDY ON DIFFUSION WEIGHTED IMAG- sensitivity was 86% and specificity was 80%. ING FOR LUMBAR DISEASES ~ITS USEFUL- In addition, 2 spondylolysis and 2 metastatic NESS AND LIMIT ~ tumors were detected. Hatakeyama Kenji, Ato Shogo, Aihara Takato, Urusibara Makoto Funabashi Orthopedic Hospital

INTRODUCTION: Conventional MRI is very useful for lumbar diseases, but it is often not sensitive for intra- and extra foraminal lesions. Since Jun.2011, we are trying to picturize the nerve root lesions by using

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week, and if they still had LBP, we per- formed CT and/or MRI. Spondylolysis were divided into three stages; early, progressive, terminal stage. RESULTS: Of the 94 subjects, 68 athletes remained LBP. The number of spondylolysis was 42 (44.7%), lumbar disc herniation was 18 (19.1%), fatigue fracture of sacrum was 1 (1.1%), and 6 (3.2%) were unable to be di- agnosed. Of 42 spondylolysis, early stage was 26, progressive 10, terminal 6. The number of the subjects who became pain free after rest, was 28, and they resumed athletic training with no difficulty. As to the DISCUSSION: DWI in our hospital is able to clinical findings, when there were both LBP be performed for short time enough to be on extension and facet joint tenderness, the added to conventional MRI examination. It sensitivity and specificity for spondylolysis was useful for intra- and extra foraminal was 95.2% and 53.8% respectively. For lum- lesions but not for in spinal canal les bar disc herniation, LBP on flexion was 88.9% and 60.5% respectively. CONCLUSION: In this study, spondylolysis GP160 caused LBP in 44.7% of young athletes. The LOW BACK PAIN IN YOUNG ATHLETES AND findings of LBP on extension and tenderness THEIR EXAMINATION FINDINGS on facet joint were very important for diag- Hatakeyama Kenji, Ouchi Juntarou, Aihara nosis of spondylolysis. When you examine Takato, Urusibara Makoto young athletes with low back pain, you have Funabashi Orthopedic Hospital to think of spondylolysis and record these findings. INTRODUCTION: Many young athletes come to our hospital suffering low back pain (LBP). Their etiology is often different from GP161 that of adult’s, of which over 80% is non- FACTORS ASSOCIATED WITH PARASPINAL specific; on the contrary, young athletes’ MUSCLE ASYMMETRY IN A GENERAL LBP is considerably due to lumbar POPULATION SAMPLE OF MEN. spondylolysis. Maryse Fortin, BSc, CAT(C), PhD Candidate, OBJECTIVES: The purpose of this study was Faculty of Rehabilitation Medicine, Universi- to investigate the etiology of young ath- ty of Alberta Michele C. Battie, PhD, De- letes’ LBP and to evaluate the usefulness of partment of Physical Therapy, University of examination findings. Alberta METHODS: From 2010.1, we prospectively Faculty of Rehabilitation Medicine, Universi- investigated a total of 94 young athletes ty of Alberta, Edmonton, AB, Canada with LBP (54 men and 40 women; mean age; 14.9 years; range 12 to 18). We evalu- INTRODUCTION: Paraspinal muscle asym- ated them at their first visit with following metry in cross-sectional area (CSA) and findings; LBP 1) on flexion and 2) on exten- composition (e.g. fatty infiltration) have sion in standing position, 3) tenderness on been associated with low back pain (LBP) facet joint, 4) straight leg raising (SLR) test. and pathology. Yet, substantial multifidus We restricted their sport activities for one asymmetry has also been reported in 212

GENERAL POSTERS asymptomatic men and little is known about other factors influencing asymmetry. GP162 The goal of this study was to identify a THE USA FUNGAL MENINGITIS OUTBREAK range of behavioral, environmental and AFTER EPIDURAL STEROID INJECTIONS: constitutional factors associated with THOUGHTS ON EPIDEMIOLOGY AND FU- paraspinal muscle asymmetry. TURE PATIENT SAFETY METHODS: A cross-sectional study of a gen- David A Wong MD, MSc, FRCS(C) eral population sample of 202 adult male Co-Chairman NASS Patient Safety Commit- twins was conducted. Data were collected tee through a structured interview, physical examination and MRI. Multifidus and erec- INTRODUCTION: The September 2012 out- tor spinae CSA (muscle size), and the ratio break of fungal meningitis in the United of fat-free CSA to total CSA (muscle compo- States following epidural steroid injections sition) measurements were obtained from (ESI) has raised a number of issues concern- T2-weighted axial images at L3-L4 and L5-S1 ing the epidemiology of the infection and spinal levels. future patient safety. RESULTS: In multivariable analyses, greater METHODS: The Patient Safety Committee of asymmetry in multifidus CSA (size) at L3-4 the North American Spine Society (NASS) was associated with less occupational phys- has liased with the US Centers for Disease ical demands and disc narrowing. No factors Control (CDC) through the outbreak. CDC studied were associated with multifidus CSA and various state department of health asymmetry at L5-S1. For erector spinae, websites were monitored to follow the in- greater age and disc narrowing were associ- vestigation. Literature on complications of ated with CSA asymmetry at L3-4 and sports ESI's was reviewed. activity, disc narrowing and familial aggre- RESULTS: Recent CDC data indicates 461 gation at L5-S1. In multivariable analyses of cases of meningitis from approximately asymmetry in muscle composition, familial 14,000 injections/exposures. This translates aggregation was associated with side to side to an infection rate of approximately 3%. differences in multifidus and erector spinae There have been 32 deaths. The CDC has at both levels measured, explaining 9-17% suggested that the epidemiology is inocula- of the variance. Sports activity and pain se- tion of the epidural space from an ESI, com- verity also entered the model for erector promise of the immune system from the spinae asymmetry at L5-S1, and disability systemic steroid effect and the fungus even- and disc narrowing for multifidus at L5-S1. tually "boring" through the dura to infect CONCLUSION: Few of the factors investigat- the CSF causing meningitis. ed were associated with paraspinal muscle DISCUSSION: Questions arise whether there asymmetry, and associations were generally is an alternate explanation to the epidemi- modest, explaining little of the variance in ology suggested by the CDC. A literature paraspinal muscle asymmetry. With the review indicates that the accepted rate of exception of familial aggregation, and disc inadvertent intrathecal injection is about 3% narrowing to a lesser degree, associated . This is similar to the rate of meningitis in- factors were not consistent across muscles fection after ESI with tainted methylpredni- or spinal levels. solone. Thus, one explanation for the epi- demiology of the meningitis would be that we are seeing infections develop as a result of the expected incidence of transdural in- jection with ESI's. Other technical issues include whether there is a higher rate of 213

GENERAL POSTERS infections using a sharper Quincke needle returned to the operating room when using versus a duller Tuohy, if use of fluroscopy the O-arm to assess the placement of pedi- allows more precise needle placement, cle screws. Based on the 1% rate of return- whether multiple ESI's are a risk factor to ing to the operating room for pedicle screw infection and whether a transforaminal ESI revision in the control group, the annual has a lower rate of infection compared to rate of cases nationwide requiring pedicle translaminar. These questions will hopefully screw revision would be approximately be clarified as the investigation proceeds. 2300 with a cost of approximately The answers will assist in deciding on the $40,595,000. safest injection techniques for our patients DISCUSSION: These results suggest that the into the future. use of intraoperative CT can reduce the need for return to the operating for revision of a breeched pedicle screw. This can po- GP163 tentially lead to a major cost savings. REDUCTION OF SURGICAL REVISION RATES AND ECONOMIC ANALYSIS OF USING AN INTRAOPERATIVE CT-BASED NAVIGATION GP164 SYSTEM FOR PEDICLE SCREW PLACEMENT ROD BREAKAGE AFTER LONG CONSTRUCT Scott D. Hodges, DO; Jason C. Eck, DO, MS; FUSION IN SPINAL DEFORMITY: CLINICAL Dannette Newton, MS AND RADIOGRAPHIC RISK FACTORS Center for Sports Medicine and Orthopae- Akazawa, Tsutomu; Kotani, Toshiaki; dics, Chattanooga, TN Sakuma, Tsuyoshi; Nemoto, Tetsuharu; Sato, Yusuke; Kitamura, Mitsuhiro; Minami, INTRODUCTION: Incidence of pedicle screw Shohei; Ohtori, Seiji; Takahashi, Kazuhisa. breech varies based on anatomic location, Seirei Sakura Citizen Hospital, Dept. body habitus, surgeon experience, spinal Orthopedic Surgery, Sakura, Japan; Chiba deformity, and surgical technique. Pedicle University, Graduate School of Medicine, breeches have been reported to occur in up Dept. Orthopedic Surgery, Chiba, Japan. to 40% of screws. The purpose of the cur- rent study was to compare the rates of re- INTRODUCTION: The aim of this study was turning to the operating room for revision to analyze clinical and radiographic risk fac- of pedicle screw placement when using C- tors of rod breakage after long construct arm versus O-arm assessment of pedicle fusion in spinal deformity. screws. METHODS: The survey subjects were 155 METHODS: A retrospective study was per- cases who were diagnosed with spinal de- formed to determine the rates of returning formity and underwent correction and fu- to the operating room for revision of a sion surgery with long construct instrumen- breeched pedicle screw when using C-arm tation (>3 levels, average 10.3 levels) be- versus O-arm visualization. An economic tween July 2004 and June 2010. The sub- analysis was also performed based on esti- jects comprised 32 males and 123 females mated cost of return to the operating room with a mean age of 19.0 (range 8-78) years. for revision of the pedicle screws. The mean follow-up period was 46.1 RESULTS: There were 4 (1%) of 386 control months (range: 24-94 months). All patients cases that required a return to the operat- were examined for rod breakage in x-rays at ing room for pedicle screw revision for a a follow-up visit. Univariate analysis and breeched pedicle screw not identified with logistic regression analysis were performed. intraoperative C-arm fluoroscopy. In the RESULTS: Rod breakage occurred in 8 of 155 study group none of the 331 patients were cases (5.2%). The mean period from surgery 214

GENERAL POSTERS to rod breakage was 18.1 months (range 2- we assessed fusion rate and clinical results 37). Six patients had breakage near the of FF. fused lower end and two patients had it at METHODS: Forty-eight patients who un- the thoracolumbar junction. The clinical derwent FF for single-level DLS were retro- symptoms were pain in 2 patients and a spectively reviewed at a minimum one year breaking sound of a crack in 2 patients. follow-up. They consisted of 27 women and There was no symptom in 4 patients. 21 men with an average age of 68.4 years. Univariate analysis revealed that non- In our surgical method, we added 5cm skin ambulatory status, preoperative kyphosis, incision, bilateral laminar fenestration and small diameter rods, multiple surgeries, and FF with autologous bone harvested from use of iliac screws were significant risk fac- spinous process. Then, pedicle screws were tors in rod breakage. Sex, obesity, severity inserted bilaterally by minimum access of preoperative scoliosis, and rod material technique. were not significant risk factors. Logistic We evaluated facet fusion rate by comput- regression analysis revealed that the follow- ed tomography (CT), range of motion (ROM) ing were risk factors for rod breakage: use at the fused level on a flexion-extension of iliac screws (odds ratio: 81.9, 95% confi- lateral X-ray preoperatively and at the final dence interval: 7.2-935.0, p<0.001) and follow-up, and therapeutic effectiveness of small diameter rods (diameters of less than FF using Japanese Orthopaedic Association 6 mm) (odds ratio: 16.3, 95% confidence Back Pain Evaluation Questionnaire interval: 1.7-152.6, p=0.015). (JOABPEQ). DISCUSSION: The incidence of rod breakage RESULTS: The facet fusion rate was 83.3% of after long construct fusion in spinal deform- patients. ROM at fused level was less than ity was 5.2%. Iliac screw fixation and small two degrees at the final follow-up in all the diameter rod were risk factors for rod patients whose facets were sufficiently breakage. fused on CT. In eight patients whose facet fusion wasn’t sufficient, the average ROM significantly decreased to 3.8 degrees, GP165 whereas it was 13.4 degrees preoperatively. GOOD FUSION RATE AND CLINICAL RE- The percentage of the patients who showed SULTS OF LESS INVASIVE FACET FUSION therapeutic effectiveness in JOABPEQ were WITH SEXTANT PEDICLE SCREW SYSTEM 92.7% in Walking ability and 75.0% in Low FOR DEGENERATIVE LUMBAR back pain. SPONDYLOLISTHESIS DISCUSSION: Park et al reported FF alone is Tomohiro Miyashita *1, Hiromi Ataka *2, an effective surgical option for DLS. Howev- Takaaki Tanno *2 er, in their method, a bone graft was har- *1: Spine Center, Matsudo City Hospital, vested from the iliac crest and conventional Matsudo, Japan *2: Spine Center, Matsudo pedicle screw system was used. We devised Orthopaedic Hospital, Matsudo, Japan less invasive FF using local bone graft and SEXTANT system. The fusion rate and the INTRODUCTION: After a long clinical and clinical results of FF compared well with radiological follow-up study of those of conventional PLF. Thus, FF is a use- posterolateral fusion (PLF) for degenerative ful technique for DLS. lumbar spondylolisthesis (DLS), we recog- nized that facet fusion (FF) alone would be sufficient for spinal fusion. We devised a new, simple, less invasive FF using SEXTANT pedicle screw system for DLS. In this study,

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in Table. All measurements reached statisti- GP166 cal significance. INTEROBSERVER RELIABILITY OF CT SCANS TO ASSESS RADIOGRAPHIC FUSION CRITE- RIA WITH A NOVEL TITANIUM INTERBODY DEVICE Paul J. Slosar MD; Jay Kaiser MD; Luis Mar- rero MD; Damon Sacco MD SpineCare Medical Group/ San Francisco Spine Institute DISCUSSION: Clinicians have been reluctant to rely on CT scans with titanium devices

INTRODUCTION: The accuracy of CT scans due to concerns that the interpretation of of titanium implants to assess lumbar the images may be inaccurate. This device interbody fusion has been questioned in the demonstrated minimal artifact, minimal past. Published reports have focused on subsidence, and trabecular bone was easily older cage technologies. Radiologists report identified through the implant in the majori- difficulty assessing fusion bone due to arti- ty of cases. Our study confirms radiographic fact and small graft windows. A new titani- fusion criteria can be assessed with high um interbody implant has been developed interobserver reliability with this new tita- with a large footprint and wide aperture for nium implant. graft. Purpose: To determine the interobserver reliability of CT scans to as- GP167 sess radiographic fusion variables with a MICROENDOSCOPIC DISCECTOMY FOR new titanium interbody device. LUMBAR DISC HERNIATION: DOES THE METHODS: Patients underwent ALIF at L3- INSTABILITY AFFECT THE LOW BACK PAIN? S1 as part of a separate clinical outcomes Takato Aihara, Kenji Hatakeyama, Makoto study. All patients received the same im- Urushibara, and Juntaro Ouchi plant type (Endoskeleton TA®; Titan Spine.). Dept. of Orthopedic Surgery, Funabashi Each cage was packed with 2 sponges of Orthopedic Hospital, Funabashi-city, Japan InFuse® (Medtronic) plus 1-3 cc of HA/ TPC

(MasterGraft®). CT scans with reconstructed INTRODUCTION: This study was undertaken images were performed randomly at 6, 9, or to determine the influence of instability on 12 months. Two independent radiologists low back pain (LBP) after microendoscopic reviewed the scans and were blinded to the discectomy (MED) for lumbar disc herni- other’s interpretation. Interobserver relia- ation (LDH). bility was calculated using the kappa statis- METHODS: MED was used to treat LDH in tic. 42 patients, and the intensity of their leg RESULTS: 33 patients/ 56 spinal fusion seg- pain, leg numbness, and LBP measured on a ments were analyzed. 17 had CT at 6 visual analogue scale (VAS) was recorded months, 9 at 9 months, 7 at 12 months. No before and after MED. The degree of im- differences in results were noted between provement (DOI) was calculated by the fol- time points. Kappa coefficient was calculat- lowing formula: preoperative score - post- ed separately for each variable. The kappa operative score, and the patients were clas- for the overall study was 0.88 (p<.001) sified into two groups based on the DOI in demonstrating agreement between the 2 LBP concerning VAS: a group whose DOI radiologists in 345 of the 392 data points was more than twenty (M group) and a reviewed. The agreement for fusion for- group whose DOI was less than twenty (L mation was 0.77 (p<.001). Other criteria are 216

GENERAL POSTERS group). Clinical outcomes were evaluated and postoperative translation in flexion and using the Japanese Orthopaedic Association extension in the L group had slipped signifi- Back Pain Evaluation Questionnaire cantly posteriorly in comparison with the M (JOABPEQ). Lateral radiographs in maximal group (Fig.) flexion and extension, and in neutral posi- DISCUSSION: From the results of this study, tion were obtained before and after MED to the large posterior translation in flexion and measure the intervertebral angle and hori- extension could lead to poor improvement zontal displacement (translation) in flexion in LBP after MED. These findings suggest and extension, and to measure the disc that posterior translation in flexion and ex- height of the affected intervertebral space. tension may be a cause of LBP in LDH. Using MRI, disc degeneration was also graded. All measurements and DOIs were statistically compared by unpaired t test GP168 between the M and L groups. INFECTION RATE AND COMPLICATIONS FOLLOWING ASSOCIATED WITH EPIDURAL STEROID PASTE USED IN POSTERIOR LUMBAR SURGERY - A CASE-CONTROLLED REVIEW Eva U Asomugha, M.D., Robert F McLain, M.D., Cleveland Clinic Center for Spine Health, and Cleveland Clinic Department of Orthopaedic Surgery

INTRO: The use of various epidural agents to reduce postoperative pain and inflamma- tion following lumbar surgery is common. These agents are typically administered as steroid and/or analgesic laced paste, spong- es, or foams. Studies have shown the effica- cy in reducing pain and narcotic usage acutely with minimal adverse effects. How- ever, Kramer found a nearly 8-fold increase in surgical site infections (SSI) after laminec- tomy when a morphine-prednisolone nerve paste was used. We tested the hypothesis that a steroid containing epidural pain paste, applied after laminotomy, does not increase risk of acute SSI.

METHODS: A case-controlled retrospective RESULTS: The DOIs in LBP concerning VAS review of patients treated by lumbar de- and JOABPEQ were significantly greater in compression, either with or without analge- the M group (n=19) than in the L group sic steroid paste, was done. Demographic (n=23). There were no statistically signifi- characteristics including age, gender, BMI, cant differences between the two groups in smoking and alcohol status, and type of DOI in leg pain or leg numbness concerning operation were analyzed. VAS, nor in DOIs in the other four functional Acute SSI were defined as any infection scores concerning JOABPEQ. Preoperative within the first six weeks postoperatively. 217

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Late infections were not encountered. SSI METHODS: Data from the Nationwide Inpa- was coded as superficial, deep-suprafascial, tient Sample database was obtained from or deep-subfascial. 2002-2009. Patients undergoing anterior or RESULTS: We analyzed 62 consecutive pa- posterior cervical fusions (ACF/PCF), anteri- tients with no paste, and 61 patients receiv- or or posterior lumbar fusions (ALF/PLF), or ing pain paste. Male patients represented thoracic fusions were identified and BMP 57. 4% in the paste group and 66.1% in the use was examined by year. Demographics, no paste group (p=0.32). The average age co-morbidities, costs (adjusted for inflation), of patients in the two groups was 49.8 and and mortality were assessed. Statistical 46.1 respectively (p=0.15). There were four analysis was performed using Pearson’s suspected or documented infections, (6.7%) correlation to assess for trends with a p- in the paste group, and one (1.67% [0.03%, value <0.01 to denote significance. 8.7%]) in the no paste group (p=0.21). One additional patient in the paste group had a slow healing wound. There were no wound complications in the no paste group. DISCUSSION: Our data does not demon- strate a statistical difference in the rates of infection with the use of an epidural steroid paste, but the observed three-fold increase in the rate is concerning. This trend neces- sitates a larger review, currently ongoing, which will allow better statistical certainty. For the moment we use no steroids in our paste.

GP169 EPIDEMIOLOGICAL TRENDS IN THE USE OF BONE MORPHOGENIC PROTEIN IN SPINAL FUSIONS FROM 2002-2009 RESULTS: An estimated 482,141 procedures Steven Fineberg MD*, Matthew Oglesby utilized BMP from 2002-2009 in the United BA*, Alpesh Patel MD^, Miguel Pelton BS*, States (Table 1). The number of procedures Kern Singh MD* per year that utilized BMP significantly in- *Rush University Medical Center, Chicago, IL creased from 1,734 in 2002 to 106,168 in ^Loyola University Medical Center, May- 2009 (p<0.0005, R=0.9). ALF had the highest wood, IL rates of BMP use, increasing to 53.9% of all ALFs in 2007 and then decreasing to 50.2% INTRODUCTION: The use of bone in 2009 (Figure 1). PLFs accounted for the morphogenic proteins (BMP) as an adjunct majority of cases that used BMP with to spinal fusion has increased since first 290,237 cases from 2002-2009. There was a approved for use in anterior lumbar significant trend of older patients with in- interbody fusions in 2002. The purpose of creasing co-morbidities receiving BMP dur- this study was to analyze a population- ing this time period. Hospital costs signifi- based database to describe national trends cantly increased an average of $5,875 from of BMP use in terms of incidence, de- 2002-2009 (Table 2). Mortality did not mographics, costs and mortality. change with utilization of BMP from 2002-

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2009. The mean pre-operative CCI increased from DISCUSSION: Our study demonstrates that 4.59 in 2004 to 5.06 in 2009 the use of BMP has dramatically increased (p<0.0005)(Table 1). from 2002-2009. Off-label use of BMP ac- Mean in-hospital costs significantly in- counts for the vast majority of BMP utiliza- creased from $12,815 in 2004 to $16,853 in tion. The increase in costs from 2002-2009 2009 (p=0.006). Mortality did not change is likely multi-factorial; older patients with across this time period (p=0.32). Predictors more co-morbidities undergoing surgery as of mortality in patients undergoing well as increasing use of BMP are likely to kyphoplasty were metastatic cancer, flu- affect costs. Further studies are needed to id/electrolyte disorders, congestive heart identify long-term outcomes of BMP use in failure, pulmonary circulation disorders, spinal fusions renal failure, and weight loss.

GP170 EPIDEMIOLOGICAL TRENDS IN KYPHOPLASTY PROCEDURES BETWEEN 2004-2009 Steven Fineberg MD*, Miguel Pelton BS*, Alpesh Patel MD^, Matthew Oglesby BA*, Kern Singh MD* *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, May- wood, IL DISCUSSION: Our study demonstrates that kyphoplasty procedures have increased in INTRODUCTION: Kyphoplasty was intro- incidence from 2004-2009. We identified a duced as a minimally invasive procedure to trend of older patients with increasing co- treat vertebral compression fractures with morbidities undergoing kyphoplasty. Mor- deformity. The purpose of this study was to tality has not changed despite the increas- analyze a population-based database to ing co-morbidity of patients. This patient describe national trends of kyphoplasty population also incurred increasing hospital- procedures in the United States. ization days and costs which may be due to METHODS: Data from the Nationwide Inpa- increasing chronic illnesses. Patients with tient Sample database was obtained from mortality risk factors indicative of chronic 2004-2009. Patients undergoing illness should be carefully followed for kyphoplasty for the diagnosis of pathologic complications in the peri-operative period fractures of the thoracolumbar spine were after kyphoplasty procedures. identified. Demographics (gender, age, and race), Charlson Co-morbidity Index (CCI), costs (adjusted for inflation), and mortality GP171 were assessed. Statistical analysis was per- TRENDS IN COMPLICATIONS AFTER LUM- formed using Pearson's correlation to iden- BAR SPINE SURGERY FROM 2002-2009 tify trends. Logistic regression was per- Miguel Pelton BS*, Steven Fineberg MD*, formed to identify predictors of mortality. Alpesh Patel MD^, Matthew Oglesby BA*, RESULTS: The total number of patients un- Kern Singh MD* dergoing kyphoplasty increased from *Rush University Medical Center, Chicago, IL 44,459 in 2004-2005 to 85,530 in 2006-2007 ^Loyola University Medical Center, May- and then decreased to 76,583 in 2008-2009. wood, IL 219

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(p=0.02). INTRODUCTION: The frequency of compli- CONCLUSION: Our findings demonstrate cations after lumbar decompressions (LD) that from 2002-2009, patients undergoing and lumbar fusions (LF) varies widely in the lumbar procedures had increasing trends of reported literature. The purpose of this age and co-morbidities reflecting increases study was to analyze a population-based in surgical challenges and complexity. These database to describe national complication changes in patient demographics may ex- trends of these two procedures. plain the increasing complication rates after METHODS: Data from the Nationwide Inpa- LDs. Both groups demonstrated a trend of tient Sample database was obtained from increasing costs, which may be explained by 2002-2009. Patients undergoing LD or LF for increasing ages and co-morbidities of pa- degenerative etiologies were identified. tients as well as the increasing complication Eight categories of complications were rates. The complication rate in the LF group tabulated using ICD-9 codes including pul- was approximately double that of the LD monary embolism (PE), deep vein throm- group for all years. Despite a trend of in- bosis (DVT), infection, cardiac complica- creasing risk factors during this 8-year peri- tions, hematomas, CSF leaks, post-operative od, mortality did not change. shock, and neurologic complications. GP172 INCIDENCE AND MORTALITY OF THROM- BOEMBOLIC EVENTS AFTER LUMBAR SPINE SURGERY Steven Fineberg MD*, Matthew Oglesby BA*, Alpesh Patel MD^, Miguel Pelton BS*, Kern Singh MD* *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, May- wood, IL

INTRODUCTION: Pulmonary embolism (PE) and deep vein thrombosis (DVT) are poten- RESULTS: A total of 578,457 LDs and LFs tial complications of orthopaedic proce- were identified from 2002-2009 (Table 1). dures. Incidences of these complications are Both surgical groups demonstrated signifi- not well characterized after lumbar spine cant trends of increasing ages, co- surgery. A population-based database was morbidities, and costs during this time peri- analyzed to identify incidence, risk factors, od. LFs had higher complication rates at all and mortalities associated with lumbar de- time points compared to the LD group. compression (LD) and lumbar fusion (LF). There were significant trends in the LD METHODS: Data from the Nationwide Inpa- group of increasing overall complications: tient Sample database was obtained from specifically increasing rates of DVTs, infec- 2002-2009. Patients undergoing LD or LF for tions, hematomas (p<0.01). Increasing rates degenerative etiologies were identified. of post-operative shock from 2002-2009 Acute PE and DVT incidences and mortality was the only statistically significant trend in rates were calculated. Co-morbidities were the LF group (p=0.005), while increasing calculated using a modified Charlson Co- rates of DVTs approached significance morbidity Index. Statistical analysis using a

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GENERAL POSTERS p-value of <0.0005 was used to denote sta- tistical significance. Logistic regression was GP173 used to identify independent predictors of EPIDEMIOLOGICAL TRENDS IN LUMBAR thromboembolic events. SPINE SURGERY BETWEEN 2002-2009 RESULTS: A total 578,457 LDs and LFs were Steven Fineberg MD*, Matthew Oglesby identified from 2002-2009. DVT incidences BA*, Alpesh Patel MD^, Miguel Pelton BS*, were 2.4 and 4.3 per 1,000 cases in the LD Kern Singh MD* and LF groups respectively (Table 1). PE in- cidences were 1.0 and 2.6 per 1,000 cases in *Rush University Medical Center, Chicago, IL the LD and LF groups (Table 2). ^Loyola University Medical Center, May- LF patients with thromboembolic events wood, IL were younger, had less co-morbidity, and incurred higher costs than LD patients. Sta- tistically significant predictors of DVT were INTRODUCTION: Lumbar decompressions pulmonary circulation disorders, coagulopa- (LD) and lumbar fusions (LF) are routinely thy, fluid/electrolyte disorders, anemia, performed for lumbar degenerative pathol- obesity, teaching hospital status, and larger ogy. The purpose of this study was to ana- hospitals. Predictors for the development of lyze a population-based database to de- a PE were pulmonary circulation disorders, scribe national trends of these procedures fluid/electrolyte disorders, anemia, African- in terms of incidence, demographics, co- American ethnicity and teaching hospitals morbidities, cost and mortality. METHODS: Data from the Nationwide Inpa- tient Sample database was obtained from 2002-2009. Patients undergoing LD (i.e. laminectomy +/- discectomy) or LF for de- generative etiologies were identified. Co- morbidities were calculated using a modi- fied Charlson Co-morbidity Index (CCI). De- mographics, costs (adjusted for inflation), and mortality was also assessed. Statistical analysis was performed using Pearson’s correlation to assess trends. A p-value of p<0.01 was used to denote significance. status. RESULTS: The percentage of the population undergoing lumbar procedures did not DISCUSSION: Patients undergoing LD or LF change from 2002-2009 (p=0.789)(Table 1- are at inherent risk of thromboembolic adjusted for U.S. Census reported popula- events. DVT and PE are more common after tion). Patients undergoing LD decreased LF procedures. Pre-operative pulmonary 33% while LF surgeries increased 50% circulation disorders, fluid/electrolyte dis- throughout this time period (Figure 1). orders, deficiency anemia, and teaching The mean age of patients increased by 4.0 hospital status were significant risk factors years (p<0.0005). The mean pre-operative for both DVT and PE. Preventive measures CCI increased by 0.5 points (p<0.0005). This in patients at risk may decrease the inci- co-morbidity increase was due to an in- dence of thromboembolic events. creasing trend towards patients with colla- gen vascular disease, anemia, coagulopathy, diabetes, and hypertension. Hospital costs

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GENERAL POSTERS increased by $8,296 over the 8-year period tient Sample database was obtained from (p<0.0005). In-hospital mortality did not 2002-2009. Patients undergoing LD or LF for change significantly for any cohort. degenerative etiologies were identified. DISCUSSION: Our study demonstrates that Incidences of hematomas, neurologic com- the total number of lumbar procedures has plications, and mortalities were calculated. not changed over the 8-year period. There Co-morbidities were calculated using a was an overall trend towards more lumbar modified Charlson Co-morbidity Index. Sta- fusions and fewer decompressions per- tistical analysis was performed using p- formed. Mortality did not change despite an value <0.0005 to denote significance. Lo- aging population with greater medical co- gistic regression was used to identify inde- morbidities. There was a trend towards in- pendent predictors of hematoma and neu- creasing hospital costs despite decreasing rologic complications. hospitalizations in the lumbar fusion group which may be due to increased utilization of more expensive implants and biologics.

RESULTS: A total of 578,457 lumbar proce-

dures were identified in the database from GP174 2002-2009. Incidences of hematomas were RISK FACTORS FOR HEMATOMAS AND 6.3 and 14.1 per 1,000 cases for LD and LF NEUROLOGIC COMPLICATIONS AFTER groups, respectively (p<0.0005). Incidences LUMBAR SPINE SURGERY of neurologic complications were 7.6 and Matthew Oglesby BA*, Miguel Pelton BS*, 7.3 for LD and LF groups (p=0.152). In both Alpesh Patel MD^, Steven Fineberg MD*, surgical groups, patients who suffered from Kern Singh MD* both complications were older with more *Rush University Medical Center, Chicago, IL co-morbidities (p<0.0005). Independent ^Loyola University Medical Center, May- predictors of hematomas were emergent wood, IL admissions, Native-American ethnicity, pre- existing coagulopathy, paralysis, and flu- INTRODUCTION: Post-operative hemato- id/electrolyte disorders. Predictors for neu- mas and neurologic complications are po- rologic complications were emergent ad- tentially catastrophic events that can occur mission, female gender, pre-operative pa- after spine procedures. A population-based ralysis, obesity, and teaching hospital sta- database was analyzed to identify inci- tus. dence, mortality, and risk factors associated DISCUSSION: Our results identified that with these complications after lumbar de- older patients with more co-morbidity are compression (LD) and lumbar fusion (LF). at increased risks for hematomas and neu- METHODS: Data from the Nationwide Inpa- rologic complications. Our findings suggest

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GENERAL POSTERS patients undergoing LF have greater hema- 16.4 (per 1000 cases) for the LD and LF toma risk, whereas LD patients are more groups (p<0.0005). An increased rate of prone to neurologic complications. Patients SSIs, increased hospitalizations and costs undergoing LD or LF procedures with pre- was observed in LF patients over LD patients operative paralysis or obesity should be (p<0.0005). The most significant predictors counseled regarding these risks and warrant of SSI were anemia, drug abuse, liver dis- careful post-operative monitoring. ease, fluid/electrolyte disorders, and weight loss. GP175 INCIDENCE AND MORTALITY OF SURGICAL SITE INFECTIONS AFTER LUMBAR SPINE SURGERY Matthew Oglesby BA*, Miguel Pelton BS*, Alpesh Patel MD^, Steven Fineberg MD*, Kern Singh MD* *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, May- wood, IL

INTRODUCTION: Surgical site infections

(SSI) are a common complication after or- DISCUSSION: Our study demonstrates a thopaedic procedures. The incidence of SSI national incidence of 0.8% for SSI in patients in lumbar spine surgery has not been re- undergoing lumbar spine surgery. SSI's in ported in large patient populations. A popu- both surgical groups resulted in increased lation-based database was analyzed to iden- hospitalizations, costs, and mortality. The tify incidence, mortality, and costs of SSIs incidence of SSI is significantly higher after associated with lumbar decompressions LF compared to LD. We conclude that pa- (LD) and lumbar fusions (LF). tients undergoing lumbar surgery with spe- METHODS: Data from the Nationwide Inpa- cific co-morbidities are at an increased risk tient Sample database was obtained from for SSI. Perioperative antibiotic protocols 2002-2009. Patients undergoing LD or LF for and pre-operative risk factors identified to degenerative etiologies were included. Cas- decrease the incidence of SSI in patients at es of SSI were identified and associated risk for infection mortality was assessed. Co-morbidities were calculated using a modified Charlson Co-morbidity Index. Statistical analysis was GP176 performed a p-value of <0.0005 to denote OUTCOMES OF LUMBAR TOTAL DISC significance. Logistic regression was used to ARTHROPLASTY REVISIONS AND ANTERIOR identify independent predictors of SSI. LUMBAR INTERBODY FUSION REVISIONS RESULTS: A total 578,457 lumbar proce- FROM 2002-2009 dures were identified from 2002-2009 (Ta- Matthew Oglesby BA*, Steven Fineberg ble 1). Incidences of SSI were 7.4 and 8.4 MD*, Alpesh Patel MD^, Miguel Pelton BS*, (per 1000 cases) for the LD and LF groups Kern Singh MD* respectively. Patients with SSI had increased *Rush University Medical Center, Chicago, IL co-morbidity scores, hospitalizations, and ^Loyola University Medical Center, May- costs (p<0.0005). SSI's were associated with wood, IL increased in-hospital mortality of 18.9 and 223

GENERAL POSTERS

revisionsand 390 lumbar TDR revisions rec- INTRODUCTION: Lumbar total disc re- orded in the NIS database from 2002-2009. placements (TDR) and anterior lumbar There were no significant differences be- interbody fusions (ALIF) are both proce- tween groups when comparing average age, dures for the treatment of lower back pain. gender, and co-morbidity scores. Costs were Revisions of these procedures are less significantly greater in ALIF revisions com- common pared to TDR revisions (p<0.0005). There and little is known about their outcomes. were statistically significant longer hospital- This study aims to identify the epidemiolo- izations (p=0.001) and greater costs gy, complication rates and cost differences (p<0.0005) in ALIF revisions compared to based upon revisions of these two proce- lumbar TDR revisions. There were no signifi- dures. To characterize these differences on cant differences of complications between a national level, a population-based data- groups. base was analyzed with regards to patient DISCUSSION: Our study demonstrated a demographics, complications, mortality and larger amount of ALIF revisions than revi- costs. sion lumbar TDRs from 2002-2009. Patient’s METHODS: Data from the Nationwide Inpa- age, gender, and co-morbidities were not tient Sample database was obtained from significantly different between groups. Pa- 2002-2009. Patients undergoing revision for tients undergoing revision ALIF had longer either lumbar TDR or for ALIF were identi- hospitalizations and greater costs compared fied. Patient demographics, co-morbidities, to the TDR revision cohort. In the acute set- major complications, hospitalization days, ting, there appears to be minimal differ- and costs were assessed. SPSS v.20 was ences in complications between these two used to calculate statistical significance us- procedures. ing χ2 tests for categorical data and Inde- pendent-Samples T tests for continuous data. A p-value of 0.001 was used to denote GP177 statistical significance. OUTCOMES OF LUMBAR TOTAL DISC RE- PLACEMENT AND ANTERIOR LUMBAR INTERBODY FUSION FROM 2002-2009 Matthew Oglesby BA*, Steven Fineberg MD*, Alpesh Patel MD^, Miguel Pelton BS*, Kern Singh MD* *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, Maywood, IL

INTRODUCTION: Favorable outcomes have been reported using anterior lumbar interbody fusion (ALIF) and total disc re- placement (TDR) for lumbar disc degenera- tion. Epidemiology, complication rates and cost differences based upon these surgical approaches are not well known. To character- ize these differences on a national level, a population-based database was analyzed with regards to patient demographics, complica- RESULTS: There were 2,899 ALIF tions, mortality and costs. 224

GENERAL POSTERS

METHODS: Data from the Nationwide Inpa- tically significant greater complications in- tient Sample (NIS) of the Healthcare Cost and cluding infections, hematomas, and DVTs. Utilization Project was obtained for each year from 2002-2009. Patients undergoing lumbar DISCUSSION: Our study demonstrates that TDR and primary ALIF were identified. ALIFs were performed much more frequently Patientdemographics, co-morbidities, hospi- than lumbar TDRs in the United States from talization days, costs, major complications, 2002-2009. The data demonstrates that pa- and mortalities were assessed. SPSS v.20 was tients undergoing ALIF are more susceptible used to calculate statistical significance using to developing complications including infec- the χ2 test for categorical data and Student's tions, hematomas, and DVTs. We suggest that T-test for continuous data. A p-value of 0.001 older age and increased co-morbidities of the patient population undergoing ALIFs may ex- plain this discrepancy in complication rates as there is a similar approach to both proce- dures.

GP178 OUTCOMES OF LUMBAR SPINE SURGERY IN TEACHING AND NON-TEACHING HOSPITALS Miguel Pelton BS*, Steven Fineberg MD*, Alpesh Patel MD^, Matthew Oglesby BA*, Kern Singh MD* *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, May- wood, IL

INTRODUCTION: Lumbar decompression (LD), and Lumbar fusion (LF) are commonly performed procedures in both academic and private settings. Perception biases exist on outcomes based upon the hospital envi- ronment. A population-based database was analyzed to characterize differences regard- ing teaching-hospital status on the national level. METHODS: Data from the Nationwide Inpa- was used to denote statistical significance. tient Sample database was obtained from 2002-2009. Patients undergoing LD (i.e. RESULTS: There were 51,778 ALIFs and 2,255 laminectomy and discectomy), or LF for de- lumbar TDRs identified from 2002-2009 in the generative etiologies were identified and United States. Patients undergoing ALIF were separated into cohorts (Teaching and Non- significantly older with more co-morbidities teaching hospitals). Demographics, hospital- (p<0.0005). Females underwent significantly ization days, costs, complications, and mor- more ALIFs, whereas males underwent more tality were assessed for both groups. Statis- TDRs (p<0.0005). Hospitalization duration and tical analysis was performed using a p-value costs were significantly increased in the ALIF of <0.0005 to denote significance. Logistic group (p<0.0005). ALIFs demonstrated statis- regression was used to assess independent 225

GENERAL POSTERS predictors of mortality. hospitals for lumbar spine surgery were RESULTS: A total of 578,457 lumbar proce- younger, had longer hospitalizations, but dures were identified from 2002-2009 (Ta- equivalent costs and mortality compared to ble 1). Patients treated in teaching hospitals patients treated in non-teaching hospitals. were younger, more likely to have African- Incidences of several complications were American ethnicity, and Medicaid or private identified as higher in teaching hospitals. insurance (P<0.0005). The incidence of pro- Our analysis confirmed that teaching- cedure-related complications was higher at hospital status is not a significant predictor teaching hospitals across both surgical of mortality. groups. DVTs, pulmonary embolisms, surgi- cal site infections, and cardiac complications were increased in LF patients in the teach- GP179 ing hospital cohort. Mortality did not signifi- RISK FACTORS FOR URINARY COMPLICA- cantly differ between teaching and non- TIONS AFTER LUMBAR SPINE SURGERY teaching hospitals. Regression analysis re- Steven Fineberg MD*, Matthew Oglesby vealed that significant predictors of mortali- BA*, Alpesh Patel MD^, Miguel Pelton BS*, ty were male gender, congestive heart fail- Kern Singh MD* ure, coagulopathy, and neurologic disor- *Rush University Medical Center, Chicago, IL ^Loyola University Medical Center, May- wood, IL

INTRODUCTION: Complications of the uri- nary-renal system are common after ortho- paedic procedures. In order to characterize the national burden of urinary complica- tions, a population-based database was analyzed to identify incidence, mortality, and costs associated with lumbar decom- pression (LD) and lumbar fusion (LF). METHODS: Data from the Nationwide Inpa- tient Sample database was obtained from 2002-2009. Patients undergoing LD or LF for degenerative conditions were included. Uri- nary complications were identified as uri- nary tract infections (UTI) and renal compli- cations (e.g. anuria/oliguria, acute renal failure). Co-morbidities were assessed using a modified Charlson Co-morbidity Index (CCI). Mortality associated with urinary complications was also assessed. Statistical analysis was performed using a p-value of <0.0005 to denote significance. RESULTS: A total 578,457 lumbar proce- dures were identified from 2002-2009. The incidence of UTIs (per 1,000 cases) was 14.8 ders, and weight loss. and 24.6 for the LD and LF groups respec-

tively (p<0.0005)(Table 1). The incidence of DISCUSSION: Patients treated in teaching renal complications was 9.9 and 9.7 for the 226

GENERAL POSTERS

LD and LF groups (p<0.0005) (Table 2). Department, Hiroshima, Japan Patients who developed either urinary complication were significantly older with INTRODUCTION: Decompression alone un- more co-morbidities (p<0.0005). Women der microscopy or endoscopy has been de- were significantly more likely to have a UTI, veloping into a reliable option for lumbar while men were more likely to have a renal spinal stenosis (LSS) with degenerative complication (p<0.0005). Hospital stays, spondylolisthesis (DS). Proper management costs, and mortality were significantly of epidural membrane (EM) and greater in patients with urinary complica- periradicular sheath (PS) has been reported tions. to be useful for successful decompression. The purpose of this prospective study was to report how to successfully perform de- compression alone for LSS, its outcomes and limitation.

DISCUSSION: Our study identified that old- er, female patients with greater co- METHODS: With a more than 2 year-follow morbidities are at significantly increased up period, 122 patients with LSS who un- risk of developing UTIs, whereas male pa- derwent decompression alone at the L4-5 tients are at increased risk for renal compli- under microscopy were evaluated. Patients cations. Urinary complications in both surgi- were classified into three groups: Group A cal groups increased hospitalizations, costs, as a control without DS had < 10% slip, B and mortality. Early removal of Foley cathe- had 10 to 20% slip and C had ≥ 20% slip. The ters and careful monitoring of fluid status in remarkable EM and PS (Fig.): obstructing patients at risk may help decrease the rate dural tube expansion and compressing the of urinary complications after lumbar spine nerve root were recorded and detached. surgery. The clinical outcomes were compared among the 3 groups with JOA score. RESULTS: The age at surgery averaged 68.5 GP180 years; 60 males and 62 females. Among the EFFECTIVENESS OF DECOMPRESSION 3 groups: A (n = 63), B (n = 39) and C (n = ALONE WITH PROPER MANAGEMENT OF 20), there was no difference in the age at EPIDURAL MEMBRANE AND surgery, symptom duration, follow-up peri- PERIRADICULAR SHEATH FOR LUMBAR od or preoperative JOA score (p = 0.29, SPINAL STENOSIS AND ITS LIMITATION 0.98, 0.21 and 0.98, respectively). The % slip Miyauchi, Akira; Sumida, Tadayoshi; increased significantly in Group B and C (p < Manabe, Hideki; Kobayashi, Kenji; Mikami, 0.01). The remarkable EM and PS were ob- Yukio served in 7 and in 35 patients, respectively; Hiroshima City Asa Hospital, Orthopaedic the latter was more frequently in Group C

227

GENERAL POSTERS than in A (p < 0.05). However, the JOA score 130 days. Surgical outcome was evaluated of each group increased significantly (p < “excellent” when muscular strength of TA 0.01) without any significant difference in recovered to 4 or 5, “good” when it reached the recovery rate (p = 0.66). Eight patients to 3 or 3＋, “fair” when it recovered but (6.6%) had secondary surgery due to steno- within less than 3, and “poor” when there sis: 2 at the same level (one each in A and B) was no improvement in palsy of TA. The and 6 at the different levels. preoperative factors we studied were diag- DISCUSSION: Despite slip progression after nosis, number of involved segment, age, surgery, decompression alone is effective severity of palsy and duration of palsy. for LSS patients with DS. However, re- RESULTS: Surgical result was “excellent” in 8 stenosis due to degeneration at the decom- patients, “good” in 4, “fair” in 3 and “poor” pressed level requires re-operation in a tiny in 4. 63% of all cases showed excellent to number of patients, which is the limitation good results after surgery. Looking at the of decompression alone. results by dividing each factor, there was significant difference in duration of palsy. GP181 But the other factors have no significant difference. SURGICAL RESULTS OF PAINLESS FOOT DISCUSSION: There are a few reports of DROP CAUSED BY DEGENERATIVE LUMBAR foot drop by lumbar degenerative diseases DISEASES including our previous report. However, no Hiroyuki Aono MD, PhD, Yukitaka report can be found which focused on pain- Nagamoto MD, PhD, Hidekazu Tobimatsu less foot drop. In current study, 63% of the MD, Motoki Iwasaki MD, PhD patients had recovered from foot drop. As Department of Orthopedic Surgery, Osaka this surgery only aims recovery of palsy, we National Hospital have to be careful with surgical intervention for patients with long duration period. PURPOSE: Foot drop can be seen by several etiologies and claudication caused by foot drop is known as steppage gait. Foot drop GP182 caused by lumbar degenerative disease of- 2-YEAR PROSPECTIVE COHORT STUDY FOR ten involves radiating leg pain. However, we THE CHANGE OF BONE MINERAL DENSITY have patients who has foot drop without leg FOLLOWING LUMBAR SPINE SURGERY pain. In these cases, it is questionable if we Y.Kawaguchi, M.Nakano, T.Yasuda, S.Seki, have to have the operation to expect neuro- T.Hori, K.Suzuki, T.Kimura logic improvement. We retrospectively Department of Orthopaedic Surgery, Univer- studied recoveries after surgeries for pain- sity of Toyama, Toyama, Japan less drop foot caused by degenerative lum- bar diseases. We also studied the factors INTRODUCTION: Inactive patients may have which influence on recovery from drop foot. a low bone mineral density (BMD) due to METHODS: This study consisted of 19 pa- immobilization. Successful lumbar spine tients presented foot drop without leg pain surgery improves the ADL. Thus, it might preoperatively who underwent lumbar provide an increase in BMD. The purpose of spine surgery for degenerative lumbar dis- this study was to determine whether or not eases. Foot drop was defined as motor lumbar spine surgery increases BMD of the weakness of tibialis anterior (TA) by MMT body, and if in fact lumbar surgery is related less than 3 of 5. Mean age at surgery was 51 to an increase of postoperative BMD, this years. Mean follow-up period was 2.2 years. study was further designed to analyze the Mean duration of palsy before surgery was factors involved in the BMD increase. 228

GENERAL POSTERS

MATERIALS AND METHODS: Forty-seven was to perform a retrospective analysis of a patients, aged more than 60 years old who series of varied lumbar spine surgeries on had lumbar surgery in the period from Jan. hemodialysis patients determine and to risk to Dec. 2009, were participated. BMD of the factors for life prognostic factors after lum- vertebral body and the femoral neck was bar spinal surgery. measured by DEXA preoperatively, at 1 year METHODS: Between 4/2003 and 7/2012, 30 and 2 years after surgery. The surgical re- lumbar spinal surgeries for hemodialysis sults were evaluated by JOA score. Walking patients were performed at our institution. ability was evaluated using the Nurick scale. Perioperative (life prognostic) risk factors RESULTS: The average preoperative BMD were compared between the death group gradually decreased postoperatively. De- and the survival group. This study was a spite the age-related loss of BMD, 11 pa- follow-up study using medical records and tients had increased BMD of the lumbar telephone. The mortality rate was calculat- spine at 2 years postoperatively. There were ed using the Kaplan-Meier method. For also 9 patients who showed increased BMD each factor, the comparison between the of the femoral neck. The % decrease of BMD two groups was used Student's t-test. was lower in excellent and moderate groups RESULT: The 15 patients were operated on compared to that in poor group evaluated the herniotomy & the laminectomy, and 15 by the postoperative Nurick scale. Accord- patients were operated on the anterior or ing to the analysis of repeated measures the posterior spinal instrumentation. Of ANOVA, there were significant differences these patients, already 13 patients (43.3%) in the % change of BMD among the groups died after the surgery. The perioperative by postoperative Nurick scale. The % de- complication ratio was 40%. Survival rate crease of BMD in excellent and moderate after the surgery was 89.6% one year later groups was significantly less compared to and 77.4% five years later. Perioperative that in poor group. risk factors, which were compared in the CONCLUSIONS: Postoperative BMD was death group and survival group, almost affected by postoperative walking ability. have no significant difference. But in the The postoperative Nurick scale was the total protein and the albumin, the survival most significant factor regarding the % group data were higher than the death change of both BMDs. These results indicate group data (p<0.05). that postoperative activity, especially walk- ing ability, might directly effect on the change of postoperative BMD. Successful lumbar spine surgery might increase BMD of the femoral neck. Thus, it might be useful for the prevention of hip fracture.

GP183 ANALYSIS OF LIFE PROGNOSTIC FACTORS IN HEMODIALYSIS PATIENTS AFTER LUM- BAR SPINE SURGERY DISCUSSION: In spinal surgery, it has been Hanaoka E reported that many complications on he- Orthopedic Department, Chiba Social Insur- modialysis patients happen to compared ance Hospital, Chiba, Japan with healthy patients. After the start of he- modialysis, 1-year survival rate was 87.7% INTRODUCTION: The purpose of this study 229

GENERAL POSTERS and the 5-year survival rate was 60.3% in 377 g) were significantly less in the CBT the year 2010 in Japan. By comparison, the group. The VAS score of the low back on the results of this study were good. Ejection first postoperative day (C: 48.6/100, W: fraction, Ca × P and intact PTH data, which 56.8/100) tended to be less in the CBT is known to relation to survive on the he- group but was not significant. There was no modialysis patients, were no significant dif- difference in the length of hospital stay (C: ference in survival. But total protein and 11.1, W: 10.0 days). The CPK decreased sig- albumin were involved in the survival of nificantly in the CBT group of every postop- dialysis patients after lumbar spinal sugary. erative day. There were no differences in So perioperative dialysis management was CRP and WBC. important to lumbar spinal surgery patients, The operation time and the blood loss were especially nutritional management. less and CPK decreased in the CBT group, so the CBT method is probably less invasive than the Wiltse approach. The operation GP184 time was shorter than the Wiltse approach, COMPARISON OF CORTICAL BONE which indicates there is no learning curve in TRAJECTORY METHOD TLIF AND WILTSE the CBT method whereas the learning curve APPROACH TLIF AIMING AT LESS is one of the issues to solve in order to per- INVASIVENESS form MIS procedures. Some of the merits of Yuzawa Yohei, Morito Toshiyuki MIS procedures especially in percutaneous Spine Center Tokyo-West Tokushukai screwing are less muscle injury and dener- Hospital, Tokyo Japan vation. The CBT method will probably in- volve less muscle injury and denervation INTRODUCTION: Cortical bone trajectory and there is no learning curve. (CBT) is a method of placing a pedicle screw using a more medial-to-lateral path than the conventional one. The trajectory follows a GP185 caudocephalad path sagittally and a lateral- MINIMALLY INVASIVE PERCUTANEOUS ly directed path in the transverse plane. As ENDOSCOPIC LUMBAR DISCECTOMY FOR the entry point is on the medial side of the ATHLETES facet joint, it likely decreases the need for Atsuhisa Yamada, Koichi Sairyo, Akira muscle stripping during exposure and the Dezawa. possibility of damaging the medial branch Department of Orthopedic Surgery, Teikyo nerve of the dorsal rami. The CBT method is University Mizonokuchi Hospital assessed aiming at less invasiveness com- pared with the Wiltse approach. INTRODUCTION: Percutaneous endoscopic METHODS: Twenty-one single level TLIF discectomy (PED) was first reported in 2002 patients (CBT group (C) : 11, Wiltse group and showed good clinical outcome for nor- (W) : 10) were examined retrospectively. mal subjects. However, there are few re- The survey items included operation time, ports for athletes. Since the PED is minimal- intraoperative blood loss, VAS score of the ly invasive for the back muscles, the tech- low back on the first postoperative day, nique must be suitable for athletes. The length of hospital stay and CPK, CRP and purpose of this report is to understand the WBC of the first, third and seventh postop- effectiveness of PED for athletes. erative day. METHODS: Ten male athletes with herniat- RESULTS AND DISCUSSION: The mean op- ed nucleus pulposus underwent PED surgery eration time (C: 127, W: 163 min) and the under local anesthesia. Magnetic resonance mean intraoperative blood loss (C: 164, W: imaging (MRI) revealed HNP (herniated nu- 230

GENERAL POSTERS cleus pulposus) in the lumbar spine in all thoracolumbar burst fracture treated by cases. The affected level was L2–L3 (n=1), posterior fixation with or without vertebral L3–L4 (n=1), and L4–L5 (n=8). One patient reduction. had far-lateral disc herniation at L4–L5, and METHOD: Among thirty-three patients, 12 the remaining nine patients showed patients with type A and 11 patients with intracanal type HNP. Operation time, blood type B fractures were treated with loss, and surgery-related complications posterolateral fusion (L). Five patients with were recorded. Time to return to play (RTP), type A and 5 patients with type B fractures RTP rate, and recurrence were also evaluat- were treated with transpedicular reduction ed. Changes in visual analog scale (VAS) using the Schanz system combined with scores for low back pain and leg pain before vertebroplasty by hydroxyapatite blocks (S). and after surgery were reviewed. Operative time, blood loss, radiographic RESULTS: Herniated fragments were suc- analysis including vertebral wedge deformi- cessfully removed endoscopically with local ty and segmental kyphosis were evaluated anesthesia. Mean operation time was 53.5 at 1-year follow-up. min, blood loss during operation was negli- RESULT: All cases achieved fusion. Opera- gible, and no surgery-related complications tive time was shorter and less bleeding was such as dural tear, nerve root injury, hema- found in cases treated by S (p<0.05). In type toma, or surgical site infection were ob- A fractures, differences were not seen in served. Subjects returned to their sport 6 to wedge deformity (L: pre-op 36.9% post op 8 weeks after surgery. The mean VAS score 25.6%, S: pre-op 30.8% post op 22.1%) and (out of 10) for low back and leg pain was 0.5 kyphosis (L: 6.3° S: 6.5°). However, in type B and 0, respectively at the final follow-up, fractures, wedge deformity was significantly compared with 6.5 and 4.5 before surgery. reduced and maintained in cases treated Of the patients, 9 (90%) had complete RTP, with S (L: pre-op 43.4% post op 36.5%, S: and one (10%) showed recurrence. pre-op 52.3% post op 24.1%)(p<0.05). In- CONCLUSION: The minimal invasiveness terestingly, in type B fractures treated with and good clinical outcome of PED favor it as S tended to increase kyphosis 1-year post a gold standard for disc surgery in athletes operation (L: 7.0° S: 10.3°). with HNPs. DISCUSSION: Result showed that thoracol- umbar burst fractures treated with Schanz system offer less operative time and blood GP186 loss compared to PLF. For wedge deformity COMPARISON OF POSTERIOR FIXATION and segmental kyphosis, type A fractures WITH OR WITHOUT VERTEBRAL REDUC- showed no differences between proce- TION FOR THORACOLUMBAR BURST FRAC- dures. However, in type B fractures with TURE posterior ligament complex disruption, Nagai T, Watanabe M, Sakai D, Hiyama A, wedge deformity was superiorly reduced Sato M, Mochida J with Schanz system, but segmental kyphosis Department of Orthopaedic Surgery Tokai was increased. Results of the current study University School of Medicine suggest that type B thoracolumbar burst fractures, surgical treatment with Schanz INTRODUCTION: In order to evaluate the system assisted with posterior bone graft efficacy of transpedicular reduction with may be ideal. anterior column reconstruction without posterior fusion for thoracolumbar burst fracture, we compared the surgical outcome of patients with AO classification type A or B 231

GENERAL POSTERS

because of penetration of pedicle screws, 2 GP187 cage retropulsions and 1 reoperation be- CLINICAL OUTCOMES AND COMPLICA- cause of pseudoarthrosis. The overall rate TIONS OF MINIMALLY INVASIVE POSTERI- of screw perforation rate was 12% in group OR LUMBAR INTERBODY FUSION: COM- M, and 6% in group T. PARISON OF MINIMALLY INVASIVE AND DISCUSSION: We retrospectively compared TRADITIONAL OPEN SURGERY. 114 cases who underwent instrumented Kentaro Yamane, Masato Tanaka, Kazuo PLIF using either MIS systems or open tradi- Nakanishi, Yoshihisa Sugimoto, Haruo tional approach. The results indicate that Misawa, Tomoyuki Takigawa, Yasuyuki MIS-PLIF could achieve similar clinical re- Shiozaki, Teturo Mazaki, Syuhei Osaki sults as conventional procedures, and on Department of Orthopaedic Surgery, the other hand this is technically demanding Okayama University because of the higher screw misplacement rate. INTRODUCTION: Minimally invasive poste- rior lumbar interbody fusion (MIS-PLIF) has rapidly been spreading because of lower GP188 tissue damage. This procedure can deliver SELECTIVE DECOMPRESSION AND LONG similar clinical outcomes when compared to SEGMENTAL FUSION OF DEGENERATIVE a traditional approach. There has been also LUMBAR SCOLIOSIS reported some complications by using MIS Meng Xianglong, Hai Yong. instruments. The purpose of this study was Orthopedic Department, Chaoyang Hospital, to investigate the clinical outcomes and Capital Medical University, Beijing, China complications of MIS-PLIF. METHODS: A retrospective study was per- INTRODUCTION: To analyse the surgical formed with 144 cases treated for more results of selective decompression and long than one level fusion between March 2007 segmental fusion for degenerative lumbar and February 2012. 74 cases received MIS- scoliosis (DLS). PLIF (group M), while another 70 cases un- METHODS: 19 patients with DLS were derwent through a traditional open ap- treated surgically. 7 males and 12 females proach (group T). The clinical outcomes were included, aged from 56 to 78 years were assessed with following question- old. The selective decompression and long naires: Oswestry Disability Index (ODI), the segmental fusion with pedicle screws were Short Form of the Medical Outcome Study employed and fusion levels exceed scoliosis (SF-36), and pain scales in 63 cases who curves. The follow-up time was 1.5 to 3.5 answered the questions. In all 114 cases, we years. We evaluated preoperative and post- investigated complications associated with operative cobb angle, lumbar lordotic an- both spinal fusion surgeries. In particular, gles, Visual Analog Pain Scale (VAS) and the accuracy of pedicle screw placement Oswestry Disability Index (ODI), and statisti- was evaluated by using computed tomogra- cal difference was analysed. phy scan. RESULTS: Mean number of fusion range RESULTS: There was no significant differ- from 5 to 9 vertebral bodies. Preoperative ence in ODI, SF-36 and pain scales between VAS score was 4 to 9, averaged 6.3±2.1, and the two groups. In group M, there were 2 final follow-up VAS score was 1 to 7 points, cases that had reoperations because of se- averaged 3.3±2.3. Preoperative ODI score vere frank penetration of pedicle screws, 2 was 21 to 43 points, averaged fractures of transverse process and 2 cage 32.5±13.9，and final follow up ODI score retropulsions. In group T, 2 reoperations was 5 to 33, averaged 18.2±13.5. The statis- 232

GENERAL POSTERS tical difference between preoperative and to Oswestry Disability Index (ODI), EQ-5D follow-up VAS score was significant, and and Visual Analogue Scores (Back and Leg). statistical difference was also found be- Results of first 39 patients are included. 26 tween preoperative ODI scores and final patients had operative intervention and 13 follow-up scores. Preoperative cobb angle had non-operative rehabilitation. In the of lumbar spine was between 26° and 43°, operative group we found no strong corre- averaged 31.2°±5.6°. Final follow up cobb lation between any of the angles and out- angle of lumbar spine was between 7°and come scores (r ranged from 0.002 to 0.05). 22°, averaged 10.1°±6.9°. Lumbar spine In the non-operative group there was evi- lordotic angle was between 9°and 36°, av- dence of a stronger correlation between eraged 19.1±10.2°, and postoperative lum- some of the variables but this did not reach bar spine lordotic angle was between statistical significance. Pelvic Tilt had a posi- 21°and 48°, averaged 31.4±11.6°. The signif- tive correlation with ODI (r = 0.2) and a neg- icant difference was found between pre- ative correlation with EQ-5D (r = 0.08). Sa- operative and follow-up cobb angles. Early cral slope had a negative correlation with complication occurred to 47.4 percent of ODI (r = 0.17) and a positive correlation with patients, including urinary infection, ileus et EQ-5D (r = 0.05). Pelvic Incidence did not al. have any correlation to outcome scores in DISCUSSION: Selective decompression and the non-operative group. long segmental fusion is an effective way to DISCUSSION: The preliminary results in this treat degenerative lumbar scoliosis with study appear to support the limited evi- main symptom of lower back pain and low- dence available on the correlation of pelvic er limbs discomforts, large coronal cobb parameters with patient reported outcome angle, coronal or sagittal imbalance. measures. Lazennec reported that those with a larger pelvic tilt were more likely to experience residual back pain following sur- GP189 gery. Lafage had similar findings in a more CORRELATION OF PELVIC PARAMETERS heterogeneous group and no differentiation WITH PATIENT REPORTED CLINICAL was made between operative and non- OUTCOMES—A FOLLOW-UP STUDY OF THE operative cases. Our results have shown MRC SPINE STABILISATION TRIAL that a larger degree of pelvic tilt has a less Steven McGillion, Jing Yu, Anne Mannion, favourable outcome. Pelvic incidence and Jeremy Fairbank sacral slope do not appear to be strong indi- Nuffield Orthopaedic Centre, Oxford cators of patient reported outcomes. University Hospitals NHS Trust, Oxford, UK

INTRODUCTION: It is claimed there is a pre- GP190 dictive relation between pelvic parameters TREATMENT OF NEUROPATHIC PAIN BY (Pelvic Incidence (PI), Sacral Slope (SS) and SENSORY NERVE STIMULATION OF THE Pelvic Tilt (PT)) and patient reported clinical LUMBAR EXITING NERVE DRG USING A outcomes in spinal fusion. PERCUTANEOUS TRANSFORAMINAL AP- METHODS: We calculated PI, SS and PT on a PROACH recent radiograph in a cohort from the MRC Anthony Yeung, MD Laura Tyler Perryman, Spine Stabilisation Trial previously random- MS, MBA ised to either operative management or Desert Institute for Spine Care Stimwave intensive rehabilitation for chronic low back Technologies, Scottsdale Arizona pain. 10-year follow up data imaging are available for 131 patients. This was related INTRODUCTION: Epidural Spinal column 233

GENERAL POSTERS stimulation (SCS) is used to salvage FBSS. imally invasive treatment option for chronic This study investigated the advantages of low back and/or leg pain from FBSS. direct nerve placement of a wirelessly pow- ered Sensory Nerve Stimulator (SNS) placed transforaminally by the DRG of the painful GP191 spinal segment. THE MINIMALLY INVASIVE METHOD: Five FBSS patients with back and TRANSFORAMINAL ENDOSCOPIC AP- leg pain were implanted with a SNS lead PROACH IS EFFECTIVE FOR THE TREAT- containing four electrodes. A 14 gauge MENT OF FBSS DUE TO RECURRENT HNP Tuohy needle guided the lead AND LATERAL STENOSIS percutaneously to the axilla of the exiting Anthony T. Yeung, M.D. and traversing nerve by the DRG. After func- Desert Institute for Spine Care tional verification of pain relief stimulation, the needle is removed and the lead’s tubing INTRODUCTION: Treatment of Failed back is anchored subdermally. The SNS lead is surgery syndrome due to recurrent herni- not anchored. Patients continue the stimu- ation and foraminal stenosis can be as suc- lation at home for up to 30 days before cessful as the index procedure, but revision explantation. Anterior-posterior and lateral surgery often incorporates more extensive X-rays were used every three days to moni- decompression necessitating fusion. tor lead migration. METHODS: 40 consecutive patients with RESULTS: All five patients reported success- FBSS from recurrent HNP and lateral steno- ful stimulation as defined by at least 50% sis elected to undergo percutaneous reduction of VAS and 50% paresthesia cov- transforaminal endoscopic discectomy and erage of the pain distribution area. Baseline foraminoplasty. Outcome data at each visit VAS score averaged 8.5 to 2.3 by the end of included MacNab, VAS and ODI. All patients the trial period. Lead migration ranged from requested the non-fusion procedure first, 1.1 mm to 5.4 mm after 30 days. even if fusion is indicated in the face of DISCUSSION: Placement of a SNS directly to Isthmic or grade I spondylolisthesis. All pro- the DRG is closer to the pain source com- cedures were performed at an ambulatory pared to traditional epidural SCS. Patients surgical center under local anesthesia. The with bilateral pain that received only one average follow up time was, average 40 SNS lead on one side of the dorsal column months, Minimal 12 months. only reported one-side coverage of their RESULTS: Average pre-operative VAS im- total pain area. This suggests that optimal proved from 7.2 to 4.0, and ODI 48% to treatment and complete coverage may re- 31%. Endoscopic foraminoplasty was per- quire multi-level or bilateral stimulator formed to either decompress the bony fo- placements. The patient with dual lead ramen for foraminal stenosis, and allow for placement had close to 100% pain relief endoscopic visual confirmation of the de- coverage. Although lead migration was ob- compressed traversing and exiting nerve. served in all patients, the SNS electrode While temporary dysesthesia occurred in 4 coverage area overcompensated for any patients in the early post-operative period, migration effects. all were happy with to avoid “open” de- Wirelessly powered SNS enables direct compression or fusion surgery. transforaminal implantation of the lead DISCUSSION: The transforaminal endoscop- closer to the pain generator in FBSS pa- ic approach is effective for FBSS due to re- tients. Wireless SNS is a practical and simpli- current HNP and lateral stenosis. Failed in- fied therapy that may provide a viable, min- dex surgery may involve failure to recognize

234

GENERAL POSTERS pathoanatomy in the axilla of the foramen 44%-30%. Complications=1 seroma, housing the traversing and the exiting 1durotomy. Patients receiving MLD was for nerve, including the DRG. The extruded, migrated, or sequestered HNP transforaminal endoscopic approach effec- believed better for MLD and not appropri- tively decompresses the foramen and does ate for SED฀. Patients in this spine practice, not further destabilize the spine. It avoids known nationally for SED฀, usually chose going through the previous surgical site. SED฀over MLD when given a both choices Residual axial back pain may be improved by the operating surgeon. SED฀ included further with dorsal endoscopic rhizotomy extruded, migrated, sequestered HNP at all performed dorsally or from the foramen. levels felt possible by the operating sur- Foraminal endoscopic decompression is a geon. The SED group numbered 250, with MIS technique that does not “burn bridges” 309 total levels. Average VAS was 6.6-2.5 for a more conventional approach. Endo- and ODI was 46%-32%. 37 patients (15%) scopic foraminal decompression will at least developed temporary dysesthesia in the 2 add to the surgical armamentarium of FBSS. week post-operative period. Improvement in VAS and ODI was comparable to MLD. Patient satisfaction in the endoscopic group GP192 was high in spite of dysesthesia, usually oc- A COMPARATIVE OUTCOME EVALUATION curring and predicted when furcal nerves OF LUMBAR TRANSFORAMINAL ENDO- were identified and occasionally sacrificed. SCOPIC DISCECTOMY VERSUS MICRO- DISCUSSION: In spite of dysesthesia not LUMBAR DISCECTOMY FOR LUMBAR DISC usually experienced by MLD patients, pa- HERNIATION tient satisfaction remained high, as the pa- Anthony T Yeung , M.D. Presenting author, tient’s ultimate results were similar. The Christopher Yeung, M.D, Justin Field, M.D. more difficult extruded herniations where Desert Institute for Spine Care, Phoenix, access was not possible or limited due to Arizone anatomic considerations were encouraged to chose MLD. INTRODUCTION: The outcome of MIS tech- niques for lumbar disc herniation treated by transforaminal endoscopic discectomy GP193 (SED฀) versus micro-lumbar discectomy ENDOSCOPICALLY GUIDED DORSAL were compared. RHIZOTOMY IS MORE EFFECTIVE THAN METHOD: 250 consecutive patients who PULSED RADIOFREQUENCY LESIONING FOR underwent transforaminal “selective endo- NON-DISCOGENIC AXIAL BACK PAIN. scopic discectomy” (SED฀) and 50 consecu- Anthony T. Yeung, MD Yinggang Zheng, MD tive patients who underwent micro-lumbar Desert Institute for Spine Care Phoenix, Ari- discectomy (MLD) were compared using zona (VAS) and (ODI). The procedure MLD vs SED฀was a shared patient/surgeon decision. INTRODUCTION: Pulsed Radiofrequency Data was collected and recorded at each lesioning of the medial branch, dorsal ra- office visit and at final follow up before dis- mus, a standard technique to treat facet charge from care. All procedures were per- pain, is compared to an endoscopic visually formed in a spine ambulatory surgical cen- guided technique. ter owned by the practice. Average follow METHOD: A prospective non randomized up was, minimum 12, average 38 months. study of 50 initial patients assessed the effi- RESULTS: 50 Cases of MLD: L4-5=15, L5- cacy of endoscopic rhizotomy. Patients with S1=35. Average VAS=6.5-1.7, Average ODI lumbar spondylosis and facet arthrosis who 235

GENERAL POSTERS had at least 50% pain relief by medial branch blocks met the inclusion criteria. The GP194 initial 50 patient study expanded to over CLINICAL AND RADIOLOGICAL OUTCOMES 400 patients by May 2012. The surgical OF MINI-TLIF VIA PARASPINAL APPROACH technique was guided by cadaver dissec- USING CAGE FILLED WITH MORSELIZED tions that revealed variable locations of the LOCAL EXCISED BONE AS AUTOGRAFT AND media branch, thus the need for visualized ADDITIONAL ALLOGRAFT: MINIMUM 2- rhizotomy. YEAR FOLLOW-UP RESULTS: At one year follow-up, VAS im- Won Noh*, Dong-Yun Kim†, Sang Ki Chung†, proved 6.2-2.5, and ODI 48-28. All patients Joon Ki Hong‡, Sei-Yoon Kim†, Deok-Joo had VAS improvement equal or greater than Rhee†, Sung-Woo Lee§, Youn-Woong Lim†, injection. The results remained constant Ho Seok Jeong†, and Hee-Cheol Cho† with additional surgical cases. Approximate- *Department of Orthopedic Surgery, ly 10 percent returned at one year follow-up Uijeongbu Chuk Spine Hospital, Gyeonggi, with mild recurrence of their axial back Korea; †Department of Neurosurgery, Seoul pain. Rhizotomy of the upper lumbar facets Chuk Spine Hospital, Seoul, Korea; provided additional relief in selected pa- ‡Department of Neurosurgery, Uijeongbu tients. Chuk Spine Hospital, Gyeonggi, Korea; and DISCUSSION: The cadaver studies demon- §Department of Orthopedic Surgery, Seoul strated considerable variability in the loca- Chuk Spine Hospital, Seoul, Korea tion of the medial and lateral branches. Var- iability was most common cephalad to L3-4. INTRODUCTION: Paraspinal Mini-TLIF has The dorsal ramus can be visualized ventral become a favored surgical treatment for the to the intertransverse ligament. Neuromas management of lumbar degenerative dis- of the dorsal ramus have been identified eases. Autologous iliac bone is more suita- endoscopically, and may also contribute to ble for biologic bone healing ability alt- axial back pain. In the upper lumbar spine, hough there may be some questions such as we were not able to find the medial branch donor site morbidity. The purpose of this to the facet consistently. The nerve to the study was to evaluate the clinical and radio- facet joint did not cross the transverse pro- logical outcomes of paraspinal Mini-TLIF cess. Nerve Ablation at these two levels using cage filled with morselized local ex- may require lesioning of the dorsal ramus or cised bone. targeting the innervation on the facet wall METHODS: Retrospectively, 46 patients or capsule. who underwent paraspinal Mini-TLIF using Discussion: Endoscopically guided facet cage filled with local excised bone graft and rhizotomy provides more consistent abla- additional allograft at single hospital were tion of the medial and lateral branches of evaluated with minimum 2-year follow-up. the lumbar dorsal ramus than Clinical outcomes were assessed with pre- radiographically guided pulsed radiofre- operative and postoperative Oswestry Disa- quency. The variations in the location of bility Index (ODI) and visual analogue scale facet innervation dictate a need for visually (VAS) for leg and low back pain. Radiological guided MIS procedure. fusion was evaluated using dynamic plain radiographs and computed tomography (CT) scan with coronal and sagittal reconstruc- tions. RESULTS: Of the 46 patients, there were 37 females and 9 males, with a mean age of 62.22 years (range, 44-80). The mean fol- 236

GENERAL POSTERS low-up period was 32.6 months (range, 26- 39). The mean preoperative and last follow- INTRODUCTION: While the vertebral frac- up ODI, leg pain VAS and back pain VAS tures have been the focus of extensive stud- were 28.1/7.9, 7.7/1.6 and 5.2/1.6, respec- ies, little is known about the difference be- tively. Average improvement of ODI, leg tween the compression fracture with vacu- pain VAS and back pain VAS were 20.1, 6.1 um cleft and without that. We hypothesized and 3.6 at last follow-up after surgery, re- that the compression fracture with the vac- spectively (p<0.001). Excellent or good clini- uum cleft showed more intra-vertebral in- cal improvement was seen in 93.5% (43/46) stability and severe symptoms, while of the patients. Solid fusion was demon- vertebroplasty for that would have more strated on plain X-ray and reconstructed CT favorable clinical outcomes compared with scan in 89.1% (41/46) of the patients at last the simple osteopenic compression frac- follow-up. Reconstructed sagittal and coro- ture. nal CT scan at last follow-up showed a con- METHODS: Eighty-three patients who un- tinuity of the trabecular bone traversing the derwent vertebroplasty for the treatment of inferior and superior endplates both inside vertebral compression fracture were partic- and around the cages (Figure 1). ipated. Patients were divided into two groups; the vacuum group with the intra- vertebral vacuum cleft (IVC) (n=45, mean age: 74.2 [61-87]) and the non-vacuum group without IVC (n=38, mean age: 72.5 [53-86]). The intra-vertebral instability was identified by analyzing the kyphotic angle and the body height of 6 different dynamic plain radiographs: the combinations of (1) DISCUSSION: In conclusion, paraspinal Mini- neutral, extensional, and flexional, (2) su- TLIF using cage filled with morselized local pine and standing. Visual Analogue Scale excised bone can provide satisfactory clini- (VAS) and Oswestry Disability Index (ODI) cal outcomes and high fusion rates without for pain were measured before surgery and harvesting autologous iliac bone graft. at 1-month follow-up. RESULTS: The range of the change of single vertebra kyphotic angle was higher in the GP195 vacuum than the non-vacuum group THE COMPRESSION FRACTURE WITH THE (p<0.05). The mean percentage of the ver- VACUUM CLEFT SHOW MORE tebral body height (standing flexional to INTRAVERTEBRAL INSTABILITY AND SEVERE standing neutral) was significantly lower in SYMPTOMS COMPARED WITH THE SIMPLE the vacuum group (88.5 ± 13.4) than the OSTEOPENIC COMPRESSION FRACTURE non-vacuum group (95.2 ± 9.0) (p=0.038). At Yongchan Kim‡, Won Noh*, Hee-Cheol 1-month follow-up, the mean improvement Cho†, Youn-Woong Lim†, Ho Seok Jeong†, of VAS and ODI were significantly higher in Deok-Joo Rhee†, Sei-Yoon Kim†, Joon Ki vacuum group compared to those of non- Hong‡, Sang Ki Chung†, and Dong-Yun Kim† vacuum group (p<0.05). ‡Department of Neurosurgery, Uijeongbu Chuk Spine Hospital, Uijeongbu, Korea; *Department of Orthopedic Surgery, Uijeongbu Chuk Spine Hospital, Uijeongbu, Korea; and †Department of Neurosurgery, Seoul Chuk Spine Hospital, Seoul, Korea 237

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nosis: DDD n= 52 (67%); Spondylolisthesis n=19(25%); Nonunion n=6 (8%). 48 (63%) had ALIF + decompression + pedicle screw fixation, 24 (31%) had ALIF + percutaneous pedicle screw fixation, 5 patients (6%) had stand-alone ALIF. VNS and ODI scores im- proved significantly at 6, 12, and 24 months DISCUSSION: The compression fracture with (Table). Clinical outcomes at 6 months were the vacuum cleft show more intra-vertebral statistically unchanged at 12 and 24 instability and severe symptoms compared months. Radiographic analysis revealed 94 with the simple osteopenic compression % fusion rate between 6-12 months and no fracture. After the vertebroplasty, there was appreciable subsidence or lysis. 1 case of a marked improvement in the vacuum retrograde ejaculation (2.3%) resolved by 3 group. Therefore, the compression fracture months. with the vacuum cleft should be treated with vertebroplasty earlier and actively.

GP196 A PROSPECTIVE STUDY OF A UNIQUE TITANIUM INTERBODY FUSION IMPLANT; CLINICAL AND RADIOGRAPHIC OUTCOMES DISCUSSION: This study confirms the acid AT 1 AND 2 YEAR FOLLOW UP etched Ti cage with BMP is safe and effec- Paul J. Slosar MD, Adam Cabalo MD, James tive in achieving excellent outcomes in lum- B. Reynolds MD bar disc degeneration. Meaningful Clinical SpineCare Medical Group/ San Francisco Improvements (ODI >15 and VNS >3) were Spine Institute noted in the majority of cases. Clinical out- comes did not change significantly after the

INTRODUCTION: Acid etched titanium is 6 mo data point. We postulate this is due used extensively in dental implants. Pub- to rapid bone-implant incorporation and lished research found acid etched Ti induces lack of subsidence. Further study (without better osteoblast differentiation and BMP BMP) is underway to determine if a less than PEEK or smooth Ti. Purpose: assess the expensive biologic can be used without sac- outcomes of patients having ALIF with an rificing clinical results. acid etched Ti implant. METHODS: Prospective consecutive en- GP197 rollment between 2008-2010. Surgical UNI- AND BI-LATERAL INSTRUMENTED technique: ALIF interbody cage (Titan POSTEROLATERAL FUSION OF THE LUMBAR Spine) + Infuse (Medtronic) 3 mg/ cage. SPINE WITH LOCAL BONE GRAFTING: A Pedicle screw fixation/ decompression at PROSPECTIVE STUDY WITH A 2-YEAR the discretion of the surgeon. Visual Numer- FOLLOW-UP. ical Scale (VNS) and Oswestry Disability In- Ohtori S, Koshi T, Suzuki M, Inoue G, Orita S, dex (ODI) scores were collected 0, 6, 12, and Yamauchi K, Eguchi Y, Aoki Y, Ishikawa T, 24 months. Fusion assessed by independ- Miyagi M, Kamoda H, Suzuki M, Sakuma Y, ent radiologist review of X-rays and CT Kubota G, Oikawa Y, Inage K, Sainoh T, Sato scans. J, Toyone T, Yamagata M, Takahashi K. RESULTS: 77 patients; 42 male and 35 fe- Dept. Orthop. Surg., Chiba University, Chiba, male. Ave age 46 years (range 23-67). Diag- 238

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Japan GP198

INTRODUCTION: The iliac crest bone graft REDUCING BLOOD LOSS USING A BIPOLAR technique for lumbar posterolateral fusion SEALER IN LUMBAR POSTEROLATERAL surgery is widely used; however, donor site FUSION: A RANDOMIZED CONTROLLED problems such as pain and sensory disturb- TRIAL ance have been reported. Local bone has Fukui D., Kawakami M., Nakao S., Ando M., been used for bilateral multi-segment fu- Sasaki S., Morishita S., Matsuoka T. sion surgery; however, outcomes have been Spine Care Center, Wakayama Medical poor because of insufficient amounts of University Kihoku Hospital Department of local bone used. The current study evaluat- Orthopaedic Surgery, Wakayama Rosai ed unilateral and bilateral posterolateral Hospital fusion at 3 levels using a local bone graft. MATERIALS AND METHODS: Forty-two pa- INTRODUCTION: Although a bipolar sealer, tients diagnosed with degenerated which provides hemostasis at lower tem- spondylolisthesis at 3 levels were divided peratures than conventional electrocautery, into 2 groups. All underwent decompression was an effective coagulation alternative for and bilateral instrumented posterolateral total hip and knee arthroplasties, it is still fusion. However, a unilateral local bone unknown if this devise reduces blood loss graft was used in 22 patients and bilateral and tissue damage in lumbar posterolateral local bone graft was used in 20 patients. fusion (PLF). The purpose of this study was The amount of bone grafting, proportion of to analyze the efficacy of this devise in af- patients with bone union, duration of bone fecting blood loss during exposure of the union, visual analog scale (VAS) score, Japa- lumbar spine for PLF and postoperative nese Orthopedic Association (JOA) score, pain. and Oswestry Disability Index (ODI) were METHODS: A randomized controlled trail evaluated before and 2 years after surgery. was conducted. Thirty-five patients, who RESULTS: VAS score, JOA score, and ODI underwent PLF, were prospectively enrolled were not significantly different between the between October 2011 and August 2012. 2 groups before and after surgery (P > 0.05). Eighteen patients were randomized to the The amount of local bone graft used for bipolar sealer (BS) group, and 17 patients each segment was significantly less in the were assigned to a standard electrocautery bilateral group (P < 0.05). The rates of bone (control) group. Demographic data, the union and instability were 86% and 9% re- number of fusion levels, time and blood loss spectively in the unilateral group, but signif- during exposure of posterior bony elements icantly poorer at 60% and 34% in the bilat- including the transverse process for PLF, eral group. visual analog scale (VAS) of postoperative DISCUSSION AND CONCLUSION: If multi- pain and the period from the surgery to segment fusion (3 level fusions) is per- hospital discharge were compared. Data formed, bilateral local bone grafting results were analyzed and P < 0.05 was considered in a poor rate of bone union because of an significant. insufficiency of local bone. Unilateral bone RESULTS: There were no differences in de- grafting is recommended because better mographic data, the number of the fusion rates of bone union and stability are level, time and blood loss during the expo- achieved. sure between two groups. Time and blood loss during the exposure one per level were significantly lower in the BS group than those in the control group (exposure time: 239

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15 vs 24 min, blood loss: 37 vs 72 ml) There without follow-up. The average follow-up was a tendency towards lower VAS at post- was 50 months (range 36-75 mo). There was operative 1 week and shorter hospitaliza- significant improvement in average JOAS tion from the surgery in the BS group than (16.1 to 22.6), in ODI (39.3 to 20.1), and NRS the control group (VAS: 26 vs 47 mm, hospi- scores for low back pain (3.7 to 2.1), leg talization: 15 vs 26 days). pain (5.3 to 1.6), and leg numbness (6.4 to DISCUSSION: We found that a bipolar sealer 3.8). Satisfaction rate was 91%. Radiological is effective in PLF to reduce time and blood instability (including more than 3 mm slip- loss during the exposure for the PLF. A ten- page and >3° wedge disc, as defined by dency toward less postoperative pain and Ohtani) appeared in 30 of 76 spinal seg- shorter hospitalization might result from a ments (39.4%). less invasiveness against soft tissue. Collec- tively, these results suggest that the bipolar sealer is an effective coagulation alternative for PLF.

GP199 MIDTERM RESULTS OF THE YELLOW LIGA- MENT FLOATING METHOD FOR LUMBAR SPINAL CANAL STENOSIS Takashi Yamazaki, Sei Terayama, Keiji Hayakawa, Hiroshi Nakamura

Dept. Orthopedic Surgery, Musashino Red Cross Hospital, Japan DISCUSSION AND CONCLUSIONS: Because the deep layer of the yellow ligament and INTRODUCTION: We found our yellow liga- epidural fat are preserved in the YLFM, and ment floating method (YFLM) useful for the dura is rarely seen during surgery (fig- decompression of lumbar spinal canal ste- ure), this technique is relatively safe for nosis without disc herniation because of nerve tissue. The midterm results are com- less incidental dural tears, less postopera- parable with our previous results using con- tive hematoma disorders, and good short- ventional methods (JOAS improvement term results (J. Spine. Res 2010). However, from 14.6 to 22.9). Weinstein et al. reported midterm results have not yet been report- an ODI improvement from 43.2 to 22.7 and ed. 68.2% satisfaction rate (NEJM 2008). Ohtani METHODS: The Japanese Orthopedic Asso- reported an appearance of instability of ciation score (JOAS); Oswestry disability 34% in wide fenestration. Thus, the mid- index (ODI); numerical rating scale (NRS) for term results of the YLFM are comparable low back pain and other variables; satisfac- with results using conventional methods. tion rate; and the appearance of radiologi- We recommend the YLFM as more useful cal instability were measured in patients because of its safety. followed for more than three years. RESULTS: We evaluated 55 patients (aver- age age 71.2 years) from 77 consecutive cases treated with the YLFM. We excluded 5 patients because they had no preoperative record, 6 patients with other disease that made evaluation difficult, and 12 patients 240

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the negative predictive value was 89.4%. GP200 The results for the PEEK group were almost VERTEBRAL ENDPLATE CYST AS A PREDIC- identical to those of the Ti group. TOR OF NONUNION AFTER LUMBAR DISCUSSION: Our radiological findings con- INTERBODY FUSION: TITANIUM ALLOY cerning bony union and vertebral endplate CAGE VS PEEK CAGE cysts were almost identical in the Ti and Shunsuke Fujibayashi, Mitsuru Takemoto, PEEK groups. Regardless of the material Masanori Izeki, Bungo Otsuki, Shuich used, vertebral endplate cyst formation in Matsuda the early period after surgery was con- Department of Orthopaedic Surgery, Gradu- firmed as a significant predictor of nonun- ate School of Medicine, Kyoto University ion. We also found no advantage in using the PEEK cage rather than the Ti cage for INTRODUCTION: We reported the clinical LIF. significance of vertebral endplate cyst for- mation as an early predictor of nonunion after lumbar interbody fusion (LIF) at the GP201 annual meeting of ISSLS in 2011. One of the DISCOGRAPHY FOLLOWED BY DISCOBLOCK limitations of that study was the lack of data ENSURES SUCCESSFUL SURGERY FOR on the effects of different cage materials. DISCOGENIC LOW BACK PAIN. PEEK has gained significant popularity as the Tomoyuki Ozawa1, Tomoaki Toyone1, Seiji biomaterial of choice for interbody fusion Ohtori2, Kunimasa Inada3 , Ryutaro because of its radiolucency and low elastic Shiboi1, Kazuhisa Takahashi2 modulus, similar to that of cortical bone. A 1 Teikyo University Chiba Medical Center. 2 prospective comparative study of the titani- Department of Orthopedic Surgery, Gradu- um alloy (Ti) cage and the PEEK cage in LIF ate School of Medicine, Chiba University, 3 was performed to clarify the different ef- Katuira orthopedic clinic, Chiba, Japan. fects of the two materials. METHODS: Nineteen patients treated with INTRODUCTION: Discogenic low back pain 22 PEEK cages were compared with 76 pa- (LBP) is usually diagnosed by magnetic res- tients treated with 93 Ti cages. The relation- onance imaging and discography. However, ship between vertebral endplate cyst for- the reliability of discography is still contro- mation and bony union was assessed with versial. Recently, the usefulness of CT preoperatively, three months postopera- discoblock for diagnosis was reported. The tively, and one year postoperatively. Cases purpose of the current study was to evalu- of the de novo appearance of endplate cyst ate the results of surgery for discogenic LBP or a progression in cyst size after surgery which was diagnosed by discography and were defined as cyst positive. Cases with no discoblock. development of an endplate cyst or a re- METHODS: This study was based on a pro- gression in cyst size were defined as cyst spective cohort of 14 consecutive patients negative. with a chief complaint of low back pain who RESULTS: In the PEEK group at three responded to the diagnostic procedures; months, the patients were cyst positive at discography (1.5 mL of contrast medium) three levels and cyst negative at 19 levels. and discoblock (intradisc injection of 0.75 The union rate was 77.3% after one year. mL of 1% lidocaine.) for intervertebral disc The sensitivity of cyst positivity/negativity at to confirm pain provocation and reduction three months to subsequent bony union at were done. All patients underwent one level one year was 60%, the specificity was 100%, fusion using cages which was performed at the positive predictive value was 100%, and L4/5 in 6 patients and at L5/S in 8 patients. 241

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Clinical and radiologic findings were exam- minimally invasive surgical (MIS) approach ined preoperatively and 1-year after sur- is preferred by many surgeons. The direct gery. lateral transpsoas approach does however RESULTS: Low back pain improved from the pose potential risk to neural structures of mean visual analogue scale score of 48mm the lumbar plexus as they course through (25-73) preoperatively to 18mm (5-25) the psoas. The lumbar plexus and overlap of postoperatively (P<0.05). The mean Roland the iliac crest cause access to the L4-5 disc and Morris Disability index also improved to be more complex. The L5-S1 level has from 12.5 preoperatively to 2.1 postopera- not been a viable option from a direct lat- tively (P<0.05). Radiologically, the mean eral perspective. angle of lumbar lordosis (L1-S1) improved METHODS: Twenty fresh frozen cadaveric from 37.9o (28.7-56.3o) preoperatively to specimens (11 female, 9 male; 31-103 yrs; 40.3o (28.2-54.7o) postoperatively, and the BMI 15.0-39.7) with peritoneal contents mean lordotic angle of the fused segment intact were dissected while in a right lateral changed from 14.0o (9-25o) to 15.7o (0- decubitus position. An oblique anatomic 22o), respectively. window to access the L2-S1 discs was exam- Based on patient satisfaction, excellent and ined. Measurements were taken in a static good results were obtained in all patients. state and then with mild retraction of the DISCUSSION AND CONCLUSIONS: Inflam- psoas. The access window was defined at matory cytokines are expressed in the L2-3, L3-4, and L4-5 as the left lateral border pathological human intervertebral disc. Ad- of the aorta (or iliac artery) and the anterior ditional discoblock following discography medial border of the psoas. The L5-S1 win- should ensure the diagnosis of discogenic dow of access was defined transversely pain, leads to success of the surgery. from the mid-sagittal line of the inferior endplate of L5 to the medial border of the left common iliac vessel and vertically to the GP202 first vascular structure that crosses midline. RETROPERITONEAL OBLIQUE WINDOW TO RESULTS: The mean static/retracted access THE L2-S1 INTERVERTEBRAL DISCS IN THE window was as follows; L2-3 = LATERAL POSITION: AN ANATOMIC STUDY 17.8mm/24.6mm, L3-4 = 18.7mm/26.3mm, Timothy T Davis, MD-1, Richard A Hynes, L4-5 = 14.5mm/23.8mm. The L5-S1 disc MD FACS-2, Scott W Spann, MD-3, Michael space means were 15.1mm between mid- MacMillan, MD-4, Brian Kwon, MD-5, John line and left common iliac vessel, and Liu, MD-6, Frank Acosta, MD-6, Thomas E 24.6mm from the first midline vessel to the Drochner, MS-7, Daniel A. Fung, MD-1 inferior endplate of L5. 1. The Center for Spine and Joint Restora- DISCUSSION: The MIS oblique window al- tion, Santa Monica, CA, 2. The B.A.C.K Cen- lows access to the L2-5 discs as well as L5-S1 ter, Melbourne, FL, 3. Westlake Orthopae- while keeping the patient in a lateral decu- dics and Spine, Austin, TX, 4. University of bitus position. Minimal psoas retraction Florida Orthopaedics and Rehabilitation, without significant tendon disruption al- Gainesville, FL, 5. Tufts Universiy School of lowed for a generous corridor to the disc Medicine, Boston, MA, 6. Cedars-Sinai Med- space.This study supports the potential of ical Center, Los Angeles, CA, 7. Medtronic an MIS oblique retroperitoneal approach to Spine & Biologics, Memphis, TN the L2-S1 discs.

INTRODUCTION: Access to the interverte- bral discs from L2-S1 in one surgical position can be challenging. The lateral transpsoas 242

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Pre-surgical psychological screening of spine GP203 surgery candidates might ultimately lead to PSYCHIATRIC DISORDERS AND MAJOR the enhancement of perioperative out- SPINE SURGERY: EPIDEMIOLOGY AND comes in this growing segment of the US PERIOPERATIVE OUTCOMES population. Mariano E. Menendez, Valentin Neuhaus, Arjan G. J. Bot, David Ring, Thomas D. Cha Orthopaedic Spine Service, Massachusetts GP204 General Hospital, Boston (MA), U.S.A. CLINICAL OUTCOMES OF SPINOUS PRO- CESS-SPLITTING LAMINECTOMY FOR LUM- INTRODUCTION: Psychiatric comorbidity is BAR SPINAL CANAL STENOSIS. a known risk factor for impaired health- Satoshi Komatsubara, Nobuo Arima, Sei related quality of life and poor long-term Shibuya, Shiro Oka, Tetsuji Yamamoto outcomes following spine surgery, yet little DEPARTMENT OF ORTHOPAEDIC SURGERY, is known about its impact in the periopera- FACULTY OF MEDICINE, KAGAWA UNIVER- tive spine surgery setting. The purpose of SITY this study was to evaluate the influence of preoperative depression, anxiety, schizo- INTRODUCTION: Spinous process splitting phrenia or dementia on in hospital (1) ad- lumbar laminectomy (SPL) for the treatment verse events, (2) mortality and (3) non rou- of one or two levels of lumbar spinal canal tine discharge in patients undergoing major stenosis has been reported to be less inva- spine surgery. sive that conventional laminectomy (CON). METHODS: Using the National Hospital However, no studies have evaluated the Discharge Survey database for the years invasiveness of SPL in multilevel decom- 1990 through 2007, all patients undergoing pression. The aim of this study is to evaluate either spinal fusion or laminectomy were the invasiveness of SPL and CON. identified and separated into groups with METHODS: This study comprised 102 pa- and without psychiatric disorders. Multivar- tients (male, 57; female, 45; mean age, 73 iable binary logistic regression analysis was years) with lumbar spinal canal stenosis performed for each of the outcome varia- treated by lumbar laminectomy retrospec- bles. tively. CON was performed from January RESULTS: Between 1990 and 2007, an es- 1995 to December 2004, and SPL was per- timated 5,382,343 spinal fusions and lami- formed from January 2005. Intra-operative nectomies were performed. The prevalence time, intra-operative blood loss and Japa- of diagnosed depression, anxiety and schiz- nese Orthopaedic Association (JOA) score ophrenia among the study population in- were evaluated. The serum level of C- creased significantly over time. Depression, reactive protein (CRP), white blood cell anxiety, schizophrenia and dementia were (WBC) count and creatine phosphokinase associated with higher rates of non routine (CPK) were evaluated preoperatively and on discharge. Depression, schizophrenia and postoperative day (POD) 1, 7 and 14. Pa- dementia were associated with higher rates tients were grouped according to whether of adverse events. Dementia was the only decompression was performed at one, two, psychiatric disorder associated with a higher three or four levels. risk of in hospital mortality. RESULTS AND DISCUSSION: For each num- DISCUSSION: Patients with a psychiatric ber of decompression levels, no differences comorbidity undergoing major spine surgery were observed between groups for the in- are at increased risk for perioperative ad- tra-operative blood loss, JOA score, WBC verse events and post hospitalization care. count and CRP levels. SPL intra-operative 243

GENERAL POSTERS time was shorter than that with CON when respectively. MIS-TLIFs were performed by one or two levels of decompression were one spine surgeon and open TLIFs by three performed. The level of CPK on POD 1 was experienced spine surgeons. Operation lower after SPL than after CON when one time, blood loss, complications, ODI, and level of decompression was performed, but VAS for low back pain and leg pain at pre- when two or more levels of decompression operative and final follow-up period were were performed, the level of CPK on POD 1 assessed. was not significantly different between RESULTS: Significant differences were found groups. In conclusion the SPL approach for in operating time (MIS/Open: lumbar laminectomy is less invasive for one 127±38/186±57 min, p=0.002), blood loss or two levels of decompression. However, in (135±131/362±240ml, p=0.004), final ODI multilevel decompression, the extent of (14.6±3.8/23.6±4.4, p=0.01), and final VAS invasion is not significantly different than for low back pain (23.5±15.9/38.8±14.9, with the CON approach. p=0.006). Significant improvements were obtained in ODI (MIS: 53.3±15.6 to 14.6±3.8, p<0.001; Open: 45.5±15.2. to GP205 23.6±4.4, p=0.02) and VAS for leg pain (MIS: EFFECTIVENESS OF MIS-TLIF AS REVISION 68.8±15.6 to 17.9±7.7, p<0.001; Open: SURGERY 74.1±15.3 to 22.8±14.0, p<0.001). Im- Kaneko Y.１, Ishii K.2, Ishihara S.4, Hikata provement of VAS for low back pain in MIS T.2, Iwanami A.2, Hosogane N.2, Watanabe was significant (63.6±19.4 to 23.5±15.9, K. 3, Nakamura M.2, Koyanagi T.１,Toyama p<0.001), while in Open not significant Y.2, Matsumoto M.2 (45.0±19.7 to 38.8±14.9, p=0.35). Complica- 1Dept. of Orthopedic Surgery, Kawasaki tions in MIS group included transient leg Municipal Kawasaki Hospital, Kanagawa, pain due to epidural hematoma in two pa- Japan; 2Dept. of Orthopedic Surgery, School tients. In Open group, there were two cases of Medicine, Keio University, Tokyo, Japan; of deep wound infection. Dural tear oc- 3Dept. of Advanced Therapy for Spine and curred in two cases each in MIS and Open Spinal Cord Disorders, Keio University, groups. Tokyo, Japan; 4Dept. of Orthopedic Surgery, DISCUSSION: MIS-TLIF can yield better im- Nerima General Hospital, Tokyo, Japan; provement in low back pain than conven- tional TLIF in revised patients with less sur- INTRODUCTION: To evaluate short- to mid- gical invasiveness, although it is associated dle-term clinical and radiographic outcomes with several complications including dural of minimally invasive transforaminal lumbar tear and epidural hematoma. interbody fusion (MIS-TLIF) and convention- al open TLIF as revision surgery for patients who previously had undergone discectomy GP206 or decompression surgery. Empty METHODS: A total of 33 patients (19 males, 14 females) who underwent 1-level MIS- TLIF (MIS: n=17, mean 65.4±11.7 years) or conventional open TLIF (Open: n=16, mean 53.6±14.0 years) as revision surgery were retrospectively reviewed. Follow-up period averaged 18.3±12.6 months. Previous sur- geries performed were discectomy (n=13), laminectomy (n=12), and fenestration (n=8), 244

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measures. Strong correlations were ob- GP207 served between moderate/vigorous range CORRELATIONS BETWEEN SELF-REPORT, activity and the SF-36 physical component LABORATORY, AND ACCELEROMETY score (r=0.5 to 0.7) and the SSS physical MEASURES 6-MONTHS FOLLOWING DE- function subscale (r=0.6 to 0.7). Moderate COMPRESSION SURGERY FOR LUMBAR correlations were observed for SPINAL STENOSIS light/moderate range activity and the NCOS Matthew Smuck1, Matthew P. Buman2, (r=0.4 to 0.6) and the ODI (r=0.4 to 0.5). Agnes Martinez-Ith1, William L. Haskell3, Light range activity demonstrated moderate Ming-Chih J. Kao4 correlations to the SPWT (r=0.4 to 0.6) and 1 Stanford University, Department of Ortho- strong correlations to the balance portion of paedics, Redwood City CA, USA, 2 Arizona the SPPB (r=0.6 to 0.8). Overall, bout-based State University, Department of Exercise accelerometry measures appeared more and Wellness, Phoenix AZ, USA, 3 Stanford sensitive to change than daily count thresh- University, Department of Medicine, Palo olds. Alto CA, USA, 4 Stanford University, De- DISCUSSION: In patients with lumbar steno- partment of Anesthesiology, Redwood City sis, post-surgical improvements in free- CA, USA living physical activity, especially activity bout lengths, are more sensitive to change INTRODUCTION: Accelerometers record linked to self-reported measures than la- free-living physical activity and recently boratory assessments of function. gained the attention of spine researchers. An objective and quantifiable outcomes tool has obvious advantages, yet the role of GP208 acceleromety in spine research remains RISK FACTORS FOR ADJACENT SEGMENT undefined. The aim of this study was to DISEASE AFTER POSTERIOR LUMBAR evaluate, in patients undergoing lumbar INTERBODY FUSION AND EFFICACY OF stenosis surgery, correlations between in- SIMULTANEOUS DECOMPRESSION SUR- terval changes in accelerometry and those GERY FOR SYMPTOMATIC ADJACENT SEG- in laboratory and self-reported outcomes. MENT DISEASE. METHODS: A prospective observational Tomohiro Hikata, Akio Iwanami, Naobumi study of 16 patients scheduled for lumbar Hosogane, Kota Watanabe, Ken Ishii, Ma- stenosis surgery. Baseline and 6mo post-op saya Nakamura, Michihiro Kamata, Yoshiaki evaluations included accelerometry for 7 Toyama and Morio Matsumoto. consecutive days (Actigraph GT3x+), self- Department of Orthopaedic Surgery, School reported measures (ODI, NCOS, SF-36 and of Medicine, Keio university. SSS), and laboratory evaluation with a self- paced walking test (SPWT) and Short Physi- INTRODUCTION: Posterior Lumbar cal Performance Battery (SPBB). Interbody Fusion (PLIF) increases mechani- Accelerometry data was computed as daily cal stress and can cause degenerative count thresholds and activity bouts. Spear- changes at the adjacent segment. However, man Correlations were used to investigate the precise causes of ASD after PLIF are not the relationships between interval changes known, and it is unclear whether simulta- in accelerometry and those in laboratory neous decompression surgery for sympto- and self-reported measures. matic ASD is effective. The aim of this study RESULTS: Overall, stronger correlations is to investigate, radiographically and symp- were observed between accelerometry and tomatically, the risk factors for adjacent self-reported outcomes than laboratory segment disease (ASD) in the lumbar spine 245

GENERAL POSTERS following L4/5 PLIF and to examine whether Makoto Suzuki, Miki Hayakawa, Koichi decompression surgery for the adjacent Nakagawa, Arata Nakajima, Masato segment (L3/4) reduces the occurrence of Sonobe, Yoshifumi Shibata, Hiroshi symptomatic ASD. Takahashi, Shinji Taniguchi, Manabu METHODS: Fifty-four patients who under- Yamada, Yasuchika Aoki went L4/5 PLIF for L4 degenerative Department of Orthopaedic Surgery, Toho spondylolisthesis and could be followed for University Sakura Medical Center at least 2 years were included. Of these, 37 were treated simultaneously with decom- INTRODUCTION: Patients are usually placed pression surgery at L3/4. We measured ra- in a supine position after lumbar surgery; diographic changes and assessed symptoms however, a considerable number of patients from the cranial adjacent segment. are unable to maintain that position. To RESULTS: Thirty-one patients (57.4%) met date, there have been no studies comparing radiological criteria for ASD. The length of postoperative pain and discomfort between follow-up (p=0.004) and simultaneous de- the two positions. A prospective random- compression surgery at L3/4 (p=0.009) were ized study was conducted to determine statistically significant factors for radiologic which position is more comfortable for pa- diagnosis of ASD. Seven patients (13.0%) tients. had symptomatic ASD: 6 in the decompres- METHODS: Patients with lumbar degenera- sion group (16.2%) and one in the PLIF-only tive disease (n=45) treated by decompres- group (5.9%). Simultaneous decompression sion surgery (n=23) or fusion surgery (n=22; surgery did not reduce the incidence of <2 levels) were randomly assigned to re- symptomatic ASD (p=0.256). Local lordosis ceive either supine (n=24) or lateral (n=21) at the fused segment (p=0.005) and the postoperative positions. Patients were sagittal angle of the facet joint at L3/4 asked to maintain that postoperative posi- (p=0.024) were statistically significant pre- tion until a day after surgery; those unable dictors of symptomatic ASD, which was ac- to do so were allowed to change their posi- companied by postoperative anterior tion. A day after surgery, postoperative back listhesis above the fused segment (S group, pain and discomfort were evaluated using a 8.4 ± 8.0%; NS group: -0.7 ± 5.0%, P=0.024). visual analogue scale (VAS; 0-100 mm). DISUCUSSION: Patients whose facet joint at Rates of patients able to maintain their po- the adjacent segment had a more sagittal sition were also evaluated. orientation had postoperative anterior RESULTS: VAS scores for postoperative back listhesis, which caused symptomatic ASD. pain (supine: 64.4; lateral: 54.7) showed no Simultaneous decompression surgery with- significant difference. VAS scores for the out fusion at adjacent level was not effec- supine group did reflect a non-significant tive for these patients, but rather there was trend to experience more severe discomfort a possibility that it induced symptomatic (74.1), compared to the lateral group (63.7, ASD p=0.08). In the supine group, significantly fewer patients were able to maintain their position (29.2%) than in the lateral group GP209 (58.3%). When limited to patients that re- A PROSPECTIVE RANDOMIZED CON- ceived decompression surgery, there was TROLLED STUDY COMPARING SUPINE PO- no significant difference in the rate of pa- SITION AND LATERAL POSITION FOR POST- tients who maintained their position be- OPERATIVE POSITIONING; WHICH POSI- tween the supine (45.5%: 5/11) and lateral TION IS COMFORTABLE AFTER SURGERY (75.0%: 9/12) groups. When limited to fu- FOR LUMBAR DEGENERATIVE DISEASE? 246

GENERAL POSTERS sion surgery, there was a non-significant blood. The concentration of growth factors trend of a difference (p=0.07) between the in PRP was more than 10 times higher than supine (15.4%: 2/13) and lateral groups that in normal blood. The Catwalk analysis (55.6%: 5/9). showed that contact pressure by the hind DISCUSSION: A difference in patients’ post- paws was decreased and the duration of operative back pain and discomfort be- paw contact was shortened in the surgery tween the supine and lateral postoperative and surgery with PRP groups compared with positions has been demonstrated. Particu- the sham group (P<0.05). No significant dif- larly, patients receiving fusion surgery may ference was found between the surgery and have difficulty maintaining the postopera- surgery with PRP groups. The proportion of tive supine position. FG-labeled and CGRP-immunoreactive DRG neurons was increased in the surgery group compared with the sham group, and was GP210 significantly lower in the surgery with PRP THE EFFECT OF PLATELET-RICH PLASMA ON group compared with the surgery group. INVASIVE PARASPINAL MUSCLES DURING The histology showed that the numbers of SPINAL SURGERY neutrophils and lymphocytes were in- Kamoda H., Ohtori S., Ishikawa T., Miyagi creased in the surgery group. The increase M., Suzuki M., Sakuma Y., Oikawa Y.,Kubota was significantly suppressed in the surgery G., Inage K., Saino T., Orita S., Yamauchi K., with PRP group. Inoue G., Takahashi K. DISCUSSION: Local inflammation of back Dept. of Orthopedic Surgery, Chiba Univ muscles was suppressed by adding PRP, but no significant difference was found in be-

INTRODUCTION: We examined the effect of havior suggesting the presence of back pain. platelet-rich plasma (PRP) on spinal muscle PRP did not significantly reduce low back pain and inflammation in a rat model of a pain resulting from surgical damage. posterior surgical approach. METHODS: Rats were divided into three GP211 groups: a sham group, a surgery group, and ANATOMICAL EVALUATION OF THE a surgery with PRP group. In the sham LUMBAR SPINAL NERVE ROOTS WITH group, only an incision was made. In the DIFFUSION TENSOR TRACTOGRAPHY: surgery group, bilateral lumbar back mus- PRESURGICAL IMAGING FOR DIRECT cles were separated and the neurotracer LATERAL INTERBODY FUSION FluoroGold (FG) applied between the sepa- Oikawa, Yasuhiro1; Eguchi, Yawara1; rated muscles. In the surgery with PRP Ohtori, Seiji1; Inoue, Gen2; Yamauchi, group, the same surgery was performed Kazuyo1; Orita, Sumihisa1; Kamoda, applying PRP in the same area. One and two Hiroto1; Ishikawa, Tetsuhiro1; Miyagi, Ma- weeks after treatment, a Catwalk system sayuki1; Suzuki, Miyako1; Sakuma, Yoshihi- was used to evaluate back pain, and back ro1; Kubota, Go1; Inage, Kazuhide1; muscles were resected and evaluated histo- Sainoh,Takeshi1; Nakata, Yukio1; Sato, logically using hematoxylin and eosin stain- Jun1; Watanabe, Atsuya3; Takahashi, ing. In addition, dorsal root ganglia were Kazuhisa1 resected to evaluate inflammation using 1.Department of Orthopaedic Surgery, immunohistochemistry with CGRP as a Graduate School of Medicine Chiba marker. University, Japan 2.Department of RESULTS: The platelet concentration in PRP Orthopaedic Surgery, Kitasato University, was 4.3 times higher than that in normal School of Medicine, Japan 3.Department of 247

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Orthopaedic Surgery, Teikyou University Chiba Medical Center, Japan

INTRODUCTION: Direct lateral interbody fusion (DLIF) has been reported as a new surgical procedure with a minimally invasive lateral transpsoas approach. Although real- time electromyography (EMG) is recom- mended to avoid complications related to lumbar spinal nerve and lumbosacral plexus injury, the risk of such complications re- mains high. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) have been reported as novel imaging tools with which to evaluate and visualize highly anisotropic peripheral nerve fiber tracts. Several authors have reported the course of Fig. Diffusion tensor tractography merged with T2- lumbar spinal nerves and the lumbosacral weighted images DISCUSSION AND CONCLUSION: DTT can plexus, but these were all in cadavers. The visualize lumbar spinal nerve roots. The purpose of this study is to provide an ana- nerve distribution we found was similar to tomical evaluation of the spinal nerve that found in previous cadaveric studies. It course using DTT, to investigate its efficacy is safe to access the anterior half of the disc for presurgical imaging. space during DLIF, but there is risk of the METHODS: Thirty-five patients underwent nerve injury for the posterior half. The risk DTT with 3.0T MR imaging. Tractography of of nerve injury during DLIF may be de- L3 and L4, and the location on each spinal creased by using DTT for presurgical imag- nerve root at the L3-4 and L4-5 levels were ing. evaluated. The location of the nerve roots was categorized into one of six zones (1 through 4, A, P), defined as: 1 through 4 GP212 denote the disc space divided into quartiles IS THE POSITIVE NERVE ROOT SEDIMENTA- from anterior to posterior, A denotes ante- TION SIGN IN PATIENTS WITH LUMBAR rior to the disc space, and P denotes poste- SPINAL STENOSIS REVERSIBLE AFTER DE- rior to the disc space. COMPRESSION SURGERY? RESULTS: L3 nerve roots were found in zone M. Melloh (1), T. Barz (2), L.P. Staub (3), S.J. 4 and P at L3-4. A quarter of L3 nerve roots Lord (3), H.R. Merk (4) were found in zone 3 at L4-5. L4 nerve roots (1) Western Australian Institute for Medical were found in zone 4 and P at L4-5. At L3-L4 Research (WAIMR), University of Western nerve roots were located in the most poste- Australia, Nedlands, Australia (2) rior quarter of the vertebral body and dor- Department of Orthopaedic Surgery, sally, and at L4-L5 nerve roots were located Asklepios Klinikum Uckermark, Schwedt/ in the mid posterior and dorsally. Oder, Germany (3) NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia (4) Department of Orthopaedic Surgery, University of Greifswald, Greifswald, Germany

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INTRODUCTION: The Nerve Root Sedimen- the reversibility of a positive SedSign is cor- tation Sign (SedSign) has been established related with an improved clinical outcome. as a new radiological sign in the diagnosis of lumbar spinal stenosis (LSS). In patients without LSS, on supine Magnetic Resonance GP213 Imaging (MRI) lumbar nerve roots sediment INVERTED Y APPROACH TO LUMBOSACRAL to the dorsal part of the dural sac. In pa- REGION- ANALYSIS OF 525 CASES OVER 10 tients with LSS, this nerve root sedimenta- YEARS. tion is not always seen. The absence of Krishna Kumar Ramachandran Nair, nerve root sedimentation has been defined Renjitkumar J as positive SedSign. As patients with a posi- Department of Orthopaedics, Amrita Insti- tive SedSign may benefit from surgical de- tute of Medical Sciences, Cochin, Kera- compression the Sign might assist the spine la,India surgeon to determine the indication for surgery. The aim of this study was to inves- INTRODUCTION: Traditional approach to tigate if in patients with LSS the positive lumosacral region utilizes midline incision, SedSign will turn negative after lumbar de- which often requires long incision to get compression. sufficient exposure. We describe our expe- METHODS: Retrospective cohort study of rience with inverted Y approach to lum- consecutive spine patients with an initial bosacral junction. MRI of the lumbar spine in whom a follow- OBJECTIVE: To analyze the surgical steps, up MRI was performed after decompression complications and results of inverted Y inci- surgery. Comparison of the primary MRIs sion to approach lumbosacral region in a with the follow-up MRIs in regard to the tertiary care referral center( Amrita Insti- presence of nerve root sedimentation (neg- tute of Medical Sciences, Kochi) by file re- ative SedSign). view. RESULTS: Fifty-seven of 118 LSS patients MATERIALS AND METHODS: Total of 525 had a positive SedSign, of these 39 had un- patients were included in the study with the dergone spine surgery. In this group, 12 range of age from 17 to 75 years and mean patients were identified who had a post-op age being 51.24 years. Mean follow-up pe- MRI of the lumbar spine (7 male, 5 female, riod was 26 months, with a range from 10 mean age 69 yrs [range 52-83]). Eight pa- to 64 months. The surgeries included tients demonstrated a negative SedSign, 3 PLF,PLIF,TLIF and Iliolumbar fixations. patients had a positive SedSign associated RESULTS: 522 patients had primary wound with a newly occurred stenosis in another healing and 3 patients had wound break- previously not affected segment. One pa- down. Of these 3 patients, two had previous tient had an arachnoiditis with a positive radiation treatment to lumbosacral region SedSign but without stenosis. and one patient had multiple surgeries for DISCUSSION: Despite several limitations of spondylodiscitis earlier. this study the reversibility of a pre-op posi- Discussion: Inverted Y Approach to tive SedSign was demonstrated after de- lumosacral region is a simple and safe tech- compressing the affected level; except for a nique with minimal wound complications. case of arachnoiditis which could not be differentiated from spinal stenosis due to the parietal clumping of nerve roots. Fur- ther research is required to investigate in a prospective representative patient sample if

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(P=0.427). Spondylolisthesis was found in 1 GP214 of thoracolumbar fusion and 2 of lower ADJACENT SEGMENT PATHOLOGY AFTER lumbar fusion (P=0.328). THORACOLUMBAR FUSION IN THORACOL- DISCUSSION: The occurrences of ASPs after UMBAR FRACTURE: AN AGE AND SEX thoracolumbar fusion were not different MATCHED-COHORT STUDY WITH LOWER with those of lower lumbar fusion. The limi- LUMBAR FUSION tation of this study was devoid of including Jeon, Chang-Hoon, Chung, Nam-Su, Park, thoracolumbar fracture without fusion. Jeong-Uk, Kim, Jea-Joong Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, Re- GP215 public of Korea DO RISK FACTORS MATTER IN PROPHYLAC- TIC ANTIBIOTICS REDUCTION AFTER SPINAL INTRODUCTION: Although numerous stud- SURGERY?: A PROSPECTIVE COMPARATIVE ies have reported the adjacent segment STUDY pathology (ASP) after lumbar fusion, little Jeon, Chang-Hoon, Chung, Nam-Su, Park, attention has been paid to the ASP after Jeong-Uk, Kim, Jea-Joong thoracolumbar fusion. The purpose of this Department of Orthopaedic Surgery, Ajou study was to investigate the ASP after University School of Medicine, Suwon, thoracolumbar fusion as compared with Republic of Korea lower lumbar fusion. METHODS: Forty-four patients with thora- INTRODUCTION: Prophylactic antibiotics columbar (T10-L2) fracture treated with duration after spinal surgery remains con- posterior fusion using pedicle screw instru- troversial, especially for patients with risk mentation that had taken MRI at the time factors. We designed a prospective compar- of index treatment and at least 2-year fol- ative study to evaluate whether risk factors low-up were included. A matched cohort of affect the occurrence of surgical site infec- 47 patients that underwent lower lumbar tion (SSI) and the changes of host immune (L3-S1) fusion with pedicle screw instrumen- responses depending on the duration of tation was identified. The ASPs including prophylactic antibiotics. disc degeneration, disc herniation, spinal MATERIALS AND METHODS: This study in- stenosis and spondylolisthesis between the volved 150 consecutive patients who had 2 groups were compared with MRI. undergone a spinal surgery and were ad- RESULTS: There was no difference regarding ministrated first generation cephalosporin the patients’ age (P=0.066), gender as prophylactic antibiotics. The duration of (P=0.152), and the duration of follow-up antibiotics administration had been altered MRI (P=0.150) between thoracolumbar fu- for each fifty consecutive patients as 5-day, sion group and lower lumbar fusion group. 3-day, and 1day. Preoperative antibiotics The mean instrumentation level was 3.5 ± prophylaxis was commonly administrated 0.9 in thoracolumbar fusion and 1.6 ± 0.7 in for the 3 groups within 1 hour prior to sur- lower lumbar fusion (P< 0.001). Adjacent gical incision with the same trial antibiotics. disc degeneration was found in 11 of thora- Intraoperative bacterial culture on the sur- columbar fusion and 14 of lower lumbar gical site was performed. The occurrences fusion (P=0.567). Adjacent disc herniation of SSI were evaluated as described by Na- was found in 4 of thoracolumbar fusion and tional Nosocomial Infection Surveillance 6 of lower lumbar fusion (P=0.201). Spinal guideline. SSI was considered as acute if it stenosis was found in 5 of thoracolumbar occurred within postoperative 1 month, fusion and 7 of lower lumbar fusion subacute for < 3 months, and chronic for > 3 250

GENERAL POSTERS months. Serial changes of hematologic in- der which occurred within one year after flammatory markers and DIC profiles were surgery (early ASD) and an adjacent seg- compared until postoperative 2 weeks. Risk ment disorder which occurred in the later factors such as age, sex, body mass index, periods (late ASD). Intervertebral height, estimated blood loss, diabetes mellitus, range of motion, slip, and sagittal alignment smoking, nutritional status, baseline labora- were measured by preoperative XP and in- tory values, catheter indwelling, the dura- tervertebral joint angle by CT, and then ad- tion of drain, and type of surgery were ana- jacent vertebral narrowing, absence or lyzed. presence of instability, and an increase or RESULTS: Incisional SSI was found in 2, 3, decrease of range of motion with time dur- and 3 patient with 5-day, 3-day, and 1-day ing postoperative follow up were examined. administration, respectively (P=0.887). Or- RESULTS AND DISCUSSION: Adjacent verte- gan/space SSI occurred in 1 patients in all bral narrowing occurred in 15 of 69 patients the three groups. All SSIs were acute infec- (21.0%), including ten in the early ASD and tion. There was no difference for intraoper- five in late ASD, showing that more ASD ative bacterial culture. Laboratory results occurred within one year. In the early ASD, revealed that postoperative changes of he- L3/4 disorder occurred in three patients by matologic inflammatory markers and DIC L4/5 PLIF + L3/4 fenestration, L2/3 disorder profiles were not different among the three occurred in four. Rregarding to the onset of groups (all P>0.05). The occurrence of SSI ASD, there were no significant difference was not affected by having risk factors. about the facet angle. However, sagittal DISCUSSION Prophylactic an plane was affected to the onset of ASD. Ta- ble showed the results of sagittal alignment. In early ASD group, the trunk tilted forward GP216 more severely, and the pelvis tilted more THE LUMBO-PELVIC SAGITTAL ALIGNMENT forward. before the operation. In general, AND EARLY ADJACENT SEGMENT DISOR- DS has posterior rotated pelvis in order to DER AFTER PLIF IN PATIENTS WITH LUM- compensate for lumbar slip. However, if the BAR DEGENERATIVE SPONDYLOLISTHESIS . pelvic anterior rotation was severe before Nishimura H, Endo K, Suzuki H, Tanaka H, surgery, the LLA should be correct enough. Yorifuji M, Yamamoto K Otherwise, because the postoperative Department of Orthopedic Surgery, Tokyo change of pelvic rotation is small, the me- Medical University chanical stress above PLIF segment would be increased.

PURPOSE: Spondylodesis is indicated for a number of patients with lumbar degenera- GP217 tive spondylolisthesis (SD); however, its in- VERTEBROPLASTY FOR VERTEBRAL fluence on early onset adjacent segment PSEUDOARTHROSIS IN PATIENTS WITH disorder is a concern. The purpose of this SECONDARY OSTEOPOROSIS: COMPARA- study was to evaluate the early onset adja- TIVE STUDY WITH PRIMARY AND SECOND- cent segment disorder (ASD) after PLIF and ARY OSTEOPOROSIS lumbo-pelvic sagittal alignment. Yoshikazu Shinohara, Hiromitsu Toyoda, SUBJECTS AND METHODS: Subjects were 69 Hidetomi Terai, Akinobu Suzuki, Sho patients with unstable DS who underwent Dohzono, Tomiya Matsumoto, Kentaro PLIF and postoperative follow-up for 3 years Yamada, Shinji Takahashi, Kuniaki or longer. Subjects were classified into 2 Tsukiyama, Hiroaki Nakamura groups; namely, an adjacent segment disor- Osaka City University Graduate School of 251

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Medicine rection in the treated vertebrae.

INTRODUCTION: Osteoporosis has been classified as either primary or secondary. GP218 Although secondary osteoporosis is less SURGICAL DECOMPRESSION OF THE THO- common, it is becoming more frequently RACIC SPINAL CANAL IN diagnosed. The purpose of this study was to ACHONDROPLASIA; INDICATION AND compare the clinical outcomes of OUTCOME vertebroplasty (VP) for patients with prima- CL Vleggeert-Lankamp and WC Peul ry and secondary osteoporosis. Department of Neurosurgery, Leiden Uni- METHODS: In our hospital we perform VP versity Medical Centre (LUMC), Leiden, the using calcium phosphate cement (CPC) for Netherlands the treatment of vertebral pseudoarthrosis.

We reviewed 45 patients (Pts) undergoing INTRODUCTION: The achondroplastic spinal 49 VPs with more than 1 year follow up. canal is narrow due to short pedicles and a There were 7 men and 38 women with an small interpediculate distance. Compression average age of 76.0. We divided these pa- of neural structures passing through this tients into patients with primary osteoporo- canal is therefore regularly encountered, sis (P-group) and patients with secondary but scarcely described. Symptomatology, osteoporosis (S-group). Outcomes including radiologic evaluation, and treatment of 20 pain, complications, frequency of new frac- achondroplasts that underwent decompres- tures and radiographic changes (anterior sion of the thoracic medulla is described vertebral height restoration) in S-group and outcome is correlated to the size of the were compared with P-group. spinal canal and the thoracolumbar RESULTS: Fourteen Pts were included in S- kyphotic angle. group. The causes of secondary osteoporo- METHODS: The modified JOAscore, Nurick sis were followed. Long-term corticosteroid score, European Myelopathy Score, Cooper therapy for the treatment of the coexisting myelopathy scale for lower extremities, and illness such as rheumatologic diseases was Odom criteria before and after surgery were 7, Diabetes mellitus was 7, gastrectomy compared. MR imaging was evaluated for patient was 2, and Liver cirrhosis was 1. the size of the spinal canal, medullary com- There was no significant difference between pression, and presence of myelomalacia. the two groups in pre- and post- operative The thoracolumbar kyphotic angle was JOA score and VAS. The frequency of new measured on fluoroscopy. fractures was not significantly different be- RESULTS: Symptomatology included deteri- tween the two groups. The 23.0% of the oration of walking pattern, pain, cramps, anterior vertebral body height correction spasms, and incontinence. MRIs of all pa- was lost in S-group, but 13.5% in P-group. tients demonstrated medullary compression Number of cases of height loss > 10% were due to degenerative changes. Surgery re- significantly higher in the S- group than P- sulted in (slight) improvement on all afore- group mentioned ranking scales. Surgery at the DISCUSSION: VP performed for vertebral wrong level occurred in 15%, but no serious pseudoarthrosis as a result of secondary complications occurred. The mean thora- osteoporosis is as safe and effective in re- columbar kyphotic angle was 20 degrees, lieving pain as those of primary osteoporo- and no correlation was established with sis. However, patients with secondary oste- outcome after surgery. No post-operative oporosis showed higher risk in loss of cor- increase in this angle was reported. Neither

252

GENERAL POSTERS was there a correlation between size of the score of 16.4 changed to 24.4 at final fol- spinal canal and outcome. low-up, with a recovery rate of 64.1%. The DISCUSSION: Decompressive surgery of the mean pre-op VAS of 62.7mm was reduced achondroplast thoracic medulla can be per- to 20.6mm at final follow-up. Re-operation formed safely if anatomical details are taken was performed on 4 patients (proximal into account. Spondylodesis did not appear junctional kyphosis in 2 cases; disc herni- obligatory. Special attention should be paid ation at L5/S in 2 cases). The fusion rate was to the method of surgery, how to identify 89% with 8 of 9 non-union cases were those the level of interest and follow up of the at L5/S. Subsequent vertebral fracture was thoracolumbar kyphotic angle. observed in 14.6% of the patients. The pre- op lumbar lordosis (L1-S) of 2.5˚ changed to 48.8˚ at post-op and 34.8˚ at follow-up. The GP219 obtained lordosis at the fusion area was DORSAL VENTRAL DORSAL THREE STAGE 48.6˚ at post-op and 35.2˚ at follow-up. The CORRECTION SURGERY FOR LUMBAR single level obtained lordosis at DVD correc- KYPHO-SCOLIOSIS DEFORMITY tion level was 17.6˚at post -op and 15.1˚ at Kazuyuki Otani M.D., Ph.D., Osamu Nakai follow-up. The pre-op sagittal vertebral axis M.D., Ph.D., Shigeo Shindo M.D., Koichi of 98.0mm changed to 49.2mm at follow- Mizuno M.D., Ph.D. up. Department of Orthopaedic Surgery, Kudanzaka Hospital, Tokyo, Japan

INTRODUCTION: Sagittal balance restora- tion is essential in achieving positive out- comes in correction of adult spinal deformi- ties. We have performed dorsal ventral dor- sal (DVD) three-stage correction for patients with maximum kyphosis correction re- quired. The aim of the study was to deter- mine the efficacy of the DVD procedure for patients with severe lumbar kyphosis de- formity. DISCUSSION: The DVD procedure was use- ful in the correction of kyphosis and provid- ed good clinical results. The remaining chal- METHODS: Retrospective review of 82 pa lenges are how to determine the fusion area tients (8 male and 74 female). Mean age 66 and how to avoid L5/S pseudarthrosis, sub- years (46-78). Mean follow-up period 3.7 sequent vertebral fracture and proximal years (1-12). Facetectomy at 2-3 levels per- junctional kyphosis. formed in first stage, followed by anterior release and interbody fusion at same level; posterior fusion with instrumentation per- formed in final stage. Mean fused levels 5.4 (range 3-11). Clinical assessment performed using JOA score and visual analog scale for low back pain. Radiological measurement performed using pre-operative, post- operative and final films. RESULTS: The mean pre-operative JOA 253

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the surgical group compared to an increase GP220 from 3 to 11% in the conservative group. ASSOCIATION BETWEEN VERTEBRAL The prevalence of type 2 VESC decreased ENDPLATE SIGNAL CHANGES AND LOW from 39 to 29% in the surgical group while BACK PAIN IN PATIENTS WITH CURRENT remaining comparable in the conservative OR PREVIOUS SYMPTOMS OF SCIATICA group. The prevalence of LBP at one year A. el Barzouhi1, C.L.A.M. Vleggeert- was 12% in patients with no VESC, 16% in Lankamp1, B.F. Van der Kallen2, G.J. patients with type 1 VESC, 11% in patients Lycklama à Nijeholt2, W.B. van den Hout3, with type 2 VESC and 3% in patients with B.W. Koes4, and W.C. Peul1,5 mixed type 1 and 2 VESC (P=0.34). Patients 1 Department of Neurosurgery, Leiden who showed an increase in the amount of University Medical Centre, Leiden, the VESC after one year did not significantly Netherlands 2 Department of Radiology, report more LBP compared to patients who Medical Centre Haaglanden, the Hague, the did not (OR 1.21, 95% CI 0.57-2.58, P=0.61). Netherlands 3 Department of Medical Undergoing surgery was associated with Decision Making, Leiden University Medical progression in the amount of VESC (OR Centre, Leiden, the Netherlands 4 8.56, 95% CI 4.67-15.67, P<0.001). Department of General Practice, DISCUSSION: Surgery highly accelerates the ErasmusMC, University Medical Centre, development of VESC. However, in this Rotterdam, the Netherlands 5 Department group of patients with current or previous of Neurosurgery, Medical Centre sciatica no association existed between the Haaglanden, the Hague, the Netherlands presence or progression of VESC and LBP. Therefore, VESC cannot be responsible for BACKGROUND: Patients with current or remaining or new LBP after surgical or con- previous symptoms of sciatica frequently servative treatment for sciatica. experience low back pain (LBP). One of the proposed causes for LBP is Vertebral End- plate Signal Changes (VESC) visualized by GP221 Magnetic Resonance Imaging. We investi- PREDICTION OF SURGERY FOR SCIATICA gated the association between VESC and WITH MRI LBP in patients with current or previous A. el Barzouhi1, C.L.A.M. Vleggeert- symptoms of sciatica. Lankamp1, B.F. Van der Kallen2, G.J. METHODS: The study population consisted Lycklama à Nijeholt2, W.B. van den Hout3, of 283 patients who were randomized to B.W. Koes4, and W.C. Peul1,5 surgery or to prolonged conservative care 1 Department of Neurosurgery, Leiden with surgery if needed. Participants under- University Medical Centre, Leiden, the went MRI both at baseline and after 1 year. Netherlands 2 Department of Radiology, The presence of VESC was correlated to LBP Medical Centre Haaglanden, the Hague, the (defined as a visual-analogue scale of at Netherlands 3 Department of Medical least 40mm on a scale of 0-100) using Fish- Decision Making, Leiden University Medical er’s exact tests and logistic regression. Centre, Leiden, the Netherlands 4 RESULTS: VESC were observed in 43% of the Department of General Practice, patients at baseline. Of the patients with ErasmusMC, University Medical Centre, VESC at baseline 40% had LBP compared to Rotterdam, the Netherlands 5 Department 38% of the patients with no VESC (P=0.70). of Neurosurgery, Medical Centre The prevalence of type 1 VESC increased Haaglanden, the Hague, the Netherlands from 1% at baseline to 35% one year later in BACKGROUND: A randomized trail showed 254

GENERAL POSTERS that surgery compared to a prolonged con- servative care strategy for patients with 6 to GP222 12 weeks sciatica yields similar functional SURGICAL OUTCOME OF DROP FOOT recovery rate results by one year. However, CAUSED BY DEGENERATIVE LUMBAR 39% of the patients assigned to prolonged DISORDERS; FOCUSED ON THE RECOVERY conservative care underwent surgery during OF MOTOR DEFICITS AND THE the first year after randomization. Previous- IMPROVEMENT OF LOW BACK AND LOWER ly we reported that sequestered herniations EXTREMITY SYMPTOMS. and the level of the disc herniation on Mag- Hiroshi Takahashi, Yasuchika Aoki, Arata netic resonance imaging (MRI) were not Nakajima, Masato Sonobe, Yoshifumi predictive for delayed surgery. The objec- Shibata, Shinji Taniguchi, Manabu Yamada, tive of this study was to evaluate the Teruo Furufu, Koichi Nakagawa, Kazuhisa preditice value of a more detailed qualita- Takahashi tive and quantitative MRI assessment for Toho University Sakura Medical Center delayed surgery. METHODS: MRIs of the 142 patients who INTRODUCTION: Drop foot, sometimes were assigned to receive conservative care caused by degenerative lumbar disorders, is were assessed, both qualitatively (by two a neuromuscular condition in which pa- neuropradiologists and one neurosurgeon tients are unable to dorsiflex the ankle. It is who were not previously involved in earlier important to advise patients as to how published papers) and quantitatively (by an much motor function will improve after independent investigator also not previous- surgery, and whether low back and lower ly involved). Logistic regression model and extremity symptoms will resolve, but there Receiver operating characteristic (ROC) are no reports describing surgical outcomes curve analysis were used to determine the such as residual pain and numbness in pa- predictive value of qualitative and quantita- tients with lumbar degenerative disorders tive MRI measurements on the occurrence complicated by drop foot. We conducted a of surgery during the first year. Area under retrospective study to evaluate these out- the ROC curve (AUC) above 0.7 was consid- comes. ered acceptable. METHODS: Between April 2010 and Sep- RESULTS: MRI variables such as the proba- tember 2011, 20 patients (12 men, 8 wom- bility of definite nerve root compression, en) with degenerative lumbar disorders and location and form of the disc herniation, drop foot underwent lumbar spine surgery. and baseline size of the disc herniation did We evaluated patient age, the causative not have any predictive value for delayed disorder, and the duration from symptom surgery. Size of the dural sac spinal canal did onset to surgery. We measured preopera- predict delayed surgery (per 25 mm2 in- tive and 1 year postoperative tivialis anteri- crement in size odds ratio 0.80 [95% CI 0.67- or (TA) strength using the manual muscle 0.96] and 0.82 [95% CI 0.71-0.95] respec- test (MMT). Low back and lower extremity tively). Using the size of the dural sac and symptoms were evaluated with a visual ana- spinal canal to predict delayed surgery re- logue scale (VAS), and activities of daily liv- vealed an AUC of 0.62 (95% CI 0.53-0.72) ing (ADL) by Oswestry Disability Index (ODI). and 0.62 (95% CI 0.53-0.72) respectively. RESULTS: Twelve patients had lumbar disc DISCUSSION: MRI is not acceptably able in herniation (LDH) and 8 had lumbar spinal assisting clinical decision making for surgical stenosis (LSS). TA strength was improved in or non-surgical management in patients LDH patients (pre-op, post-op: 2.46±0.77, who suffer from sciatica for 6 to 12 weeks. 4.23±1.09) to a significantly greater degree than in LSS patients (1.43±0.79, 3.14±1.77). 255

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The age at onset was negatively correlated METHODS: Twenty-eight patients (7 males with the TA strength recovery rate (p<0.01). and 21 females) underwent vertebroplasty There was also a negative correlation be- for neurological deficits caused by insuffi- tween this rate and the duration from onset cient union following OVF. Twenty-one pa- to surgery (p<0.05). Following surgery, sig- tients who underwent posterior decom- nificant improvement in low back pain, low- pression and fusion surgery with instrumen- er extremity pain, and numbness was ob- tation were selected as controls (group- served by both VAS and ODI in patients with PDF). Neurological improvement (modified both unfavorable (MMT<4), and favorable Frankel classification), invasiveness of sur- (MMT≥4) motor recovery. gery, surgical complications, and radio- CONCLUSIONS: Causative disorder, age, and graphic results were evaluated between the duration to surgery are prognostic factors 2 groups. for surgical outcome in patients with drop RESULTS: The neurological function deter- foot. ADLs, low back pain, and lower ex- mined using the modified Frankel classifica- tremity symptoms were improved after sur- tion were as follows: C1, 2; C2, 4; D1, 10; gery even when motor deficits remained. D2, 1; and E, 11 preoperatively and C1, 0; C2, 0; D1, 2; D2, 10; and E, 16 at the final follow-up. The symptoms improved in all GP223 patients with sensory disturbances or blad- VERTEBROPLASTY FOR PATIENTS WITH der and rectal disturbances. The mean op- NEUROLOGICAL DEFICITS CAUSED BY eration time was 120 min, mean blood loss INSUFFICIENT UNION FOLLOWING was 119 mL, and transfusion rate was 3.6%; OSTEOPOROTIC VERTEBRAL FRACTURE these were significantly lower than corre- Masatoshi Hoshino 1, Tadao Tujio 1, Minori sponding values in group-PDF. Subsequent Kato 2, Akinobu Suzuki 3, Tomiya adjacent vertebral fracture rate was 32% (9 Matsumoto 3, Hiromitsu Toyoda 3, Akira patients). Among these 9 patients, 2 with Matsumura 2, Hidetomi Terai 3, Sadahiko adjacent vertebral collapse in the early Konishi 2, Masahiko Seki 1, Hiroaki postoperative period developed severe Nakamura 3 thigh pain. In the kyphotic angle, there were 1 Spine center, Shiraniwa Hospital, Nara, no significant differences between the 2 Japan, 2 Department of Orthopedic Surgery, groups. Osaka City General Hospital, Osaka, Japan, DISCUSSION: We obtained satisfactory re- 3 Department of Orthopedic Surgery, Osaka sults of vertebroplasty for insufficient union City University Graduate School of Medicine, of OVF with lower limb neurological symp- Osaka, Japan toms. Advanced collapse of the adjacent vertebral body in the early postoperative INTRODUCTION: We have previously re- period caused poor results. ported that intravertebral instability is a significant factor in neurological deficits following insufficient union after osteopo- GP224 rotic vertebral fracture (OVF). On the basis INSTRUMENTATION AND EQUIPMENT of this finding, we prospectively performed RELATED INEFFICIENCY IN SPINE SURGERY: vertebroplasty without decompression in POTENTIAL FOR COST SAVINGS patients with neurological deficits. The pur- Zhou, Hanbing; Egge, Natalie; Lari, Hamid; pose of this study was to clarify the useful- Lapinsky, Anthony; Eck, Jason; Connolly, ness and limitations of vertebroplasty for Patrick; DiPaola, Christian; insufficient union of OVF with lower limb University of Massachusetts neurological symptoms. 256

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INTRODUCTION: Spine procedures repre- capturing equipment issues than adminis- sent a large portion of healthcare expendi- trative process (43.5% vs. 14%). ture in the orthopedics specialty. Studies have shown that intra-operative waste has exacerbated the high cost of surgeries. Our GP225 objective is to identify and quantify the in- RISK FACTORS FOR RECOLLAPSE OF THE cidence of pre- and intra-operative equip- TREATED VERTEBRAE IN PATIENTS WITH ment related events that generate ineffi- VERTEBRAL PSEUDARTHROSIS AFTER ciency. VERTEBROPLASTY METHODS: Data was collected over a 9- Hitomitsu Toyoda, Hidetomi Terai, Shinji month period. A data collection instrument Takahashi, Akinobu Suzuki, Sho Dozono, was developed to record procedure related Tomiya Matsumoto, Kentaro Yamada, details and instrument/equipment related Kuniaki Tsukiyama, Yoshikazu Shinohara, issues. Administrative records of equip- Hiroaki Nakamura ment issues were also obtained for the Dept. Orthopaedic Surgery, Osaka City same period. For each case with equipment University Graduate School of Medicine, related issues, estimates of cost increase Osaka, Japan and time delay was made. Operating cost of OR time is based on hospital financial INTRODUCTION: Recollapse of the treated data ($1061.03/hour). vertebra after vertebroplasty (VP) is one of RESULTS: 53% of the spine procedures the severe complications. Pre-operative (325/613) were recorded in the database. vertebral pseudoarthrosis has been report- Equipment related issues occurred in 43.5% ed as predisposing factor. However, which of cases. Issues included missing equipment characteristics of vertebral pseudoarthrosis (19.2%), improperly packaged pans (7.1%), increase the risk of recollapse remains un- improperly maintained equipment (16.2%), clear. The purpose of this study was to in- and other (1.0%). Unanticipated extra pans vestigate the risk factors for this complica- were opened in 18.6% of the cases (total of tion using uni- and multivariate regression 91 pans, range 1-5). In cases requiring extra analysis. pans, the average cost increase was $135.6 METHODS: A total of 49 vertebral (range $26.05 to $742.75). Comparing cas- pseudoarthrosis treated with VP using calci- es with pre-operative equipment issues and um phosphate cement were include in this those without: the difference in the first study. Demographic data, comorbidities and cases of the day is 15 minutes ($265.26, 29 all complications were analyzed. Morpho- vs. 14 minutes, P<0.05), the difference in logical variables, including posteri- the rest of the cases is 7.8 minutes ($137.9, or/anterior wall injury, endplate injury and 48 vs. 40.2 minutes, P=0.06). Examining the anterior vertebral height restoration (AVH) administrative record of the cases in our of treated vertebrae were also analyzed. In study, hospital record captured 46 (14%) this study, we made a new scoring system equipment related issues. based on the extent of damage to the ver- DISCUSSION: Perioperative inefficiency in tebral wall (Vertebral wall injury severity spine surgery can be material or temporal. score. 1: only anterior wall injury, 2: anteri- Material inefficiency is demonstrated by the or and posterior walls injury without end- high incidence of equipment related issues. plate injury, 3: both anterior and posterior Indirect costs such as delay in OR start time walls injury with upper or lower endplate can be a contributor to overall hospital injury, 4: both anterior and posterior wall waste. Our method was more capable of injury with both upper and lower endplate injuries) 257

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RESULTS: Recollapse was occured in 14 ver- group (avg age 39.3+14.1 yrs) and 26 in O tebrae (28.6%). In univariate analysis, he- group (avg age 63.7+2.7 yrs), with similar moglobin level, bone metabolic marker, ASA F/U (Y=2.9 v O=2.6 yrs, p=0.27). There were physical classification system (ASA), poste- no differences in avg preop main thoracic rior wall injury, lower endplate injury, ver- (MT) curve magnitude (Y=50.0deg, tebral wall injury severity score, and AVH O=54.8deg, p=0.27), however O patients were significantly associated with the inci- had significantly greater # of lumbar (5.9 v dence of recollapse. In multivariate analysis, 4.2, p=0.00), thoracic (9.1 v 7.3, p=0.00), ASA (odds ratio, 6.2; p=0.065) and vertebral and total (15.0 v 11.5, p=0.00) levels fused. wall injury severity score (odds ratio, 6.8; We also found O patients had significantly p<0.05) were significantly associated with lower absolute pre-op FEV1 (2.1 v recollapse. 2.6L,p=0.02) and FVC (2.7 v 3.3L, p=0.05), DISCUSSION: Recollapse after VP is com- but no differences in %pred PFTs. This rela- mon in patients with vertebral tionship remained at 2 yrs, with lower abso- pseudoarthrosis and the residual bone con- lute FEV1 (1.9 v 2.5L, p=0.00) and FVC (2.5 v dition (vertebral wall injury severity score) 3.1L, p=0.00). A clinically significant decline was the most important predictive factor in PFTs (greater than 10% pred FEV1) oc- for this complication than other predictive curred in 8 (31%) O patients and 26 (25%) Y factors such as age and bone mineral densi- patients, which was not statistically differ- ty. ent. (p=0.63). We also observed pre-op PFT impairment (less than 65%pred FEV1) in 1 (4%) O patient, which significantly increased GP226 to 6 (23%; p=0.02) postoperatively, com- COMPARISON OF PULMONARY FUNCTION pared to Y group experiencing no change in IN ADULTS YOUNGER AND OLDER THAN the number of patients (n=12, 12%) with AGE 60 UNDERGOING SPINAL DEFORMITY PFT impairment postoperatively. SURGERY DISCUSSION: Despite age related reduction Robert W. Tracey, MD; Ronald A. Lehman, in PFTs, older patients (over age 60) had no MD; Daniel G. Kang, MD.; John P. Cody, MD; significant difference in %pred PFTs com- Lawrence G. Lenke, MD; Jeremy J. pared to younger patients following spinal Stallbaumer, MD; Brenda A Sides, MS deformity surgery and no differences in the Walter Reed National Military Medical rate of clinically significant PFT decline Center, Bethesda, MD Washington (≥10% pred FEV1). However, older patients University School of Medicine, Saint Louis, more frequently (23% v 12%) experience MO PFT impairment (<65%pred FEV1) after spi- nal deformity surgery. INTRODUCTION: The objective of this study was to determine differences in pulmonary function in adult patients who are either GP227 younger (Y) or older (O) than age 60 follow- RETURN TO SPORTS AFTER SURGERY TO ing spinal deformity surgery. CORRECT ADOLESCENT IDIOPATHIC METHODS: 128 consecutive adult deformity SCOLIOSIS patients with idiopathic scoliosis undergoing Robert W. Tracey, MD; Ronald A. Lehman, surgical treatment were evaluated at a sin- MD; Daniel G. Kang, MD.; John P. Cody, MD; gle institution with minimum 2 yr follow-up. Lawrence G. Lenke, MD Prospectively collected PFTs, clinical records Walter Reed National Military Medical Cen- and radiographs were analyzed. ter, Bethesda, MD Washington University RESULTS: There were 102 patients in Y School of Medicine, Saint Louis, MO 258

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There was only one reported catastrophic INTRODUCTION: Participation in sports and construct failure after return to sports post- athletic activities by children and adoles- operatively. cents has become an important aspect of society, and is a frequent question following surgery for adolescent idiopathic scoliosis. GP228 No studies in the last decade using modern THE RELIABILITY OF THE posterior spinal implants have provided THORACOLUMABAR INJURY CLASSIFICA- recommendations on when surgeons’ TION AND SEVERITY SCORE AMOUNG OR- should allow patients’ to return to athletic THOPEDIC SURGEONS AT DIFFERENT LEV- activities following spinal fusions for de- ELS OF TRAINING formity surgery. Robert W. Tracey, MD; Adam J. Bevevino, METHODS: A survey was administered to MD; Ronald A. Lehman, Jr., MD; Daniel G. members of the Spinal Deformity Study Kang, MD; John P. Cody, MD Group (SDSG). The survey consisted of sur- Walter Reed National Military Medical geon demographic information, 6 clinical Center, Bethesda, MD case scenarios and three different construct types (hooks, pedicle screws, and hybrid). INTRODUCTION: Despite the increased use RESULTS: Twenty-three (23) surgeons com- of Thoracolumbar Injury Classification and pleted the survey, with 43% being ortho- Severity Score (TLICS), it has not yet gained paedic spine surgeons and 57% being pedi- universal acceptance. Our objective was to atric orthopaedic surgeons. Respondents examine the reliability of TLICS between were all experienced, expert deformity sur- orthopedic physicians from intern to staff geons, supported by 50% performing an level surgeons. average of 21-50 AIS cases per year with METHODS: Ten cases of thoracolumbar 44% of surgeons with >20 years in practice. spine fractures were reviewed and scored Most patients were allowed to return to using TLICS by eight evaluators: intern (n=2), both non-contact and contact sports within junior level resident (n=3), senior level resi- 3-6 months, and collision sports within 6-12 dent (n=2), spine surgeon (n=1). Each par- months postoperatively. We also found ticipant evaluated the same cases on three pedicle screw instrumentation allows earlier different occasions. Statistical analysis with return to contact & non-contact sports. For Intraclass Correlation Coefficient (ICC) was all construct types, approximately 20% of calculated assessing the inter- and intra- respondents never allow return to collision observer reliability of the TLICS classifica- sports, whereas all surgeons allow eventual tion. return to contact & non-contact sports re- RESULTS: Interobserver reliability yielded gardless of construct type. Of all surgeons’ moderate to excellent agreement between surveyed, there was only 1 reported cata- evaluators in all three rounds of testing. strophic failure in a patient with implant Neurologic injury produced the highest ICC pullout after snowboarding 2 weeks post- values, ranging from 0.820 to 0.902. Frac- operatively. ture morphology demonstrated the lowest DISCUSSION: Our study found that modern interobserver ICC scores with moderate posterior instrumentation allows surgeons agreement of 0.449 and 0.423. to recommend earlier return to sports fol- Intraobserver ICC scores improved with in- lowing fusion for AIS, with the majority al- creasing levels of training. The intern eval- lowing non-contact and contact sport at 6 uators recorded the lowest intraobserver months and collision sports at 12 months. ICC values, while the staff surgeon scored the highest. Staff surgeon ICC values all 259

GENERAL POSTERS ranked above 0.800 for excellent compression for symptomatic unilateral intraobserver agreement. Fracture mor- radiculopathy. 37 patients with unilateral phology produced the lowest intraobserver radiculopathy were received unilateral de- ICC values, ranging 0.586 to 0.683. The to- compression without fusion and 30 patients tal severity score yielded the highest were followed more than 3 years (SP: 25 intraobserver ICC values of 0.768 to 0.920 pts, DS: 5 pts). Contralateral symptom of for interns through senior residents. the initial operation level and new symptom CONCLUSIONS: The use of TLICS demon- due to the different site from the initial op- strated moderate to excellent intra- and eration level were assessed. inter-observer reliability among all training RESULTS: 1) Six of 30 patients (20%) showed levels. Senior residents and Staff demon- contralateral symptom at the same of the strated improved ICC scores in higher train- initial operation level. Five of 6 patients re- ing levels, however, interns and Junior Resi- ceived the additional operation. dents were able to reliably classify spinal 2) Three of 5 patients who received the ad- trauma injuries. This suggests that the ditional operation showed that the different TLICS scheme is a reliable way to successful- level from the initial operation was the re- ly communicate thoracolumber injury in- sponsible level for the new symptom. formation. 3) One of 5 patients with DS showed new symptom but did not receive the second operation. On the other hand, five of 25 GP229 patients with SP received the additional CLINICAL OUTCOME OF UNILATERAL DE- operation. COMPRESSION WITHOUT FUSION FOR DISCUSSION AND CONCLUSION: From the UNILATERAL RADICULOPATHY DUE TO current study, there could not detect the LUMBAR SPINAL STENOSIS prognostic factors for the occurrence of the Koji Otani, Shinichi Kikuchi, Soji Yabuki, contralateral symptom. So it is concluded Takuya Nikaido, Kazuyuki Watanabe, Kinshi that unilateral decompression is the first Kato, Shinichi Konno choice of operation procedure for unilateral Dept. of Orthopaedic Surgery, Fukushima radiculopathy due to LSS, and when contra- Medical University School of Medicine, Fu- lateral radiculopathy occurs, the additional kushima City, Japan operation should be considered. Preventa- tive operation for the contralateral side might not be necessary at the initial opera- INTRODUCTION: It is still controversy that tion. unilateral decompression without fusion for unilateral radiculopathy due to lumbar spi- nal stenosis (LSS) is sufficient or not. The GP230 purpose of this study was to assess the clin- COMPLICATIONS FOLLOWING ANTERIOR ical outcome of unilateral decompression LUMBAR SPINAL FUSION IN PATIENTS without fusion for unilateral radiculopathy WITH A HISTORY OF PRIOR INTRA- due to LSS. ABDOMINAL SURGERY PATIENTS AND METHODS: From 2001 to Kim SD, DeBlasi GJ, McGuire KJ, Berger D, 2008, 258 patients with LSS caused by Mansfield FL, Wood KB spondylosis (SP) or degenerative Massashusetts General Hospital, Boston, spondylolisthesis (DS) received the initial MA operation at the University hospital. Repeat operation was excluded. At those periods, INTRODUCTION: With different approaches there were no fusion and no bilateral de- available for lumbar interbody grafting, it is 260

GENERAL POSTERS unclear whether a history of prior ab- related complication. dominal/ pelvic surgery confers an in- creased risk of approach related complica- tions when undergoing anterior lumbar GP231 interbody fusion via an anterior retroperi- LUMBAR STABILIZATION WITH A toneal approach. PARASPINOUS TENSION BAND DEVICE IN METHODS: We present a retrospective PATIENTS WITH DEGENERATIVE chart review of 104 patients who under- SPONDYLOLISTHESIS AND SPINAL STENO- went an infra-umbilical retroperitoneal ap- SIS: 24-MONTH DATA. proach to the anterior aspect of the lower JNA Gibson, MD, FRCS [1] C Beadle, BSc, BA lumbar spine. There was a minimum 1 year [1] L Fielding, MS [2] M Wachna, BS [2] TF follow-up. Data collected included age, Alamin, MD [2,3] gender, procedure performed, levels fused, 1] The Royal Infirmary and Edinburgh intraoperative blood loss, length of hospital University, Edinburgh, Scotland 2] Simpirica stay, duration of surgery, preoperative di- Spine, San Carlos, CA 3] Stanford University, agnosis, blood transfused, intraoperative Stanford, CA and peri-operative complications, and reso- lution of any complications. INTRODUCTION: Segmental instability and RESULTS: Out of 104 patients, 23 patients recurrent symptoms can occur after surgical (23%) had 24 approach-related complica- decompression in the presence of degener- tions, either intraoperatively (9%), during ative spondylolisthesis (DS), so surgeons the immediate postoperative period (5%), often perform a segmental fusion. However, or within 1 year of surgery (10%). One pa- fusion can result in morbidity and adjacent tient had both an intraoperative or immedi- segment degeneration. This study evaluated ate postoperative complication in addition clinical and radiographic outcomes after to a delayed complication. After control- implantation of a paraspinous tension band ling for other factors such as age, gender, (PTB) device designed to control lumbar diagnostic groups, and level of procedure, sagittal plane instability. there was a statistically significant increase in the odds of having a complication when there was a history of abdominal or pelvic surgery (OR 1.35 P <0 .014). 19% of pa- tients with a history of abdominal or pelvic surgery had a delayed complication; com- pared to only 4% who did not have ab- dominal or pelvic surgery in the past (p < .024) METHODS: Patients with DS were enrolled DISCUSSION: Anterior lumbar interbody in a single arm prospective study. Clinical fusion via a midline incision and a retroperi- and radiographic evaluations were per- toneal approach was associated with a 23% formed preoperatively and at 3, 6, 12, and overall rate of complication. Many of these 24-months, and included evaluation of pain complications were minor and did not re- (VAS) and function (ODI), along with anal- quire intervention. However 5 (4.8%) pa- yses of segmental rotation, flexion- tients did require revision procedures. Our translation, anterolisthesis, and device sta- study suggests that a history of prior ab- tus. dominal or pelvic surgery puts the patients RESULTS: Twenty-five patients (23f, 2m, at a significantly higher risk for approach- mean age 69) were surgically decompressed and stabilized with the PTB at L4/5 (n=20) 261

GENERAL POSTERS and at L3/4 (n=5). One device was explant- ed because of an epidural hematoma, and INTRODUCTION: MISS is intended to reduce one patient died due to unrelated causes. approach related morbidities and complica- One patient was lost to followup. Figure 1 tions. However, the novelty of the approach shows statistically significant improvements and the potential for complications has (p<0.001) in VAS and ODI compared to been a big concern for surgeons in adopting baseline at 12 and 24 months. All patients these techniques. with 12 or 24 month follow up were satis- METHODS: A review of 102pts with>3 levels fied. Radiographic measurements showed fusion indentified11pts in 2007, 18pts in the following changes (∆): 2008, 28pts in 2009, 21pts in 2010, 20pts in 2011 and 4pts in 2012 including: Idiopathic Baseline Δ @ Δ @ Scoliosis(29), Degenerative Scoliosis(64), 12mo 24mo Iatrogenic Scoliosis(8), Kyphosis(1). All un- (n=21) (n=11) derwent a combination of 3MISS: Posterior Anterolisthesis 4.6±3.0 0.4±1.2 -0.6±1.7 (mm) (p=0.07) (p=0.13) instrumentation(100),DLIF(88) and Flexion- 1.1±1.1 0.0±1.2 -0.5±0.8 AxiaLIF(51). Translation (p=0.90) (p=0.05) RESULTS: Mean age was 63yrs(21-85). A (mm) total of 580levels were operated(5.7 lev- Segmental 3.4°±3.5° 0.0°±3.2° - els/pt,3-13). There were a total of Rotation (p=0.99) 1.5°±2.9° (p=0.11) 14technique-related complications in 14pts. Segmental 8.2°±4.6° 1.2°±2.4° - In 2007 a total of 51 levels were operated Lordosis (p=0.03) 0.2°±4.6° (4.6/pt) and only there was 1quadriceps (p=0.89) palsy that made a complete recovery within 6mths. Total of 92 levels were operated in Qualitative radiography showed no change 2008(5.2levels/pt) with 4complications: in device condition, no migration, no device- 1quadriceps palsy, 1retrocapsular renal related spinous process fractures, and no hematoma with no untoward effect, bone-implant interface remodeling. 2wound dehiscence that underwent deb- DISCUSSION: Clinical and radiographic out- ridement. 148 levels were operated in comes at 1 and 2 years suggest that the PTB 2009(5.3/pt) with 3complications: provides stability while preserving spinal 1quadriceps palsy which made a complete function, and may be an alternative to fu- recovery within 6mths, 1 pleural effusion sion for patients with LSS and DS. who underwent thoracentesis, 1 screw loosening that needed reinstrumentation. GP232 133 levels operated in 2010(6.3levels/pt) with2 complications: 1pleural effusion that TECHNIQUE RELATED COMPLICATIONS OF underwent thoracentesis and 1 sacral CIRCUMFERENTIAL MINIMALLY INVASIVE wound dehiscence that underwent deb- SPINAL SURGERY (MISS) FOR CORRECTION ridement. 131levels were operated in OF SPINAL DEFORMITY - A 5 YEAR 2011(6.5 levels/pt) with4 complications: 1 EXPERIENCE foot drop post DLIF, 1 Uretero-pelvic injury 1.Neel Anand, MD, Mch Orth, 2.Babak with DLIF who underwent nephrostomy and Khandehroo, MD, 3.Eli M. Baron, MD, paracentesis, 1screw loosening and cut out 4.Sheila Kahwaty, PA-C and 1hardware pull out that underwent Cedars-Sinai Medical Center, 444 S. San posterior reinstrumentation. There was no Vicente Blvd., Suite 800, Los Angeles, CA complication in 2012. 90048 Office: 310-423-9779, Fax: 310-423- CONCLUSIONS: This study documents a 9773

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GENERAL POSTERS technique-related complication rate of first pt, the pre-op angle changed from 8.1o 13.7%. Most were not life threatening and to 28.9o at 5mths post-op. This pt under- were easily treated with proper interven- went kyphoplasty with MIS extension of tion. Understanding these possible compli- post. instrumentation 3 levels cephalad. In cations can lead to effective adoption of the 2ndpt the angle increased from 0.6o to MISS. 17.8o at 15mths post-op secondary to a compression fracture and it was corrected by kyphoplasty. In the 3rdpt, the pre-op GP233 angle was 10o and increased to 26.5o at DOES MINIMALLY INVASIVE SURGICAL 24mths post-op. In the 4th patient the pre- (MIS) TREATMENT OF ADULT SPINAL op angle increased from 1.7o to 13.7o, at DEFORMITIES AFFECT THE INCIDENCE OF 28mths post-op. Although theoretically this PROXIMAL JUNCTIONAL KYPHOSIS (PJK)? patient was placed in PJK group, she was 1.Neel Anand, MD, Mch Orth, 2.Babak asymptomatic and declined any revision. Khandehroo, MD, 3.Eli M. Baron, MD, Last FU shows all pts were asymptomatic. 4.Sheila Kahwaty, PA-C CONCLUSIONS: A combination of 3 novel Cedars-Sinai Medical Center, 444 S. San MIS techniques offers excellent curve cor- Vicente Blvd., Suite 800, Los Angeles, CA rection, maintains lumbar lordosis and ap- 90048, Office: 310-423-9779, Fax: 310-423- propriate kyphosis at thoracolumbar junc- 9773 tion. The incidence of PJK in our study was 3.8% that is considerably less than the 26- INTRODUCTION: PJK as a possible side ef- 46%rate quoted regarding surgery for spinal fect of surgical treatment for spinal deform- deformity. ities is the result of trunk self-adjustment after surgery to achieve overall balance in the sagittal plane. GP234 METHODS: A review of 176pts underwent THE SELECTION OF THE DISTAL MIS correction identified 105pts with>2 INSTRUMENTATION LEVEL IN LENKE TYPE levels (age:21-84) including Degenerative 1A CURVES USING SEGMENTAL SCREW Scoliosis(73),Idiopathic Scolio- FIXATION: THE NOTTINGHAM EXPERIENCE sis(22),Iatrogenic Scoliosis(8),Kyphosis(2). Eyal Behrbalk Hossein Mehdian; George All underwent a combination of 3 MIS tech- Arealis, Sherief Elsayed niques: Post. instrumentation(103), DLIF(92) Centre for Spinal Studies and Surgery, and AxiaLIF(45). PJK was defined as the sag- Queens Medical Centre, Nottingham ittal Cobb angle between the lower end- plate of the uppermost instrumented verte- INTRODUCTION: To define the correct Low- bra and the upper endplate of two vertebra est Instrumented Level (LIV) in Lenke Type supra-adjacent, which is >10o and at least 1A curves, in order to prevent the adding- 10o greater than the pre-op. on phenomenon. RESULTS: Mean FU was 33mths(10-59) METHODS: Over a 3 year period (May 2008 with>1yr in 99pts.The mean pre-op Cobb onwards), 35 Type 1A Lenke curves were was 27oand corrected to 11o.The pre-op operated upon. The average age was 17 Sagittal balance was 51.9mm(-47 to160) years (range 13-20). The average thoracic and corrected to 11mm(-119 to113.9). The spine curve was 45 degrees (range 40 to 95 pre-op lumbar lordosis which was 43o, degrees). Review of the pre- and post- maintained at 41.7o by the last FU. The in- operative radiographs was undertaken in cidence of PJK was 3.8%(4 of 103pts) and order to determine potential risk factors for only 2pts needed revision surgery. In the the ‘adding-on’ phenomenon. 263

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RESULTS: The average correction obtained operation and who were able to measure was 76%. We noted an average operative spino-pelvic sagittal alignment before and duration of 148 minutes (range 120 – 220) after the operation were divided to two and an average operative blood loss of 653 groups. The group of low back pain was mls (range 510-850). more than seven at VAS score (LBP group: The ‘adding-on’ phenomenon was noted in 16 persons, average of 72.7 years old). The 5 cases early on. There was no correlation group of no low back pain does not use with the pre-operative Cobb angle, degree painkiller (N-LBP group: 43 persons, average of curve correction or utilising the stable of 68.0 years-old). We measure lumbar vertebra (SV) as the Lowest Instrumented lordotic angle(LLA)，pelvic tilt（PT）, sa- Level (LIV). Selecting the End Vertebra (EV) cral slope(SS) and PI. Then we evaluated as the LIV was associated with distal adding- sagittal imbalance (SI) by using the SRS- on in most cases. We also noted an in- Schwab classification (PI-LL> 20 degrees, creased incidence of the adding-on phe- SVA>95mm, PT>30 degree). nomenon when the preoperative LIV had a RESULT: The result of spino-pelvic sagittal greater than 10mm distance from the cen- alignment of LBP group and N-LBP group tre sacral vertical line (CSVL) to the mid- were SVA 93.8/55.3(mm), LLA26.9/32.2 (°) point of the vertebral body. PT 32.0/27.0 (°) SS 20.7/25.2 (°) PI 53.0/52.0 DISCUSSION: Selecting the Stable Vertebra (°) respectively. The incidences of abnormal minus 1 level or Neutral Vertebra plus 1 SI parameters in each group were PI-LL level as the LIV in Lenke Type 1A curves is 68.8/44.2%, SVA 43.8/11.6%, and PT less likely to result in the adding-on phe- 68.8/43.9%. In results, the LBP group had nomenon. In addition, the LIV should be less significant large SVA, PI-LLA and large PT. than 10mm from the CSVL. DISCUSSION: In recent years, PI has been reported which peculiar to an individual, GP235 made a large influence on a lumbar align- ment and lumbar disease. When flatback is SPINO-PELVIC SAGITTAL ALIGNMENT IN evaluated, PI should be included. The cause PATIENTS WITH POSTOPERATIVE PERSIS- of postoperative low back pain is known as TENT LOW BACK PAIN multifactorial factors, however, our results Makiko Yorifuji, Kenji Endo, Hirosuke confirmed SI due to flat back and posterior Nishimura, Hidekazu Suzuki, Hidetoshi rotated pelvis was an important element. Tanaka, Kengo Yamamoto Optimal LLA considered by PI would keep a Department of Orthopedic Surgery, Tokyo suitable inclination of pelvis and prevent the Medical University forward inclination of trunk.

INTRODUCTION: Postoperative spino-pelvic sagittal mal alignment causes persistent GP236 chronic low back pain and gait disorder in- POSTERIOR LUMBAR INTERBODY FUSION patient with lack of lumbar lordosis, hip OUTCOMES IN 17 PATIENTS WITH extension disorder, and gravity imbalance. RHEUMATOID ARTHRITIS The aim of this study was to analyze spino- Shuhei Murase, Satoshi Ogihara, Toshihito pelvic sagittal alignment including a pelvic Mori incidence (PI) and understand the relation- Department of Orthopaedic Surgery, ship of postoperative low back pain and National Hospital Organization Sagamihara flatback deformity. National Hospital OBJECT AND METHOD: 59 patients who passed after two years or more from the INTRODUCTION: Compared with the cervi- 264

GENERAL POSTERS cal spine, little attention has been paid to surgical treatment. lumbar spine with rheumatoid arthritis(RA). Because of the instability and deformity of lumbar spine accompanied by lumbar spinal GP237 canal stenosis, we often need lumbar fusion PROSPECTIVE COHORT STUDY OF THE PER- for RA patients. But only a few articles have FORMANCE STATUS AND ACTIVITY OF DAI- described the outcomes of lumber fusion in LY LIVING IN PATIENTS WITH METASTATIC RA patients. We performed posterior lum- SPINE TUMORS bar interbody fusion ( PLIF ) on seventeen Kakutani K1. Sakai Y2. Maeno K1. Yurube patients with RA and evaluated the effec- T1. Yamamoto J1. Hirata H1. Kurakawa T1. tiveness. Miyazaki S1.Takada T1. Doita M3.Kurosaka METHODS: The subjects were 17 patients M1. Nishida K1. with RA who underwent instrumented PLIF , 1. Department of Orthopaedic Surgery, Kobe 1 man and 16 women, mean age 62.5 years University Graduate School of Medicine, old (range, 47 to 75 years), and the mean Kobe, Japan 2. Division of Rehabilitaion duration of RA was 22.3 years (range, 10 to Medicine, Kobe University Graduate School 34 years). The mean duration of follow-up of Medicine, Kobe, Japan 3 Deparment of was 46 months ( range, 11 to 74 months ). Orthopaedic Surgery, Takatsuki General As the clinical questionnaires we checked Hospital, Osaka, Japan VAS, Zurich Claudication Questionnaires ( ZCQ ), and Oswestry Disability Index ( ODI ) INTRODUCTION: With the improvement of at the time of preoperative and final follow- prognosis of malignant tumor, the patients up and a student’s t-test was used to com- with a spinal metastasis are increasing, pare them. We also evaluated radiographic which severely deteriorated the ability of assessment. life (ADL). The aim of this study was to clari- RESULTS: Statistically significant improve- fy longitudinal transition of the ADL in spinal ment was achieved in VAS, ZCQ, and ODI. metastasis patients who received surgery or Plain radiographics showed adjacent seg- did not. ment degeneration in 5 patients ( 29.4% ), METHODS: Consecutive 37 patients with collapse of adjacent vertebra in 3 patients ( progressive paralysis due to metastatic spi- 17.6% ), migration of pedicle screw in 1 pa- nal tumors were prospectively followed. 25 tient ( 5.9% ). Two patients required re- patients received spine surgery (Group S); operation because of severe radiculopachy 12 patients chose conservative treatment caused by adjacent segment disease (Group C). At the day of surgical indication, (11.8%). 1 and 6 month later, final follow-up, ADL DISCUSSION: Because of osteoporosis and was evaluated by the Eastern Cooperative subluxation, we were concerned about Oncology Group Performance Status (PS) complications and poor results of lumbar and Barthel index. Neurological status was fusion in RA patients . But little has been assessed by the Frankel classification. reported about that. In our cases postoper- RESULTS: 2 patients underwent laminecto- ative radiographic assement showed some my while 23 patients had it with instrumen- complications related to osteoporosis and tation. The mortality was 12 cases (48%) in subluxation which included two reopera- the Group S whereas 8 cases (67%) in the tion, but clinical outcomes at final follow-up Group C; mean lifetime after the day of sur- showed an overall improvement. This re- gical indication was 202 and 211 days, re- sults suggest that PLIF for RA patients can spectively. Mean lifetime of survival pa- expect good clinical outcome and option for tients was 460 days in both groups. Group S patients reduced PS with time (mean: 3.68 265

GENERAL POSTERS at the day of surgical indication, to 1.89 at included radiographs of instrumentation of the final follow-up,) but Group C patients 2 densities: C. segmental pedicle screws and deteriorated PS (3.31 to 3.62). In the Group D. hybrid instrumentation with wiring. We S, 92% of patients improved PS but 16% re- asked 4 questions for each set: Q1. Which deteriorated at the final follow-up. Group S procedure seems more painful? Q2. Which patients elevated Barthel index and re- procedure seems better for correction? Q3. tained it through the final follow-up (mean: Which procedure seems more difficult? Q4. 39.2→63.6→75.8→65.2 ) but Group C pa- Which procedure would you choose? tients lost scores with time (50.4→33.1). RESULTS: For the first set, the probability of 80% of Group S improved Barthel index but choice B was significantly greater than that 12% re-deteriorated. 84% of Group S pa- of choice A when staff members were asked tients improved 1≥ scores for the Frankel which images were associated with pain, classification but 8% re-deteriorated, while good correction and difficulty. The probabil- no patient in the Group C improved Frankel ity of choice A was significantly greater than classification. that of choice B when they were asked DISCUSSION: Surgery for metastatic spinal which procedure they preferred. For the tumors elevated and maintained PS and second set, the probability of choice C was Barthel index in more than 80% patients. significantly greater than that of choice D This study suggests that surgical treatment when staff members were asked which im- can improve ADL as well as neurological ages were associated with pain, good cor- deficit in patients with metastatic spinal rection and difficulty. The probability of choice C was greater than that of choice D (but not significant) when they were asked GP238 which procedure they preferred. PERCEPTIONS OF SCOLIOSIS SURGERY FROM RADIOGRAPHS Toshiaki Kotani1, Tsutomu Akazawa1, Tsuy- oshi Sakuma1, Tetsuharu Nemoto1, Yusuke Sato1, Mitsuhiro Kitamura1, Kazuhisa Takahashi2, Shohei Minami1 1. Dept. of Orthopaedic Surgery, Seirei Sa- kura Citizen Hospital, Chiba, Japan, 2. Dept. of Orthopaedic Surgery, Chiba University, DISCUSSION: Long fusion seemed painful Chiba, Japan and difficult, but was associated with good correction versus short fusion; subjects INTRODUCTION: We investigated whether tended to prefer short fusion. Segmental the length and density of instrumentation pedicle screws seemed painful and difficult, for scoliosis surgery could provide a prelim- but were associated with good correction, inary determination of medical staff mem- and twice as many subjects preferred seg- bers’ perceptions of pain, outcome, and mental pedicle screws to hybrid methods. desire for surgery. The perceptions of scoliosis patients should MATERIALS: Subjects (N=52) completed a be investigated. These results may impact questionnaire containing 2 sets of 4 postop- patient satisfaction. erative radiographic images with similar curve magnitudes and patterns. The first set included radiographs of instrumentation of 2 lengths: A. thoracic, B. upper thoracic, thoracic, and lumbar fusion. The second 266

GENERAL POSTERS

GP239 LESS INVASIVE SURGICAL INTERVENTION CAN PREVENT THE LONG-TERM DEVELOP- MENT OF LUMBAR DEGENERATIVE SCOLI- OSIS. 10-YEAR-FOLLOWUP STUDY OF CON- CAVE PLIF AT THE WEDGED DISC BELOW THE CAUDAL END VERTEBRA FOR DEGEN- ERATIVE LUMBAR SCOLIOSIS Toyone T, Ozawa T, Inada K, Shirahata T, Watanabe A, Matsuki K, Kitahara S, Shiboi R, Wada Y, Hasue F, Fujiyoshi T, Tanaka T, DISCUSSION: The results of this study sug- Ohtori S, Takahashi K. gest that this less invasive surgical interven- Teikyo University Chiba Medical Center, tion may prevent the long-term develop- Department of Orthopaedic Surgery, ment of lumbar degenerative scoliosis. Ichihara, Chiba, Japan. GP240 INTRODUCTION: The objective of this study DEGENERATIVE DISC DISEASE: A CASE OF was to assess the efficacy of concave PLIF MISTAKEN IDENTITY for lumbosacral hemi curve in treating pa- Michele C. Battié tients with degenerative lumbar scoliosis. Faculty of Rehabilitation Medicine, METHODS: Twelve patients (53-72 years University of Alberta, Canada old) were operatively treated and prospec- tively studied. The surgical procedure was; INTRODUCTION: Degenerative disc disease following decompression of the affected (DDD) is an important concept in the cur- nerve root, to correct the wedged disc be- rent diagnosis and care of common spinal low the caudal end vertebra, which allowed disorders. It drives much diagnostic imaging for the end vertebra to become horizontal, and increasingly underlies decisions for as well as restoration of lumbar lordosis by spine surgery. Yet, DDD as a concept and way of concave PLIF using cages filled with term remains controversial and advances in local autologous bone. The follow-up peri- its understanding have been modest since od was 10 years. use of the term appeared in the scientific RESULTS: Mean VAS (100mm) was 77 be- literature in 1947. The objective of this fore surgery, 19 at 2 years after surgery, and study was to investigate the current status 18 at the final follow-up in leg pain, 68, of the concept of DDD through a systematic 27,and 30, respectively, in low back pain, investigation of definitions of DDD used in and 13, 6, and 8, respectively, in the disabil- recent genetic studies, where precise phe- ity score (Rolland-Morris). The mean Cobb notype definitions are of particular im- angle was 24, 17, and 18 degrees, respec- portance. tively, in scoliosis, 16, 8, and 10 degrees, METHODS: To get a sense of phenotypes respectively, in caudal end vertebral tilt, and currently representing DDD in genetic stud- 22, 28, and 26 degrees, respectively, in ies, a simple Medline search of publications lumbar lordosis. In six patients with Cobb from the year 2000 to the time of this re- angle less than 30 degrees, the Cobb angle view in 2012 (in the English language) using of the unoperated lumbar or thoracolumbar the terms “degenerative disc disease” and curve improved over time (fig.). “gene*” was conducted. RESULTS: The search yielded gene associa-

267

GENERAL POSTERS tion studies of 11 independent samples METHODS: 15 patients with severe thoraco- from eight countries, representing pheno- lumbar kyphosis with normal pre-operative types under the rubric of disc disease. The neurology undergoing PSO at or above L1 phenotype definitions varied greatly. Under were included. Average age was 12.3 years the term “lumbar disc disease”, phenotypes (range 7 to 14). Relative sagittal angle cor- ranged from “discogenic sciatica” with se- rection at the osteotomy and at the five vere, unilateral pain radiating below the cephalad and caudal adjacent discs was knee, to a complaint of back pain with ra- measured to analyze the individual contri- diological confirmation of lumbar disc dis- bution. Radiological measurements were ease on MRI, to a 4-point ordinal scale of made utilizing pre & post-operative stand- disc signal on MRI regardless of back pain ing AP & lateral radiographs and measure- history. Phenotypes of “degenerative disc ment software. disease” showed a similar lack of consisten- RESULTS: There were no post-operative cy, with phenotypes of DDD varying from neurological deficits. Mean pre-op kyphosis observations of disc signal loss, narrowing, was 107.3 degrees (range 93-133) which bulging or osteophytes, irrespective of back was corrected to 53.7 degrees. Mean per- symptom history, to chronic low back pain centage correction of kyphosis was 45.7% with a diagnosis of DDD for which spine (SD=6.6). The proportion of sagittal plane surgery was planned. correction contributed directly by the oste- DISCUSSION: Despite well over a half- otomy was 49.3 degrees (range 42-55), century of increasingly common use of the whereas the five cepahlad thoracic discs term DDD, the research community has yet together contributed 10.1 degrees to agree on an underlying concept or defini- (Apex+1=4.50, Apex+2=2.30, Apex+3=1.30, tion. Until then, related research and Apex+4=10 and Apex+5=10) and five knowledge are likely to remain underdevel- caudad lumbar disc segments contributed a oped and conflicting. total of 36.1 degrees of the correction (Apex-1=5.50, Apex-2=7.80, Apex-3=8.50, Apex-4=7.50, Apex-5=6.80). GP241 ROLE OF INTERVERTEBRAL DISCS IN THE SAGITTAL PLANE CORRECTION OF THORACO-LUMBAR ANGULAR KYPHOSIS AFTER SPINAL OSTEOTOMY Naresh-Babu J, Suresh Ch, Neelima Govada, Narayana-Rao VV Mallika Spine Centre, Hyderabad, India.

INTRODUCTION: Pedicle subtraction oste- otomies (PSO) for kyphosis correction in CONCLUSION: The results document the children result in better radiological and significant contribution of lumbar disc in cosmetic correction compared to that of correction of thoraco-lumbar kyphosis after adults. PSO for thoraco-lumbar kyphosis spinal osteotomy. Lower lumbar discs con- results in better correction compared tributed more than the upper lumbar discs. tothoracic kyphosis which can be attributed Surgeons can take advantage of the flexibil- to the flexibility intervertebral discs. We ity of the lumbar spine in performing oste- analysed the role of lumbar and thoracic otomies at thoraco-lumbar level to obtain discs in surgical correction of thorao-lumbar better radiological correction. kyphosis. 268

GENERAL POSTERS

60% in VAS leg pain (3.9 pre to 1.8 at 24 mo) GP242 and 63% in Oswestry disability (57.1 pre vs. FREEDOM DISC VS. PRODISC-L FOR 21.2 at 24mo) were observed by 6 weeks TREATMENT OF 1-LEVEL LUMBAR DISC and maintained to 24 months. There was DISEASE: RESULTS FROM ONE slight earlier treatment benefit for Freedom INVESTIGATIVE SITE OF THE USA FDA by 6 wks [VAS back: 2.6 (FD) vs 4.2 (PD) at RANDOMIZED CLINICAL TRIAL 6wks, p< 0.02; 2.3 (FD) vs 3.9 (PD) at 3 Harvinder Bedi,MD; Michael. Kropf,MD; mo,p< 0.04, and 1.5 (FD) vs 3.8 (PD) at 6 L.E.A. Kanim,MA; Janice Kim,BA; Hyun mos p< 0.001; ODI: 19.3 (FD) vs 30.5 (PD) at Bae,MD; Alexandre Rasouli,MD; Rick B. 6 mos, p< 0.02] that disappeared at longer Delamarter, MD follow-up (NS) Spine Center, Cedars-Sinai Medical Center, CONCLUSIONS: Significant recovery was Los Angeles, CA similarly reported by patients treated using either the ProDisc-L or Freedom ADRs with INTRODUCTION: The Freedom Artificial Disc earlier recovery with Freedom. (FD) is studied in order to treat single-level lumbar disc disease L3 to S1. The design of the Freedom Artificial Disc allows potential- GP243 ly less range of motion in flexion, extension, SINGLE-LEVEL INSTRUMENTED axial rotation, and translation than does the POSTEROLATERAL FUSION VERSUS POSTE- comparison ProDisc-L (PD). RIOR LUMBAR INTERBODY FUSION FOR OBJECTIVE: To assess and compare the self- UNSTABLE LUMBAR SPONDYLOLISTHESIS reported outcomes for patients treated for Shuugo Kuraishi, M.D.1), Jun Takahashi, 1-level lumbar disc disease with the FD M.D.1),Hiroki Hirabayashi, M.D.1), , Keijiro compared to PD. To report the two year Mukaiyama, M.D.1),Masayuki Shimizu, results from one site participating in the M.D.1) ,Futatugi Masatoshi, M.D.1), Hi- RCT. royuki Kato, M.D.1) ,Hisatoshi Kinoshita, METHODS: USA-FDA approved prospective M.D.2) Yutaka Tateiwa, M.D.2) and randomized (1:1) clinical trial of the 1)Departments of Orthopaedic Surgery, Freedom® Lumbar Disc (AxioMed Spine Shinshu University, School of Medicine Corp., Cleveland, OH) versus ProDisc-L 2)Nagano Prefectural General Rehabilitation (Synthes, West Chester, PA). Self-reported Center inventories of Visual Analog Scale for back pain (VAS back pain) and VAS leg pain, INTRODUCTION: Surgery for lumbar Oswestry disability Index, physical exams, spondylolisthesis is widely performed. adverse events, and range of motion (ROM) However, few reports have compared out- were collected preoperatively and at 6 comes between posterolateral fusion (PLF) weeks, 3, 6, 12, 18, and 24 months annually and posterior lumbar interbody fusion postoperatively. (PLIF). This study retrospectively compared RESULTS: For FD treated patients (n=20 1- the clinical and radiographic outcomes of level), significant improvements of 80% in PLF and PLIF for L4 unstable VAS back pain (7.3 pre vs 1.5 24mo), 86% in spondylolisthesis. VAS leg pain (2.7 pre to 0.3 at 24mo) and METHODS: Patients with L4 unstable 74% in Oswestry disability (59.5 pre vs. 14.2 spondylolisthesis with Meyerding Grade II 24mo) were observed by 6 weeks and well or more, slip of >10°or >4 mm upon maxi- maintained to 24 months (p< 0.05). For PD mum flexion and extension bending, and (n=19 1-level), significant improvements of posterior opening of >5° upon flexion bend- 68% in VAS back pain (7.3 pre vs 2.5 24mo), ing were studied. Patients were treated by 269

GENERAL POSTERS

L4-L5 level decompression and posterior instrumented fusion from January 2008 to January 2010. Patients who underwent PLF and PLIF (n = 11 per group) and were fol- lowed-up for >2 years were studied. The mean age and follow-up period of the PLF group were 71.3 years and 2.8 years, re- spectively, and those of the PLIF group were 70.0 years and 2.6 years, respectively. Radi- ographic findings and clinical outcomes evaluated by the Japanese Orthopaedic As- sociation (JOA) score were compared be- tween groups. RESULTS AND DISCUSSION: JOA scores of the PLF group before surgery and at final follow-up were 11.6 ± 4.8 and 23.9 ± 3.7, respectively; those of the PLIF group were 14.0 ± 4.8 and 21.2 ± 7.8, respectively, with no significant difference between groups. Correction of slip estimated from postoper- ative slip angle, translation, and mainte- nance of intervertebral disc height was bet- ter in the PLIF group (P < 0.05); however, there was no significant difference in lum- bar lordotic angle and slip angle and transla- tion angle upon maximum flexion and ex- tension bending. Fusion rates of the PLIF and PLF groups were 91.0% and 72.3%, re- spectively, showing no significant differ- ence. These results suggest that L4-L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF ameliorates clinical symptoms when local stability is achieved.

270

INDEX

A Ataka H, O49,SP58,GP100,GP165 C Aakash A, GP22 Atanasio S, GP158 Cabalo A, GP196, Aalto T, O65,SP40,SP56 Aya S, O50,GP122,GP159 Callary S, SP34, Abdullah KG, O35 Azuma S, O44 Cambridge EDJ, O30, Abe K, SP20,GP112 Cappuccino A, O59, Acharya N, GP145 B Carandang G, SP12 Acharya S, GP145 Bae H, GP242 Cardoso MJ, GP19, Acosta F, GP202 Bae WC, O21,O26,GP40,GP80-82 Carolin Miltenburger5 O57, Adachi K, GP101 Bai M, O14 Carroll LJ O66,GP94 Adams MA, O27,SP0,SP11, Bajaj N, O53 Carstens C, GP52, SP14,GP73 Baker H, O27,SP11 Carstensen M, SP09, Adams SL, GP84 Balderston RA, O60 Carter T SP03, GP111,GP151 Afifi M, GP39 Balkovec C, SP09 Cavanaugh JM, O29, Agarwal A, GP18,GP37,GP38 Barnsley S, GP93 Cedraschi C, GP116, Agarwal AK, GP37, GP38 Baron EM, GP232-233 Cha T, GP83,GP203 Aghdasi B, SP06 Barz T, O74,SP45,GP13,GP212 Chak JD, O25,GP7 Aihara T, SP36,SP58,SP108,SP125 Basu S, GP145 Chan D, O16,O20 GP141, GP147,GP159-160,GP167 Battié MC, O12,O66,GP94,GP155, Chang BS, SP23,GP29,GP33, Airaksinen O, O65,SP30,SP40,SP56, GP161,GP240 GP142-143 GP35 Beadle C, GP231 Chen AC, GP44,GP83-85 Aithala J, GP145 Becker H-J, O58 Chen AF, GP137, Aiyangar A, GP45 Beckingsale TB, GP92 Chen CW, GP46, Aizawa M, O24,SP42 Bedi H, GP242 Chen CY, O29, Akazawa T, GP152,GP164,GP238 Behrbalk E, GP113,GP234 Chen D, GP57, Akeda A, SP50 Bell KM, GP34,GP42 Chen HM GP1, Akeda K, GP56 Ben-Abraham EI, GP41 Chen J, GP41,GP55 Akune T, O38, O40 Bendix T, GP149 Chen L, GP79, Ala-Korpela M, O16 Benneker L, GP78 Chen WJ, GP145, Alamin TF GP231 Ben-Porath Y, O63 Chen Y, GP46, Alimasi W, GP68 Benzel EC, O35 Chen YF, GP88, Alini M, O20,GP77,GP78 Berg S, O78 Cheung KMC O16,GP154 Alvares L, O68, Berger D GP230 Chiba K, SP38, GP54 An HS, O8,SP10,SP25,GP23-26, Best TM GP69 Ching A, O77, GP36,GP83-85,GP93 Bethea S GP49 Cho HC, GP194-195 Anand N, GP232-233 Bevevino AJ, GP20, GP228 Chou CC, GP46, Andersson GBJ, O8, SP10,GP11, Bhaduri S, GP18 Christensen FB, O36, GP6 GP23-26,GP36,GP84-85 Binette F, GP81 Chung NS, O11,GP214-215 Anderst W, GP45 Bishop PB, O2,GP144 Chung SK, GP194-195 Ando K, O20 Block AR, O63 Cody JP, GP19-21, GP226-228 Ando M, GP198 Blumenthal SL, O56, O59 Colbrunn R, GP8-9 Annesley-Williams DJ, SP11, Bonner T, GP8, GP9 Colli B, GP127, Aoki M, SP31,SP51,SP52, SP58 Bonzanini B, GP127 Colloca CJ, GP39, Aoki Y, GP2,GP51,GP89,GP98-99, Boonen S, O57 Condor R, GP145, GP130-131,GP197,GP209, GP222 Boszczyk BM, GP113 Connolly P, O43,O55,GP224 Aono H, GP181 Bot AGJ, GP203 Cooper J, GP93, Arai F, GP70 Bradley W, SP48 Coric D, O59, Arai G, GP17,GP157 Braun S, O68 Courvoisier DS, GP116, Arai I, SP22, SP58 Brayda-Bruno M, SP08,GP52 Coyne E, O3, GP91 Arai T, GP65 Brisby H, GP71-72 Cripton PA, O25,GP7 Arealis G, GP234 Brochhausen C, GP52 Cs-Szabo G, GP84-85 Arima N, GP204 Brox JI2, O54 Cuperman T, GP61, Arisaka M, O61 Buchanan S, GP85 Armijo-Olivo S, O4 Buller C, SP45,GP212 D Arthur B, O2,GP144 Buman MP, SP59,GP207 Dagenais S GP139 Asahara H, O26 Bydder GM, GP40 Daisuke S, GP10, Asante AK, GP94 Bünger CE, O36 Danielson E O18, Asomugha EU, GP168 271

INDEX

Daubs MD, SP06, Fabeck LG, GP39, Gilbert S, O27, SP11 Davis K, SP05, SP24 Fairbank JC,O5,O42,O54, SP01, Goda Y, GP10,GP109,GP118-119 Davis TT, GP202, GP189 Goel V, GP18, DeBlasi GJ GP230 Fan Y, SP16, Goel VK, GP18,GP22,GP37-38,GP47 Deissroth K, O48, Farber NJ, GP137, Gogate S, GP54, Delarmarter RB O22,SP41,GP242 Fehlings M, GP58, Gorth DJ, GP74, Demetropoulos CK GP47, Ferguson SA, O9, Goumoëns P, GP116, Denaro V GP77-78 Field J GP192, Grad S, O20, GP77-78 Desmoulin C, GP116, Fielding L, GP30,GP231 Gregg C, GP111, DeSouza L, GP63, Fineberg S, O47, SP46,GP169-179 Gross D O4,GP93-94 Deyo RA O7, O77,GP95 Fisher CG, O25,GP7 Gruber HE, GP48-49 Dezawa A, GP5,GP102,GP185 Follak N GP13, Gu T, SP18,GP50 Dhanvin D, GP22 Foltz V, GP116, Gunzburg R, GP39, Dick B, O4, Foocharoen T, GP145, Guruprakash DK, O29, Dimmig T, O59, Fortin M, GP161, Guyer RD O56,O59,O63,SP43 Ding Y, GP55, Fraser RD SP34,GP16 DiPaola C O43,O55,GP224 Fredrik Borgström1,2, O57, H Dmitriev AE, GP19-21 Freedman BA, O28, Ha JW, O32, Dobscha SK GP95, Freeman BJC, SP34,GP16,GP39 Ha KY GP3,GP105-106 Dodge GR, GP74, Fruensgaard S, O36, Haapea M, GP115, Dohzono S, O69,GP217 Fuentes J, O4, Hada Y, GP5, Doita M, GP60,GP62,GP237 Fujibayashi S, GP15,GP200 Hai Y GP188, Dolan P,P14,P27,SP07,SP11,GP73 Fujii T, SP37, Haig AJ, O75, Donaldson WF GP137, Fujimaki H, SP33, Haldin K, SP34, Dong Q, SP16, Fujimiya M, GP10, Hall DJ, SP34, Donovan M, GP95, FujitaN, GP54, Hall H, SP03, GP111,GP151 Dozono S, GP225, Fujiwara H, GP90, Halpern P, GP113, Drochner TE, GP202, Fujiwara T,O21,SP19,GP40,GP80-81 Hamasaki T, O28, Dugan T, GP34, Fujiyoshi T, O34,GP239 Hanaoka E, SP58,GP183 Dvorak MF, O25,GP7 Fukuda H, SP22, Handa J, SP22, Fukuhara S, O37,GP114 Hanley EN GP48-49 E Fukui D O23,O76,GP104,GP198 Hansson T O13, Ebata S, O71, Fukumori N, O37, Happel JP, GP20, Eck J, O43,O55,GP163,GP224 Fukuoka M, GP134, Hara N, O44,SP37,GP135 Edidin AA, O67, Fumiaki K, SP54, Harada M, GP118 Egge N, O43,GP224 Funabashi M, O4, Harada T, GP118, Eguchi Y, O17, SP51,SP58,GP51, Funao H, SP42, Harding IJ, SP14, GP73 GP98-99,GP117,GP157, GP197, Fung DA GP202, Hargens AR, O26, GP211 Furufu T, SP31,GP222 Haro H, O71, Ehman RL GP41, Furuichi I, GP126, Harrigan M, O43, Ehrhart EJ, GP30, Furusawa S, GP110, Harris MB, O51, el Barzouhi A, GP220-221 Försth P, O31, Hart R, O48, Elfering A O62, Hartman RA, GP42, Elliott DM, GP74, G Haruki F, GP122, Elsayed S GP234, Galbusera F, SP08, GP52 Hasebe K, GP5, Endo K, GP68, GP216,GP235 Galimberti F, O35, Hasegawa K, SP32, Endo T, SP04, SP29 Gao M, GP57, Hasegawa T, O71, Enyo Y, SP04, Gaume R, GP20 Hashikawa T, GP110,GP128, GP146 Erwin MW GP58, Geiss A, SP28, Hashimoto T, O72, Erwin WM GP63, Genevay S, GP116, Hashizume H, O38,O39,O40 Espinoza Orías AA, O8,SP10,SP25, Gerard D, GP85, SP04,SP29 GP23. GP25,GP26,GP36 Gerdhem P O78, Haskell WL, SP59,GP207 Eysel P SP28, Ghanayem AJ, SP12 Hasue F, O34, GP239 Ezure T, GP141, Gibons L, O12, Hatakeyama K SP36,GP125,GP159- Gibson AC SP44, 160,GP167 F Gibson JNA, GP231, Hatta S, GP107, Gierasimowicz Fontana A, GP116, Havey RM, SP12 272

INDEX

Haws C, GP93, Iida R, GP56, Kahwaty S GP232-233 Hayakawa J, GP199, IkedaS,GP138, Kaito T, GP90, Hayakawa K, GP124, Imura T, SP33, Kakinuma H, O24,SP42 Hayakawa M, GP209, Inada K, O34,GP117,GP148, Kakutani K, SP17,GP60,GP62, Hayashi T, SP06,GP31 GP153,GP156-157, GP197,GP201, GP75,GP150,GP237 He J, O21,O26,GP82 GP210-211,,GP239 Kallakuri S, O29, He Q GP50,SP18 Inage K, O1,O70,SP15,SP35, SP51, Kamata M, GP208, Healy AT, GP14, SP58,GP17,GP51,GP59,GP64-65, Kamoda H, SP35,SP51,SP58, GP2, Hebelka H, O13, GP98-99 GP17,GP51,GP59,GP64-65,GP98- Helgeson MD, GP20,GP21 Ingram JA, GP48-49 99,GP117,GP148,GP153,GP157, Henriksson HB, GP72, Inoue G, O17, SP33,SP35,SP51, GP197,GP210-211 Hidekazu S, GP120,GP123 SP58,GP2,GP17,GP51,GP59,GP64- Kanaya K, GP107, Hideki M, GP129, 65,GP98-99,GP101,GP117, GP153, Kanayama M, O72,GP128,GP146 Hideki S, SP54, GP157,GP197,GP210-211 Kane M, O48, Hidetoshi,T, GP120121,GP123 Inoue N O8,O26,SP10,GP23, GP25, Kaneko S, SP38, Higashino K, GP10, GP103,GP109, GP26,GP36,GP44,GP82 Kaneko Y, O33, GP32,GP205 GP118-119 Inuzuka K, O61, Kanematsu F, GP138, Hikata T, O33,GP32,GP205,GP208 Ishigaki N, GP108,GP147 Kaneoka K, GP5,GP27 Hilario R, GP58,GP63 Ishihama H, O24,SP42 Kang DG, GP19-21, GP226-228 Hirabayashi H, O71,GP243 Ishihara S, O33, GP32,GP205 Kang JD, O14, O19,SP16,GP34, Hirata H,SP17, GP60,GP62,GP75, Ishii K, O24,O33,SP32,SP38, SP42, GP42, GP44-45,GP53,GP61,GP137 GP150,GP237, GP32,GP205,GP208 Kang KT, GP29,GP33,GP142-143 Hiratzaka S, O48, Ishii T, GP90, Kang YM, GP67, Hirayama J, SP58, Ishikawa T, O17, SP35,SP51,SP58, Kangas AJ, O16, Hiroaki K, O50, GP2,GP17,GP51,GP59,GP64-65, Kanim L, O22,SP41 Hiroaki N, GP121, GP98-99,GP117,GP148,GP153, Kanim LA, SP41, Hiroko I, GP122, GP157,GP197,GP210-211 Kanim LEA, GP242, Hiromitsu T, GP121, Ishimoto Y, O38,O40 Kankaanpää M, SP30,GP35 Hirosuke N, GP120,GP123 Ishizaki T, GP130, Kanna R, O53, Hiroto K , O17, Ito M, GP145, Kanna RM, O10, Hiyama A, GP70,GP96,GP186 Ito T, SP58,GP145 Kanzaki T, SP53, Hodges SD, GP163, Iwanami A, O33,SP38,GP32,GP205, Kao MCJ SP59,GP207 Hoelscher GL, GP48-49 GP208 Kao TH, GP83, Hoffman C, GP111, Iwasaki H, SP04,SP29 Karim MZ, GP58,GP63 Homma T SP32, Iwasaki M, GP145,GP181 Karppinen J, O16, GP115,GP154 Hong JK, GP194-195 Iwasaki R, SP21, Kasperk C, O68, Hori T, GP66,GP182, Iwata A, O72,GP128,GP146 Kato H, GP243, Hoshino M, O69,GP223 Izeki M, GP15,GP200 Kato K, O64,SP55,SP60,GP107, Hosogane N, O33,SP38,SP47,GP32, Izumi A, GP66 GP229 GP205,GP208 Kato M, GP223, Hsieh AH, GP46,GP87, J Kato S, O44 GP103 Hu R, GP136, Jabir RA, GP145, Kato T, SP50, Hu S O45, Jahng TA, GP145, Kato Y GP12,GP107 Hu Y, SP02, Jarvik JG, O77, Katoh S, GP109,GP118-119 Huang Z, GP55, Jennum P, GP149, Katsuhira J, GP28, Huellstrung R, GP94, Jeon CH, O11,GP214-215 Kaul V, GP37, Huh J-S, GP36, Jeong HS, GP194-195 Kawaguchi H, GP99, Humadi AH, SP34, Jeong JH, GP145, Kawaguchi Y SP52,GP145,GP182 Hutton WC O28,O52,GP10 Jiang J, GP55, Kawakami M, O23,O76,GP145, Hynes RA, GP202, Johnson ES, GP95, GP198 Johnsson R, O78, Möller A, O78, Kawamura N, O44, GP66 I Jones CF GP16, Kawano O, GP31, Ibsen R GP149, Jönsson B, O73, Kayama S, SP22, Ichiji K, SP22, Kazuhiro C GP122, Ida K,GP135, K Keeney BJ, O46, Ignatius A, GP52, Kadosaka Y, GP104, Kelly A, O25, GP7 Iguchi T GP150 Ken I, O50,GP122 273

INDEX

Kengo Y GP120,GP123 Kosaka H, GP119, Lee J, O19,GP86 Kenji E, GP120,GP123 Koshi T, GP197, Lee JYB, SP25, GP137 Kenji Y, O50,GP122 Kotani T, GP164,GP238 Lee LH, GP92, Kentaro Y, GP121, Kotowski S, SP05,SP24 Lee SH, SP39,SP57 Khandehroo B, GP232, Koyanagi T, GP205, Lee SW, GP194, Khong PL, SP13, Koyasu S, O24,SP42 Lee YT, O32, Kiapour AM, GP47, Kreuter W, O77, Lehman Jr. RA, GP19-21 Kikuchi K, GP112, Kropf M, GP242, Lehman RA, GP226-228 Kikuchi N, O61, Kröger H, SP56, Lehto S, O65,SP40 Kikuchi S, O37, O64,SP55,GP114, Kubota G, O1,O70,SP15,SP35, SP51, Leinonen V, SP56, GP140,GP229 SP58,P17,BP51,GP59, GP64-65, LeMaitre C, GP73, Kikuchi T, GP129,GP132 GP98-99,GP117, GP148, GP153, Leme A, O19, Kim DW, GP143, GP156-157,GP210-211 Lemen L SP24, Kim DY, GP194-195 Kugisaki H, GP126,GP133 Lenke LG, GP226-227 Kim H, GP87, Kuh S, GP145, Lenz ME, O21,SP19,GP40, Kim HJ, SP23GP29,GP33,GP67, Kuittinen P, SP56, GP80-81 GP142-143 Kumar GV, GP145, Leung A, SP09, Kim HS, SP39,SP57 Kumar K, GP213, Lim YW, GP194-195 Kim HY, O14, Kuniyoshi K, SP21, Limbäck Svensson G, O18, Kim J, GP242, Kuraishi S, GP243, Lin B, GP18, Kim JH, O28, Kurakawa T, SP17GP60,GP62, Lindahl A, GP72, Kim JJ O11,GP214-215 GP75,GP150,GP237 Liu J, GP202, Kim S O51, Kuramoto T, O24,SP42 Liu ZH, GP88, Kim S, GP58,GP63 Kurata J GP140 Lo HJ, GP1, Kim SD, GP230, Kurosaka M, SP17,GP60,GP62, Lord SJ, SP45,GP212 Kim SY, GP194-195 GP75,GP150,GP237 Lotz J, O26, Kim TH, SP57, Kurtz SM O67, Lozito T, GP61, Kim YC, GP195, Kuy Han SK, GP46, Lubelski D, O35,GP14 Kim YH GP105-106 Kwok JWL, SP02, Luk KDK, O16,SP02,SP13, GP145, Kimiaki SK, SP37, Kwon B, GP202, GP154 Kimura S, GP51, Kyllönen E, GP115, Luo J, SP07, Kimura T GP182, Kyo Y, GP138, Luo ZJ GP88,GP145 Kinoshita H, GP243, Käser A, O62, Lurie JD, O7, O74 Kinoshita T, SP58, Könönen M, SP30, GP35 Lycklama à Nijeholt GJ GP220-221 Kinoshita Y, O76,GP104 Kita T, GP138, L M Kitagawa Y, Lafave LZ, GP136, Machida M, SP38, Kitahara S, GP239,O34 Lama P, SP14,GP73 MacMillan M, GP202, Kitajima M, GP133, Landham PR, O27,SP07,SP11 Maeda T, GP31, Kitamura M, GP152,GP164,GP238 Lange A, O68, Maedler M, GP63, Kitou K, GP130, Lange J, GP13, Maeno K, SP17,GP60,GP62,GP75, Kjellberg J, GP149, Lapinsky A, O55,GP224 GP150,GP237 Kjellby Wendt G, O18, Lari H, O43, GP224 Magee D, O4, Klöting I, GP13, Larsson K, GP71, Mageswaran P, GP8, GP9,GP14 Kobayash T, GP10, Lau E, O67, Mahieu G, GP116, Kobayashi K GP180 Law T, SP13, Makino T, GP90, Kodigudla M, GP22 Lavender SA, O9, Malhotra NR, GP74, Koes BW GP220-221 Lazary A, GP52, Mamoru A, O50, Koivisto K, GP115, Leaman D, GP18, Mamoru K GP104, Komatsubara S, GP204, Lee A, SP12 Manabe H GP180 Konari Y, GP66 Lee BH, SP39,SP57,GP67 Manman G, GP4, Konishi S, GP223, Lee CK, SP23, GP29,GP33,GP142- Mannion AF, O42,O54, O58,SP01, Konishi H O61, 143 GP189 Konno S O37,O64,SP22,SP55,SP60, Lee CS, GP145, Manoj-Thomas A, GP92, GP99,GP114,GP140,GP229 Lee DB, GP142-143 Mansfield FL GP230 Kono H, SP38,SP47 Lee GW, GP143, Marek R, O63, Konstantinos V, O3, Lee HM, SP39,SP57,GP67 Markova D, GP84, 274

INDEX

Marras WS, O9,SP05,GP69 Melloh M, O62, O74, SP45,GP13, Moses RA, O74, Marrero L, GP166, GP212 Moudgil V, GP145, Martin BI, O7, O46,O77 Melnyk AD, O25,GP7 Mroz TE O35,GP14 Martin JT, GP74, Mendel E O9, Mukaiyama K, GP243, Martinez A, SP59, GP207 Menendez ME, GP203, Munakata Y , SP22, Marty M, GP116, Meng X, GP188, Murak S, O39, Maruyama H GP28, Merk HR SP45,GP13,GP212 Murakami H, GP66,GP132, Maruyama T, O44, Metzger M, O22,SP41 Murakami M, O44, Marx J, SP19, Michael J, SP28, Muraki S, O38, O40 Masatoshi F, GP243, Michaëlsson K, O31, Murase S, GP236, Masatoshi H, GP121, Miciak M, O4, GP94 Murata K O15,SP50,GP56 Massimo T, SP16, Mietsch A, GP52, Murata Y, SP58,GP12,GP107 Masuda K, O20, O21,O26,SP19, Mikalsky M, GP94, SP20,GP44,GP80-82 Mikami H, GP147, N Masuda M, GP31, Mikami Y GP180 Nagai S, O24,SP42 Masui O, GP63, Mimura M, SP58, Nagai T, GP96,GP186 Matsu Y, GP140, Minami S GP152,GP164,GP238 Nagamachi A, SP49, Matsuda S GP15,GP200 Minamide A, O38,SP04,SP29 Nagamoto Y, GP181 Matsudaira K , O61,GP28 Mirza SK, O7,O46,O77 Nagashima H, GP145, Matsuki K, O34, GP239 Misawa H, GP187, Nagata K, O38,O40,SP37,GP135 Matsumoto M, O24,O33,SP38, Miyagi M, O17,SP35,SP51,SP58, Naiki M SP20,GP80 SP42,SP47,GP32,GP54,GP205, GP2,GP17,GP51,GP59,GP64-65, Nair R, GP213, GP208 GP98-99,GP117,GP148, GP153, Nakagawa K, SP31,GP89,GP209, Matsumoto T, O69,GP217, GP223, GP157,GP197,GP210-211 GP222 GP225 Miyake T, GP104, Nakagawa Y, SP04,SP29 Matsumura A, GP223, Miyamoto E, O76, Nakai O, GP219, Matsunaga N, GP27, Miyashita T O49, Nakai T, O20, Matsuo Y, O64, SP58,GP100,GP165 Nakajima A, SP31,GP89,GP209, Matsuoka T O76,GP104,GP198 Miyauchi A, GP180, GP222 Matsushita O, SP33, Miyazaki S, SP17, GP62,GP75, Nakamura H O69,SP06,GP124, Matsuura M, GP12, GP150,GP237 GP199,GP217,GP223,GP225 Matsuura T, GP10, Miyoshi K, O44, O61 Nakamura K, O20,GP131 Matsuura Y, SP21, Mizuno K GP219, Nakamura M, O33,SP38,GP32, Matsuyama Y O71, Mizutani J, GP134, GP205,GP208 Matthew P. SP59 Mochida J O20,GP60,GP70, Nakamura Y GP5, Mattsson J, GP72, GP96,GP186 Nakanishi K, GP187, Mauck RL, GP74, Montgomery SR, SP06, Nakano M, GP182, Mausda K GP40, Moon HJ, GP61, Nakao S, O23, O76,SP29, GP104, Mawatari M SP26,SP27,GP126, Moon SH SP39,SP57,GP67 GP198 GP133 Moore R, SP34,GP95 Nakata Y, GP153,GP211 Mayer JM, GP139, Moran J, GP22 Nakata Y, SP15, GP17 Mazaki T, GP187, Morasco BJ, GP95, Nakazawa T, SP33,GP101 McAviney J, GP39, Mori E, GP31, Narayana-Rao VV GP241, Mcclincy M, O14, Mori H, SP53, Naresh-Babu J, GP76, GP241 McGill SM O30,SP09 Mori T GP236, Nasto L, O19,GP53, McGillion S, GP189, Moriartey S GP136, Natarajan RN, GP11,GP24 McGuire KJ GP230 Morii J, O44, Neelima G GP76,GP241 McIntosh G, SP03,GP93,GP111, Moriki T, GP104, Negrini A, GP158, GP151 Morimoto R, GP56, Negrini S GP127,GP158 McIntosh TC O60, Morimoto T, SP26,SP27,GP126, Neidlinger-Wilke C, SP08,GP52, McKay WF, SP19,GP81 GP133 Nemoto T, GP152,GP164,GP203 McKillop AB, O66, Morinaga T, SP58, Neuhaus V, GP203, McLain R GP8,GP9 Morio M O50,GP122 Newton DGP,163, McLain RF GP168, Morishita S, GP198, Ngo K, O19, SP16,GP53,GP61 MD, Khandehroo B, GP233, Morishita Y, GP31, Nguyen QT, GP44, Mehdian H, GP234, Morita Y, GP62, Nielsen CV, O36, Mehrkens A, GP58,GP63 Morse LJ, GP79, Niemeläinen R GP94, 275

INDEX

Niinimäki J, GP115, GP117,GP148,GP153,GP156-57, Prijambodo B, GP145, Nikaido T, O64, SP55,SP60, GP140, GP197,GP210-211 Puttlitz CM, GP30, GP229 Osaki S GP187, Nilsson A, O13, Oshita Y, GP23, Q Nishi H, SP04,SP29 Otani K, O37, SP55,SP60,GP114, Qasim M, GP24, Nishida K SP17,GP60,GP62,GP72, GP219,GP229 Quillen WS, GP139, GP150,GP237, Otoshi K, O64, Quon JA, O2,GP144 Nishikawa S GP89,GP130-131 Otsuka S, GP134, Nishimura A, SP50, Otsuka T GP134, R Nishimura H, GP216,GP235 Otsuka Y, GP36, Rade M, SP30, GP35 Nobukiyo M, SP52, Otsuki B, GP15,GP200 Rajasekaran S O10,O53,GP145 Noh W, GP194-195 Otsuki K, GP130-131 Ramsey T, SP05, Norberg M, GP116, Ouchi J, SP36,GP160,GP167 Rashiq S, O4, Nordborg C, GP71, Oxland TR O25,GP7 Rasouli A, GP242, Norimoto M, GP98, Oyama T, GP131, Rechtine GR O3,GP91 Nowicki AL, GP137, Ozawa T, O17,O34,O70,SP58, Rege A, GP145, Nukaga T, GP70, GP201,GP239 Rempel J, GP136, Numazawa T, SP20, Renjitkumar J GP213, P Reynolds JB GP196, O Paik H, GP19 Rhee DJ,GP194-195 O’Dowd JK , O5, Pakarinen M, O65,SP40 Ring D, GP203, Obara H, GP131, Paldanius P, GP115, Risbud M, O20,GP54 Obata, T, GP59, Palepu V, GP22 Robie B, GP6, Oestergaard LG, O36, Pan CC, O8,GP26 Robinson S, O22, Ogihara S, O44,GP236 Park CK, GP145, Robinson ST, SP41, Oglesby M, O47,SP46,GP169- Park DK, GP25, Robson-Brown K, O27, GP179 Park JH, SP23,GP29,GP142-143 Rogerson M, GP136, Oh IS, GP3, Park JO, SP57,GP67 Roh J O59, Oha F, O72, GP128,GP146 Park JU, O11,GP214-215 Romano M, GP158, Ohnmeiss DD, 041,O56,O63,SP43 Park Y, O32, Roughley P, O19, Ohtori S, O1,O17,O34, O70,SP15, Parks RM, GP113, Rozenberg S GP116, SP21,SP31,SP35,SP51,SP52,SP53,SP Parnell J, GP136, Ruan DK, SP18,GP50 58,GP2,GP17,GP51,GP59,GP64- Parzini S, GP158, Ruehlman DR, GP30, 65,GP89,GP98-99,GP110,GP112, Patappa G, GP77-78 Runesson E, GP71, GP117,GP148,GP153,GP156-157, Patel A, gp177 Russo F, SP16,GP77-78 GP164,GP197,GP201,GP210-211, Patel A, O47,SP46,GP169-179 Rydevik B GP71, GP239 Patwardhan AG SP12 Ohzone H, GP59, Pedtke A, O45, S Oikawa Y, O1,O17,O70, SP15, Pehkonen T, GP115, Saari T, SP56, SP35,SP51,SP58,GP2,GP17,GP51,G Pelton M, gp177 Sacco D GP166, P59,GP64-65,GP98-99, GP117, Pelton M, O47,SP46,GP169-179 Sah RL, O26,GP44 GP148,GP153,GP156-157, GP197, Peng C, GP83, Sahlstrand T, O78, GP211GP210, Penta K, GP81, Saino T, SP35,GP148,GP210-211 Oka H, O38, O40 Peroglio M, GP77-78 Sainoh T, O1, O70,SP15,SP51-52, Oka S GP204, Perry E, O48, SP58-59,GP5,GP10,GP17,GP98- Okada T, SP20, Petrik A, GP95, 99,GP102-103,GP117-119,GP151, Okada Y, O24,SP42 Pettine K, O59, GP153,GP156-157,GP185,GP197, Okamoto Y, SP58, Peul WC GP218,GP220-221 GP211 Okubo T, GP59, Phan K, SP06, Sairyo K, GP5, Okubo Y, GP5,GP27 Pichika R, O21,GP40,GO80-81 Saito M, SP38,SP47 O'Neill C, GP97 Pittet V, O58, Saito W, SP33,GP101 Ong KL, O67, Pohl PHI, GP61, Sakai D, O20,GP60,GP70, GP96, Onishi T, O72,GP128,GP146 Pokharel R, GP145, P186 Onishi Y, O37,GP114 Pollintine P, O27,SP07,SP11,GP22 Sakai H, GP31, Orita S, O1, O17,O70,SP15,SP35, Porchet F, O58, Sakai T, GP103,GP109,GP118-119 SP51,SP52,SP53,SP58,GP2,GP17,GP Portia-Anthony M, SP13, Sakai Y, GP237, 51,GP59,GP64-65,GP98-99, GP110, Prasarn ML, O3,GP91 276

INDEX

Sakaida C, GP131, Shibata Y, SP31,GP64,GP209, St Joseph JB, GP73, Sakanaka H, GP138, GP222 Stadelmann V, GP77, Sakon N, GP104, Shiboi R, O34,GP201,GP239 Stallbaumer JJ, GP226, Sakuma T, GP152,GP164,GP238 Shibuya S, GP204, Staub LP, O74,SP45,GP13,GP212 Sakuma Y, O1,O17,O70,SP15,SP35, Shieh I, O21,GP82 Stauff MP, O28, SP51,SP58,GP2,GP17,GP51,GP59, Shiga T, GP130-131 Steenstra I, GP93, GP64-65,GP98-99,GP117, GP148, Shigehiro I, SP54, Stefanakis M, SP07,SP14 GP153,GP156-157,GP197, Shigenobu K, O72,GP128,GP146 Steiger F, O58, GP210-211 Shigenori N, O50,GP122 Ström O, O57, Samartzis D, O16, SP13,GP86, Shigeo K, O50,GP122 Strömqvist B O73,O78 GP88,GP145,GP154 Shimamura T GP129, Sudo A SP50,GP56 Sameda H, SP58, Shimizu M, GP243, Sugimoto Y, GP187, Sandella DE, O75, Shimoda H, SP32, Sugiura S, GP89,GP130-131 Sandén B O31, Shindo S, GP219, Suh BG, GP143, Sanderson PL GP92, Shingo M, GP60, Sumida T GP180 Santoni AL, GP30, Shinji T, GP121, Summers B, SP14, Santoni BG, GP30, Shinohara Y, SP53,GP217,GP225 Sun A, GP94, Sasaki A, O24, SP42 Shinsuke S, GP120,GP123 Sun Z, GP88, Sasaki N, GP71, Shiono Y, O24, SP42 Sundqvist K, GP115, Sasaki S, GP198, Shiota M, SP38, Sung NY O32, Sato J, O1,O70,SP15,SP51,GP17, Shiozaki Y, GP187, Sur DW, GP3, GP51,GP59,GP64-65,GP98-99, Shirahata T, O34,GP239 Suresh Ch, GP241, GP117,GP148,GP153,GP156, Shiraki M, SP26,GP133 Suzuki A, O69,SP06,GP217, GP197,GP211 Shivers J, SP43, GP223,GP226 Sato M, GP96,GP186 Sho D, GP121, Suzuki H, GP68,GP216,GP235 Sato N, GP119, Shoji S, SP20, Suzuki K,GP182, Sato Y, GP152,GP164,GP238 Sides BA GP226, Suzuki M, O1,O17,O70,SP15,GP2, Satoh S, GP145, Sidorkewicz N, O30, GP17,SP35,SP51,SP58,GP51,GP59, Satoshi Y, GP129, Siemionow K, SP25, GP64-65,GP98-99,GP117,GP148, Sauermann S, O68, Sigmundsson FG, O73, GP153,GP156-157,GP197,GP209- Sawaji Y, GP68, Simamura T GP132, 211, Savolainen S, SP56, Simon P, O8, SP10,GP36 Suzuki N, GP134, Schairer W, O45, Sinclair MK, SP12 Suzuki T, SP21, Schiuma D, GP78, Singh K O47,SP46,GP169-179 Sychev I, SP14, Schreck M, GP91, Singh V, GP7, Szpalski M, GP39, Scott TP, SP06, Sinikallio S, O65, SP40,SP56 Seim III HB, GP30, Sipola P, SP56, T Seitsalo S, GP115, Skioldebrand E, GP72, Taborek A, O21,GP44 Seki M, GP223, Slikker III W, SP25, Tadao T GP121, Seki S, GP182, Slosar PJ, GP166,GP196 Takada T, SP17, GP60,GP62,GP75, Sekiguchi M, O37,O64,GP114, Smith DHM, GP95, GP150,GP237 GP140 Smith LJ GP74, Takahashi H, SP31,GP89,GP209, Senoo I, GP25, GP26 Smuck M, SP59,GP207 GP222 Shacklock M, SP30, GP35 Sobottke R, SP28, Takahashi J, GP243, Shah SB, GP87, Sogaard R O36, Takahashi K, O1,O17,O34,O70, Sham P, GP145, Soininen P, O16, O71,SP15, SP21,SP31,SP35, SP37, Shapiro I, GP54, Soliman A, O78, SP51-53,SP58-59,GP2,GP17, GP64- Shapiro S, O19, Sonobe M, SP31,GP209,GP222 65,GP89,GP98-99,GP110, GP112, Sharan AD GP79, Sonohata M, SP26, SP27,GP126, GP117,GP148,GP152-153,GP156- Shen Y, GP145, GP133 157,GP164,,GP197, GP201,GP210- Shetty AP, O10,O53 Sowa G, O14,O19,SP16,GP42, 211,GP222,GP238-239, Shetty JY, O10, GP53,GP61 Takahashi N, SP22, Shi P, GP83-84 Spann SW, GP202, Takahashi S, GP217,GP225 Shi Z, SP18,GP50 Splittstoesser R, O9,GP69 Takahashi Y SP49, Shiba K GP31, Spooner L, GP73, Takahira N, SP33,GP101 Shiba M, GP12,GP107 Spratt KF, 06 Takao S, GP118, Spruit M, O5, Takao T, GP31, 277

INDEX

Takaso M SP33,GP101 Tracey RW, GP19-21, GP226-228 Watanabe M, GP96,GP186 Takata Y, GP103,GP109,GP118-119, Truumees E, GP47, Vavken P, GP86, GP130 Tse JYH, SP02, Welch J, GP94, Takatori R, O8, Tsuji T, SP38, Wen TL, O25, Takayama K, SP54,GP138 Tsujio T, O69, Wenbin D, GP4, Takebayashi T, SP37,GP99,GP135 Tsukamoto M, SP26,SP27,GP133 Whang PG SP48, Takegami M, O37, Tsukiyama K, GP217,GP225 Videman T, O12, Takemoto M, GP15,GP200 Tsutsui S, SP04,SP29 Viinamäki H, O65, Takeshita K, SP37,GP135 Tuan R, GP61, Viinamäki H, SP40, Takigawa T, GP187, Tubaki V, O53, Wilke H-J SP08,GP6,GP52 Takiguchi N, O38,O40, Tujio T, GP223, Williams R GP145, Tamura Y, GP148, Tukamoto M, GP126, Wilsey JT, SP19, Tan K, O21, Tullberg T O78, Wilson P, GP136, Tanaka H, GP68,GP216,GP235 Turner AS GP30, Virk GS, O29, Tanaka M O72,GP128,GP146, Turunen V, SP56, Vleggeert-Lankamp CL, GP218, GP187 Tyler Perryman L GP190 GP220-221 Tanaka T, O34,GP239 Tängemo C, GP72, Vo N, O14,O19,SP16,GP42,GP53, Tang SY, GP79, GP61 Taniguchi H, GP119, U Wojewnik B, SP12 Taniguchi S, SP31,GP209,GP222 Uchida K, SP33, GP101 Volkheimer D, GP6, Taniguchi T, GP119, Ueno M, SP33, GP101 Wong DA, GP162 Tanimoto K, O29, Ueta T, GP31, Wood KB GP230 Tanno T, O49, GP100,GP165 Uri O, GP113, Voronov LI, SP12 Tassanawipas WA, GP145, Urushibara M, SP36GP125, GP159, Wu J, SP18,GP50 Tateiwa Y GP243 GP160,GP167 Wu X, GP55, Tcherveniakov P, GP16, Wuqikun A GP123, Techy F, GP8,GP9 V-W Terada M, SP29, Wachna M, GP231, X Teraguchi M, O39, Wada H, GP107, Xin HK, SP18,GP50 Terai H, O69, GP217,GP223, GP225 Wada K, GP12,GP107 Xuejun D, GP4,GP57 Terakado A, SP53,GP110 Wada T, GP66 Xuenong Z GP4,GP57 Terayama S, O44,GP124,GP199 Wada Y, O17,O34GP239 Teruo K, SP54, Vadalà G, SP16,GP77-78 Y Tervonen O, GP115, Vader J-P, O58, Yabuki S, O37, SP55,SP60,GP229 Tetsuhiro GP148, Wakita T, O37,GP114 Yagi M, SP38, Tetsuya K, O50,GP122 van den Hout WB GP220-221 Yaldo J, O29, Thomeé R, O18, Van der Kallen BF GP220-221 Yamabe D, GP129,GP132 Tibiletti M, SP08, van Hooff ML, O5,O42 Yamada A, GP185, Tillotson CJ, GP95, van Limbeek J O5, Yamada H, O38,O39,O40,SP04, Tobimatsu H, GP181 Wan ZY, GP88, SP29 Toki S, SP49, Wang CF, SP18,GP50 Yamada K O44,GP217,GP225 Tolhurst S, GP8, GP9 Wang CM, GP88, Yamada M, GP209,GP222, Tomiya M, GP121, Wang D, O19,SP18,GP50 Yamada T, O44, Tomkins-Lane CC O75,GP136, Wang HQ, GP88, Yamagata M, SP58,GP197 GP155 Wang JC SP06, Yamaguchi T, O21,O26,SP19,GP40, Toshiaki K, GP152, Wang T, O35, GP44,GP80-82 Toshiya Y, SP54, Wang Z, O52, Yamakawa KSJ, O75, Toshiyuki M GP184, Vanhanen S, O65,SP40 Yamamoto J, SP17,GP60, GP62, Tosteson ANA, O7,O77 Vanninen R, SP30,GP35 GP75, GP150,GP237 Toyama Y, O24,O33,SP38,SP42, Wardlaw D, O57, Yamane K, GP68,GP187,GP216, SP47,GP32,GP54,GP205,GP208 Warren S, O4, GP235 Toyoda H, O69,GP217,GP223, Watanabe A, O17, O34,GP59, Yamano Y GP138, GP225 GP117,GP211,GP239 Yamaoka A, GP112, Toyone T, O17,O34,O70,SP51, Watanabe K, O33, SP38,SP47, Yamashita K, GP112, SP59,GP2,GP51,GP59,GP98-99, SP55,SP60,GP32, GP205,GP208, Yamashita M, SP58, GP112 GP197,GP201,GP239 GP229 Yamashita T, SP37,GP135 Toyooka T, GP130-131

278

INDEX

Yamauchi K, O1, O70,SP15,SP35, Zhou J, GP55, SP51,SP58,GP17,GP51,GP59,GP64- Zhu Q GP55, 65,GP98-99,GP17,GP117, GP148, Zhu S, GP88, GP153,GP156-157,GP197, Zigler JE O56, SP43 GP210-211, Zinchenko N, GP49, Yamazaki K, GP129,GP132 Yamazaki T, O44,GP124,GP199 Ö Yan Y, GP34, Örndal C, GP71, Yang S-H, GP26,GP83 Yang X, GP95, Yasuda H, O69, Yasuda T, GP182, Yasui N GP10,GP118-119 Yasunori O, O50, GP122 Yeom JS SP23,GP29,GP33, pGP142-143 Yeung A, GP190-193 Yim RL, GP86, Yogoro M, SP33, Yokoyama K, GP70, Yonenobu K GP90, Yoon ST, O28,O52 Yorifuji M, GP216,GP236 Yoshiaki T, O50,GP122 Yoshida K GP140 Yoshida M O38,O39, O40,SP04,SP29 Yoshida S, GP132, Yoshihara T, SP26,SP27,GP126, GP133 Yoshiki Y SP54, Yoshimura N, O38, O39,O40 Yoshinori K, SP54, Yoshioka K, O24, SP42 Yu J, GP189, Yuasa A, GP146, Yugue I, GP31, Yurube T, SP16,SP17,GP42, GP60-62,GP75,GP150,GP237

Z Zaina F, GP127,GP158 Zammerilla LL, GP137, Zhang C, SP18,GP50 Zhang J, GP93, Zhang WL, GP88, Zhang X GP45, Zhang Y, SP18,GP50,GP83-85 Zhang YZ, GP88, Zhang Z, GP60,GP145 Zhao L, O22, SP41 Zhao W, O74 Zheng L, GP45, Zheng Y GP193, Zheng Z, GP145, Zhiyu Z, GP4,GP57 Zhou H, O43,O55,GP18,GP224 279

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