MID AMERICA ORTHOPAEDIC ASSOCIATION 27 th Annual Meeting April 22 26, 2009 Amelia Island Plantation Amelia Island, Florida
MAOA FIRST PLENARY SESSION April 23, 2009
1. The Effect of Tissue Bite Size on Rotator Cuff Stitch Strength: Is Bigger Better? Brent A. Ponce, M.D. Birmingham, AL (a DePuy Mitek) *Chad D. Hosemann, III, M.D. (n) Birmingham, AL Parthasarathy Raghava, M.S. (n) Birmingham, AL Alan W. Eberhardt, Ph.D. (n) Birmingham, AL
INTRODUCTION: The tissue suture interface is the weakest aspect of a rotator cuff repair. Hence, it is critical to identify techniques to increase stitch strength and improve healing rates. Larger tissue purchase has demonstrated improved footprint coverage; however, we are unaware of any relationship between tissue bite size and stitch strength. The purpose of this study was to evaluate the effect of tissue bite size on the holding strength of commonly used stitches.
METHODS AND MATERIALS: 192 sheep infraspinatus tendon grafts were randomized to suture placement either 1.0 cm or 0.5 cm away from the distal end . An equal number of four commonly used stitches were placed: simple, mattress, modified Mason Allen (MMA), and massive cuff (MAC). Each graft was cyclically loaded using a Materials Testing System and then loaded to failure. A mixed model multivariate regression model was used to test the effect of bite size and suture type on peak to peak displacement, cyclic elongation, and load to failure.
RESULTS: Average load to failure (LTF) was 31 N higher for 1.0 cm purchase as compared to 0.5 cm purchase (p<0.0001). Stitch type was the most important predictor of LTF: simple 48N, mattress 68N, MMA 130N, and MAC 152N (p<0.02 for all). Elongation was 10% higher with the larger bite size: 1.57 mm vs. 1.43 mm (p = 0.0008).
CONCLUSION: The size of the bite obtained in rotator cuff repair appears to be a significant factor in the strength of the stitch. Among the stitch types, the massive cuff stitch had the highest load to failure in both of the purchase groups . 2. Outcomes Following Hemiarthroplasty with Tuberosity Coverage for Chronic Rotator Cuff Deficiency and Arthritis *Ryan M. Arnold, M.D. (n) Omaha, NE Junfeng Sun, Ph.D. (n) Omaha, NE Jason P. Weber, B.S. (n) Omaha, NE Edward V. Fehringer, M.D. (n) Omaha, NE
INTRODUCTION: Treatment for rotator cuff deficiency and associated arthritis includes various arthroplasties. Yet, no reports include results following hemiarthroplasty with tuberosity coverage. The purpose of this study was to assess functional and radiographic outcomes following shoulder hemiathroplasty with tuberosity coverage for rotator cuff deficiency and associated arthritis.
METHODS: Thirty four shoulders with rotator cuff deficiency and associated arthritis treated by one surgeon with an uncemented hemiarthroplasty with tuberosity coverage were evaluated with radiographs, the Simple Shoulder Test, and a Constant score at a minimum two years postoperative. Shoulders were classified according to Seebauer.
RESULTS: 24/34 shoulders were evaluated at a mean of 29.9 months postoperative. Of the remaining ten, four were in deceased patients, two were in patients with end stage renal disease, and four were in patients unable to return due to illness or distance. There were no cases of Seebauer IIB shoulders. Mean active forward elevation improved from 109° (range 20 150) to 127° (range 45 165). Mean postoperative Simple Shoulder Test score was 9.3 and mean postoperative Constant Score was 66.7. Shoulders maintained the active elevation present prior to surgery. There were no cases of glenoid sided bony changes or instability. One complication occurred, an infection treated with primary exchange and antibiotics. None have been revised.
DISCUSSION AND CONCLUSION: Hemiarthroplasty with tuberosity coverage for rotator cuff deficiency and associated arthritis without escape results in excellent shoulder function and bone preservation with limited complications. Preoperative active elevation is predictive of postoperative active elevation. 3. A Radiographic Analysis of the Effect of Glenosphere Position and Prosthetic Design on Scapular Notching Following Reverse Total Shoulder Arthroplasty *Laurence B. Kempton, M.D. (n) Royal Oak, MI J. Michael Wiater, M.D. (n) Royal Oak, MI
PURPOSE: Scapular notching is a well recognized complication of reverse total shoulder arthroplasty (TSA). This paper presents a prospective analysis of the effects of inferior glenosphere tilt and prosthesis neck shaft angle on scapular notching.
METHODS: Since 2004, 200 consecutive reverse TSAs were performed by a single surgeon in 192 patients with an average age of 71 years. Patients with less than three months follow up were excluded, leaving 161 shoulders with an average follow up of 11 months (range 3 41 months). AP shoulder radiographs were taken at follow up to assess the degree of scapular notching and whether an inferior scapular neck spur was present. The first 50 shoulders that were implanted with the glenosphere base plate parallel to the native glenoid surface were compared to the remainder that were implanted with the base plate inferiorly tilted approximately 15°. To avoid the confounding effect of prosthesis design on scapular notching, only shoulders that received a prosthesis with a 155° neck shaft angle were included in this analysis. Next, shoulders that received a prosthesis with a neck shaft angle of 155° were compared to those that received a prosthesis with a neck shaft angle of 142°. To avoid the confounding effect of glenosphere tilt on scapular notching, only shoulders with an inferiorly tilted glenosphere were included in this analysis.
RESULTS: No patients developed loosening of the glenosphere component. Both the grade (p = 0.002, r = 0.32) and rate (p = 0.04) of notching were higher with neutral compared to inferior tilt. Both the grade (p = 0.0001, r = 0.36) and rate (p = 0.00008) of notching were higher with the greater neck shaft angle prosthesis. An inferior scapular neck spur was highly correlated with both notching grade (p = 0.0003, r = 0.24) and rate (p=0.0007).
CONCLUSIONS: Scapular notching is usually apparent within several months of surgery and may progress over time. An inferior tilt of the glenosphere and use of a prosthesis with a smaller neck shaft angle can significantly reduce scapular notching when performing a reverse TSA. Reduction of scapular notching may improve prosthesis survival. MAOA BREAKOUT SESSION #1 TOTAL KNEE REPLACEMENT April 23, 2009
4, Developing the Occupational Activities Knee Scale (OAKS) for Primary Total Knee Replacement Patients *Joseph F. Styron, B.S. (n) Cleveland, OH Alison K. Klika, M.S. (n) Cleveland, OH Mendel Singer, Ph.D. (n) Cleveland, OH Trevor G. Murray, M.D. (n) Cleveland, OH Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew, Stryker, TissueLink, Zimmer; b Stryker; c Exactech, SS White, Wright Medical Technology; e Otismed, SS White, Stryker, Wright Medical Technology)
BACKGROUND: Patients under 65 years of age represented only 24.1% of all total knee arthroplasty (TKA) patients in 1997, which increased to 37.4% of patients in 2005. Younger patients have greater demands for their TKA than the historically older patient population, with many that want to continue working and avoid premature retirement.
METHODS: A bank of questions assessing both psychological and physiological aspects of a person’s motivation and ability to work was developed, which we have named the Occupational Activities Knee Scale (OAKS). These were evaluated by a multidisciplinary panel of experts to assess the validity of the questions regarding an individual’s ability to work. Patients are asked whether their job requires them to perform physical tasks that have been shown to have an association with the development of osteoarthritis or pose difficulty to patients recovering from a TKA. Patients undergoing primary TKA have been enrolled in the study with the intention of a six month postoperative follow up period to assess which preoperative factors can be used to predict what type of jobs lend themselves to a person returning to work and in what time frame a person can reasonably anticipate returning to work.
5. Clunk is Solved but Patellar Crepitus Persists: Prevalence, Severity, and Natural History in Two Contemporary Posterior Stabilized Knee Designs Mir H. Ali, M.D. (n) Rochester, MN Mark W. Pagnano, M.D. Rochester, MN (e DePuy) *Robert T. Trousdale, M.D. (n) Rochester, MN
INTRODUCTION: Design changes to the depth, length, and transition zone of the trochlea have largely eliminated frank clunk in current generation Posterior Stabilized (PS) knees. However, symptoms of grating, grinding, or crunching (crepitus) are reported in a subset of patients with current PS knees.
METHODS: 599 patients who had a PS TKA (DePuy Sigma or Zimmer Legacy PS) were comprehensively queried about patellar crepitus. 428 patients (251 LPS and 177 Sigma PS) with a mean age of 67 and a mean follow up of 3.9 years completed the survey.
RESULTS: Twenty four percent of patients reported crepitus after PS TKA. Most symptoms appeared within the first year, but 21% developed it after one year. For the majority (68%), crepitus was neither painful nor audible; for those with pain, it was typically occasional (65%) and described as a nuisance (66%). Some patients (23%) had the crepitus resolve, most often after one year. For most (69%), the crepitus did not decrease satisfaction with their TKA although seven patients were very dissatisfied. Trends included: a higher chance that crepitus adversely affected satisfaction and activity limiting in the LPS design, a higher likelihood of crepitus disappearing in the Sigma design, a higher chance crepitus was painful in the Sigma.
CONCLUSION: The prevalence of crepitus (24%) was surprisingly high in these two contemporary PS knee designs though it was only occasionally a limiting problem for patients. No substantial differences in the quantitative or qualitative aspects of crepitus could be discerned between the Sigma and LPS designs.
6. Antibodies to Hylan G F20 and Hyaluronan in Patients Receiving Viscosupplementation Paul H. Wooley, Ph.D. (n) Wichita, KS Zheng Song, M.D. (n) Wichita, KS *David C. Markel, M.D. Southfield, MI (b Genzyme)
INTRODUCTION: This study examined the frequency of antibodies to Hylan G F20 (Synvisc) and purified bovine and human HA in patients with advanced osteoarthritis undergoing viscosupplementation.
METHODS: Sera from 24 patients undergoing viscosupplementation were obtained at two months following their third intra articular HA injection. All patients had significant arthritic changes and were evaluated by both physical examination and a Patient Questionnaire. Control sera were obtained from OA patients not receiving viscosupplementation. Sera were assayed for antibody binding to Hylan G F20, and highly purified bovine and human hyaluronic acid preparations using an ELISA, with control assays using both BSA and HSA blocking agents to avoid false positives. Antibody binding that exceeded the mean plus two standard deviations of control sera was defined as positive.
RESULTS: Specific antibodies binding Hylan G F20, bovine HA, and human HA were all higher in viscosupplementation patients compared to the TKA controls, but only binding to Hylan G F20 reached statistical significance (p<0.03). Five of 24 viscosupplementation patients exhibited positive Hylan G F20 binding. Although the positive antibody patients did not report any overt adverse reactions, this group was significantly worse than the antibody negative patients with respect to level of knee pain while walking and current activity levels.
CONCLUSION: Twenty percent of patients receiving intra articular injection of hyaluronan in this study developed antibodies reactive with Synvisc. The data indicate that further studies are necessary to determine whether an immune response to Hylan G F20 is correlated with reduced efficacy of viscosupplementation.
7. Computer Assisted Surgery in Total Knee Arthroplasty *Todd C. Kelley, M.D. (n) Cincinnati, OH Michael L. Swank, M.D. Cincinnati, OH (a,e DePuy, BrainLab)
INTRODUCTION: Computer assisted TKA improves alignment accuracy; however, few articles cite any clinical benefit over conventional TKA. The author’s experience and outcomes with CAS for TKA including ligament balancing with a spring loaded tensioning device is reported.
METHODS: This is a retrospective review of prospectively collected data on 1005 TKAs (975 had OA). Seventy six were conventional TKAs and 929 were CAS TKAs. Average follow up was 17 months. Outcome variables included radiographic alignment, Knee Society Scores, and complications.
RESULTS: Eighty eight percent of CAS TKAs were placed within 3° of neutral mechanical axis. Eighty one percent were placed within 3° of optimal sagittal tibial component angle. Ninety two percent were placed within 3° of optimal coronal tibial component angle. Mean pain score improved 39.4 points, Knee Score improved 47.8 points, and the functional component improved 17.1 points. The pain score improvement for CAS was 39.2 compared to 33.0 for conventional knees (p<0.002). The Knee Society Score improvement for CAS was 48.3 compared to 41.4 for conventional knees (p<0.013). The functional component improvement was not significant between CAS and conventional TKA. When CAS is utilized along with the spring loaded tensioning device for ligament balancing, manipulation rates dropped to 7% (p<0.01). There were a total of 13 infections, 3 deep infections (0.3%), and 10 superficial infections (1%). There were no fractures from the pin sites, and no patients were revised for instability.
CONCLUSION: Our series showed a statistically significant improvement in pain and Knee Society Scores compared with conventional TKA. In addition, CAS resulted in excellent radiographic alignment and well balanced knees with the spring loaded tensioning device. Furthermore, improved radiographic alignment is likely to increase implant survivorship and provide further cost savings. With continued use of CAS, long term studies may show significant beneficial clinical effects.
8. Postoperative Pain and Contracture Following TKA Comparing Parapatellar and Subvastus Approaches Arthur L. Malkani, M.D. (n) Louisville, KY Madhusudhan R. Yakkanti, M.D. (n) Louisville, KY *Brian M. Curtin, M.D. (n) Louisville, KY Dale L. Baker (n) Louisville, KY
INTRODUCTION: Subvastus approach to total knee arthroplasty theoretically minimizes trauma to the extensor mechanism. Purpose of this study was to see if subvastus approach would decrease incidence of postoperative contracture and pain after total knee arthroplasty compared to standard parapatellar incision.
METHODS: A retrospective review of 546 patients in Group A undergoing total knee arthroplasty using parapatellar incision were compared to 280 patients in Group B undergoing subvastus approach to primary total knee arthroplasty. In Group A there were 362 females and 184 males. In Group B there were 168 females and 87 males. The average age of Group A was 64 years and for Group B, 65 years.
RESULTS: There were no statistically significant differences with respect to OR time, blood loss, BMI, or length of stay. There were a total of 23 (4%) manipulations under anesthesia for contracture in Group A compared to 6 (2%) manipulations in Group B (not statistically significant). Seventy percent of manipulations in Group A were in patients with posterior stabilized implants. Eighty three percent of manipulations were in females. Postoperative pain requiring multimodal oral pain medications, or pain management, and continued use of narcotics after six weeks was greater in Group A, p<.05.
DISCUSSION AND CONCLUSION: Based on this review, we feel that a subvastus approach minimizes trauma to the extensor mechanism, and therefore decreases the incidence of postoperative pain in patients undergoing knee arthroplasty. We were unable to demonstrate a statistically significant difference in the incidence of manipulation. Further work needs to be performed to identify etiology of contracture.
9. Intraoperative Fracture During Primary Total Knee Arthroplasty Kris J. Alden, M.D., Ph.D. (n) Chicago, IL William H. Duncan, M.D. (n) Springfield, MO *Robert T. Trousdale, M.D. (n) Rochester, MN Mark W. Pagnano, M.D. (n) Rochester, MN George J. Haidukewych, M.D. (n) Temple Terrace, FL
Iatrogenic intraoperative fracture during primary TKA has received little attention in the orthopedic literature. We reviewed all primary TKAs with intraoperative fractures to describe their prevalence, location, timing, treatments, and clinical and radiographic outcome. We reviewed 17,389 primary TKAs performed between 1985 and 2005 and identified 66 patients with 67 intraoperative fractures including 49 femur fractures, 18 tibia fractures, and no patella fractures. There were 12 men and 54 women with a mean age of 65.2 ± 16 years, a majority of whom had osteoarthritis (57.4%). Of the 49 femur fractures, locations included medial condyle (20), lateral condyle (11), supracondylar femur (8), medial epicondyle (7), lateral epicondyle (2), and posterior cortex (1). Tibia fractures (18) included lateral plateau (6), anterior cortex (4), medial plateau (3), lateral cortex (3), medial cortex (1), and posterior cortex (1). Twenty six fractures occurred during exposure and preparation, 22 while trialing, 13 during cementation, and 3 while inserting the polyethylene spacer. Three fractures were indeterminate and were diagnosed after obtaining postoperative radiographs. Treatment method varied, including modified weightbearing, fixation with screws and plates, addition of stems, bone grafting, and alteration of postoperative rehabilitation. The minimum follow up was 0.15 years (mean, 5.1 years; range, 0.15–15.4 years). Knee Society scores and function scores improved from 46.4 and 34.6 to 79.5 and 61.0, respectively. Thirteen patients were revised at an average of 2.76 years for osteolysis and loosening (four), instability (four), infection (two), patellar maltracking (one), stiffness (one), and patellar resurfacing for anterior knee pain (one). Intraoperative fracture is an uncommon complication of primary TKA with a prevalence of 0.39%. Intraoperative fracture occurred more commonly in women (80.6%) and in the femur (73.1%), and posterior stabilized implants were associated with an increased relative risk (4.74). The majority of fractures occurred during exposure and bone preparation and trialing of the components. Knee Society scores improved substantially; however, there was a 19.4% overall revision rate.
10. Do Porous Tantalum Implants Help Preserve Bone? Evaluation of Tibial Bone Density Surrounding Tantalum Tibial Implants in TKA Terence J. Gioe, M.D. Minneapolis, MN (a Zimmer, Inc.) *Alicia K. Harrison, M.D. (n) Minneapolis, MN Christine Simonelli, M.D. (n) Woodbury, MN Penny Tatman, MPH, MT (ASCP) (n) St. Paul, MN
INTRODUCTION: Total knee arthroplasty (TKA) with conventional metal backed tibial implants subjects the tibial metaphysis to stress shielding, with resultant loss of bone density. We hypothesized that tibial bone mineral density (BMD) in patients with porous tantalum (trabecular metal, TM) tibial baseplates would be better maintained than in conventional historic controls, and would more closely parallel tibial BMD in the nonoperative control limb.
METHODS: Forty patients (35 M/ 5 F) ≤ 60 years old underwent TKA with uncemented TM tibial components (Zimmer NexGen®, Warsaw, IN). Patients underwent dual energy x ray absorptiometry (DEXA) scans of the bilateral proximal tibiae with designated precision knee software (GE Lunar Prodigy Advance®, vs.10.5) preoperatively, and at 2 months, 1 year, and 2 years postoperatively. Three selected regions of interest (ROI) (Zone 1=between the pegs; Zone 2=beneath the pegs; Zone 3=directly below entire baseplate) were chosen to evaluate BMD using a standardized protocol. Precision analysis revealed precison error ≤ 4% for each of the ROI, indicating adequate power to detect BMD changes of ≥ 8%.
RESULTS: BMD was not significantly different between the operative and nonoperative knees in any ROI at any time period. BMD decreased significantly in all ROI in the nonoperative knee at the one and two year evaluations (p=.004 to p=.01). Only in Zone 3 (immediately below the baseplate) did the BMD decrease significantly at 2 months (p=.03) and 2 years (p=.05) in the operative knee.
DISCUSSION: This is the first report of BMD measurement surrounding a TM tibial implant utilizing the contralateral non operative limb as a control. Although BMD decreases immediately below the baseplate at 2 months and 2 years in TM implants, similar changes occur in the nonoperative limb. Trabecular metal implants appear to maintain tibial BMD in a parallel fashion to the nonoperative limb in this population, and better than historical controls.
11. Cruciate Retaining Total Knee Arthroplasty Using a Third Generation System with a Four Pegged Tibial Component: A Minimum 10 Year Follow Up Study Adam Schwartz, M.D. (n) Los Angeles, CA *Craig J. Della Valle, M.D. Chicago, IL (a,b,c,e Zimmer; b Smith & Nephew, Stryker) Aaron G. Rosenberg, M.D. Chicago, IL (a,c,d Zimmer) Joshua J. Jacobs, M.D. Chicago, IL (a Smith & Nephew, Stryker; a,e Zimmer) Richard A. Berger, M.D. Chicago, IL (a Smith & Nephew; a,c,e Zimmer) Jorge O. Galante, M.D. Chicago, IL (a,c Zimmer)
INTRODUCTION: While numerous reports describe the long term results of total knee arthroplasty (TKA), many of the systems described are not currently in use today. Further, several manufacturers have recently introduced tibial components with abbreviated keels that have no reported clinical results. The purpose of this study is to report our results using a third generation cruciate retaining prosthesis that utilizes four short pegs for tibial component fixation that is currently in use today at a minimum of ten years postoperatively.
METHODS: One hundred seventy nine consecutive cemented cruciate retaining TKAs were performed in 161 patients. Patients were evaluated clinically and radiographically at a minimum of ten years. The patella was resurfaced in all cases. Patients were evaluated clinically using the Knee Society Score and radiographically for evidence of component loosening and osteolysis.
RESULTS: At mean follow up of 127 months (range 120 to 131 months), 43 patients had died and 17 patients were lost to follow up, leaving 120 knees available for study. The KSS score improved from a mean of 47.4 to 92.3 (p value < 0.05). Nonprogressive tibial radiolucency was identified in 39 knees (32.2%). Three knees were revised; one for infection, one for arthrofibrosis, and one for periprosthetic fracture. There were no reoperations for patellofemoral problems, polyethylene wear, or aseptic loosening.
CONCLUSION: This third generation cruciate retaining design demonstrated low risk of loosening, wear related problems, or problems associated with the patellofemoral articulation. The use of four short pegs for tibial component fixation is associated with durable fixation at a minimum of ten years postoperatively. 12. Complications Following Total Knee Arthroplasty in the Superobese, BMI > 50 Aaron J. Altenburg, M.D. (n) Pocatello, ID David J. Polga, M.D. (n) Rochester, MN *Jessica A. Woodcock, M.D. (n) Rochester, MN Robert T. Trousdale, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN
To our knowledge, there have been no published results on the outcomes of total knee arthroplasty (TKA) in the superobese patient. We retrospectively reviewed 133 knees in 105 patients undergoing primary TKA from 1996–2006 with a mean BMI of 53.6 (50 65.9). The mean age at time of index arthroplasty was 60.73 (42 84) with a mean follow up of 35.6 months. Overall, there were 54 (40.6%) surgical complications and 15 (14.3%) medical complications including 2 perioperative deaths. Surgical complications included 20 knees with prolonged wound drainage, 4 knees with cellulitis or stitch abscesses, and 6 legs with residual neuropathy for a minor complication rate of 22.6%. There were 19 (14.3%) reoperations/major complications including 9 irrigation and debridements with component retention, 6 resection arthroplasties for deep infection, 2 revisions for aseptic loosening or malalignment, 1 revision for periprosthetic fracture, and 1 quadriceps tendon rupture. There were 5 intraoperative complications in 4 patients.
We conclude that while technically feasible, TKA in superobese patients (BMI >50) is associated with an alarmingly high complication rate. Patients should be counseled preoperatively regarding these risks and encouraged to lose weight or referred to a bariatric specialist optimally. 13. Prospective Evaluation of EIUS Unicompartmental Replacement: The Early Failures C. Lowry Barnes, M.D. Little Rock, AR (a Stryker) *Daniel Lincoln, B.S. (n) Little Rock, AR Becky Brewer B.S. (n) Little Rock, AR
INTRODUCTION: Unicompartmental replacement has become popular again, and many designs are now available. The purpose of this study is a prospective review of the fixed bearing EIUS design (Stryker, Mahwah, NJ).
MATERIALS/METHODS: This cohort represents one site of a prospective multi center study of the EIUS Unicompartmental Replacement. Preoperative and postoperative evaluation included demographics, Patient Satisfaction, WOMAC, SF 12, and KSS scores. Radiographic reviews were also performed.
RESULTS: Thirty four knees in 26 patients were included. There was a failure rate of 14.7% at three years. Four patients underwent successful conversion to TKR, and one patient is still planning revision. Those patients who did not require revision did extremely well. Pain and function scores increased from 16 to 49.6 and 23 to 48.5, respectively. Factors predicting failure were not identified.
DISCUSSION: This fixed bearing unicompartmental replacement provides excellent function, but has an unacceptable early failure rate. Design and technique modifications are necessary to provide a predictably long lasting and highly functioning UKA.
CONCLUSION: Patients are currently counseled regarding a potential early high failure rate with this design. 14. Use of a Novel Three Dimensional Titanium Porous Scaffolding on Tibial Components to Promote Bone/Prosthesis Osseointegration *Paul S. Lux, M.D. Chesterfield, MO (a,e Wright Medical Technology) Jeffrey W. Martin, M.D. St. Louis, MO (a,e Wright Medical Technology) Myron Stachniw, M.D. Galesburg, IL (a,e Wright Medical Technology) David D. Waddell, M.D. Shreveport, LA (a,e Wright Medical Technology) Jonette Hodge, R.N. Arlington, TN (e Wright Medical Technology)
INTRODUCTION: Survivorship and performance of cementless tibial components are closely related to their ability to resist forces at the bone/prosthesis interface. A novel, highly porous, foam metal material in the form of a titanium lattice has been developed to optimize osseointegration. The purpose of this study is to report on the early results of a series of cementless knees that utilize this foam metal material.
MATERIALS AND METHODS: One hundred and four knees in 89 patients were consecutively enrolled at four sites with a foam metal tibial component and beaded femoral component. Approximately 95% of the cases used screws to affix the tibial bases, whereas the remaining 5% did not. Radiolucencies, functional, and pain outcomes were assessed at six months using the Knee Society systems.
RESULTS: Eighteen knees were unavailable for follow up, and 14 were not yet due for the six month visit, leaving 72 knees for follow up. Demographics for age, BMI, and preop KSS were 64 years, 31, 53, respectively. A subvastus approach was taken in 68% of the cases, with the remainder being medial parapatellar. Mean KSS improvement from baseline at six months was 36 points, with 94% of knees reporting no or slight pain during walking. There were no radiolucencies identified out of the 10 KSS tibial component zones examined.
CONCLUSIONS: This novel three dimensional lattice exhibited no radiolucencies at the implant/bone interface even in the screwless tibias. The absence of greater than slight pain suggests that this material is providing an environment for osseointegration. Longer term data will be collected to determine if absence of radiolucencies continues. 15. Cost Effectiveness of a Blood Salvage System in Primary Total Knee Arthroplasty *Clifford K. Boese, M.D. (n) Council Bluffs, IA Theresa Gallo, P.A. (n) Council Bluffs, IA Michaela Carlson, M.S. (n) Council Bluffs, IA Marcia Weis, R.N. (n) Council Bluffs, IA Rebecca Baker, R.N. (n) Council Bluffs, IA Brian Cooley, R.N. (n) Council Bluffs, IA
OBJECTIVES: To assess if using a Blood Salvage System (BSS) reduced the incidence of allogeneic blood transfusion (ABT) and the cost of blood management during Primary Total Knee Arthroplasty (PTKA) in a community hospital.
METHODS: 618 patients underwent PTKA performed by a single surgeon from January 2004 through December 2007. Patients who pre donated autologous blood were excluded from these analyses. All patients received wound drains and postoperative Warfarin anticoagulation. The BSS was used to salvage wound drainage in 160 of these procedures. A control group of 69 PTKA patients who did not use the BSS were selected by matching age, gender, BMI, ASA score, estimated blood loss, and preoperative hemoglobin. Direct costs of blood management were calculated for each group.
RESULTS: Thirty patients (22.2%) in the BSS group received reinfusion from the BSS after their PTKA averaging 160 cc (35 cc 475 cc). ABT occurred in 17/135 (12.6%) BSS patients vs. 5/69 (7.2%) for the control group (p=0.244). Seventeen units of banked blood were transfused in the BSS group (1 4 units, average 1.88/patient transfused) vs. 5 units in the control group (1 2 units, average 1.60/patient transfused). Cost of the BSS was $455/procedure and cost of ABT was $397/unit resulting in a total direct cost of blood management averaging $549.10/case for the BSS group vs. $46.03/case for the control group (p<0.001). No complication in reinfusion or transfusion occurred.
CONCLUSION: The BSS did not lower the risk of ABT following PTKA , and its use significantly increased the cost of blood management. 16. Lateral Unicompartmental Knee Arthroplasty: Results at a Minimum of Two Years David Weimer, M.D. (n) Poland, OH *Craig J. Della Valle, M.D. Chicago, IL (a,b,c,e Zimmer; b Smith & Nephew, Stryker) Richard A. Berger, M.D. Chicago, IL (a Smith & Nephew; a,c,e Zimmer) Aaron G. Rosenberg, M.D. Chicago, IL (a,c,d Zimmer) Jorge O. Galante, M.D. Chicago, IL (a,c Zimmer)
INTRODUCTION: Lateral unicompartmental arthroplasty of the knee is an accepted treatment for lateral compartment disease. There are few published reports examining the outcomes of this intervention and none using a limited capsular exposure.
METHODS: Forty two consecutive lateral unicompartmental knee arthroplasties (38 patients) were performed between 2000 and 2005 by three surgeons using a cemented fixed bearing component. Indications included osteoarthritis or post traumatic arthritis and a clinical examination consistent with laterally based pain. The cohort consisted of 26 women (68%) with a mean age of 65 years at the time of surgery. At a minimum of 24 months, 2 patients had died, 3 were lost to follow up, leaving 37 knees in 33 patients.
RESULTS: At a mean of 46 months (minimum 24 months), the mean Knee Society Score was 73 points (range 45 to 100). Two knees were converted to TKA within six months of the index operation for persistent pain. One knee underwent a medial unicompartmetal arthroplasty at 11 months for progression of contralateral compartment disease. In the remaining knees, there was no evidence of component loosening, wear, or osteolysis. Five knees demonstrated radiographic findings of patellofemoral impingement, and two had progression of medial compartment joint space narrowing.
CONCLUSION: Lateral unicompartmental arthroplasty remains a viable treatment alternative, but is associated with more moderate KSS than is typically associated with TKA. Care must be taken to avoid impingement. Loosening, osteolysis, and polyethylene wear were not observed with this design. 17. Results of Postoperative Positive Blood Cultures Following Total Joint Arthroplasty Joseph W. George, Jr., M.D. (n) Cleveland, OH *Trevor G. Murray, M.D. (n) Cleveland, OH Robert Molloy, M.D. (n) Cleveland, OH Alison K. Klika, M.S. (n) Cleveland, OH Viktor E. Krebs, M.D. Cleveland, OH (a Stryker, TissueLink; b,e Shukla Medical, Stryker, TissueLink) Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew, Stryker, TissueLink, Zimmer; b Stryker; c Exactech, SS White, Wright Medical Technology; e Otismed, SS White, Stryker, Wright Medical Technology)
INTRODUCTION: Infection following total joint arthroplasty (TJA) is a devastating complication occurring 1% of the time in primary surgery and up to 10% in revisions. Bacteremia with subsequent hematogenous spread is a mechanism for infection. The purpose of this study is to examine TJA patients with positive blood cultures during their postoperative course, with the ultimate goal of providing a framework for the treatment of this subset of patients.
METHODS: Between January 1997 and April 2006, 15,571 TJA surgeries were conducted at our institution. These cases were cross referenced with documented positive blood cultures, which identified 187 TJA patients with postoperative positive blood cultures. Inclusion criteria were evidence of a positive blood culture for reasons other than a known joint infection, and a minimum of two years of follow up after the positive result.
RESULTS: Eighty cases met the inclusion criteria, with an average follow up of 4.5 years (range 2.0 11.0). Of these, four went on to develop an infected joint (5%), in which the bacteria identified were methicillin resistant Staphylococcus aureus (MRSA). There were 3/80 additional positive cultures with MRSA identified which did not result in infection. The positive cultures occurred within one week of TJA in 3/4 cases, all for presumed pneumonia.
DISCUSSION: These results show that the treatment for TJA patients with postoperative positive blood cultures is antibiotics alone, supported by the fact that 95% of the cases never progressed to infection. The exception to this may be when MRSA is detected, as the progression to infection occurred 57% of the time. MAOA BREAKOUT SESSION #2 TRAUMA April 23, 2009
18. A Comparison of Early Postoperative Wound Complications Following the Anteromedial versus Anterolateral Approaches for Pilon Fractures *Michael S. Khazzam, M.D. (n) Columbia, MO Brett D. Crist, M.D. (n) Columbia, MO Allison M. Wade, M.D. (n) Columbia, MO Thomas W. McEwan, B.S. (n) Columbia, MO Yvonne M. Murtha, M.D. (n) Columbia, MO Gregory J. Della Rocca, M.D. (n) Columbia, MO
INTRODUCTION: Wound complications after open reduction and internal fixation (ORIF) of pilon fractures are not uncommon. The anteromedial approach to the distal tibia leaves a thin soft tissue envelope covering implants and can be prone to wound breakdown. The anterolateral approach is thought to provide better soft tissue coverage. The purpose of this study was to compare early wound complications after utilizing either anterolateral or anteromedial approaches for pilon fracture ORIF.
MATERIALS AND METHODS: A retrospective review was done to compare the rate of wound complications within six weeks after ORIF of pilon fractures. Of 83 consecutive pilon fracture patients, 46 formed the anterolateral group (AL) and 37 formed the anteromedial group (AM). All were treated with a staged protocol, including immediate external fixation followed by delayed ORIF.
RESULTS: Most of the fractures were high energy (79% AO/OTA type C fractures, 34% open fractures). Eight AL patients (17%) had early wound complications. Six had minor complications treated with dressing changes and oral antibiotics, and two had major complications treated with irrigation and debridement. Seven AM patients (18%) had early wound complications. Two had minor complications and five had major complications (four irrigation and debridement, one below knee amputation). There was no significant difference between groups in overall rates of wound complications (p=.66) or rates of major complications (p=.15).
CONCLUSION: Open reduction and internal fixation of tibial pilon fractures utilizing an anterolateral approach is associated with a low incidence of early wound complications, comparable to that seen utilizing an anteromedial exposure. Although the overall complication rates are similar in these patients, the anterolateral approach had a lower rate of major complications requiring operative treatment. 19. Biomechanical Comparison of Polyaxial Type Locking Plates and a Fixed Angle Locking Plate for Internal Fixation of Distal Femur Fractures *Randall J. Otto, M.D. (n) St. Louis, MO Berton R. Moed, M.D. (n) St. Louis, MO J. Gary Bledsoe, Ph.D. (n) St. Louis, MO
INTRODUCTION: The purpose of this study was to test the stability under axial loading of two new polyaxial distal femoral locking plate designs, analyzing varying angles of screw insertion by comparison to a fixed angle locking plate.
METHODS: Twenty five synthetic femurs (Pacific Research Labs, Inc., Vashon, WA) were randomized into five groups, and an AO/OTA 33A3 fracture was created. Group I was fixed with a fixed angle Synthes LISS plate (Paoli, PA). Groups IIA and IIB were fixed with DePuy POLYAX plates (Warsaw, IN). Groups IIIA and IIIB were fixed with Zimmer NCB polyaxial plates (Warsaw, IN). The polyaxial constructs were divided into parallel and crossed angle distal condylar screw fixation. Constructs were tested under axial loading using a MTS 858 Mini Bionix II testing machine (Eden Prairie, MN) and stressed to failure at a displacement rate of 5 mm/min with a preload of 100 Newtons. Outcome measurements included stiffness, load to failure, and mode of failure.
RESULTS: All LISS and POLYAX constructs failed by plastic deformation of the plate, while 9 of 10 NCB constructs failed by an intra articular fracture propagating from the distal posterior screw. No failure occurred at the screw plate interface in either polyaxial construct. Load to failure of the LISS was 33% greater than the parallel POLYAX (p=0.008) and 24% greater than the crossed POLYAX (p=0.008). Load to failure of parallel and crossed NCB were 24% greater than the parallel POLYAX (p=0.008 and p=0.008) and 15% greater than the crossed POLYAX (p=0.008 and p=0.01). The POLYAX also had significantly lower stiffness than the LISS and NCB. There was no difference between the LISS and NCB with regards to stiffness and load to failure. Screw angle did not affect the strength of the polyaxial constructs.
CONCLUSION: The POLYAX supported smaller loads under axial loading compared to the LISS and NCB. There were no failures of either polyaxial screw plate interface despite large forces, supporting the biomechanical soundness of both polyaxial designs under axial loading. 20. Wound Closure in Open Fractures: A Prospective Protocol Using Post Debridement Culture Results *Christopher J. Lenarz, M.D. (n) St. Louis, MO J. Tracy Watson, M.D. (n) St. Louis, MO Berton R. Moed, M.D. (n) St. Louis, MO
INTRODUCTION: The purpose of this study was to determine the efficacy of a prospective protocol using post Irrigation & Debridement (I & D) cultures as a guide to the timing of wound closure following open extremity fracture.
METHODS: All open fractures were taken emergently for I & D, fracture stabilization, and open wound management. Post I & D cultures were obtained for aerobic and anaerobic analysis. At 48 hours, patients were returned to surgery, if culture positive, repeat I & D was followed by additional cultures. The procedure was repeated and the wound NOT closed until negative culture results achieved. Patients were considered infection free if there were no secondary procedures performed for infectious complications for a minimum of six months after injury. 465 open fracture patients were treated with 346 patients available for long term follow up > 1 year.
RESULTS: The overall deep infection rate was 4.3%; grade II fractures (4%) and grade III fractures (5.7%). Grade III fractures demonstrated a difference between fracture grades (1.8%) Grade 3A (OTA 62 3A) vs. (12.9%) Grade 3B/C (OTA 62 3B/C). Fractures requiring multiple debridements, diabetics, and patients with increased BMI demonstrated a higher rate of infection (p=0.043). Wound closure in the presence of positive cultures (protocol breech), had a significant risk of deep infection (p<.01).
DISCUSSION AND CONCLUSION: The use of this prospective protocol has been shown to achieve a very low deep infection rate compared to historical controls, when used to accomplish competent wound closure for the management of open fractures. Furthermore, it appears that an increased number of I & D procedures are required to attain this successful outcome. 21. Outcome Comparison of Closed Reduction Percutaneous Pinning versus Locked Plating of Proximal Humerus Fractures *Daniel K. Williams, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: The purpose of this study was to compare the functional outcome measurements and complications of closed reduction percutaneous pinning (CRPP) and locked plating (LP) of unstable displaced proximal humeral fractures.
METHODS: Over a five year period of time, 2002 2006, 177 fractures in 173 patients were treated, 99 with CRPP and 78 with locked proximal humeral plating techniques. All patients had prospectively gathered outcome data consisting of DASH, SMFA, and SF 36 measurements at 6, 12, and/or 24 months.
RESULTS: Gender was predominately female (CRPP: 47 female, 28 males; LP: 74 female, 24 male). Age occurred bimodally and similarly for CRPP and LP with a mean age of 61. The mechanism of injury was similar between groups and occurred primarily by low energy fall (59%). CRPP treatment was more frequent among isolated injuries compared to LP for polytrauma injuries. Fracture parts were Neer 4 (23), 3 (55), 2 (21) for CRPP and 4 (33), 3 (25), 2 (20) for LP. Technical complications were evident in 31 (31.6%) of CRPP and 16 (21.3%) of LP patients. AVN was significantly less for CRPP (2, 2%) than LP (7, 9.3%) in 3 and 4 part fractures. At two years, DASH scores were significantly different by age for CRPP and LP, 32.41 and 17.62 respectively for the < 60 year olds and 28.84 and 38.36 respectively for the older patients. Neer 4 fractures at two years had DASH scores that were significantly worse with LP (34.49) than CRPP (19.88). At two years, LP performed significantly worse in all SMFA indices for 4 part Neer fractures when compared to CRPP treatment. At two years, those < 60 with LP performed worse than CRPP treatment in all SMFA indices except arm/hand. In older patients, LP had worse daily activity and bother scores compared to CRPP. Polytrauma patients with LP have significantly worse dysfunction in all SMFA indices at two years. All statistical significance was noted at p<0.05.
CONCLUSIONS: CRPP and LP are demanding procedures. LP treatment tends to have poorer outcomes in young polytrauma patients. AVN rates are less with CRPP than LP in 3 and 4 part fractures.
22. Anterolateral Approach for Pilon Fractures: Rate of Wound Complications in the Early Postoperative Period *Michael S. Khazzam, M.D. (n) Columbia, MO Brett D. Crist, M.D. (n) Columbia, MO Allison M. Wade, M.D. (n) Columbia, MO Gregory J. Della Rocca, M.D. (n) Columbia, MO
PURPOSE: The anterolateral surgical exposure to the distal tibia for pilon fractures has become more popular. Minimal data exists regarding the rate of complications with the anterolateral approach. The purpose of this study was to evaluate wound complications in the early postoperative period associated with the use of the anterolateral approach for pilon fractures.
METHODS: A retrospective review was conducted to identify operatively treated pilon fractures at our university level 1 trauma center from September 2005 through July 2007. Sixty eight pilon fractures were identified. All patients were treated with a staged protocol (immediate external fixation followed by delayed ORIF). Patients who had an anterolateral surgical approach were identified and medical records were reviewed for the first six weeks postoperatively to determine the rate of wound complications. The endpoint of six weeks was chosen to identify complications related to the surgical exposure alone.
RESULTS: Thirty six of the 68 patients with pilon fractures had an anterolateral surgical exposure. One additional patient had an anterolateral incision performed for revision of a previously treated pilon fracture. Ninety seven percent of these fractures were AO/OTA 43 C (3 C1, 9 C2, and 23 C3). The median time delay to definitive fixation was 19 days (10 38 days). Sixteen (44.4%) of the fractures were open, 10 of which were Gustilo type III (5 IIIA, 4 IIIB, and 1 IIIC). Eight of the 37 patients had wound complications related to the anterolateral incision within the first six weeks of definitive fixation. Six patients (16%) had minor complications successfully treated with dressing changes and oral antibiotics, and two (5%) had major complications, with evidence of deep wound infection that required formal irrigation and debridement.
CONCLUSION: In a case series with a high rate of complex open pilon fractures, ORIF utilizing an anterolateral approach provided good exposure of the distal tibia with a low incidence of early wound complications .
SIGNIFICANCE: Pilon fractures have a high risk of wound complications. Avoiding complications is the key in managing high energy pilon fractures. This case series provides evidence that the anterolateral approach has a low rate of wound complications. 23. Biomechanical Analysis of a Proximal Humerus Locking Plate with Two Types of Head Fixation *Ross A. Schumer, M.D. Dayton, OH (a OTA resident research grant, b DePuy Orthopaedics) Kara L. Muckley (n) Dayton, OH Jonathan Heflin, M.D. (n) Dayton, OH Michael J. Prayson, M.D. (n) Dayton, OH Tarun Goswami, Ph.D. (n) Dayton, OH
INTRODUCTION: Locking plates have emerged as the implant of choice for stabilization of proximal humerus fractures. There is little support in the literature for use of locked threaded screws versus locked non threaded pegs. This study evaluates the biomechanical properties of a proximal humerus locked plating system with comparison of smooth pegs and threaded screws for humeral head fixation.
MATERIALS/METHODS: Fifteen pairs of fresh frozen cadaveric humeri were randomized to have a surgical neck gap osteotomy (1 cm) stabilized with a locked plate using either threaded screws (n=7) or smooth pegs (n=8). The contralateral humerus was left intact and served as a control. Each specimen was tested with simultaneous cyclic axial compression (40Nm) and torsion (both ±2Nm and ±5Nm). All specimens were then loaded to failure. Inter fragmentary motion and load displacement curves were analyzed to identify any difference between groups.
RESULTS: There were no differences between groups in age and bone mineral density. There was a significant difference when comparing the test specimens to their paired control (p < .001). Yet no significant differences were noted between the smooth pegs and threaded screws. Average axial load to failure was 3119 N for the control group compared to 1314 N and 1305 N for the peg and screw groups, respectively (p < .001).
DISCUSSION/CONCLUSION: There is no biomechanical difference between the use of smooth pegs and threaded screws for humeral head fixation in an unstable 2 part proximal humerus fracture model. 24. Comparison of Superior and Anteroinferior Plate Placement in the Treatment of Clavicle Fractures *Robert S. Rice, M.D. (n) Rochester, MN S. Andrew Sems, M.D. (n) Rochester, MN Michael E. Torchia, M.D. (n) Rochester, MN Peter A. Cole, M.D. (n) St. Paul, MN Adam Bloemke, M.D. (n) St. Paul, MN Andrew H. Schmidt, M.D. (n) Minneapolis, MN
PURPOSE: Surgical treatment of diaphyseal clavicular fractures is a controversial and debated issue that has recently received support in the orthopedic literature. Recent studies have shown that nonoperative treatment is not uniformly associated with a successful outcome. The purpose of this study is to determine whether there is a difference between fixation with plates placed along the superior aspect of the clavicle and fixation with plates placed on the anteroinferior aspect of the clavicle.
METHODS: Over a 5.5 year period, open reduction and internal fixation for displaced midshaft clavicle fractures (OTA code 6) was performed in 97 clavicles at three Level I trauma centers. A chart and radiographic review of all patients who underwent plate fixation of diaphyseal clavicle fractures from 1/1/01 to 7/31/06 was undertaken. Evaluation of preoperative, immediate postoperative, as well as all subsequent radiographs were performed to evaluate the OTA fracture classification and to assess fracture union, loss of reduction, and hardware failure. Review of patient charts and clinical notes was performed to determine if patients required reoperation for nonunion, infection, delayed union, or for plate removal.
RESULTS: Plates were located on the superior aspect of the clavicle in 41 (42.7%) of fractures while 55 (57.3%) were plated in an anteroinferior fashion. There was no difference in the groups with regard to age, gender, mechanism of injury, or fracture type. Nonunion was present in two cases, one in the anteroinferior group and one in the superior group. Reoperation occurred in 13 patients, including 10 for painful hardware, 1 for infection, and 2 for repeat open reduction and internal fixation secondary to nonunion. There was a trend toward higher re operation rates with the plate in the superior position (8/41, 19.5%) compared to the anteroinferior position (5/55, 9.1%) but the difference was not statistically significant.
CONCLUSION: This study confirms the high overall success rate of surgically treated midshaft clavicle fractures using plate fixation. No statistically significant differences were detected with regards to union or infection rates between anteroinferior and superior plating. Plate placement on the superior aspect of the clavicle trended towards higher reoperation rates. Although this is the largest comparative study of the two plating methods to our knowledge, because of the potential Type – II statistical error that exists in this study, larger scale studies are appropriate in order to obtain more definitive data. 25. Closed Reduction Percutaneous Pinning of Proximal Humeral Fractures: Complications and Functional Outcomes *Praveen C. Perni, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: The purpose of this study was to evaluate the complications and functional outcomes of closed reduction percutaneous pinning (CRPP) of unstable displaced proximal humeral fractures.
METHODS: Over a five year period, 2001 2006, 90 fractures were treated in 89 patients with percutaneous pinning techniques and retrospectively identified. All patients had prospectively gathered outcome data consisting of DASH, SF36, and SMFA measurements at 6, 12, and/or 24 months.
RESULTS: Average age was 61 years (range 17 90). Gender was predominately female (74%). The mechanism was primarily low energy falls (68, 76%). Complications were noted: 12 malunion (13.5%), 4 nonunion (4.4%), 2 AVN (2.2%), 3 adhesive capsulitis (3.3%), and 1 neurological complication (1.1%). Pin complications included: 6 loosening (6.7%), 7 migration (7.8%), 4 pin impaction (4.4%), and 10 fixation failures (11.1%). At two years, DASH score mean was 30.5. SMFA arm/hand index demonstrated significant improvement over time to the two year interval (p<0.05). Younger patients continued to have significantly better SMFA scores until the two year mark for function, mobility, and daily activity (p<0.05). AO/OTA class A had significantly better SMFA scores as compared to class B&C in function, arm/hand, mobility, and daily activity (p<0.05).
CONCLUSIONS: With strict attention to detail, pin placement, fracture reduction, and postoperative management, CRPP is a valid treatment option for proximal humeral fractures. 26. Trochanteric Cephalomedullary Intramedullary Nailing of Reverse Oblique Pertrochanteric Fractures (AO/OTA 31 A3.1) *Scott M. Holthusen, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI
INTRODUCTION: Trochanteric nailing of unstable proximal femoral fractures is gaining popularity. Reverse oblique pertrochanteric femoral fractures are unstable injuries which may benefit from cephalomedullary nailing. The start site may relate to reduction quality and final outcomes. This has yet to be analyzed in a clinical review.
METHODS: From May 2002 to July 2006, all proximal femoral fractures were identified at a level one trauma center. Only reverse oblique (AO/OTA 31 A3.1) pertrochanteric femoral patterns were selected. All fractures were stabilized with a trochanteric cephalomedullary nail. Start site was assessed and classified as piriformis, medial trochanteric, or lateral trochanteric. Also, reduction quality, age, obesity, and failures were analyzed in relation to the start site utilized.
RESULTS: Thirty one patients with a mean age of 68 (range 26 92) and BMI of 27.5 (range 16.6 44.5) were identified. Ninety percent of these were related to low energy falls. The quality of reduction was anatomic in 14 (45.2%) and varus in 17 (54.8%). All anatomic reductions had piriformis or medial trochanteric start sites. Varus reductions occurred in 2/9 piriformis, 8/15 medial trochanter, and 7/7 lateral trochanteric start sites demonstrating a statistically significant difference in start sites and corresponding reduction quality (p=0.008). A trend for more piriformis (83%) and medial (55%) trochanteric start sites resulting in anatomic reductions were noted with BMI < 30. Age did not affect start site or reduction quality (p>0.05). Tip apex distance average 18.9 mm (range 7 38 mm) with no screw cut outs. One failure occurred by nonunion and implant failure in a patient with a lateral start site, varus malreduction, and BMI of 40.43.
CONCLUSIONS: Properly inserted trochanteric start intramedullary nails efficiently manage reverse oblique pertrochanteric femoral fractures. Piriformis and medial trochanteric start sites predictably relate to more anatomic reductions than lateral start sites. 27. Knee Injuries in the Floating Knee *Mr. Ulfin Rethnam (n) Rhyl, United Kingdom Mrs. Rajam Yesupalan (n) Rhyl, United Kingdom Mr. Rajagopalan Nair (n) Bangalore, India
BACKGROUND: There is a high incidence of ipsilateral knee injuries with the floating knee, which makes these fractures even more challenging to manage. We present the impact knee injuries have on the final outcome of the floating knee. We propose a protocol for assessment and management of knee injuries with the floating knee.
MATERIALS AND METHODS: This prospective study included 29 patients with floating knee injuries. Knee injuries encountered were divided into bony, ligamentous, and soft tissue. Bony injuries were assessed with radiographs and managed surgically along with the floating knee injury. Patients were assessed clinically for knee ligament injuries after fixation of the fractures intraoperatively and managed surgically. Soft tissue injuries around the knee were managed conservatively. Final outcome was assessed using the Karlstrom criteria.
RESULTS: 10/29 patients had knee injuries. Two anterior cruciate ligament injuries, one posterior cruciate ligament injury, one medial meniscus injury, and three extensive soft tissue injuries to the knee were encountered. The complications were knee stiffness and superficial infection. The end results according to the Karlstrom criteria were good – 6, acceptable – 1, and poor – 3.
CONCLUSION: The associated knee injuries in the floating knee are an important prognostic indicator. Soft tissue injury seems to have a very poor prognosis. We propose clinical evaluation of the knee after fixation of the fractures, surgical management of ligament and bony injuries, and a proper rehabilitation program to improve outcomes. 28. The Protective Effect of Locking Screw Placement on Nonlocking Screw Insertion Torque in an Osteoporotic Supracondylar Femur Fracture Model *David J. Dalstrom, M.D. (n) Dayton, OH Michael J. Prayson, M.D. (n) Dayton, OH Emmanuel Konstantakos, M.D. (n) Dayton, OH
Modern fracture fixation commonly employs a combination of nonlocking and locking screws (hybrid fixation), especially in osteoporotic bone and for comminuted fractures. A relative lack of biomechanical information exists regarding hybrid fixation. This study examines the effects of number and position of locking screws in the diaphysis of an osteoporotic distal femur fracture model .
METHODS: Four groups of five osteoporotic Sawbones models were created with varying combinations of diaphyseal locking and nonlocking screw fixation: Group 1 (Control) 4 non locking screws; Group 2 (Close Lock) 1 locking screw adjacent to a metaphyseal gap osteotomy and 3 nonlocking screws; Group 3 (Far Lock) 1 locking screw most proximal from the osteotomy and 3 nonlocking screws; and Group 4 (Double Lock) 1 locking screw adjacent to and 1 locking screw most proximal from the osteotomy, with 2 intervening nonlocking screws. Testing was performed for 50,000 cycles at 2Hz using simultaneous axial compression (700 N) and bi directional torque (+/ 5 Nm). All screws were inserted with 4Nm of torque using a digital torque meter.
RESULTS: Loosening of diaphyseal fixation occurred in all groups. When the nonlocking screws were evaluated in a separate subgroup analysis, the insertional torque values in non locking screws for the Close Lock group remained significantly higher than the Control group (p=.008) and the Far Lock group (p=.032). With the numbers tested, there were no significant differences found for axial stiffness, torsional stiffness, or deformation between the constructs. Although not statistically significant, gross clinical failures occurred in 3/5 Control, 2/5 Far Lock, and 0/5 Close Lock and Double Lock.
CONCLUSION: The position of a single locking screw adjacent to the osteotomy resulted in a significant protective effect upon the insertional torque of neighboring nonlocking screws. This result was not found when a single locking screw was placed farthest away from the osteotomy site. Two locking screws placed at opposite ends of the diaphyseal fixation segment does not appear to offer further benefit in maintaining nonlocking screw insertional toque over a single locking screw placed adjacent to the osteotomy. 29. Locked Plate Fixation of Humeral Shaft Fractures in Osteoporotic Bone *David E. Lukowski, M.D. (n) Akron, OH Andrew J. Schoenfeld, M.D. (n) Boston, MA Mark C. Leeson, M.D. (n) Akron, OH Gregory A. Vrabec, M.D. (n) Akron, OH Jake P. Heiney, M.D. (n) San Diego, CA Suneel Battula, Ph.D. (n) San Diego, CA Glen O. Njus, Ph.D. (n) Akron, OH
INTRODUCTION: While locking plates enjoy the advantage of a fixed angle monoblock construct, such characteristics may have an adverse impact on fracture healing. In these situations, clinicians may opt to employ a hybrid locked plate construct. In this investigation, a synthetic unstable osteoporotic fracture model was used to determine if plate function could be altered by limiting the number of locked screws in the construct.
METHODS: Eighteen custom made synthetic humeri representative of osteoporotic bone were divided into three groups of 6 humeri each. A 5 mm fracture gap was created in each group and all humeri were fixed with an 8 hole locked plate construct employing all locking screws (Group A), 4 locking screws (Group B), or 2 locking screws (Group C). A materials testing system was used to perform cyclic four point bending to 12 N m for 10,000 cycles. Strain and stiffness were measured for the construct as a whole, as well as at the fracture gap, and results were compared. Statistical analysis was performed using ANOVA.
RESULTS: There was no significant difference in initial stiffness between the locked and hybrid constructs. After 1,000 cycles, all three constructs retained 99% of their initial stiffness. Beyond 1,000 cycles, the stiffness of all three constructs decreased in a similar fashion. At 10,000 cycles, the locked plate constructs retained 96% of their initial stiffness while the hybrid constructs retained 95% (B) and 94% (C). Similarly, stiffness across the fracture gap remained greatest in the locked construct (98% of initial stiffness at 10,000 cycles) with the hybrid constructs retaining 94% (B) and 90% (C) of their initial stiffness. There was no significant difference between the locked and hybrid constructs in Group B (p = 0.09), but there was a difference between the locked and hybrid constructs in Group C (p = 0.02). There was no significant difference in stiffness between the hybrid constructs in Groups B and C (p = 0.21).
DISCUSSION: Hybrid constructs perform remarkably similar to locked plate constructs under cyclic four point testing. While stiffness across the fracture gap may be diminished in hybrid constructs employing only two locked screws, such constructs, as a whole, still retain 94% of their initial stiffness. Varying screw configuration does not alter the performance of hybrid locked plate constructs. Such findings have important implications regarding the risk of nonunion and financial considerations when employing these implants. 30. Cytokine Availability from Intramedullary Reaming Aspirate in Diabetic Nonunion Surgery *Todd A. Schubkegel, M.D. Maywood, IL (a Synthes USA) Michael S. Pinzur, M.D. (n) Maywood, IL Frederick Wezeman, Ph.D. (n) Maywood, IL Michael D. Stover, M.D. (n) Maywood, IL John Callaci, Ph.D. (n) Maywood, IL
BACKGROUND: Most experienced fracture surgeons believe that the bone products obtained from intramedullary reaming provide cytokines with the potential for upregulating bone formation. It is well accepted that adult diabetics have an impaired capacity for wound and bone healing that may be due to apparently low levels of these same cytokines. The aim of this study is to help define whether reaming debris from diabetic populations possess comparable levels of pro inflammatory and osteogenic regulatory proteins when compared with their healthy counterparts.
METHODS: Twenty six human subjects undergoing ankle fusion with a retrograde tibial nail for ankle nonunion over a two year period were included. Patients were divided into two groups. Patients with active infection by culture at time of surgery, or currently taking immunosuppressive drugs were excluded. A total of 8 non diabetic and 15 diabetic patients were found to be suitable for study. Intramedullary aspirates were collected using an aspirating reamer and immediately frozen at 80°C until testing. Samples were prepared by thawing in PBS/PI solution and homogenized by sonic dismembranization. Protein quantifications were then performed using a combination of commercially available ELISA kits and customized bead based multiplex immunosorbant assays. Studied proteins included BMP 2, 4, and 7, OPG, RANKL, IL 1, 2, 4, 6, 8, 10, 12, 17, and 18, FGF, GM CSF, IFNg, TNFa and b, M CSF, PDGFbb, MCAF, and VEGF.
RESULTS: Data was calculated on an absolute concentration, per total protein in sample, and per gross weight of sample basis. Analysis was performed via one way ANOVA following outlier exclusion. Results reveal a trend for decreased levels of cytokines normally associated with bone formation that was not statistically significant.
CONCLUSIONS: These data suggest that intramedullary reamings might have a positive effect on bone formation in the diabetic population. Further trend analysis may help reveal a causal relationship in bone healing. MAOA BREAKOUT SESSION #3 SPORTS April 23, 2009
31. Biomechanical Comparison of Meniscal Suture, Repair Devices, and Techniques *Brian C. Aros, M.D. (n) Montpelier, VT William K. Vasileff, M.D. (n) Columbus, OH Alan S. Litsky, M.D. (n) Columbus, OH Angela Pedroza, MPH, MT (ASCP) (n) Columbus, OH David C. Flanigan, M.D. (n) Columbus, OH
PURPOSE: To report the load to failure of the MaxFire™ meniscal repair system (Biomet Inc, Warsaw, IN) and compare it to other fourth generation meniscal repair devices and mattress suture techniques.
METHODS: After creating a longitudinal tear in 42 one year old bovine menisci, 7 specimen groups defined by the meniscal repair device, suture, and/or mattress technique used for meniscal repair were randomly established: (Group 1: Fiberwire™ vertical mattress (VM), Group 2: Fiberwire™ horizontal mattress (HM), Group 3: FasT Fix™ VM, Group 4: FasT Fix™ HM, Group 5: RapidLoc™, Group 6: MaxFire™ VM, Group 7: MaxFire™ HM). After completing the repairs, the meniscal specimens were cyclically pre loaded before load to failure testing was performed. One way analysis of variance and Scheffe post hoc tests were used to evaluate group differences.
RESULTS: The mean load to failure for each group: Fiberwire VM (185 ± 41 N), Fiberwire HM (183 ± 36 N), FasT Fix VM (125 ± 8 N), FasT Fix HM (107 ± 29 N), RapidLoc (70 ± 12 N), MaxFire VM (145 ± 44 N), and MaxFire HM (139 ± 50 N). An analysis of variance demonstrated a significant difference in the mean load to failure (F=8.31 p<0.01). Using a post hoc Scheffe analysis, statistically significant differences were seen between both Fiberwire groups vs. FasT Fix HM and Rapid Loc (p<0.05). Three modes of failure were observed: suture breakage (17/42, 40.5%), tissue failure (18/42, 42.9%), and knot failure (7/42, 16.7%).
CONCLUSIONS: 2 0 Fiberwire™ VM and HM repairs had the highest load to failure of all groups tested. The load to failure for the MaxFire™ meniscal repair system is comparable to other available all inside “4 th generation ” meniscal repair systems.
32. Reconstruction of the ACL Using an All Inside Minimally Invasive Surgical Technique *Katherine J. Coyner, M.D. (n) Royal Oak, MI Ross Cooper, M.S. (n) Royal Oak, MI Stacie Graves, P.A. (n) Royal Oak, MI James Bradley, M.D. (n) Royal Oak, MI Kyle Anderson, M.D. (n) Royal Oak, MI
PURPOSE: Anterior cruciate ligament reconstruction is commonly performed using a traditional “outside in” technique, in which a complete tibial tunnel is drilled through the anteromedial cortex. The femoral socket is created either through the tibial tunnel or through the anteromedial portal. Preserving the tibial cortex may reduce perioperative morbidity, improve precision of socket placement, and potentially enhance fixation strength. We report preliminary results of an all inside technique in which the femoral and tibial “sockets” are drilled from the intra articular direction by introducing a new retro cutting reamer that is assembled inside the joint and used to create bony sockets that do not ream the external cortices.
METHODS: Between October 2007 to present, 17 patients of a single surgeon who were candidates for allograft BTB or autograft hamstring ACL reconstruction were identified and accepted the option of this newer technique versus more traditional reconstruction. A diagnostic arthroscopy and routine notchplasty are performed. The femoral socket is created by flexing the knee to 120°, placing the guide wire and over the top guide through the medial portal, and drilling at 10 or 2 o’clock. The Retrocutter tibial guide is delivered through the medial portal and placed at the ACL insertion and the socket is retro drilled. The graft is advanced through the medial portal into the femoral and tibial sockets, and a bioabsorbable interference screw is fixed in the femoral socket. A second interference screw is placed on a retro screwdriver through medial portal in order to allow placement at aperture of tibial socket. Patients receiving this procedure are being followed at 6 weeks, 3 months, 6 months, and 1 year following surgery using the IKDC scale and SF 36.
CONCLUSION: Early results in these patients are showing decreased postoperative pain, swelling and ecchymosis, efficient restoration of range of motion, and improved overall reported knee function. We continue to add additional subjects as they arise. We hypothesize that this minimally invasive approach to ACL reconstruction may provide a reasonable alternative to traditional outside in procedures. 33. Knee Kinematics in Double Bundle ACL Reconstruction Following Destruction of the Bone Bridge Separating Tunnels: A Cadaveric Simulation of Tunnel Enlargement *Jaren M. Riley, M.D. (n) Iowa City, IA Elizabeth R. Cohen, B.S. (n) Akron, OH John P. Albright, M.D. (n) Iowa City, IA Paul D. Butler, B.S. (n) Iowa City, IA
BACKGROUND: Recent literature has shown that the more anatomic DB ACL reconstruction may more closely restore the natural kinematics of the knee. One complication following traditional ACL reconstruction with hamstring tendons and extra cortical fixation is enlargement of the tunnel due to multifactorial bone resorption (the “windshield wiper” effect). Since hamstring tendons are used in DB ACL reconstruction, there is concern that, over time, the bone bridge separating the two tunnels will be damaged as each tunnel enlarges and encroaches on the other tunnel.
METHODS: Anterior translation (AT), internal rotation (IR), and combined AT/IR were examined in 12 cadaver knees (6 matched pairs). No preload and posterior preload was applied prior to each kinematic analysis. Various ligamentous states were examined including preoperative, ACL deficient, s/p DB ACL reconstruction, and s/p destruction of the wall separating the DB ACL tunnels in both the femur and tibia. Surgical procedures were guided and measurements were stored by a computer assisted surgical device (Aesculap Orthopilot).
RESULTS: There was no difference observed with varying the preload. A significant reduction in anterior translation (p<0.0001 AT) was observed following DB reconstruction of a previously ACL deficient knee. No difference was found in IR. Mean AT in an ACL deficient knee was 8.6 mm (st dev 1.5) while mean AT in the reconstructed group was 3.18 mm (st dev 1.9). Mean IR in the ACL deficient group was 16.2 deg (st dev 4.1) and mean IR in the DB reconstruction group was 15.27 deg (st dev 2.1). No difference was observed in AT or IR following destruction of the bone bridge separating the DB ACL tunnels. Mean AT in group with no wall was 3.64 mm (st dev 2.3) and mean IR was 14.18 deg (st dev 2.5).
DISCUSSION: Originally, we expected to see increased AT and IR following wall destruction. Surprisingly, however, no difference was observed following destruction of the wall separating the femoral and tibial tunnels. Also, in contrast to what is commonly reported in the literature, we did not find the DB ACL reconstruction to control IR greater than the pre surgical state. 34. Meniscal Repair with the MaxFire Device: A Cadaveric Study Rickland L. Likes, D.O. (n) Columbus, OH Abhishek Julka, M.D. (n) Ann Arbor, MI Brian C. Aros, M.D. (n) Columbus, OH Angela Pedroza, MPH, MT (ASCP) (n) Columbus, OH Grant L. Jones, M.D. (n) Columbus, OH Christopher C. Kaeding, M.D. (n) Columbus, OH *David C. Flanigan, M.D. Columbus, OH (a Biomet Sports)
PURPOSE: The purpose of this study was three fold: to use a cadaver model to critically evaluate a new all inside meniscal repair device, to determine the learning curve in use of this device, and to determine if implantation times were shorter with greater arthroscopy experience.
METHODS: Three sports medicine fellowship trained orthopedic surgeons and two orthopedic sports fellows participated. Fourteen fresh frozen cadaveric knees (age 30 84 years old) were used. Each surgeon arthroscopically placed four MaxFire™ devices into the medial and lateral meniscus of two knees. Total time for implantation of each device and each knee was recorded. The medial and lateral aspects of each knee were dissected to determine the final location of each device in relation to important anatomic structures.
RESULTS: 103 MaxFire™ devices were placed (49 medially, 54 laterally). Laterally, five devices penetrated the iliotibial tract (layer I), all others found in layer III. Four devices were an average of 6.5 mm from the popliteal artery. Medially, 8 devices penetrated layer I, 12 layer II, and 5 layer III. Fellows were 52 seconds (SD=81.73) slower than attendings (p<0.001). There was no significant difference in the implantation times between knee 1 and 2 (p=0.52).
CONCLUSIONS: The MaxFire™ all inside meniscal repair device is easy to use, has a low risk of complications, and can be inserted expeditiously based upon arthroscopy experience. MaxFire™ device placement in the posterior horn of the lateral meniscus should be done from the contralateral portal to diminish the risk to the popliteal artery. 35. Incidence and Role of Preoperative Depressive Symptoms in Outcome Following Meniscectomy Elizabeth R. Cohen, B.S. (n) Akron, OH *John P. Albright, M.D. (n) Iowa City, IA Jingzhen Yang, Ph.D. (n) Iowa City, IA Annunziato S. Amendola, M.D. (n) Iowa City, IA Brian R. Wolf, M.D. (n) Iowa City, IA
BACKGROUND: Some meniscectomy patients struggle to return to activity after meniscectomy to a degree incongruent with their observed pathology. This suggests an additional risk factor for poor outcome. The relationship between depression and patient outcome has been studied in adult joint reconstruction and orthopedic trauma populations. There is no medical literature which has examined the relationship, if any, between symptoms of depression and outcome following meniscectomy.
OBJECTIVE: Determine: percentage of meniscectomy patients experiencing preoperative symptoms of depression and whether symptoms of depression correlate with poor short term outcome.
METHODS: Sixty two adults were prospectively studied. Data collected include demographic information, surgical observations, IKDC, and symptoms of depression measured by the CES D 10. The IKDC form served as the primary outcome measure. Multivariable regression models were completed.
RESULTS: Mean age was 42.3 +/ 13.1 years. Twenty three patients had positive preoperative depression screens (39.7%). Adjusting for age and gender, a positive preoperative depression screen was a predictor of postoperative IKDC score (p=0.0471), as was BMI (p=0.006), chondromalacia grade (p=0.0033), and insurance (p=0.0025). Using multivariable linear regression analysis, we determined that a positive depression screen score (Β = 1.53, S.E.= 0.44, p = 0.001), grade II chondromalacia (Β = 22.49, S.E. = 6.65, p = 0.002), and grade IV chondromalacia (Β = 18.3, S.E. = 8.08, p = 0.03) remained significant predictors of IKDC score.
CONCLUSION: Forty percent incidence of patients experiencing preoperative depressive symptoms was much greater than originally anticipated and the presence of preoperative depressive symptoms had the highest negative impact on surgical outcome. We believe that discovering and addressing symptoms of depression in addition to physical pathology could significantly improve short term outcomes. 36. ACL Deficient Cadaveric Knee: Single versus Double Bundle versus Extra Articular Reconstruction Methods Jaren M. Riley, M.D. (n) Iowa City, IA *Paul D. Butler, B.S. (n) Iowa City, IA Elizabeth R. Cohen, B.S. (n) Akron, OH John P. Albright, M.D. (n) Iowa City, IA Daniel R. Thedens, Ph.D. (n) Iowa City, IA Lee Bennett, M.D. (n) Iowa City, IA
INTRODUCTION: Is the best way to control rotational laxity of the ACL deficient knee joint to place the single bundle grafts more laterally than usual (10 am 2 pm vs. 11 am 1 pm), or to recreate two of the three anatomic ACL bundles, or to add an extra articular sling?
OBJECTIVE: Determine which technique provides the best axial and sagittal plane stability in fresh frozen cadavers as measured by a computer assisted surgery (CAS) system.
METHODS: Twenty cadavers received either a single or double bundle (SB, DB) ACL reconstruction followed by a Losee iliotibial band sling (ITBS). CAS based stability testing included a sequential series of tests of the ACL intact, ACL deficient, and ACL grafted states. The stability testing parameters tested included: anterior displacement (91.2 Nm) in neutral, internal and external rotation; and a rotational arc (5Nm).
RESULTS: (30°) In neutral rotation, SB femoral grafts did not prevent sagittal plane displacement to the same degree as DB grafts, but remained within clinically acceptable limits. This difference between graft types disappeared when anterior drawer test was repeated with coupled internal rotation. Both SB and DB reconstructions reduced sagittal and axial plane laxity. However, the addition of the ITBS always tightened the construct further, often constraining beyond initial anatomic ligament status. Internal rotation was tightened by both SBs and DBs, with SBs creating slightly more restriction than DB grafts. External rotation was not significantly affected. Addition of the ITBS created the greatest restriction of internal greater than external rotation.
CONCLUSION: Laterally placed single and double bundle ACL reconstructions similarly controlled anterior displacement and internal rotation to recreate kinematics within a clinically acceptable range. If either of these procedures was coupled with an ITBS, further constraint of anterior displacement and internal rotation was achieved. 37. Osteochondritis Dissecans of the Lateral Femoral Condyle: Variations in Morphology, Location, and Associated Findings Keith R. Gabriel, M.D. (n) Springfield, IL *Billy K. Parsley, M.D. (n) Springfield, IL Damion M. Harris, M.D. (n) Springfield, IL
BACKGROUND: We have seen an unusually high prevalence of osteochondritis dissecans (OCD) of the lateral femoral condyle. Lesions were often located posteriorly, and were usually unassociated with any trauma or meniscal pathology. Morphologically, lesions have significant associated fibrillary chondromalacia and the osteochondral fragment is poorly defined. The location of the lesions and the variation in morphology has made arthroscopic treatment somewhat problematic. Our study goals are to consolidate our experience and develop a more effective approach to treating these less typical lesions.
METHODS: This is a retrospective review of patients treated operatively by one surgeon (KRG). Clinic notes, operative reports and radiographs were reviewed. Lesion morphology was defined based on operative notes and intraoperative photos.
RESULTS: Eighteen patients were identified. Three were excluded due to incomplete or missing records and nine had isolated medial condyle lesions. The remaining six patients with ten lateral condyle lesions were studied. One patient had a lateral condyle OCD on the left and a concomitant medial condyle lesion on the right. Four patients had bilateral lateral condyle OCD lesions. Twin brothers each had bilateral lesions. The remaining patient had an isolated lateral condyle lesion. Five left knees and four right knees were involved. Seven of the ten knees were treated surgically. All lesions involved either the central weight bearing or posterior portion of the lateral femoral condyle. Four of the lesions had cartilage that was intact while the others showed lesion craters that were filled with fibrocartilaginous matter.
CONCLUSION: Lateral condyle OCD lesions have not followed the expected course of OCD lesions of the medial femoral condyle. The atypical location and absence of inciting trauma or meniscal pathology suggests a different etiology, supported in our study by the bilaterality and familial involvement. Treatment has been unsatisfying. We do not have a perfect answer, but intend additional research. 38. Radiographic Correlation of Knee Range of Motion Assessed on Routine Physical Examination *Paul G. Peters, M.D. (n) Dayton, OH Michael A. Herbenick, M.D. (n) Dayton, OH Philip A. Anloague, PT, DHSc, OCS, MTC (n) Dayton, OH Ronald J. Markert, Ph.D. (n) Dayton, OH L. Joseph Rubino, M.D. (n) Dayton, OH
INTRODUCTION: Knee range of motion (ROM) is a critical component of surgical outcome evaluation. This study investigates the correlation between examiners (e.g., physical therapists and physicians) and techniques (e.g., visual estimation [VE], hand goniometry [HG], and radiographic goniometric [RG]) for estimating knee ROM.
METHODS: Twenty one healthy male volunteers (age 29.7±4.9) participated in this study. Three physicians performed a routine knee exam with assessment of supine passive terminal hyperextension and maximum flexion by VE. Two physical therapists (PT) performed HG range of motion measurements. Radiographic goniometry was also used to assess supine passive terminal hyperextension and full flexion, as well as standing squat flexion.
RESULTS: Intra rater and inter rater reliability for the three methods was satisfactory (ICC >0.80) for all except for HG hyperextension. HG and VE correlated well for flexion and extension at 0.92 and .060, respectively (p < .001 and .005, respectively). The correlations between HG and RG were low (i.e., flexion = .26, p = .25 and extension = .27, p = .23). RG and VE correlated modestly to poorly (i.e., flexion = .33, p = .16 and extension = .05, p = .83). No difference among the three measurement techniques was found for hyperextension (p = 0.12), but there was a statistical difference for flexion (p<0.001). The pair wise comparisons for flexion found that HG was lower than VE for all 20 cases (p < .001) and HG was lower than RG in 17 of 21 cases (p = .001). RG squat flexion was significantly greater than RG flexion (p < 0.001) with an average 13.8 ± 6.5°.
CONCLUSION: Intra rater and inter rater reliability is acceptable for all three methods for evaluating knee range of motion. However, significant variation exists between techniques. Flexion assessments underestimate full flexion when compared to RG squat flexion. 39. Athletes with Chronic Exertional Compartment Syndrome of the Leg: Results of Two Incision Endoscopic Assisted Fasciotomy at Three Year Follow Up *Alexander K. Meininger, M.D. Chicago, IL (a Synthes) Mark R. Hutchinson, M.D. (n) Chicago, IL
INTRODUCTION: Chronic exertional compartment syndrome is a debilitating condition that can be career threatening in elite athletes. Treatment is exclusively surgical with fasciotomies described open, percutaneous, and endoscopic assisted. We hypothesize that endoscopic assisted single incision fasciotomy will improve visualization, decrease morbidity, and allow for early return to sport.
PURPOSE: Our objective was to evaluate outcomes of CECS treated with minimal incision endoscopic assisted fasciotomy.
METHODS: A retrospective review of 89 compartments in 18 patients with pressure positive chronic exertional compartment syndrome treated with endoscopic assisted fasciotomy was performed. Disease specific questionnaires and SF 36 were used to assess outcomes.
RESULTS: Twelve patients agreed to participate (30 compartments). 11/12 participated in athletics from high school to Olympic level. Follow up averaged 36 months. 11/12 reported good/excellent results. Average return to sport was 3.7 months including an Olympic gold medalist. Complications included hematoma (4), cellulitis (2), hypertrophic scar (1), and peroneal nerve laceration (1).
CONCLUSIONS: Single incision endoscopic assisted fasciotomy for chronic exertional compartment syndrome allows rapid return to sport with minimal associated morbidity. Ninety percent good to excellent results are possible, and all but one patient in our study were able to return at or above their previous level. 40. Kinematics of Isometric Extension in Normal, ACL , and PCL Deficient Knees *J. David Blaha, M.D. Ann Arbor, MI (a Arthrex, Stryker, Zimmer; a,b,c,d,e Wright Medical Technology) David K. DeBoer, M.D. Nashville, TN (a,c DePuy; e Wright Medical Technology) C. Lowry Barnes, M.D. Little Rock, AR (a Johnson & Johnson, Stryker; a,c,e Wright Medical Technology) Richard Obert, M.S. (n) Arlington, TN Paul Stemniski, M.S. (n) Arlington, TN Michael Carroll, B.S. (n) Arlington, TN
INTRODUCTION: This study compares the differences between normal and cruciate deficient knees in an open chain extension flexion activity consistent with various activities of daily living.
METHODS: Ten fresh frozen cadaver legs were digitally modeled for use in a rig that allowed full range of knee motion. The femur was fixed while the tibia could move freely under load applied through the quadriceps tendon. Extremity motion data was recorded and correlated with the digital models. After initial testing, each specimen was rendered successively deficient in the cruciate ligaments and then retested.
RESULTS: Positional and rotational kinematic profiles were virtually identical for all specimens, within a maximum of 3° variation in rotation for a given flexion angle. Within the accuracy of this system, there is essentially no difference in the kinematics of normal and cruciate deficient knees, nor the quadriceps load necessary to extend the knee. Tibiofemoral surface interactions for all conditions indicate consistent stable behavior of the medial compartment and progressive posterior lateral contact motion with increasing flexion.
CONCLUSION: The open chain model is appropriate for testing the effect of cruciate deficiency because the tibia can seek any path, as dictated by the cruciate ligaments, with no external load applied. Since there was no difference in the knee motion with and without the cruciate ligaments, it would appear that the articular surface dictated the kinematics in this open chain model. 41. Isolated Femoral Condyle Chondral Defects in a Static Bovine Model – The Effect of Size on Subchondral Bone Contact Area *Joshua D. Harris, M.D. (n) Columbus, OH Rob Siston, Ph.D. (n) Columbus, OH Pete Brockmeier, B.S. (n) Columbus, OH David C. Flanigan, M.D. (n) Columbus, OH
Most contemporary algorithms use 2 cm 2 as the threshold size to guide management of traumatic, focal chondral defects in the knee. Little biomechanical or clinical evidence exists to support this size as the critical area beyond which stresses become damaging to adjacent cartilage and underlying bone. No study has evaluated the effect of chondral defect size on the magnitude of subchondral bone (SCB) contact distribution within the knee. The objective of this study was to identify how femoral condyle chondral defect size influences SCB contact within the defect. Full thickness, femoral condyle chondral defects were created in eight healthy bovine knees. Defect diameter was between 5 and 25 mm. Knees were loaded to 1000N and knee joint pressure measurements were identified using a Tekscan sensor and I Scan software. A MATLAB program was designed to compute defect area and the area within the defect demonstrating SCB contact. A one way ANOVA with Bonferroni correction was utilized to evaluate the significance of SCB contact area for each defect size. No subchondral bone contact within the defect was observed below a defect diameter of 12.7 mm (area 1.27 cm 2). Statistically significant defect SCB contact was seen at 1.99 cm 2, although the largest increase in defect SCB contact area was between 2.87 cm 2 and 3.87 cm 2. There was also 65% greater total lateral condyle defect SCB contact area versus medial condyle, indicating greater lateral defect stress. A threshold diameter of 19.1 mm (2.87 cm 2) may be used to guide femoral condyle articular cartilage defect repair management based on a substantial increase in SCB contact within the defect beginning at this size. Lateral femoral condyle defects experience greater SCB stress than medial defects and likely progress more rapidly than medial equivalents. The progression of traumatic, focal chondral defects to osteoarthritis warrants early treatment with cartilage repair or restoration techniques to circumvent the need for early total knee arthroplasty. Our findings help elucidate the size at which chondral defects are more likely to progress and cause diffuse joint osteoarthritis. 42. Evaluation of “High Strength” Orthopedic Suture: A Head to Head Comparison *Timothy L. Miller, M.D. (n) Columbus, OH David C. Flanigan, M.D. (n) Columbus, OH Jeffrey Feinblatt, M.D. (n) Columbus, OH Alan S. Litsky, M.D. (n) Columbus, OH
BACKGROUND: Previous studies have examined “high strength” suture materials under single load to failure and low tension cyclic loading conditions. We are unaware of any previous publication that directly compared high strength materials in terms of suture failure and knot security under a high tension (180N) cyclic loading model.
HYPOTHESIS: No significant difference in cycles to failure or mode of failure will be observed between representative specimens of three high strength suture materials: Fiberwire (Arthrex), MaxBraid (Arthrotek), and Orthocord (Depuy Mitek). All three materials will require higher number of cycles than Ethibond (Ethicon) to fail.
METHODS: Ten representative specimens of Fiberwire, MaxBraid, and Orthocord were tied in six knot configurations commonly used in orthopedic procedures. Each specimen was cyclically loaded to 180 Newtons at a rate of 1Hertz until the specimen failed or reached a maximum of 3,500 cycles. Additionally, untested suture material was subjected to loading to failure at a rate of 1.25 mm/second.
RESULTS: The three strongest and most reliable knots all included the Three Reverse Half hitch on Alternating Posts (3 RHAP) configuration. All specimens tied with these three knot types failed by suture rupture. All knots utilizing the Overhand with Three of the Same Half Hitches on the Same Post (O 3SHSP) configuration failed by knot slippage regardless of suture material. When the three strongest knots were combined, Fiberwire resisted a significantly greater number of cycles than Orthocord and MaxBraid. In the single load to failure tests, Orthocord, Fiberwire, and MaxBraid all had significantly higher ultimate strength than Ethibond.
CONCLUSION: Our findings reinforce previously published reports that the use of a 3 RHAP knot configuration greatly improves knot security in a laboratory setting. All high strength suture materials tested performed better than Ethibond under both single load to failure and cyclic loading. 43. Latissimus Dorsi and Teres Major Tears in Professional Baseball Players: A Case Series *Scott G. Kaar, M.D. (n) St. Louis, MO Mark R. Schickendantz, M.D. (n) Cleveland, OH Keith Meister, M.D. (n) Arlington, TX Pamela Lund, M.D. (n) Scottsdale, AZ Laurel Beverley, M.D. (n) Parma, OH
BACKGROUND: Only a few case reports exist in the literature of latissimus dorsi and teres major tendon tears, the majority of which are in high level athletes.
PURPOSE: This study reports on a series of latissimus dorsi and teres major tendon tears in professional baseball players.
STUDY DESIGN: Case series; level of evidence, 4.
METHODS: Injury data from three major league baseball clubs was collected over a total of ten seasons. All players with a tear of either tendon were identified. Treatment was nonoperative with a goal of returning to full velocity throwing at three months from the time of injury.
RESULTS: There were 11 players who sustained injuries to either muscle. There were 5 isolated latissimus dorsi tears, 5 isolated teres major tears, and 1 combined injury. Ten of 11 players returned to baseball at the same level of competition in the same season. Nine of 11 players returned at three months from the time of their injury. The injury recurred in one athlete six months after returning to throwing; however, this healed with further nonoperative treatment and he returned to competition at the same level six weeks later. One player had continued shoulder symptoms and retired at the end of the season.
CONCLUSIONS: Tears of the latissimus dorsi and teres major do occur in professional baseball players although they are uncommon. The majority of these injuries heal successfully with nonoperative treatment and most players will be able to return to the same level of competition in three months. 44. Biomechanical Comparison of Cervical Compression Staple and Constrained Anterior Cervical Plate with Single Level Fusion Model of the Cervical Spine Guy R. Fogel, M.D. (n) San Antonio, TX Weiquiang Liu, Ph.D. (n) San Antonio, TX *John S. Toohey, M.D. (n) San Antonio, TX
A cervical staple may perform as well as a plate with the additional advantage of compression of the interbody graft. This study reports the load characteristics on the graft, adjacent motion segments, and the instrumentation, comparing the staple and plate in a single level fusion model.
METHODS: An in vitro human model simulated a C4 5 fusion. An interbody graft load cell was used. Forces were analyzed at the instrumentation, the graft load cell, and the posterior elements. Load values were normalized to the intact condition. The pre load on the graft load cell with the staple was measured with the expansion of the anterior diamond shape to apply load to the disc space. Pull out force of the staple and plate was determined.
RESULTS: At 20° of extension with the plate, C4 5 extension averaged 1° (p=0.00295<0.05) and with the staple, 1.5° (p=0.00898<0.05). At 15° of flexion with a plate, flexion averaged 1° (p=0.0155<0.05) and with a Staple local flexion averaged 0.75° (p=0.00287<0.05). There was no significant difference with motion with the plate and staple (p=0.6896>0.05). The static load distribution for the plate was 7% for the instrumentation, load cell 75%, and posterior elements 18%. For the staple, the load with the instrumentation was 1.5%, and the load cell and posterior elements were equal 49%. There were significant differences (p<0.005) between the plate and staple. In motion testing in the plate condition, the load on the graft increased in extension and decreased in flexion within physiological limits. In the staple condition, the loads are slightly more variable but also were maintained in a physiologic range. The pre load on the graft increased with expansion of the staple 152.8N (range 65.8 297.3), and once the force was removed, the pre load decreased to average 99.6 (range 35.6 194.8). Pullout of the two tined Staple versus the plate with four screws demonstrated a significant difference in pullout strength (P=7.26E 07<0.05).
CONCLUSION: A new cervical staple delivers initial compression across the fusion that a cervical plate does not. In static and motion testing, the staple has similar properties to the cervical plate. 45. Outcome of Surgical Treatment of Adjacent Segment Disease After Lumbar Fusion with Lumbar I/F Cages and the Variable Screw Placement System Guy R. Fogel, M.D. (n) San Antonio, TX Lesley Shure, M.D. San Antonio, TX (a DePuy Spine, Inc.) *John S. Toohey, M.D. San Antonio, TX (e DePuy Spine, Inc.) Arvo Neidre, M.D. San Antonio, TX (e DePuy Spine, Inc.)
Radiographic changes of adjacent segment deterioration after lumbar fusion are common. Symptomatic adjacent segment disease (ASD) requiring surgical treatment is less common. Management of ASD may require surgery. This study reviews posterior lumbar interbody fusion (PLIF) as surgical treatment for symptomatic lumbar ASD.
Between 1999 and 2002, 44 patients underwent PLIF at an adjacent segment following a previous lumbar fusion. At more than three years, 34 (77%) were available for follow up. Forty four patients with previous lumbar fusion underwent second lumbar spine surgery for adjacent segment disease. All were treated with autogenous interbody and posterolateral arthrodesis with pedicle screw fixation.
The clinical success was 88.2% with 55% rated as fair. Radiographic fusion success was 91.2%. The UCLA grades identified the worst adjacent degenerative level before the index adjacent level fusion averaged 1.3 and at last follow up was average 2.4 with an average change of 1. The lumbar lordosis averaged 45° (18 78°). There were 14 (32%) with final lordosis below 40° (average 30° [18 39°]). The sagittal alignment was mildly abnormal in three (1.5 cm off plumb) and greater than 20° scoliosis angulation from L1 S1 in two patients.
Adjacent segment disease may require surgical treatment for severe symptoms and loss of daily functional activities. Symptomatic ASD may be best treated with PLIF. When compared to previous series of treatment for ASD, PLIF gives comparable rates of clinical success and fusion success. When compared to our previous experience, clinical success has more fair and poor results in ASD. There is a statistically significant lower rate of fusion success in ASD. 46. Pedicle Subtraction Osteotomy at the Spinal Cord Level for Fixed Sagittal Imbalance *Karl F. Bowman, Jr., M.D. (n) Ann Arbor, MI Gregory P. Graziano, M.D. (n) Ann Arbor, MI Frances P. Farley, M.D. (n) Ann Arbor, MI
INTRODUCTION: Spinal surgery for the management of thoracic kyphosis with the loss of sagittal balance and deformity apex at the spinal cord level requires elective correction to be performed in a less desirable area with the potential for severe complications, including paralysis.
METHODS: IRB approval was obtained prior to a retrospective review of all spinal cord level osteotomies performed by the lead author between 2002 and 2007 for any etiology. Electronic and paper records and radiographic images were reviewed for each case. Outcomes were recorded as intraoperative, early, and late postoperative complications and the correction of preoperative thoracic kyphosis, sagittal balance, and the C7 S1 axis utilizing standard radiographic measurement techniques.
RESULTS: Eight patients underwent 11 osteotomies at T5 (3), T6, T7, T8 (2), T9, T10, T11 (2). Preoperative thoracic kyphosis averaged 91.2° (71 126°) and improved to 60.8° (40 77°). Lumbar lordosis prior to surgery averaged 49.5° (3 83°) and improved to 54.3° (28 90°). The C7 S1 vertical axis demonstrated a preoperative sagittal decompensation averaging 5.1 cm (3.8 10 cm) with correction to 1.2 cm ( 5.5 3.4 cm, 56% average correction). Coronal balance did not change significantly. Intraoperative complications included two dural tears, a pressure wound from positioning, and a C3 ring fracture during pedicle screw placement. Early postoperative complications include two periods of prolonged intubation for respiratory failure. Late complication was a single deep infection requiring serial I & D. One shear injury to the spinal cord occurred during osteotomy closure with no demonstration of postoperative deficit.
CONCLUSIONS: Pedicle subtraction (eggshell) osteotomy is a highly effective method for the correction of kyphosis, allowing restoration of sagittal balance and improvement in the C7 S1 plumb line. Careful surgical techniques are required with controlled closure of the osteotomy site. A careful assessment of the risk/benefit ratio with informed consent, and an experienced surgeon, is necessary before attempting operative correction. 47. The Effects of Lordosis, Disc Height Change, Subsidence, and Transitional Segment on Stand Alone Anterior Lumbar Interbody Fusion Using a Non Tapered Threaded Device *Kartheek K. Reddy, M.D. (n) Fort Wayne, IN Kevin A. Rahn, M.D. (n) Fort Wayne, IN Robert M. Shugart, M.D. (n) Fort Wayne, IN Mark M. Wylie, M.D. (n) Fort Wayne, IN
The use of stand alone anterior lumbar interbody fusion (ALIF) with a non tapered titanium threaded device has generated considerable controversy. Concerns about subsidence, lordosis, and their effect on outcome remain. This study reviews the outcomes of patients treated with stand alone ALIF and examines issues of lordosis, disc height change, postoperative subsidence, and transitional segment and their effect on radiographic and clinical measures.
Thirty seven consecutive patients treated with anterior lumbar interbody fusion using the BAK™ Interbody Fusion System were reviewed for this study. All patients had a primary diagnosis of degenerative disc disease, which includes a greater than 50% disc space collapse, concordant low back pain on discography, and failure of at least four months of non operative management. The mean follow up of the patients in this study was 24.2 months.
Increased lordosis, disc height, and subsidence were all positively correlated with existing literature. Patients with a transitional segment had less lordosis increase and significantly better outcomes than those without a transitional segment. Overall, 32 patients reported >75% improvement of pain, and 36 patients returned to gainful employment.
Stand alone ALIF using a threaded device provides patients with excellent clinical results and return to work rates and few complications in this study. 48. The Effect of Altered Sagittal Alignment on Posterior Fixation at the Cervicothoracic Junction *Thomas J. Sylvester, M.D. (n) Maywood, IL Alexander J. Ghanayem, M.D. (n) Maywood, IL Susan M. Renner, Ph.D. (n) Hines, IL Leonard I. Voronov, M.D. (n) Hines, IL Braden McIntosh, B.S. (n) Hines, IL Robert M. Havey, M.S. (n) Hines, IL Gerard Carandang, B.S. (n) Hines, IL Avinash G. Patwardhan, Ph.D. Hines, IL (a Synthes Spine) Anastasios Dimitriadis, M.D. (n) Hines, IL Dongkeun Lee (n) Hines, IL
INTRODUCTION: Fixation of traumatic cervicothoracic junction injuries is challenged by the transition from the flexible C spine to the rigid T spine. Because no data regarding the influence of sagittal alignment is available, particularly as the population ages, the aim of this study was to characterize the effect of sagittal alignment on posterior fusion for two column cervicothoracic junction injury.
METHODS: Eight cadaveric spines (C5 T1, age 49.8+/8.4) were used. The intact specimen was compressed to 150N using the follower load technique. The load path at C7 T1 was then varied in the AP plane to change the sagittal alignment (simulated kyphosis) and the specimen was again compressed to 150N. This was repeated with a C7 T1 posterior two column injury with and without posterior fixation (Axon, Synthes). C7 T1 segmental angular and translational motion was measured using optoelectronic instrumentation and fluoroscopy. Comparisons were made between the follower load and increased kyphotic alignments.
RESULTS: Increased C7 T1 disc space kyphosis significantly increased C7 T1 anterior slip from 0.87 ± 0.85% to 2.04 ± 1.91% (p=0.03) and angular motion from 0.20° ± 0.52° to 1.38° ±1.08° (p=0.03) with a two column injury. Increased kyphosis also significantly increased C7 T1 angular motion in the intact spine from 0.50° ± 0.35° to 2.36° ± 1.56° (p=0.03). Increased kyphosis with posterior fixation for the two column injury did not significantly affect the C7 T1 anterior slip (0.48 ± 0.47% vs. 0.68 ± 1.78%, p = 2.39) or angular motion (0.82° ± 0.50° vs. 0.53° ± 0.32°, p = 0.23).
CONCLUSIONS: This study suggests the fusion construct may sufficiently resist C7 T1 increased shear forces due to altered sagittal kyphotic alignment in two column cervicothoracic junction injuries.
49. Preoperative Predictors of Infection in Patients Undergoing Elective Spine Surgery *James T. Beckmann, B.S. (n) Cleveland, OH Krzysztof B. Siemionow, M.D. (n) Cleveland, OH Gordon R. Bell, M.D. (n) Cleveland, OH
INTRODUCTION: Evidence suggests that preoperative malnourishment in patients undergoing elective lumbar decompression and fusion is associated with an increased risk of surgical site infection. However, it has not been reported whether nutritionally supplementing malnourished patients prior to elective spine surgery decreases infection rates.
METHODS: A retrospective review of consecutive patients undergoing elective spine surgery over a three year period by a single surgeon was completed. Prior to surgery, patients identified as malnourished (Albumin < 3.5 or Total Lymphocyte Count [TLC] < 1500) were nutritionally supplemented with daily high protein nutritional energy drinks. Patients were supplemented based upon the day of their preoperative appointment in relation to their surgery date. Patients identified as malnourished within one week of surgery were not supplemented.
RESULTS: Five hundred patients who underwent elective spine surgery were available for analysis. Eleven patients (2.2%) were found to have a postoperative infection. None of these infected patients were malnourished. The mean albumin of the infected patients was 4.41 (SD +/ 0.25), mean TLC 2.21 (SD+/ 0.58). There were five females and six males with a mean age of 57.6 years. Their mean BMI was 35.1. The most common pathogen identified was Staphylococcus aureus (n=6). Of the four cervical and seven lumbar procedures, seven were instrumented. Six of the infected patients underwent a 3 level surgery (of which 3 were instrumented), 3 underwent a 2 level surgery (of which 3 were instrumented), and 2 underwent a 1 level surgery (of which 1 was instrumented).
Eighty three patients (16.6%) were preoperatively identified as malnourished based upon their albumin and TLC values. Thirty eight received preoperative nutritional supplementation, while 45 did not. There were no infections in any of these malnourished patients.
CONCLUSION: In this study, preoperative albumin and TLC were not predictive of infection. 50. Pedicle Response During Placement of Pedicle Screws in Adult Thoracolumbar Spines: A Biomechanical Comparison of Three Age Groups *Amy M. Wickman, M.D. (n) Maywood, IL Anthony S. Rinella, M.D. (n) Maywood, IL Leonard I. Voronov, M.D. (n) Hines, IL Gerard Carandang, M.S. (n) Hines, IL Robert M. Havey, B.S. (n) Hines, IL Mark J. Conroy, M.S. (n) Hines, IL Alexander J. Ghanayem, M.D. (n) Maywood, IL Avinash G. Patwardhan, Ph.D. (n) Hines, IL
INTRODUCTION: Previous studies at our institution demonstrated pediatric pedicles change shape and circumferentially expand to accommodate progressively larger pedicle screws. While biomechanical properties are different for pediatric and adult bone, it is unknown whether changes finalize with skeletal maturity or is a continuum of elastic changes over time. Our hypothesis was that pedicles would demonstrate diminishing accommodation to screws in sequentially older age groups.
METHODS: One thoracolumbar cadaver spine was used from each of the following age groups: 30 50 years, 50 70 years, 70+ years old. Pre instrumentation radiographs, CTs, and DEXA scans were performed. Each specimen was sequentially instrumented with a 2 mm pedicle finder, 4.75 mm tap, and progressively larger pedicle screws, starting at 5.5 mm until: (1) the 8.5 mm screw was reached, or (2) there was a medial or lateral cut out. The circumference, height, and width of the pedicle were taken before instrumentation, and before and after every tap and screw placement. Post instrumentation radiographs and axial cuts confirmed cortical integrity of the pedicle.
RESULTS: One spine (63 year old) was found to have osteopenia. The average pedicle expanded to 148% (41 year old), 153% (63 year old), and 144% (80 year old) of the original inner cortical diameter, and 115%, 128%, 135% of the outer diameter, respectively. There were no statistically significant changes in pedicle circumference or height in any age group. In the 41 and 63 year old specimen, most pedicles below T10 were able to accept an 8.5 mm screw without failure.
CONCLUSIONS: Adult spines do not change shape and circumferentially expand in a similar manner as pediatric spines. However, the adult spines accepted screws with as large percent of their inner cortical diameter (148%, 153%, 144%) as the pediatric spines (165%) analyzed previously. These results demonstrate there may be a spectrum related to increasing age and bone elasticity, although our study size was too small to establish age linearity versus bone quality comparisons. All specimens accepted screws between 115 135% of their outer cortical diameter.
51. Use of the Dynesys Dynamic Stabilization System for Degenerative Disc Disease and Retrospective Review of the Results *Kevin A. Rahn, M.D. (n) Fort Wayne, IN B. Matthew Hicks, M.D. (n) Fort Wayne, IN Robert M. Shugart, M.D. (n) Fort Wayne, IN Sanjeev M. Balamohan (n) Fort Wayne, IN
INTRODUCTION: Degenerative conditions of the lumbar spine have previously been treated by fusion and rigid instrumentation. The Dynesys system offers an alternative to traditional procedures, utilizing flexible materials to provide stabilization while preserving much of the spinal anatomy. Although this system has been in use in Europe for over a decade, it was only recently introduced to the U.S. Minimal longitudinal studies have been conducted to assess patient outcomes and complications.
METHODS: A retrospective review of 61 patients who underwent a Dynesys implant was performed. Included were 33 males and 28 females with a mean age of 46.4. Preoperative and postoperative x rays were evaluated to determine stability of the pedicle screws.
RESULTS: Patients had a mean follow up of 15 months. Five patients (8.2%) required revision surgery. Four of these patients underwent implantation of a more rigid pedicle system and one required a discectomy. Six patients (9.8%) had at least one screw display loosening (“halo sign”). No breakage of hardware was noted. Twelve patients (19.7%) had radicular or axial complaints greater than three months postoperative, but did not require revision surgery. Of the 14 patients who underwent Dynesys implantation in three or more spinal levels, 9 (64%) had postoperative complaints or complications. Of the 8 patients who had scoliosis, 6 (75%) had complaints or complications.
CONCLUSION: Use of the Dynesys pedicle system is a viable option for treatment of degenerative conditions of the lumbar spine. Patients with scoliosis or who have three or more spinal levels affected may be at a greater risk for postoperative complications or radicular/axial complaints. Delineation of indications and contraindications needs to be clarified, using this data and more long term follow up. 52. Characterization and Outcomes for Patients with Pathological Vertebral Fractures Related to Multiple Myeloma Treated with Kyphoplasty *Ramesh C. Srinivasan, M.D. (n) Ann Arbor, MI Gregory A. Graziano, M.D. (n) Ann Arbor, MI
INTRODUCTION: Pathologic vertebral fractures are common in patients with multiple myeloma often resulting in significant pain and progressive deformity. Vertebroplasty and kyphoplasty are low risk surgical options that have recently emerged to treat this problem. Compared to vertebroplasty, kyphoplasty offers the benefits of vertebral height restoration and reduced risk of cement extravasation due to decreased filling pressures. There is a paucity of literature characterizing kyphoplasty in multiple myeloma patients.
MATERIALS AND METHODS: We conducted a retrospective study of 30 patients who underwent kyphoplasty for pathological fracture related to multiple myeloma. Data was compiled from patient charts and pre /postoperative radiographs. The method of Genant was used to quantify the degree of vertebral collapse and deformity prior to and following kyphoplasty. Oswestry score was calculated for patients following the operation.
RESULTS: Two patients with MGUS and 27 with multiple myeloma underwent kyphoplasty at 58 vertebral levels with 26 thoracic and 31 lumbar procedures. Subjects consisted of 16 males (57%) and 13 females (43%) with the mean age of 61.3 (Stdev 11.15). Preoperative vertebral body deformity was determined for 55 levels with an average Genant grade of 1.9. Postoperative Genant grade for 56 levels was 1.5 with an average 0.4 improvement per level. Operative complications were limited to 5 patients with minimal extravasation of cement, without neurologic compromise. The mean Oswestry score for 14 patients was 25%, with data on remaining patients currently pending.
CONCLUSION: Kyphoplasty is a safe and effective procedure producing improvement in functionality and pain with minimal operative complications in patients with pathological vertebral compression fracture related to multiple myeloma. Further study is required to characterize the long term benefits of kyphoplasty in this population. 53. Guided Oblique Lumbar Interbody Fixation: A Biomechanical Study in Human Cadaveric Spine *Selvon F. St. Clair, M.D. Cleveland, OH (b Mazor Surgical Technologies) Juay Seng Tan, M.D. (n) Cleveland, OH Isador H. Lieberman, M.D. Cleveland, OH (a,b,c Mazor Surgical Technologies)
PURPOSE: The purpose of this study was to determine the biomechanical properties and mode of failure of guided oblique lumbar interbody fixation (GOLIF). GOLIF involves bilateral screws insertion through the pedicles of the inferior body that passes diagonally through both endplates to end at the anterior cortical rim of the superior body.
METHOD: L1 L5 motion segments were randomly assigned into two groups: (A) GOLIF (Group 1, n = 5) or, (B) pedicle screws (PS) (Group 2, n=5). Flexibility testing under +/ 5Nm bending moments in flexion extension (FE) and in lateral bending (LB) was carried out on the intact motion segments, following instrumentation, and interbody graft. A final failure test was carried out in either flexion or extension. Three dimensional kinematics data was captured and analysed to determine range of motion (ROM) and neutral zone (NZ).
RESULTS: In FE, the ROM and NZ for intact spine segments were 7.0° (sd=2.0°) and 0.6° (0.5°) with GOLIF, and 7.0° (2.4°) and 1.2° (0.5°) with PS, respectively. In LB, the ROM and NZ for intact spine segments were 8.1° (2.3°) and 0.9° (0.6°) with GOLIF, and 7.0° (2.3°) and 1.1° (0.4°) with PS. There were no significant differences in ROM between GOLIF and PS (p=0.39). The mean failure loads with GOLIF and PS in flexion were 1284N and 1158N, and in extension were 1879N and 1934N respectively. Failure occurred at the ventral screw bone interface without pedicle fracture.
CONCLUSION: Stiffness and failure load of GOLIF is comparable to PS fixation. Interbody graft did not affect stability. GOLIF failure occurred through the anterior cortical rim without concomitant pedicle fracture.
SUMMARY SENTENCE: GOLIF involves inserting a pair of screws diagonally across a lumbar spine motion segment. Its biomechanical performance is comparable to the contemporary standard of pedicle screws and rod fixation. 54. Management of a Pregnant Patient with a Burst Fracture Causing Neurologic Injury *Christopher J. Lenarz, M.D. (n) St. Louis, MO Howard M. Place, M.D. (n) St. Louis, MO
INTRODUCTION: There is a paucity of literature addressing the management of thoracolumbar spine fractures in a pregnant patient. We present the case and clinical course of such a case.
MATERIAL AND METHODS: A 39 year old female presented to emergency department with complaints of back pain, lower extremity weakness, and urinary and fecal incontinence. She reports having fallen two days prior causing a distal radius fracture. She was intoxicated at the time. An MRI was obtained showing a burst fracture at the 12 th thoracic vertebrae causing a significant canal impingement and compression of the neural elements. After consultation with the obstetricians, the surgical and conservative options were discussed with the patient. The patient elected to undergo a corpectomy for decompression with anterior spinal fusion.
RESULTS: The surgery was without complication to the patient or the fetus. The fetus was born at term without complication. At five months follow up, the patient was ambulating without pain or assist devices. She denied any fecal incontinence, but continued to have some difficulty with urinary incontinence.
CONCLUSION: A thoracolumbar burst fracture can be successfully managed in a pregnant patient through an anterior spinal fusion. This is the first published report of such a case. Factors to consider in the management of a pregnant female with a spinal fracture include the viability of the fetus, the use of corticosteroids, limiting the amount of radiation exposure, the management of autonomic dysfunction, and the surgical technique and approach used. 55. Evaluation of a Single Dose, Extended Release Epidural Morphine Formulation for Pain Control After Lumbar Spine Surgery *Joseph C. Vineyard, M.D. (n) San Antonio, TX Erik V. Nott, M.D. (n) San Antonio, TX John S. Toohey, M.D. (n) San Antonio, TX Arvo Neidre, M.D. (n) San Antonio, TX Guy R. Fogel, M.D. (n) San Antonio, TX Robert Joyner, M.D. (n) San Antonio, TX
STUDY DESIGN: Prospective, randomized, double blind clinical study.
OBJECTIVE: To compare the safety and analgesic efficacy of extended release epidural morphine versus the standard formulation of epidural morphine after lumbar spine surgery.
SUMMARY OF BACKGROUND DATA: Extended release epidural morphine has been used effectively for postoperative pain control following many orthopedic and general surgery procedures, and has been shown to provide prolonged analgesia compared to the standard formulation of epidural morphine. The authors are unaware of any studies comparing the analgesic efficacy and adverse events of these drugs following lumbar spine surgery.
METHODS: Sixty two patients were randomly assigned to one of two treatment groups. Group one received a standard epidural injection of morphine immediately prior to surgery, while group two received an extended release formulation of epidural morphine. All patients underwent single or multi level lumbar spine fusion. Both groups received patient controlled analgesia with morphine and oral hydrocodone postoperatively. Outcome measures included (1) visual analog scale (VAS) to assess subjective postoperative pain, (2) amount of intravenous and oral pain medicine administered over 48 hours postoperatively, and (3) any adverse events.
RESULTS: Thirty patients were randomized into each of the treatment groups. No baseline variable difference was observed between the groups. The results showed no difference between the two groups in the following outcome measures; average (1) VAS score at all times postoperatively, average (2) intravenous and oral pain medicine use, and (3) adverse events.
CONCLUSION: The administration of extended release epidural morphine for postoperative pain control after lumbar spine surgery proved to be safe and effective, but offered no prolonged analgesic activity when compared to the standard formulation of epidural morphine. MAOA BREAKOUT SESSION #5 UPPER EXTREMITY April 23, 2009
56. Analysis of 400 Consecutive Distal Radius Fractures Treated with Volar Locked Plating *Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Cory M. Stewart, B.S. (n) Detroit, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI
INTRODUCTION: Distal radius fractures are among the most common fractures in adults less than 75 years old and may cause pain, stiffness, and disability. The purpose of this study was to evaluate the results and complications of volar locked plating of distal radius fractures.
METHODS: From March 2002 to October 2006, 400 distal radius fractures were retrospectively analyzed.
RESULTS: More females (246) than males (154) were injured. Average age was 51 (range 17 96). The mechanism of injury was low energy fall (216, 54%), high energy fall (76, 19%), MVA/MCA (94, 23.6%), and other (14, 3.6%). Surgical treatment occurred within an average of six days. Refixation was required in 7 (1.7%) cases. Tendon rupture occurred in 4 (1%) of patients. Complex regional pain syndrome (CRPS) was prevalent in 25 (6.3%) patients. A greater percentage (20%) of those with CRPS had combined regional and general anesthesia as compared to those without (5%). CRPS was diagnosed at a mean of 5.3 weeks with an initial treatment of none (2, 8.0%), Medrol (12, 48%), NSAID (1, 4%), and injections (10, 40%). CRPS was somewhat (4, 16%), moderately (5, 20%), and totally resolved (16, 64%). Plate irritation occurred to some degree with six CRPS patients (24%), which was significantly different (p=0.016) compared to those without CRPS (38, 9.6%). No differences related to gender, age, body mass index, comorbidities, or mechanism of injury were evident comparing those with and without CRPS. Physical therapy (PT) was needed to a significantly greater extent by those with CRPS (21, 84%) who used PT for an average of 28 sessions compared to those without CRPS (233, 58.3%) with an average of 17 sessions (p=0.03). While motion improved for all patients, patients with CRPS did not return to normal and had significantly different supination motion from two weeks through the final visit (p<0.05).
CONCLUSIONS: Volar locked plating is an effective treatment with minimal complications. CRPS must be diagnosed and treated early to optimize treatment efficacy and extremity function. 57. ♦Direct Repair of Chronic Distal Biceps Tendon Ruptures *Jeffrey A. Greenberg, M.D. (n) Indianapolis, IN Christy F. Kellams, M.D. (n) Indianapolis, IN
Surgical repair of distal biceps tendon ruptures is the recommended treatment for patients that want to maximize functional recovery of supination strength and endurance. The treatment of chronic distal ruptures is more controversial. Many clinical series describe satisfactory results of chronic reconstructions using a variety of intercalary grafts; however, results are less predictable and suboptimal compared to primary repair of tendon to bone.
This study evaluates a sub set of patients who underwent repair of chronic biceps tendon ruptures without the use of supplementary graft material. A retrospective review of all patients who had distal biceps tendon ruptures was completed. A subset of patients with subacute (three to six weeks) or chronic (greater than six weeks) biceps tendon ruptures was identified. All of these patients had repair of their tendon directly to the bicipital tuberosity using an Endobutton® technique regardless of the tension on the repair intraoperatively. Twenty one subacute ruptures and nine chronic ruptures were evaluated.
In the subacute group, range of motion averaged 141° of flexion and 0.5° of extension with a rotational arc of 155° (79° supination, 76° pronation) achieved. No patient required dynamic bracing, and final motion was achieved by eight weeks postoperatively. In the chronic group, intraoperative extension deficits ranged from 30 65° immediately after implantation of the tendon to bone. In this group of nine patients, motion averaged 141° of flexion and 0° of extension with a rotational arc of 152° (78° supination, 74° pronation). No patient required additional therapy or dynamic extension splinting, and final motion was also achieved at eight weeks.
Evaluation of the patients in this series supports the concept that chronic biceps tendon ruptures do not always need supplemental tendon grafting. Flexion contractures seen at the time of delayed repair can be eliminated with traditional therapy and results can be similar to primary repair of acute ruptures. 58. Biomechanical Comparison of FiberLoop versus Looped Supramid Extra versus Ethibond Suture in Zone II Flexor Tendon Repair Using a Cyclic Protocol Joy V. Sharma, M.D. (n) Cleveland, OH Ryan Milks, M.S.A.E., M.S.M.E. (n) Cleveland, OH Kathleen A. Derwin, Ph.D. (n) Cleveland, OH Peter J. Evans, M.D. (n) Cleveland, OH *Jeffrey N. Lawton, M.D. (n) Cleveland, OH
The purpose of this study was to investigate differences in gap formation and failure load between FiberLoop, looped Supramid Extra (LSME), and Ethibond suture in Zone II flexor tendon repairs. In addition, the inherent properties of the sutures were tested.
Ten paired cadaveric flexor tendons were transected in zone II and repaired with either 4 0 FiberLoop or 4 0 LSME. A second set of ten human flexor tendons were repaired with 4 0 Ethibond or 4 0 FiberLoop. All repairs utilized an eight strand cruciate technique followed by a running epitendinous suture. The repaired tendons were cycled 8000 times between 2N and 25N and then pulled to failure. Suture markers were placed to analyze gap formation. In the second part of the study, an eight strand cruciate repair was performed using a custom fixture simulating a tendon construct. Failure load, method of failure, and knot volumes were recorded and statistically analyzed for the aforementioned suture products.
In the first part of the study, no significant differences were found in gap formation between suture types. All mean gaps were less than 2 mm. FiberLoop repairs failed at significantly (p=0.002) higher loads (72.9 ± 6.6 N) when compared to LSME (64.3 ± 8.8 N). However, no significant difference in failure loads was found in the paired flexor tendons comparing FiberLoop and Ethibond. All repairs failed at the tendon suture interface. In the second part of the study, FiberLoop failed by knot slippage at low loads when four throws per knot were used. When six throws per knot were used, FiberLoop (235 ± 15.6 N) was significantly stronger than LSME (114.5 ± 6.3 N) and Ethibond (123.9 ± 12.6 N).
All three suture products were able to withstand cyclical loading with less than 2 mm gap formation using an eight strand cruciate repair. The second part of the study suggests that FiberLoop is inherently stronger than LSME and Ethibond, but the increased strength is realized only when an increased number of throws is used to secure the knot. In the clinical setting, knot breakage may be irrelevant as all repair failures occurred at the suture tendon interface regardless of suture product. 59. Brunelli Reconstruction for Scapholunate Instability – Results from a District Hospital *Mr. Ulfin Rethnam (n) Rhyl, United Kingdom Rajam Yesupalan (n) Rhyl, United Kingdom Mr. Nigel Clay (n) Rhyl, United Kingdom
BACKGROUND: Scapholunate instability is the commonest carpal instability encountered. Left untreated, this injury can lead to persistent wrist pain with loss of grip strength. Outcome following repair of the scapholunate ligament is poor. Various techniques for scapholunate ligament reconstruction have been described in the literature. One of these, the Brunelli procedure, has been found to have good results. This is a complex procedure that is generally undertaken in specialist centers. We present our results of this procedure in a district hospital.
METHODS: Since 2000, we treated 11 patients with chronic scapholunate instability. The diagnosis was clinical followed by radiological and arthroscopic confirmation. All patients underwent Brunelli reconstruction using the flexor carpi radialis tendon. Patients had assessment of pain, grip strength, and wrist movement at follow up. Objective evaluation was performed using the Wrightington hospital score.
RESULTS: Ten patients were available for final follow up. The average age was 42.1 with a female preponderance. The mean follow up was 3.2 years. The mean visual analogue score for pain was 2.6. The grip strength was 82.2% of the normal side. There was only a 31° reduction in loss of flexion extension motion arc of the wrist on the operated wrist. The mean Wrightington score was 12.2/32. Higher score indicates poor results. 7/10 were satisfied with the procedure. 1/10 patients needed a wrist fusion.
CONCLUSION: The Brunelli procedure has given good results in our series with respect to pain relief, maintenance of grip strength, and range of motion. 60. Candidates for Reverse Shoulder Arthroplasty: Incidence in a Tertiary Orthopedic Center Alicia K. Harrison, M.D. (n) Minneapolis, MN *Jonathan P. Braman, M.D. (n) Minneapolis, MN
INTRODUCTION: Cuff tear arthropathy (CTA) is a challenging problem. Reverse shoulder arthroplasty (RSA) implantation rates have increased dramatically because of the improved functional outcomes associated with it. However, no attempts have been made to document the incidence of CTA in the clinical setting. Our purpose was to determine the incidence of RSA at a tertiary care university shoulder service.
MATERIALS AND METHODS: Patients seen over a period of 32 months were identified by CPT codes for rotator cuff tear and arthritis, or arthroplasty failure. Chart review confirmed the diagnosis of CTA and documented active shoulder forward flexion, procedure performed if any, and contraindications to RSA. Criteria for RSA were defined as patient with painful CTA age >65, active forward flexion <90, and functioning deltoid.
RESULTS: We identified 72 shoulders (59 patients) with CTA. Thirty six patients met the specified criteria for RSA and 12 underwent this procedure. In the timeframe of the study, there were 1,764 unique patients seen in the clinic. Therefore, the incidence of candidates for RSA was 2% (36/1,764). Furthermore, we found RSA made up 2.7% (12/451) of procedures performed. Patient factors precluding RSA included axillary nerve deficit, age <65, poor glenoid bone stock, patient choice, and associated medical comorbidities.
DISCUSSION: We believe this to be the first study examining the incidence of candidates for the RSA. Despite the good clinical outcomes reported for RSA, the population in need of this device remains small. Additionally, many potential recipients have associated factors which preclude implantation. 61. The Palmar Fat Pad is a Reliable Intraoperative Landmark During Carpal Tunnel Release *Taruna J. Madhav, M.D. (n) Cincinnati, OH Philip To, M.D. (n) Cincinnati, OH Michael T. Archdeacon, M.D. (n) Cincinnati, OH Peter J. Stern, M.D. (n) Cincinnati, OH
HYPOTHESIS: During carpal tunnel release, a palmar fat pad is visualized proximal and adherent to the dorsal aspect of the transverse carpal ligament. Knowledge of the anatomic structures and their relationship to the distal edge of the transverse carpal ligament is critical to decreasing risk of iatrogenic injury or incomplete release. Identification of the palmar fat pad allows anticipation of complete release of the transverse carpal ligament without distal dissection that could risk iatrogenic injury. This study defines the anatomic relationship of the palmar fat pad to the distal end of the transverse carpal ligament, superficial palmar arch, and motor branch of the median nerve.
METHODS: Eighteen fresh frozen cadaver hands were sharply dissected, and the proximal aspect of the palmar fat pad, distal edge of the transverse carpal ligament, superficial palmar arch, and motor branch of the median nerve were identified and tagged with small hemoclips. A precision electronic caliper was utilized to measure distances between each structure. A subset of hands was radiographically imaged with fingers flexed and extended (wrist neutral) to determine if finger positioning influenced measurements.
RESULTS: The proximal aspect of the palmar fat pad is 1.97 mm from the distal edge of the transverse carpal ligament, 12.74 mm from the most proximal aspect of the superficial palmar arch, and 6.45 mm from the nearest aspect of the recurrent branch of the median nerve. Flexing the fingers decreases the distance between the distal edge of the transverse carpal ligament and palmar fat pad, while not significantly affecting the distance to the superficial palmar arch or recurrent branch.
SUMMARY: The palmar fat pad is a reliable anatomic landmark to utilize during carpal tunnel release. Visualization of the proximal aspect of the palmar fat pad immediately precedes complete division of the transverse carpal ligament, and indicates that further distal dissection is unnecessary. It is a reliable intraoperative landmark when the fingers are extended, though flexing the fingers may bring neurovascular structures closer to the site of release. 62. Shoulder Arthroplasty in Patients 50 Years of Age or Younger with Glenohumeral Osteoarthritis: 20 Years Experience *Robert B. Bartelt, M.D. (n) Rochester, MN John W. Sperling, M.D. (n) Rochester, MN Cathy D. Schleck, B.S. (n) Rochester, MN Robert H. Cofield, M.D. Rochester, MN (c Smith & Nephew)
Between January 1, 1986, and December 31, 2005, 23 total shoulder arthroplasties (TSA) and 10 hemiarthroplasties were performed in 32 patients who were 50 years of age or younger and had chronic shoulder pain secondary to glenohumeral osteoarthritis. All 32 patients had complete preoperative evaluation, operative records, and minimum two year follow up (mean 7.1 years) or follow up until revision, and were included in the clinical and survival analysis.
Five shoulders underwent a revision operation. These were done for glenoid arthritis following hemiarthroplasty (three shoulders, mean time of revision to TSA 7.8 years) and for infection (two shoulders).
There was significant long term pain relief (p<0.001) and improvement in active abduction (p=0.01) and external rotation (p=0.002) for patients undergoing shoulder arthroplasty. There was not a significant difference in improvement in pain or motion with type of surgery (hemiarthroplasty versus TSA, p>0.05), nor with status of rotator cuff (p>0.05).
Complete radiographic records were available for 24 arthroplasties with a minimum two year follow up. Moderate to severe glenoid erosion was present in 4 of 10 hemiarthroplasties. More than minor glenoid periprosthetic lucency was present in 2 of 14 total shoulder arthroplasties.
The data from this study indicate there is marked long term pain relief and improvement in motion with shoulder arthroplasty in young patients with osteoarthritis. However, the implant survival was only 78% at 10 years (Kaplan Meier result). For the young patient with glenohumeral osteoarthritis, clinical outcomes are quite favorable for both hemiarthroplasty and TSA, but revision rates will be high. 63. Posterior Elbow Coverage: The Whole and Split Flexor Carpi Ulnaris Flaps *Robert W. Wysocki, M.D. (n) Chicago, IL Robert L. Gray, M.D. (n) Chicago, IL John J. Fernandez, M.D. (n) Chicago, IL Mark S. Cohen, M.D. (n) Chicago, IL
PURPOSE: The purpose of this study is to evaluate the coverage patterns of whole and split flexor carpi ulnaris (FCU) pedicle muscle flaps for posterior elbow soft tissue defects.
METHODS: Seventeen fresh frozen cadaveric upper extremities were used. The whole flexor carpi ulnaris was raised to the dominant vascular pedicle and transposed proximally over the olecranon. The widths of coverage at 2 cm distances about the posterior elbow were measured. Widths were also measured after making three longitudinal cuts in the fascia and after suturing the muscle to adjacent soft tissue under tension. The FCU was also split into its ulnar and humeral heads along the central tendon. The larger ulnar head was transposed and the widths again measured. Mid forearm circumference, elbow circumference, and ulnar length were assessed for ability to predict flap width.
RESULTS: The whole muscle under no tension provided an average of 2.7 cm width coverage at the tip of the olecranon process. Cutting the fascia provided approximately 15% additional width, and suturing the muscle to the surrounding soft tissue an additional 25%, to approximately 4.0 cm. The isolated FCU ulnar head provided approximately 75% of the width of the entire muscle. Mid forearm circumference was the most predictive of flap width, and divisors were generated that improved the accuracy of predicting the width for outlier specimens (p < 0.005). The dominant pedicle was a consistent distance relative to the end of the central tendon and the olecranon tip.
CONCLUSIONS: The whole and split FCU pedicle flaps provide predictable coverage for small and medium sized posterior elbow soft tissue defects. For especially large and small arms, the divisors improve accuracy in predicting flap width. Consistent locations of the olecranon tip and the end of the central tendon in relation to the dominant pedicle make them useful surgical landmarks. 64. Functional Results of Reverse Shoulder Arthroplasty versus Cuff Repair in Patients Greater Than Age 60 William T. Pennington, M.D. (n) Milwaukee, WI *Timothy I. Mullin, M.D. (n) Milwaukee, WI Brian A. Bartz, P.A. (n) Milwaukee, WI Jonathan Klinger, B.S. (n) Milwaukee, WI
PURPOSE: Historically, functional results after surgical treatment of end stage rotator cuff arthropathy have been fraught with unpredictable outcomes until the introduction of reverse total shoulder arthroplasty (rTSA). This study compares functional results and patient satisfaction of rTSA against patients at least 60 years old with arthroscopic rotator cuff repair (ARCR) of tears at least 3 cm.
METHODS: Thirty four patients (aged 65 94 years) underwent rTSA. Concurrently, 43 patients at least 60 years old (aged 60 82 years) underwent ARCR of tears measuring at least 3 cm. All patients were evaluated with ASES, UCLA, and VAS scores, and for planes of active motion and dynamometric strength. Scores and measurements were obtained preoperatively, and 3, 6, 12, and 24 months postoperatively. Results between the two groups were analyzed for statistical significance.
RESULTS: At 24 months postoperatively, significant improvement was observed in both patient groups in all parameters from preoperative values. Patients with rTSA had a faster speed to satisfaction than those with ARCR. Satisfaction at two years was 91% with rTSA and 95% with ARCR. No statistically significant difference was observed at 24 months postoperatively between outcomes measured except for a significant increase in strength in internal rotation in the rTSA group. Postoperative complications in the rTSA group included late onset acromial stress fractures in 3 (9%) patients. Three reoperations (6%) occurred in the ARCR group.
CONCLUSION: Our data suggest that functional outcomes of rTSA can approach that of ARCR in patients of similar demographics with repairable large rotator cuff defects. 65. Arthroscopic Glenoid Resurfacing: Results in Patients with Failed Previous Arthroscopic Debridement William T. Pennington, M.D. (n) Milwaukee, WI *Joseph C. McCormick, M.D. (n) Milwaukee, WI Brian A. Bartz, P.A. (n) Milwaukee, WI Jonathan Klinger, B.S. (n) Milwaukee, WI
PURPOSE: To evaluate the efficacy of treatment in patients who underwent arthroscopic glenoid resurfacing with a lateral meniscal allograft as an alternative treatment of glenohumeral arthrosis. All patients in this review failed previous arthroscopic treatments. We are reporting the two year functional outcomes of these patients.
METHODS: Sixteen patients underwent arthroscopic glenoid resurfacing with lateral meniscal allograft as an alternative to undergoing total shoulder arthroplasty. All of these patients failed previous arthroscopic procedures in the treatment of their arthrosis. All patients were evaluated with ASES, UCLA, and VAS scores, and for planes of active motion and dynamometric strength. Scores and measurements were obtained preoperatively, and 3, 6, 12, and 24 months postoperatively. Outcomes and results were analyzed for statistical significance.
RESULTS: Thirteen of 16 patients (81%) are satisfied with their outcomes at minimum of two years follow up. There was a significant improvement from preoperative scores to those obtained postoperatively in all parameters evaluated including ASES, UCLA scores, range of motion scores, strength, and VAS scores. These improvements remained at the two year postoperative period. Two of the three unsatisfied patients were successfully treated with total shoulder arthroplasty. The final patient remains dissatisfied despite two subsequent revision procedures.
CONCLUSION: Treatment of glenohumeral arthritis with arthroscopic glenoid resurfacing provided superior results in this series to their previously performed arthroscopic procedure to treat their underlying arthritic condition. Therefore, this procedure may be of benefit in the appropriate patient population as an alternative to total shoulder arthroplasty. 66. Increased Training Correlates with Performance on a Virtual Reality Simulator for Shoulder Arthroscopy *Michael E. Angeline, M.D. (n) Chicago, IL Sherwin S. W. Ho, M.D. Chicago, IL (b GMV Innovating Solutions)
INTRODUCTION: A surgeon’s skills in arthroscopy correlate with the outcome of arthroscopic procedures. As new arthroscopic procedures are rapidly being developed, surgical simulators can be used as an adjunct to the traditional apprenticeship model of surgical education. Controversy has been generated about the validity of computer based training and has thus limited its use in residency education. In order to dispel the uncertainty about the correlation of skills obtained in virtual environments with actual surgical experience, extensive validation is required. Previous studies have shown a longitudinal improvement in simulator performance after increased arthroscopic experience and that surgical experience correlates with performance on an arthroscopy simulator. The purpose of this study is to examine if increased training on a virtual reality simulator correlates with improved performance.
METHODS: In this controlled laboratory study, 20 test subjects of various levels of experience in shoulder arthroscopy were tested on an arthroscopy simulator according to a standardized protocol of 24 total exercises. Subjects were evaluated for time to completion, distance traveled with the tip of the simulated probe compared to a computer determined optimal distance, average probe velocity, and number of probe collisions with the tissues.
RESULTS: Comparing the initial to final performance results for the three benchmark training exercises, subjects improved significantly (p<0.04 for all) in all simulator parameters except average probe velocity: completion time ( 45%), distance traveled ( 42%), and probe collisions ( 46%).
DISCUSSION/CONCLUSION: The results showed that the subjects had a statistically significant improvement between three metrics confirming that improved training correlates with improved simulator performance. This study provides further validation of the utility of surgical simulators. 67. Epidemiology of Anterior Acromioplasty, 1980 to 2005 *Elizabeth M. Yu, M.D. (n) Rochester, MN Akin Cil, M.D. (n) Rochester, MN William S. Harmsen, M.S. (n) Rochester, MN Cathy D. Schleck, B.S. (n) Rochester, MN John W. Sperling, M.D. (n) Rochester, MN Robert H. Cofield, M.D. (n) Rochester, MN
INTRODUCTION: Anterior acromioplasty is commonly performed to surgically address the impingement syndrome of the shoulder. The purpose of this study is to better understand the utilization of anterior acromioplasty over time in the absence of rotator cuff repair, to examine the relationship to patient characteristics and shoulder disease and to assess the effect of arthroscopic techniques on utilization of this procedure.
METHODS AND MATERIALS: Using the resources of the Rochester epidemiology project, cataloguing medical records of residents of Olmsted County, Minnesota, we identified 246 patients who underwent anterior acromioplasty between 1980 and 2005. It has previously been shown that rarely does a resident of Olmsted County undergo an orthopedic procedure at a facility outside the county.
RESULTS: The incidence of anterior acromioplasty increased over time (p<0.001) with the crude rate of 3.3 per 100,000 in 1980 1985 to 19.0 per 100,000 in 2000 2005. Sex, age, and type of rotator cuff pathology (inflammation or fibrosis only, fraying, partial thickness tearing, full thickness tearing undergoing debridement) did not significantly change over the 26 year period. There was, however, a dramatic shift from use of the open to the arthroscopic approach over this time period (p<0.001) and also a decrease in the concomitant performance of distal clavicle resection (p<0.001).
CONCLUSIONS: The frequency of anterior acromioplasty has dramatically increased over this time period, as has the use of the arthroscopic approach. However, patient and disease characteristics have remained unchanged, seemingly indicating enhanced ability to make the diagnosis without altering the indications for the procedure. 68. Prospective, Randomized Evaluation of the Safety of Arthroscopic and Open Rotator Cuff Repair with Acellular Human Dermal Matrix Augmentation versus No Augmentation *Robert B. Litchfield, M.D. London, Ontario, Canada (a,e Wright Medical Technology) F. Alan Barber, M.D. Plano, TX (a,e Wright Medical Technology) Marc R. Labbe, M.D. Houston, TX (a,e Wright Medical Technology) Joseph P. Burns, M.D. Van Nuys, CA (a,e Wright Medical Technology) Peter B. MacDonald, M.D. Winnipeg, Manitoba, Canada (a,e Wright Medical Technology) Allen A. Deutsch, M.D. Houston, TX (a,e Wright Medical Technology) Darren Drosdewech, M.D. London, Ontario, Canada (a,e Wright Medical Technology) Delores Bentley, B.S. Arlington, TN (a,e Wright Medical Technology)
INTRODUCTION: In an effort to augment the deficient rotator cuff, some surgeons are incorporating biologic tissue scaffolds. However, some concern over infection and/or inflammatory response persists. The purpose of this study is to determine whether rotator cuff repair with acellular human dermal matrix (AHDM) differs with respect to safety, when compared to standard suture and anchor repair.
MATERIALS AND METHODS: Thirty seven patients were randomized to either receive the AHDM (Group I) or undergo repair with no augmentation (Group II). Each investigator maintained either an arthroscopic or open approach for the entire enrollment period. Patients were followed up out to six months to assess adverse events (AE) that occurred.
RESULTS: There were 18 patients in Group I and 19 in Group II. Mean age of all patients was 56 years and 72% were male. Twenty five (67%) patients underwent repair for acute tears and the others for chronic. Four AEs were identified in Group I and 3 in Group II. Group I AEs included pneumonia, shoulder bursitis, MI, and shoulder cellulitis. Group II AEs included inguinal hernia, suture abscess in shoulder, and soreness with possible re tear. There were no AEs attributed to the presence of the AHDM.
CONCLUSION: Augmentation of rotator cuff repair has the potential to significantly reduce re tear rate. This study shows comparability in AE rate and type between cuff repair augmented with an AHDM and standard non augmented repair. MAOA SECOND PLENARY SESSION April 24, 2009
69. Pet ( 11 C) PK11195 Imaging of Implant Wear Induced Periprosthetic Tissue Inflammation in a Rat Model Weiping Ren, M.D., Ph.D. Detroit, MI (a Wayne State University) Otto Muzik, Ph.D. (n) Detroit, MI Ralph B. Blasier, M.D. (n) Detroit, MI *David C. Markel, M.D. (n) Southfield, MI
INTRODUCTION: There is currently no imaging technology available to visualize periprosthetic tissue inflammation, an early sign of aseptic loosening (AL), characterized by implant wear induced macrophage activation and inflammatory osteolysis. The purpose of this study is to develop a positron emission tomography (PET) technology using a ( 11 C) PK11195 tracer to assess implant wear induced periprosthetic tissue inflammation in a rat model.
MATERIALS AND METHODS: Rat model of knee joint replacement This model was prepared by injection of UHMWPE particles into the tibia bone marrow cavity, followed by implantation of a titanium pin into the proximal parts of rat tibiae, ensuring continuity with the joint surface. CT data acquisition CT image was used as a volumetric frame to assess the periprosthetic tissue pathology, using RS 9 small animal CT Scanner. PET data acquisition Rats were injected with ( 11 C) PK11195 (2 nmol/kg body weight dosage) via the tail vein. A 30 min list mode acquisition was then initiated immediately following injection of the tracer.
RESULTS AND DISCUSSION: PET ( 11 C) PK11195 imaging has been used clinically to monitor macrophage mediated brain inflammation. Using a rat model, we found that ( 11 C) PK11195 tracer signal is significantly higher in rat knee joints with UHMWPE particle injection, as compared with unchallenged knee joint. These data supported our hypothesis that the real time changes of periprosthetic tissue macrophage kinetics in response to implant wear stimulation can be measured, mapped, and dynamically monitored using PET ( 11 C) PK11195 technology, where repeated invasive tissue pathology analysis is rarely available. PET ( 11 C) PK11195 imaging reflects the real time status of macrophage dominant periprosthetic tissue inflammation, and is an “early warning tool” for patients with total joint replacements who are at high risk of later AL development. 70. Can This Prosthesis Be Saved? Implant Salvage Attempts in Infected Primary TKA *Jeremy J. Gardner, M.D. (n) Minneapolis, MN Terence J. Gioe, M.D. (n) Minneapolis, MN Penny Tatman, MPH, MT (ASCP) (n) St. Paul, MN
INTRODUCTION: Open debridement with polyethylene liner exchange (ODPE) remains a lower morbidity option in acute infection of total knee arthroplasty (TKA), but concerns regarding its efficacy exist. Our study seeks to determine which factors help determine successful outcome of ODPE in the setting of acute TKA infection.
METHODS: Forty five patients were identified with culture positive periprosthetic infection (PPI) following primary TKA. All patients underwent ODPE with subsequent IV antibiotic therapy as the initial operative intervention. Patients were followed prospectively for a mean of 4.3 years (range 0.6 8 years) to determine final outcome. Failure was defined as any reoperation performed for control of infection or the need for lifetime antibiotic suppression. Statistical significance was determined using the Chi square test, the Student’s t test, and the Wilcoxon rank sum test.
RESULTS: Using defined criteria, 26 (58%) of the patients failed ODPE. Two patients had one additional ODPE, 21 had more than one additional procedure, and 3 required lifetime antibiotic suppression. There was a borderline significant trend (p=.07) that patients infected with S. aureus or Gram negative organisms failed at a higher rate than those with S. epidermidis or other Gram positive organisms. The mean time from onset of symptoms to ODPE in the group successfully treated versus the failure group did not differ (8 vs. 8.7d, p= 0.92). Age, gender, or ASA grade did not influence the risk of failure. A trend toward a higher failure rate (65% vs. 43%, p=0.14) was noted when the ODPE was carried out greater than 4 weeks after index TKA.
DISCUSSION: The failure rate remains high in this population even when patients are diagnosed and treated promptly (mean 8 9 days after presenting symptoms). Although certain factors favor success (infecting organism, time from index TKA), no firm algorithm can be offered. We continue to recommend individualization of treatment and careful review of the risk of additional surgery for each patient treated with ODPE. 71. Long Term Outcomes of Proximal Row Carpectomy: Minimum 15 Year Follow Up *Mir H. Ali, M.D. (n) Rochester, MN Steven L. Moran, M.D. (n) Rochester, MN Alexander Y. Shin, M.D. (n) Rochester, MN
INTRODUCTION: The long term clinical (>15 years) outcomes of this proximal row carpectomy (PRC) are not well characterized. The purpose of this study is to evaluate long term results with PRC to identify factors that may improve clinical success and patient satisfaction.
METHODS: An IRB approved retrospective study was performed on all patients who underwent proximal row carpectomy from January 1967 to 1992. All medical records and available radiographs were reviewed. Questionnaires including the Disabilities of the Arm, Shoulder, and Hand (DASH), Patient Rated Wrist Exam (PRWE), and hand motion diagrams were sent to all surviving patients. Factors associated with a poor outcome or failure were determined using multi variant analysis and a Student t test. Statistical significance was set at p<0.05.
RESULTS: Eighty one patients underwent proximal row carpectomy between 1967 and 1992. Average age at surgery was 41 years and average follow up was 19.8 years. Forty four percent of the patients did not experience adequate pain relief after the operative procedure and 81% required daily pain medication. Seventy four percent of patients were not satisfied with the results of their surgery due to persistent pain, weakness of grip, or inability to return to previous occupational activities. Fifteen percent of patients underwent wrist arthrodesis by 15 years and only 2% returned to manual labor jobs.
CONCLUSIONS: Our 15 year follow up data indicates that most patients continue to complain of persistent pain requiring daily medication and do not report great satisfaction with the outcomes of their wrist surgery. 72. Potential Use of Sox9 Transduced Mesenchymal Stem Cells in Articular Cartilage Repair *Ross A. Kessler, B.S. (n) Chicago, IL Sherwin S. W. Ho, M.D. (n) Chicago, IL Tong Chuan He, M.D. (n) Chicago, IL
Mr. Kessler is the recipient of the Edward D. Henderson, M.D. Physician in Training Award.
BACKGROUND: Articular cartilage repair remains a significant challenge for orthopedic surgeons due to its intrinsic lack of blood supply and inability to regenerate. Bone marrow derived mesenchymal stem cells (MSCs) offer an exciting source of easily isolatable cells that can differentiate into chondrocytes using cell based gene therapy. Recent studies have demonstrated the Sox9 gene to be an essential transcription factor for Type II collagen synthesis and chondrogenesis. This study investigated the use of Sox9 transduced marrow stromal cells as a potential treatment for articular cartilage repair.
METHODS: Mesenchymal stem cells were isolated from the bone marrow of mice and infected with a recombinant adenoviral vector expressing Sox9. The effect of Sox9 induced chondrogenesis was characterized in vitro using quantitative real time PCR analysis. Furthermore, the viability and differentiation of Sox9 transduced MSCs on OBI’s copolymer 3D scaffold used for bone and cartilage repair was examined using fluorescence microscopy.
RESULTS: The expression of Type 2 collagen and aggrecan mRNA were effectively up regulated by Sox9 in the adenoviral vector infected mesenchymal stem cells compared to a control. Specifically, Type 2 Collagen and aggrecan expression increased 7.0 fold and 2.5 fold, respectively, in the Sox9 infected MSCs. Using florescence microscopy, we further demonstrated that OBI’s copolymer 3D scaffold provides a viable and suitable environment for the chondrogenic differentiation of Sox9 transduced MSCs.
CONCLUSION: Our findings strongly suggest that Sox9 has a critical role in driving the differentiation of bone marrow derived mesenchymal stem cells towards chondrogenesis and the formation of a cartilage extra cellular matrix. Furthermore, the significance of the MSCs ability to respond and express the Sox9 adenoviral vector in the presence of the OBI scaffold has clear implications for the biologic treatment of articular cartilage damage. This knowledge may contribute to the development of novel cell based gene therapies for articular cartilage regeneration. 73. Adenoviral Bone Morphogenetic Protein (BMP) Induced Osteogenic Differentiation of In Vitro C3H10T1/T2 Mesenchymal Stem Cells *Ahmed A. Chaudhary (n) Chicago, IL R. Southgate (n) Chicago, IL Hanli Fan (n) Chicago, IL Wen Xin Song, M.D. (n) Chicago, IL Anthony G. Montag, M.D. (n) Chicago, IL Rex Haydon, M.D. (n) Chicago, IL David W. Manning, M.D. (n) Chicago, IL Ton Chuan He, M.D. (n) Chicago, IL
Mr. Chaudhary is the recipient of the E. W. Johnson, Jr., M.D. Physician in Training Award.
BACKGROUND: A long term goal in orthopedic treatment is the use of bone morphogenetic proteins (BMPs) for bone regeneration, such as cases of aseptic loosening, fracture nonunions, spinal fusions, and segmental bone loss. C3H10T1/T2 cells are progenitor mesenchymal stem cells (MSCs) derived from embryonic fibroblasts that can differentiate into osteogenic, adipogenic, chondrogenic, and myogenic lineages. Ongoing studies focus on the possibility of inducing osteogenesis with BMPs, which can be site specific and non invasive. We previously demonstrated that bone morphogenetic proteins 2, 6, and 9 (BMP 2, BMP 6, and BMP 9) are amongst the most potent BMPs able to induce osteogenic differentiation of MSCs. However, a complete understanding of the possible synergistic effects of various BMPs in combination has not been completed. This study investigated the osteoinductive activity of both individual BMPs and combinations of BMPs on pluripotent stem cells in vitro using BMPs 2, 4, 6, 7, and 9.
METHODS: Exponentially growing C3H10T1/T2 cells were infected in vitro with Adenoviral GFP as a control or Adenoviral BMPs, alone or in combination. Induction of alkaline phosphatase activity was used as a marker for osteogenic activity and was determined via histochemical and colorimetric assays.
RESULTS: BMPs 2, 6, 7, and 9 all induced osteogenic differentiation of MSCs in vitro , and BMP 9 was the most osteogenic by several fold, both as a single agent or when used in combination. Furthermore, the combination of BMP 7 and BMP 9 was the strongest inducer of osteogenic differentiation in MSCs. BMP 2 acted synergistically with every BMP studied, except BMP 7, and showed the highest percentage increase in activity when combined with BMP 6 (256.2%) and BMP 4 (129.3%).
CONCLUSION: Our findings suggest that BMPs, when used in combination, are able to act synergistically to increase the amount of osteogenic differentiation of MSCs in vitro . BMPs 2, 7, and 9 show the most promise as agents to induce osteogenic differentiation, and their use may contribute to new site specific and non invasive clinical therapies for bone regeneration.
74. ♦Biomimetic Calcium Phosphate Coatings as Bone Morphogenetic Protein Delivery Systems in Spinal Fusion *Michael D. Tseng, M.D. (n) Royal Oak, MI Kamran Majid, M.D. (n) Royal Oak, MI Kevin C. Baker, M.D. (n) Royal Oak, MI Jeffrey S. Fischgrund, M.D. (n) Royal Oak, MI Harry N. Herkowitz, M.D. (n) Royal Oak, MI
Dr. Tseng is the recipient of the Carl L. Nelson, M.D. Physician in Training Award.
INTRODUCTION: Currently, BMP 2 is delivered by soaking a collagen sponge in an aqueous solution of the protein immediately prior to implantation. This physical adsorption of BMP results in poor binding, which leads to rapid diffusion away from the carrier upon implantation. Rapid diffusion yields an initial burst of BMP 2 at the fusion site, which tapers off significantly within the first 12 hours of implantation. Recently, a method by which the BMPs can be delivered in a sustained, localized fashion was developed. The method involves the incorporation of BMPs within the physical structure of a calcium phosphate (CaP) coating, which can be biomimetically deposited on implant surfaces. Since the BMPs are incorporated within the coating, in vivo delivery will be more localized and sustained. The goals of this study were to (1) determine the efficacy of biomimetic CaP films as BMP delivery systems in spine fusion and (2) compare BMP delivery via hybrid CaP+rhBMP 2 coatings to the current best practice of physical adsorption.
METHODS: Collagen sponges (graft material) were coated with either a pure biomimetic CaP film alone (Group 1, positive control), a CaP film with physically adsorbed rhBMP 2 (Group 2, current best practice), a hybrid CaP+rhBMP 2 film (Group 3, experimental group), or a hybrid CaP+rhBMP+2 film plus physically adsorbed BMP (Group 4, experimental group). Eighteen New Zealand white rabbits underwent a non instrumented L5 L6 posterolateral spinal fusion. Graft material was placed on the decorticated transverse processes. At six weeks, the animals were sacrificed and the lumbar spines were harvested. Degree of fusion was assessed using weekly radiographs, manual palpation, CT scans, and histology.
RESULTS: Solid fusion was demonstrated in groups 2, 3, and 4. Equivalence was established between these groups. Additionally, fusion masses were more localized with hybrid CaP+rhBMP 2 coatings. There was no adjunctive effect of adsorbed BMP on hybrid coatings. Future studies will examine the ability to minimize the amount of BMP 2 needed in hybrid CaP+rhBMP 2 carriers to induce fusion.
75. Use of the Reamer Irrigator Aspirator for Bone Graft Harvest: A Mechanical Comparison of Three Starting Points in Cadaveric Femurs *Ryan P. Finnan, M.D. (n) Dayton, OH Michael J. Prayson, M.D. (n) Dayton, OH Tarun Gowami, Ph.D. (n) Dayton, OH Danielle Miller (n) Dayton, OH
Dr. Finnan is the recipient of the Dallas B. Phemister, M.D. Physician in Training Award.
The mechanical behavior of cadaveric femurs after IM reaming using the Reamer Irrigator Aspirator (RIA) for autogenous bone graft harvest has not been described. We hypothesized that reamed femurs, regardless of starting point, would adequately withstand cyclic loading simulating postoperative ambulation.
Twenty one cadaveric pairs were randomly assigned to 1 of 3 groups based on starting point: group 1 (trochanteric), group 2 (piriformis fossa), and group 3 (retrograde). Each femur underwent DEXA scanning and radiographs. Each test femur was reamed to 15 mm using the RIA, with the contralateral femur serving as the control. The specimens were loaded to 1400N of axial compression with 2° simultaneous torsion for 10,000 cycles. If the femur survived cyclic loading, it was then loaded to failure in axial compression. Comparisons regarding survival of cyclic loading were made using Fisher’s Exact Test.
No differences were seen between groups regarding age, sex, and T score. The mean T score for the femurs was 2.531 ± 1.372. Overall, 18 of 21 (86%) test femurs and 20 of 21 (95%) control femurs withstood cyclic loading (p = 0.606). Statistical significance was not reached for the three pair wise comparisons between test groups. The femurs failed in patterns consistent with simple pertrochanteric, basicervical, midcervical, or subcapital fractures.
IM reaming for bone graft harvest using the RIA without subsequent IM stabilization did not significantly degrade the mechanical behavior of cadaveric femurs in simulated ambulation regardless of reamer starting point. It appears safe to allow weight bearing on a reamed, unstabilized femur after bone graft harvesting using the RIA. MAOA BREAKOUT SESSION #6 TOTAL HIP REPLACEMENT April 24, 2009
76. Second Generation Cementless Total Hip Arthroplasty: Fifteen Year Results *Mark L. Dumonski, M.D. (n) Chicago, IL Craig J. Della Valle, M.D. Chicago, IL (a,b,c,e Zimmer; b Smith & Nephew, Stryker) Joshua J. Jacobs, M.D. Chicago, IL (a Smith & Nephew, Stryker; a,e Zimmer) Aaron G. Rosenberg, M.D. Chicago, IL (a,c,d Zimmer) Laura R. Quigley, M.D. (n) Chicago, IL Jorge O. Galante, M.D. Chicago, IL (a,c Zimmer)
INTRODUCTION: Second generation cementless femoral components were designed to provide reliable ingrowth and limit distal osteolysis. This report details our results of total hip arthroplasty (THA) using a cementless, circumferentially porous femoral component and a cementless cup with a standard polyethylene liner at a minimum of 15 years.
METHODS: Ninety two consecutive THAs were performed in 85 patients. The mean age of this cohort was 52 years (range, 31 to 69 years). At most recent follow up, 17 patients had died (19 hips) and 7 patients (8 hips) were lost to follow up, leaving 65 hips that were evaluated at a mean of 16.4 years (range, 15 to 18 years).
RESULTS: The mean preoperative Harris hip score of 51 improved to 88 (p<0.01). Two well fixed femoral components (3%) were revised for infection. Seven hips (11%) underwent acetabular revision; two for loosening, two for infection, two for recurrent instability and one for osteolysis. None of the unrevised components were radiographically loose. Osteolysis was seen in 18 hips (33%). Ten hips required a modular exchange of the polyethylene liner and femoral head. The 15 year survivorship (with revision for loosening or radiographic evidence of loosening as the endpoint) was 100% for the femoral component and 95% for the acetabular component.
CONCLUSION: Wear related complications, and not prosthetic fixation, are the primary mode of failure at long term follow up. The results of this study represent a benchmark for evaluating the results of total hip arthroplasty with more wear resistant bearing surfaces. 77. ♦Femoral Component Implantation Before the Neck Osteotomy Allows Accurate Leg Length and Offset Reconstruction *William B. Kurtz, M.D. (n) Nashville, TN
INTRODUCTION: This study evaluates a novel technique of restoring patients’ leg length and offset during hip replacement by implanting a modular neck femoral component through a superior approach before the hip is dislocated and before the femoral neck is cut.
METHODS: Informed consent was obtained on 44 patients. Thirty one patients requested to have their leg lengths and offset unchanged, and 13 patients requested to have their leg lengthened a predetermined amount. Measurements were taken from pre and postoperative AP pelvis x rays.
Prior to femoral neck osteotomy, a modular neck femoral component is implanted without dislocating the hip. A leg length device is attached to threads on the femoral component used for the insertion handle. A cannulated screw is inserted through the leg length device into the ilium 5 cm proximal to the femoral component and perpendicular to the femoral axis. The horizontal and vertical distance between the screw head and the device/femoral component is measured.
The device is removed, the femoral neck is cut, and the acetabular component is implanted. A trial liner, head, and modular neck are inserted. The device is reattached and leg length and offset is measured with trial components. The modular neck and head length are adjusted to recreate the desired leg length and offset, and the cannulated screw is removed.
RESULTS: The average difference between intraoperative and radiographic measurements was 2.2 mm (st.dev. 3.3 mm) for leg length and 1.7 mm (st.dev. 4.1 mm) for offset. All intra operative leg length and offset measurements were within 1 cm of the radiographic measurements. The average difference between the planned and radiographic measurements was 2.6 mm (st.dev. 3.9 mm) for leg length and 1.6 mm (st.dev. 3.3 mm) for offset.
CONCLUSIONS: Measuring the distance between the femoral component and a temporary screw in the ilium, both before the femoral neck osteotomy and after all the trial components are inserted, allows the surgeon to closely recreate leg length and offset in hip arthroplasty. 78. A Prospective, Randomized Trial of Mini Posterior and Two Incision Total Hip Arthroplasty *Craig J. Della Valle, M.D. Chicago, IL (a,b,e Zimmer) Emily Dittle, R.N. (n) Chicago, IL Scott M. Sporer, M.D. (n) Chicago, IL Mario Moric, Ph.D. (n) Chicago, IL Asokumar Buvanendran, M.D. (n) Chicago, IL
INTRODUCTION: The purpose of this study is to compare the use of a mini incision posterior approach and the two incision approach in primary total hip arthroplasty via a prospective randomized trial with an emphasis on early patient outcomes and complications. Our hypothesis was that the two incision approach would be associated with improved early outcomes.
METHODS: Seventy patients with osteoarthritis of the hip were entered into this prospective randomized trial. Preoperative teaching, anesthetic protocols, implants utilized, and rehabilitation pathways were identical for both groups. Patients were randomized using sealed envelopes following the induction of anesthesia. Power analysis determined that 35 patients would be required in each arm of the study.
RESULTS: Mean age, BMI, sex distribution, and ASA class were not statistically different between the two groups indicating successful randomization. Mean operative time was significantly longer for patients in the two incision group (100 minutes vs. 78 minutes; p=0.003 ) while mean blood loss (420 ml vs. 428 ml; p=0.9) and Hb on postoperative day one (10.1 vs. 9.9; p=0.49) were similar. The mean VAS score was not different between the two groups (1.7 vs. 1.8) as measured on the first three postoperative days. Similarly, total narcotic requirements (21.3 vs. 25.7 morphine equivalents; p=0.24) and mean length of stay (48 hours vs. 47 hours; p=0.88) were not statistically different. There was one re operation in each group; one for recurrent instability in the mini posterior group and one for a periprosthetic fracture in the two incision group.
CONCLUSION: Our hypothesis was disproved, as there were no significant differences in VAS scores, narcotic requirements, or length of stay between the two groups of patients with the sample sizes studied. Operative time was longer with the two incision approach. Outcomes were good in both groups of patients with an acceptable risk of complications. 79. The Effect of Metal Staining on Alumina Alumina Wear in Total Hip Articulations B. Sonny Bal, M.D. Columbia, MO (c Zimmer) *Michael S. Hughes, M.D. (n) Columbia, MO Thomas J. Aleto, M.D. (n) Columbia, MO Stephen Li, Ph.D. (n) Sarasota, FL Mohamed N. Rahaman, Ph.D. (n) Rolla, MO Aldo Toni, M.D. (n) Bologna, Italy
If a ceramic femoral head rubs against the metal acetabular cup during total hip implantation, metal transfer to the ceramic surface can result. Recurrent hip instability in a total hip with a ceramic femoral head can also lead to metal staining, as the head slides against the rim of the acetabular cup. We hypothesized that metal staining of alumina ceramic femoral heads would have no effect on the in vitro wear rates of alumina alumina articulations.
METHODS: Wear rates were compared between three groups of alumina alumina articulations; Group A (n=4): new, never implanted components; Group B (n=4): retrieved alumina heads with inadvertent metal staining from contact of the head with metal during total hip implantation; and Group C (n=4): retrieved alumina heads with metal staining from recurrent total hip dislocations. All femoral heads were run against new, unused alumina liners for five million cycles on a Shore Western Hip Simulator.
RESULTS: No measurable increase in alumina alumina wear rates occurred because of the presence of metal particles in the articulation. However, the alumina heads retrieved from total hips with multiple dislocations showed metal staining and surface damage to the alumina; this group showed a significant increase in alumina alumina wear rates over control bearings (p= 0.0224).
CONCLUSIONS: In the absence of surface damage to the alumina, interposed metal particles do not affect alumina alumina wear rates. These results may not extrapolate to alumina polyethylene bearings where previous studies have shown an increase in polyethylene wear from interposed third body metal particles. Superficial metal staining of alumina femoral heads that can occur during total hip implantation will not affect alumina alumina wear. However, recurrent instability can lead to surface damage and metal staining of alumina femoral heads; such bearings should be replaced during revision surgery. 80. “Hip Squeaking” Biomechanics Study of Ceramic on Ceramic Bearing Surface Christophe J. Chevillotte, M.D. (n) Lyon, France *Robert T. Trousdale, M.D. (n) Rochester, MN Qingshan Chen (n) Rochester, MN Olivier Guyon, M.D. (n) Rochester, MN Daniel J. Berry, M.D. Rochester, MN (a,c DePuy; a Stryker, Zimmer) Kai Nan An, Ph.D. (n) Rochester, MN
INTRODUCTION: Alumina ceramic on ceramic (COC) is one of the most common hip bearing material because of its efficacy in terms of wear and osteolysis. However, a new complication has been recognized with COC bearings: “squeaking noise”. The etiology of this phenomenon remains elusive. The aim of this in vitro study was to simulate and identify the biomechanical causes for hip squeaking with ceramic bearings.
METHODS: COC bearings were tested on a hip simulator reproducing flexion/extension motions. All bearings were third generation alumina ceramic with a 32 mm head coupled with a 56 mm cup. Several situations were tested to reproduce squeaking, modifying frequency, load, head or liner surface: micro fracture, “stripe wear”, “edge wear”, and “material transfer” with a third body between the head and the liner. Each condition was tested (2 times) in dry conditions and in lubricated conditions. Tests were performed up to 11,000 cycles, trying to reproduce squeaking.
RESULTS: Squeaking was reproduced in all dry conditions. It occurred quickly with high load (> 2000 N), stripe wear, or material transfer. Once squeaking occurred, it didn’t stop. It was also constant in all frequencies tested. Squeaking disappeared for all conditions when a small amount of lubricant was introduced. In lubricated conditions, squeaking was only reproduced for the “material transfer” conditions. Moreover, squeaking occurred immediately, but disappeared after 30 cycles.
DISCUSSION/CONCLUSION: This in vitro study suggests that squeaking is a problem of COC lubrication. Such noise occurs when the film fluid between the two surfaces is disrupted, because of particles, resulting of wear, or impingement. 81. Is Mid Term Follow Up Surveillance of Total Hip Arthroplasty Patients Necessary? John C. Clohisy, M.D. St. Louis, MO (a Wright Medical Technology) Amanda Schutz, Ph.D. (n) St. Louis, MO Saju Rajan, B.S. (n) St. Louis, MO Adewale Adeniran, B.S. (n) St. Louis, MO Katie Marshall (n) St. Louis, MO (Nader A. Nassif, M.D., St. Louis, MO to present [n])
INTRODUCTION: Routine implant surveillance for THA and TKA patients has been recommended to facilitate early diagnosis of implant failure. Nevertheless, the efficacy and cost effectiveness of patient screening protocols have not been determined. The purpose of this study was to assess the number and nature of interventions that result from routine mid term follow up visits for THA patients.
METHODS: We retrospectively reviewed 324 total hip arthroplasty patients that were seen for routine mid term (4 8 years) follow up evaluations. The clinic notes from these visits were reviewed and the reason(s) for the visit, patient’s pain rating, resulting interventions, and recommended interval for the next visit were recorded.
RESULTS: The 324 patients who were identified generated 569 clinic visits. 246 of these visits were routine (patients had minimal or no complaints related to the surgery hip). 240 of these 246 visits (93%) resulted in no further intervention. Four patients (2%) had a recommended intervention for the involved hip, including: an ipsilateral hip operation in 1 patient due to osteolysis, additional imaging for 1 patient, and referral to physical therapy for 2 patients. The average recommended interval until the next visit was 2.2 years.
CONCLUSION: Interventions resulting from routine mid term follow up visits for THA surveillance are uncommon. One patient (0.05%) in this series underwent surgical intervention. The results of this study question the efficacy and cost effectiveness of the current methods of total joint replacement surveillance.
Interventions after routine mid term follow up for THA surveillance are uncommon. The efficacy and cost effectiveness of the current methods of surveillance are questionable. 82. Direct Anterior Approach for Total Hip Arthroplasty: A Single Surgeon’s Early Experience *Billy K. Parsley, M.D. (n) Springfield, IL D. Gordon Allan, M.D. (n) Springfield, IL Bradley W. Dyrstad, M.D. (n) Springfield, IL Marty Wilson, B.S. (n) Springfield, IL Kevin Dale, B.S. (n) Springfield, IL
INTRODUCTION: The direct anterior approach for total hip arthroplasty utilizes an intermuscular plane of dissection and allows for preservation of the hip capsule. The proposed benefits are less postoperative pain, quicker rehabilitation, and fewer dislocations. We are reporting on a series of patients who have undergone primary total hip arthroplasty via the direct anterior approach since August 2007.
METHODS: Forty six of 54 patients (49 total hip arthroplasties) consented to be part of the study. All surgeries were performed by a single surgeon who had undergone formalized training in the direct anterior approach. These surgeries were all performed on an orthopedic table designed for this procedure.
RESULTS: Mean age was 61.5 years old (range 37–85). There were 23 males and 23 females. Average length of hospital stay was 2.63 days (SD + 1.05) with a range of one to six days. All patients were allowed to weightbear as tolerated after surgery with no hip motion precautions. Of patients with available data, the average time to discarding of all walking aids was 24 days. There have been no dislocations or re operations to date. Two femoral perforations and three greater trochanteric tip avulsions occurred early in our experience without sequelae. Excessive femoral anteversion was noted in two hips prior to the advent of the offset impactor handle. Three patients experienced an intraoperative blood loss of >1500 cc before we began isolating and clipping the lateral femoral circumflex artery. We have had no cases of symptomatic lateral femoral cutaneous nerve involvement.
CONCLUSIONS: There is a definite learning curve for this procedure, but the overall results at our institution have been promising. Length of hospital stay has shortened and patient return to function has been encouraging. While there have been complications, none have lead to need for revision and we have had no dislocations. Intraoperative fluoroscopy has been of benefit in judging leg length equality and implant position. Beyond the learning curve, the biggest difficulty we perceive to this approach is the need for a specialized orthopedic table. 83. Complications Following Total Hip Arthroplasty in the Superobese, BMI >50 *David J. Polga, M.D. (n) Rochester, MN Aaron J. Altenburg, M.D. (n) Pocatello, ID Robert T. Trousdale, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN
To our knowledge, there have been no published results on the outcomes of total hip arthroplasty (THA) in the superobese patient. We retrospectively reviewed a consecutive group of 43 hips in 41 patients undergoing THA from 1996 2006 with a BMI >50 (50 77). The mean age at time of index arthroplasty was 56.8 (19 77) with a mean follow up of 36.8 months. Overall, there were 17 (39.5%) surgical complications and 7 (17%) medical complications not including 5 deaths within 3 28 months following THA. Surgical complications included 10 hips with prolonged wound drainage and 1 residual sciatic neuropathy for a minor complication rate of 25.6%. There were 15 reoperations in 5 patients for a major complication rate of 12.2%. These included 1 irrigation and debridement with component retention, 3 for recurrent dislocation of which 2 became chronically infected requiring resection, 1 for a periprosthetic fracture which also became infected and required resection, and 1 fractured stem that required revision four years postoperatively. There were 2 intraoperative complications, 1 acetabular fracture and 1 femur fracture, both treated at the time of index arthroplasty.
We conclude that while technically feasible, total hip arthroplasty in superobese patients (BMI >50) is associated with an alarmingly high complication rate. Patients should be counseled pre operatively regarding these risks and encouraged to lose weight or referred to a bariatric specialist optimally. 84. Objective Measurement of Hip Range of Motion in Total Hip Arthroplasty: Correlation with Patient Satisfaction and Functional Outcome *Christophe J. Chevillotte, M.D. (n) Lyon, France Robert T. Trousdale, M.D. (n) Rochester, MN Mark W. Pagnano, M.D. (n) Rochester, MN Rafael J. Sierra, M.D. (n) Rochester, MN Kathie Bernhardt, B.S. (n) Rochester, MN Kenton R. Kaufman, Ph.D. (n) Rochester, MN
INTRODUCTION: Very little is known about hip range of motion (hip ROM) after arthroplasty. Measurements vary from examiner to examiner and disagreement exists about the accuracy of visual evaluation. The aim of the study was to objectively measure hip range of motion before and after total hip arthroplasty with a 3D optical motion analysis system and to correlate the findings with physical examination and patient satisfaction surveys.
METHODS: Ten patients with severe hip osteoarthritis were assessed preoperatively, three months and one year after surgery. Active hip ROM were measured with a 3D optical motion capture system. Passive hip ROM was measured with a standard goniometer. Patient satisfaction was evaluated with the Harris Hip score, the SF 36, the UCLA hip activity score, and the HOOS Hip survey. A paired t test was done to evaluate if the difference between pre and postoperative motion was significant. Correlation between the gain in motion and changes in clinical outcome scores was also assessed. Statistical significance was set at p=0.05.
RESULTS: A significant gain in active ROM for rotation (7° ± 5.8°) and abduction/adduction (11° ± 8.6°) occurred following THA. A significant gain was also found for all passive motions as early as three months postoperative. The increases in passive motion were higher than active motion. A significant correlation was found between the HOOS score and all hip motions. A significant correlation was also found for the Harris Hip score, except for rotation.
DISCUSSION/CONCLUSION: The 3D motion analysis system is a very efficient tool to compare hip ROM before and after surgery. THA improved passive and active hip motion, and the gain was correlated with patient satisfaction.
85. Infection Rate After Early Reoperation in Total Hip Arthroplasty *Hussein Darwiche, M.D. (n) Cleveland, OH Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew; a,b,e Stryker; a TissueLink; a Zimmer; c,e SS White; c,e Wright Medical Technology; e Otismed) Viktor E. Krebs, M.D. Cleveland, OH (a,b,e Stryker; a,b,e TissueLink; b,e Shukla Medical) Robert Molloy, M.D. (n) Cleveland, OH
INTRODUCTION: Infection continues to be a devastating complication of total hip arthroplasty (THA). It is often thought that early reoperation after THA has a high infection rate. To our knowledge, this complication has not been documented in the literature.
METHODS: Between 2000 and 2005, 60 THA patients were identified with an unexpected return to the operating room in the acute recovery phase (i.e., within three months of surgery). Using a retrospective review of medical charts, infection rate as well as implant survivorship after this subsequent surgery was calculated.
RESULTS: Average follow up was 3.7 years (range, 1 month 7 years), and included patients that required resection prior to a minimum two year follow up. Our data show that the infection rate for this cohort was 20/60 (33%). Survivorship analysis shows that only 8/20 (40%) of those infected kept their implants one year after surgery. Only 5/20 (25%) of those infected were considered infection free at one year postoperative.
CONCLUSION: A considerable percentage of our patients were infected after reoperation in the acute recovery phase. In addition, 60% of those infected eventually required a resection arthroplasty, emphasizing the need to reduce complications stemming from the initial surgery, minimize the trauma to tissues with meticulous soft tissue handling, and avoid prolonged intraoperative exposure of the implant to the air in the operating room. As a result, we recommend thorough irrigation to decrease the number of microorganisms introduced. Further investigation is necessary to elucidate methods to minimize the risk of infection in these patients. 86. The True Incidence of Osteolysis in Conventional versus Highly Cross Linked Polyethylene Ryan M. Nunley, M.D. (n) St. Louis, MO *Nathan A. Mall, M.D. (n) St. Louis, MO Jinjun Zhy, M.D. (n) St. Louis, MO William J. Maloney, M.D. Palo Alto, CA (e Zimmer) Robert L. Barrack, M.D. St. Louis, MO (a Medtronic) John C. Clohisy, M.D. St. Louis, MO (a Medtronic, e Zimmer)
BACKGROUND: Studies have demonstrated substantially lower wear rates for highly cross linked polyethylene (HCLPE) compared to conventional polyethylene (CPE). While low wear is desirable, minimizing osteolysis is the ultimate goal of improved bearing surfaces. The purpose of this study was to determine the true incidence of osteolysis in HCLPE versus CPE and to investigate the correlation between wear rate and osteolysis.
METHODS: A consecutive series of uncomplicated primary cementless total hips, in young active patients (<55 years) who were 5 10 years postoperative, were offered study enrollment. Forty eight patients with HCLPE (mean 46.5 years) were compared to 50 patients with CPE (mean 43.2 years). Linear wear was calculated with the Martell Hip Suite software and osteolysis was assessed by three blinded observers on plain radiographs as well as high resolution CT. Lesion volume was quantified on CT using the Analyze Software.
RESULTS: At follow up averaging 7.2 years, osteolysis was apparent on plain radiographs in only seven hips (53.8%), all with CPE. Conversely osteolysis was apparent on high resolution CT in 12 of 50 (24%) of CPE hips, but only 1 of 48 (2%) HCLPE hips, which indicates a highly significant difference in incidence (p<0.0001). Wear analysis demonstrated significantly decreased wear in the HCLPE (p<0.0001) and significantly less wear in the group without osteolysis (p=0.03). However, there was no correlation between wear and volume of osteolytic lesions, and the lesions present on CT and radiographs were not significantly larger than those seen on CT alone.
CONCLUSION: HCLPE dramatically diminished the incidence of osteolysis in this group of young patients. The presence of osteolysis in some cases with minimal wear and the lack of correlation between wear and osteolysis suggests that factors other than wear volume contribute to the development of osteolysis. This study also suggests that radiographic studies are inadequate in estimating the incidence of osteolysis, and in those with HCPLE liners routine CT scans in the 5 7 year follow up range would be of low yield. 87. Uncemented Total Hip Arthroplasty in Patients Less Than 20 Years of Age: A Retrospective Review Michael J. Taunton, M.D. (n) Rochester, MN *Louis S. Stryker, M.D. (n) Rochester, MN Robert T. Trousdale, M.D. (n) Rochester, MN
INTRODUCTION: Uncemented total hip arthroplasty is a reliable and effective treatment of end stage arthrosis in many patients. A subset of patients is extremely young, and represents a particular challenge.
METHODS: The computerized databases of the authors’ institution were used to identify all patients younger than 20 years of age who underwent uncemented total hip arthroplasty (THA), with a minimum of two years of clinical and radiographic follow up. The operative reports, x rays, and clinical notes were reviewed to correlate clinical factors.
RESULTS: There were a total of 35 uncemented THAs performed at the authors’ institution from 1989 to 1999. Average clinical follow up was 7.2 years. The average age at THA was 17.6 years. The operative diagnosis was avascular necrosis in 12, inflammatory arthritis in 13, degenerative joint disease in 9, and Perthes in 1. Twenty two patients had a complication after THA. There was superficial wound drainage in 1, heterotopic ossification in 1, decreased range of motion in 3, instability in 3, and aseptic loosening in 14. There were 16 patients that subsequently underwent revision THA. The average time between primary THA and revision was 7.8 years. The reason for revision was aseptic loosening in 13 and instability in 3.
DISCUSSION AND CONCLUSION: The rate of revision THA at an average follow up of 7.2 years was 45.7% in this study. Aseptic loosening and bearing surface wear were major contributors to failure. Surgeons aware of the risk of failure of uncemented total hip arthroplasty in extremely young patients may take measures to decrease failure mechanisms. 88. Influence of Administration Setting on SF 36 Scores Following Primary Total Joint Arthroplasty *Trevor G. Murray, M.D. (n) Cleveland, OH Ho H. Lee, M.D. (n) Cleveland, OH Alison K. Klika, M.S. (n) Cleveland, OH Boris Bershadsky, M.D. (n) Cleveland, OH Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew; a,b,e Stryker; a TissueLink; a Zimmer; c Exactech; c,e Wright Medical Technology; c,e SS White; e Otismed)
INTRODUCTION: Health related quality of life information using the SF 36 instrument has become a ubiquitous tool for baseline and outcome assessments in clinical research. The goal of this study was to determine if patients undergoing primary total joint arthroplasty (TJA) respond differently on the SF 36 instrument when the survey is completed in an office based setting compared to surveys completed at home and returned by mail.
METHODS: Between 2003–2004, two concurrently running IRB approved databases were used at our institution. One database collected baseline and one year status post primary TJA SF 36 scores by mailed surveys, while the other captured one year scores in the office setting. Responders and non responders were characterized by their demographic and co morbid conditions. Norm based scoring based on 1998 general US population norms was utilized. Interval changes in scores were compared between those who had a baseline form and an office or mail form at one year. Scores were then compared between groups, including a subgroup which acted as their own internal controls having filled out both office and mailed forms, using unpaired and paired t tests, respectively.
RESULTS: Responders and non responders were similar with respect to demographic and comorbidity profiles. Mental component summary (MCS), mental health (MH), and vitality (VT) scores were statistically significantly higher in the office setting at one year postoperative (p<0.05; Bonferroni corrected).
CONCLUSIONS: In the setting of primary TJA, SF 36 MCS, MH, and VT scores are affected by the mode of delivery. These findings have implications for the design and interpretation of SF 36 data in arthroplasty outcome studies. MAOA BREAKOUT SESSION #7 FOOT & ANKLE/MISCELLANEOUS April 24, 2009
89. Expanding Indications of the Distal Chevron Osteotomy with a Lateral Release in Hallux Valgus *Brian D. Kampmann, M.D. (n) Wichita, KS Steven J. Howell, M.D. (n) Wichita, KS Teresa L. Jones, MPH, MT (ASCP) (n) Wichita, KS Mark D. McDaniel, M.D. (n) Wichita, KS
INTRODUCTION: Hallux valgus is traditionally treated with osteotomies of the first ray, with moderate and severe deformities requiring proximal metatarsal osteotomies. The distal chevron osteotomy is regularly used, often with a lateral release, for intermetatarsal angles (IMA) up to 15°. We hypothesized that distal chevron osteotomies with lateral releases can routinely correct greater deformities.
METHODS: A retrospective review of one foot and ankle surgeon’s patient records over a five year period (January 2001 December 2006) identified 342 distal chevron procedures by CPT code. Of these, 91 feet (81 patients) were identified with intermetatarsal angles greater or equal to 15° using preoperative radiographs. Preoperative and postoperative chart and radiographic data were recorded for these patients.
RESULTS: Mean age of the 81 patients included in this study was 58 (SD 13.8; range 22 82) years. Mean BMI was 29 (SD 6.4; range 18.5–49.6). Ninety six percent were female. Average preoperative IMA was 18 (range 15 31). Postoperative average IMA was 7.32 (SD 3.4; range 0 16) with average follow up 5.4 months (SD 3.3; range 1 12 months).
CONCLUSION: Based on this data, distal chevrons can be reliably performed in patients with IMAs greater than the 15°. This study is limited by its retrospective nature and short term follow up. Additional prospective studies with longer follow up are needed to prove that the correction is not lost over time, and help determine the true limits of the distal chevron and lateral release. 90. Bridge Plating for Fixation of Primarily Ligamentous Lisfranc Injuries *Casey D. Johnston, M.D. (n) Omaha, NE Mark Dietrich, M.D. (n) Omaha, NE Kathleen M. Grier, M.D. (n) Omaha, NE David J. Inda, M.D. (n) Omaha, NE Timothy C. Fitzgibbons, M.D. (n) Omaha, NE Scott T. McMullen, M.D. (n) Omaha, NE
INTRODUCTION: Lisfranc injuries are relatively uncommon and can represent treatment dilemmas. The severity of the injury can range from those that are primarily ligamentous to complex midfoot fracture dislocations. While ORIF has been established as the standard treatment for most of these injuries, recent literature has suggested that primary fusion may be a more suitable alternative for ligamentous injuries. The purpose of this study is to report our experience with a potentially cartilage sparing bridge plating technique for primarily ligamentous Lisfranc injuries.
MATERIALS AND METHODS: We performed a retrospective review of patients that underwent operative fixation of Lisfranc injuries with a bridge plating technique from 2002 2008. We defined ligamentous injuries as those that had disruption of the joint but did not have a major fracture. We included those that had a fleck sign. Fourteen (7 male, 7 female, average age 25.5) patients met the criteria of our study and underwent operative fixation of their Lisfranc injury with a bridge plating technique. A standard dorsal approach was used in all cases and reduction techniques were followed using AO principals. In all cases, a bridge plate was used to provide fixation across the tarsal metatarsal joints without disruption of the joint itself. All patients underwent a standard postoperative course.
RESULTS: 14/14 patients maintained their reduction and had no hardware failures in the initial postoperative period. 13/14 patients maintained their reduction through latest follow up with one loss of reduction occurring following hardware removal. 11/14 patients had hardware removed. With an average follow up of two years, only one patient had radiographic evidence of mild midfoot arthritis. Clinically, all patients were satisfied with the results of their surgery based on visual analogue pain scores and subjective reporting of dysfunction.
SUMMARY: We believe that bridge plating of primarily ligamentous Lisfranc injuries is a suitable alternative for fixation. Our patients had no loss of fixation or hardware failures and more importantly, only one patient had evidence of midfoot arthritis at latest follow up. 91. Treatment of Syndesmosis Disruptions: Conventional Screw Fixation versus Tightrope Fiber Wire Fixation: A Prospective, Randomized Study J. Chris Coetzee, M.D. (n) Minneapolis, MN *Patrick B. Ebeling, M.D. (n) Minneapolis, MN
BACKGROUND: Open reduction and screw fixation is currently the accepted treatment for displaced syndesmoses injuries. Despite reduction and stable internal fixation, these injuries do not have uniform excellent outcomes. The objective of this study is to compare screw fixation to the fiber wire fixation.
METHODS: Twenty two patients with syndesmoses injuries, with or without ankle fractures, were followed over an average of 18.5 months (12 months to 28 months). These patients were enrolled in a prospective, randomized clinical trial comparing traditional screw fixation to tightrope (Arthrex) fiber wire. Any associated ankle fractures were treated in a conventional manner.
Evaluation was performed with clinical examination, radiography, AOFAS ankle and hindfoot Scale, visual analog scale, and a functional questionnaire.
RESULTS: At this point, there are 11 patients in each group with at least one year follow up. The potential advantage of the fiber wire fixation is that it still allows some of the normal rotation and proximal distal motion of the fibula during the normal gait cycle.
The follow up is short, but at a minimum follow up of one year the AOFAS ankle and hindfoot score for the tightrope group was 94 (82 100) and the screw fixation group was 88 (80 100). The patients in the tightrope group had better range of motion than the screw fixation, and also subjectively less stiffness and discomfort.
Complications included one broken screw in the screw group and one patient that developed an infection in a fiber wire fixation that required removal of the wire after six months.
CONCLUSIONS: At this early stage, fiber wire fixation appears to be at least equal in result as conventional screw fixation. The potential advantage is that it still allows for the normal motion in the syndesmoses complex, which appears to benefit the patient. 92. The Modified Oblique Keller Capsular Interposition Arthroplasty for Hallux Rigidus *R. Brian Mackey, M.D. (n) St. Louis, MO Brian Thomson, M.D. (n) St. Louis, MO Ohyun Kwon, Ph.D. (n) St. Louis, MO Michael J. Mueller, Ph.D. (n) St. Louis, MO Jeffrey E. Johnson, M.D. (n) St. Louis, MO
Hallux rigidus is a common problem affecting the hallux, and many operative procedures have been proposed. Despite the success of arthrodesis, there are patients who object to the metatarsophalangeal joint stiffness. For this reason, motion sparing procedures are sought. The Modified Oblique Keller Capsular Interposition Arthroplasty (MOKCIA) is a motion sparing procedure. We compared a cohort of patients who had arthrodesis to a group who had the MOKCIA. We evaluated 13 toes in 10 patients who were 23 101 months post MOKCIA. We also evaluated 14 toes in 10 patients who were 27 96 months post arthrodesis. Clinical outcomes were evaluated with the SF 36, AOFAS clinical rating system for the hallux, and the Foot and Ankle Ability Measure (FAAM). Range of motion, dynamometer strength testing, pedobarographic data, and x rays were assessed.
Significant clinical outcome differences existed between the arthrodesis and MOKCIA groups for the AOFAS MOKCIA (89.5) and arthrodesis (76.14), and social SF 36 category MOKCIA (96.25) and arthrodesis (82.29). The MOKCIA group exhibited passive (53°) and active (31°) range of motion of the MTP joint. The pedobarographic data revealed significantly higher pressures in the arthrodesis group in the hindfoot, great toe, lesser toes, and cumulative pressures, but did not for the second metatarsal head pressures. This evidence suggests that the MOKCIA is a motion sparing procedure with equal or better clinical outcomes than arthrodesis. Intuitively, higher pressures are less desirable but lower pressures may come with the cost of greater motion. 93. The Use of a Patient Controlled Stretching Device to Improve the Ankle Joint Range of Motion *Saul G. Trevino, M.D. (n) Columbia, MO William L. Buford, Ph.D. (n) Galveston, TX Santaram Vallurupalli, M.D. (n) Columbia, MO Margaret Rowell, R.N. (n) Columbia, MO Vinod K. Panchbhavi, M.D. (n) Galveston, TX
BACKGROUND: Ankle and subtalar stiffness are widely associated with many foot and ankle conditions and functional deficits. Loss of joint range of motion, particularly dorsiflexion, results in significant gait dysfunction. Currently, there is no tool described in the literature that effectively, efficiently, and precisely stretches the ankle joint and subtalar joint without requiring supervision or assistance of a trained physical therapist.
MATERIALS AND METHODS: Twenty two subjects with varying foot and ankle diagnoses who had little or no improvement in range of motion after traditional assisted physical therapy were recruited from a foot and ankle orthopedic clinic. The subjects’ ankle and subtalar range of motion (ROM) in plantar flexion (PF), dorsiflexion (DF), inversion (INV), and eversion (EVR) were measured using a standard goniometer by a single physiotherapist prior to using the stretching device. The subjects were trained on the proper use of the stretching device and then instructed to use it daily for a six week period, and then the same examiner repeated the above measurements. Statistical analysis was then run on the collected data using a two sample t test assuming unequal variances.
RESULTS: The stretching device was found to increase ROM in all planes tested. DF to PF ( p = .0052), INV to EVR ( p = .018). The ROM in the sagittal plane, which is a combination of DF+PF, increased from 24.45+/ 11.32 to 37.09+/ 17.59. PF increased from 26.27+/ 14.78 to 33.18+/ 17.66 and DF increased from 1.81+/ 8.90 to 4.72+/ 6.9. The ROM in the sagittal plane (combination of plantar flexion and dorsi flexion) increased significantly and attained statistical significance, but the increase in total range of motion in the sagittal plane was mainly due to the consistent increase in dorsiflexion. The differences in plantar flexion before and after using the stretching device are not statistically significant (PF: p = 0.163), but the differences in dorsiflexion before and after using the stretching device are statistically significant DF ( p = .0095). The total ROM in inversion and eversion plane increased significantly and attained statistical significance. The total range of motion in inversion and eversion planes increased from 23.70+/ 15.44 to 35.30+/ 14.4. The increase in range of motion is mainly contributed by eversion due to consistent improvement. Inversion increased from 14.95+/ 13.8 to 20+/ 14.0 and the eversion increased from 8.75+/ 10.62 to 14.40+/ 8.6. The increase in ROM either in inversion or eversion (INV: p = .186), (EVR: p = 0.07) individually attained statistical significance.
CONCLUSION: Stretching with the stretching device significantly increases ankle and subtalar ROM.
CLINICAL SIGNIFICANCE: The stretching device can be used at home on a regular basis with minimal training and can be effective to treat stiffness in ankle and subtalar joints. It can be cost effective when compared to use of physiotherapy services. 94. Results of 90 Consecutive Navicular Fractures Marlon O. Coulibaly, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI *James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
BACKGROUND: Navicular fractures (NF) are uncommon. The purpose of this study was to compare the results of operative and nonoperative treatment in patients with a NF.
METHODS: A retrospective analysis was undertaken on patients diagnosed with NF between March 2002 and June 2007 at a Level I teaching trauma center. Clinical outcome consisted of complications and functional ability.
RESULTS: Eighty eight patients with 90 fractures were identified. There were 56 men and 32 females with a mean age of 38 (range 17 72) and BMI of 28.2 (range 18.7–48.9). Twenty one (23.3%) injuries were isolated. Ten (11.1%) injuries were open. Treatment consisted of non operative (49, 55%), ORIF (37, 41%), and primary arthrodesis (PA, 4, 4%). Eleven (30%) of ORIF cases required bone grafting. Use of bone graft was related to reduction quality (ρ=0.473, ρ=0.002). Complications included 1 DVT, 1 AVN, 3 nonunions, 7 infections (with 2 osteomyelitis, 3 antibiotic therapies, and 2 I&D), 18 longitudinal arch collapse, and 56 post traumatic arthrosis. Operative group had significantly more post traumatic arthrosis than the nonoperative group ( χ2 =0.000). Secondary surgery was 25 HW removals (16 for irritation, 5 for prominent or broken plates), 9 arthrodeses, 2 debridement for infection, and 4 repeat ORIF. Pain was present at final follow up in 39 of 90 (43.3%) feet. Sixty two (69%) patients were able to wear normal shoes, which was related to return to work without restrictions (ρ= 0.508, ρ=0.000). Work status was 64 without restrictions, 17 with restrictions, and 5 did not return to work. Inability to return to previous work was related to pain ( ρ= 0.394), post traumatic arthrosis (ρ= 0.280), and poor reduction quality ( ρ= 0.384) at sig < 0.01. Increased BMI (>35) was related to pain ( ρ=0.250) and poor reduction quality ( ρ=0.326) at a sig < 0.05.
CONCLUSIONS: Even though navicular fractures are uncommon, operative treatment of displaced fractures is fraught with complications. Obesity, pain, and post traumatic arthrosis determine shoe wear, return to function, and employment status.
95. Rate of Nonunion Following Talonavicular Arthrodesis with the Use of Modern Fixation Techniques Srinivas Thati, M.S. (n) Grand Rapids, MI *Chad B. Carlson, M.D. (n) Grand Rapids, MI John G. Anderson, M.D. (n) Grand Rapids, MI Donald R. Bohay, M.D. (n) Grand Rapids, MI
OBJECTIVE: To determine the rate of nonunion following talonavicular arthrodesis with the use of modern fixation techniques.
MATERIALS AND METHODS: A retrospective study was performed on 273 patients (300 feet) who had talonavicular arthrodesis, either isolated or as a part of multiple joints fusion performed by the two senior authors from 1998 to 2006. All the charts, patient questionnaires, and radiographs were reviewed. Data collection included demographic data, indication for surgery, the joints fused, operative details, time to union, and a modified AOFAS ankle hind foot score.
RESULTS: 292 feet met the inclusion criteria for the study. The subjects were 160 females and 113 males with average age of 58 years (range 15 86 years) at the time of surgery. Indications, operations performed, and surgical techniques were also determined by the chart review. Fusion was healed in 286 feet while 6 developed nonunion. Average time to union was 15.2 weeks. Eleven patients developed wound problems postoperatively and five were infected. Modified AOFAS score improved from preoperative value of 37.8 to 83.7 postoperatively.
DISCUSSION AND CONCLUSIONS: Nonunion is found to be a common complication following arthrodesis of the talonavicular joint and variably reported from 0% to 70% by multiple authors. In our study of 292 feet with talonavicular arthrodesis either isolated or as a part of double and triple arthrodesis, we identified the rate of nonunion in talonavicular joint as 2%. Three of the nonunions occurred in post traumatic foot with Chopart fracture dislocation among which one was treated as isolated TNA and the other two had triple arthrodesis. One each had rheumatoid arthritis, osteoarthritis, and malaligned ankle fusion which were treated with double arthrodesis with midfoot fusion, isolated TNA, and triple arthrodesis respectively. Three patients were known smokers. On revision with bone graft, all the nonunions united eventually. 96. Results of 90 Consecutive Cuboid Fractures *Marlon O. Coulibaly, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
Cuboid fractures (CF) are uncommon. The purpose of this study was to compare the results of operative and nonoperative treatment in patients with a CF.
METHODS: A retrospective case control analysis was undertaken on patients diagnosed with CF between March 2002 and June 2007 at a Level I teaching trauma center. Clinical outcomes consisted of complications and functional ability.
RESULTS: Eighty six patients with 90 fractures were identified. There were 57 males and 29 females with a mean age of 40 (range 16 72) and BMI of 28.8 (range 17.5 48.9). Two were isolated injures. Twelve were open injuries. See Table 1 regarding the difference of associated injuries between the treatment methods. Treatment consisted of nonoperative treatment (46, 51%) and open reduction internal fixation (44, 49%). Bone grafts were required in 27 of the 44 (61.4%) operative cases. Satisfactory or bad reduction had greater occurrence of secondary osteoarthritis (OA) ( χ2 =0.046). Time to weight bearing was 11 weeks (range 1 24). Healing occurred in 16 weeks (range 6 34). Operative group had longer time to healing (t= 3.282, sig =0.002) and longer period to weight bearing (t= 2.285, sig=0.025) compared to the nonoperative group.
Complications consisted of 60 (66.7%) OA, 16 hardware irritation, 15 longitudinal arch collapse, 8 infections, and 1 delayed union. Secondary surgery was 30 hardware removals, 4 arthrodesis by fusion, 1 lateral column lengthening, and a tarsal tunnel release. Pain was present at final follow up in 48 cases (53%). In 55 of 90 (61%) injuries, patients were able to utilize normal shoes. Work status was 55 without restrictions, 21 with restrictions, and 6 did not return to work. Inability to return to previous function and work was related to pain (ρ= 0.301, p<0.01) and shoe wear (ρ= 0.482, ρ<0.01). Pain was related to the inability to wear normal shoes (ρ=0.553, ρ<0.01). Development of OA was related to pain (ρ=0.316, ρ<0.01), the ability to wear normal shoes (ρ=0.303, ρ<0.01), and return to normal function (ρ= 0.319, ρ<0.01). OA was significantly more present in the operative group ( χ2 =0.012).
CONCLUSIONS: Cuboid fractures are debilitating injuries that require restoration of lateral column length and articular surface congruity. Reduction quality influences patient outcome. Pain, post traumatic arthrosis, and inability to wear normal shoes are related to inferior results.
Table 1: Difference in associated foot injuries based on treatment Associated foot injuries n % Op % Nonop % p value Metatarsal(s) 60 66.7 (44) 36 81.8 (46) 24 52.2 .003 Navicular 43 47.8 16 36.4 27 58.7 .034 Lisfranc 40 44.4 28 63.6 12 26.1 .000 Cuneiform 36 40.0 24 54.5 12 26.1 .006 Talus 34 37.8 15 34.1 19 41.3 ns Calcaneous 30 33.3 9 20.5 21 45.7 .011 Ankle 12 13.3 6 13.6 6 13.0 ns Phalanx 3 3.3 2 4.5 1 2.2 ns Pilon 2 2.2 0 0 2 4.3 ns
97. Surgical Treatment of Plantar Fibromatosis *Erica M. Burns, M.D. (n) Omaha, NE David Minges, M.D. (n) Omaha, NE Timothy C. Fitzgibbons, M.D. (n) Omaha, NE Kathleen M. Grier, M.D. (n) Omaha, NE David J. Inda, M.D. (n) Omaha, NE Scott T. McMullen, M.D. (n) Omaha, NE
INTRODUCTION: Plantar fibromatosis is a benign lesion that arises in the substance of the plantar fascia. It is commonly seen in patients with metabolic disorders such as diabetes and also has familial tendencies. Its association with Dupuytren’s contraction and Peyronie’s disease has been well described. The primary treatment is non surgical, but in some patients who become concerned about the possibility of malignancy and those patients with large lesions which are not amenable to soft inlays, surgical excision is justified. There has been a fear among many orthopedic surgeons to surgically treat these patients because of the concerns for wound healing problems, painful plantar scars, recurrences more significant than the primary lesion, and other concerns about the morbidity of the surgery. The purpose of this paper is to present our experience with the surgical excision of these plantar fibromatosis lesions.
MATERIALS AND METHODS: A computer search from our database from 2001 through 2008 revealed a total of seven patients who were treated surgically for plantar fibromatosis. There were three males and four females. The age range was 39 to 66 with a mean of 52 years. The surgical technique involved a general or spinal anesthetic with the use of a tourniquet. A direct plantar incision was utilized dissecting the skin and subcutaneous tissue off the lesion, exposing normal plantar fascia on all four sides. These lesions were then excised with a two to three millimeter border of normal plantar fascia. All wounds were closed with 2 0 proline sutures in the skin only. All patients were kept non weight bearing for a full three weeks and then allowed to progressively bear weight in a CAM walker for an additional three weeks.
RESULTS: All patients healed their wounds primarily with no significant wound problems. There were no significant sensory deficits noted. Any recurrence that occurred was felt to be minimal and with the patients then knowing their diagnosis of a benign lesion were comfortable, easily treated with an inlay, and there were no secondary surgical procedures.
SUMMARY: Although the primary treatment of plantar fibromatosis still should remain non surgical, in those patients who are concerned about the diagnosis or if the lesion is large enough to make shoe fitting a problem, surgeons should not be afraid to excise these lesions as long as the patients are protected adequately postoperatively. It is felt that surgical excision is an acceptable alternative with minimal morbidity. 98. Procedural Competency Assessment with the Surgical Training and Assessment Tool (STAT) in Orthopedic Surgery Trainees Tessa Balach, M.D. (n) Chicago, IL Paul Roach, M.D. (n) Chicago, IL Eugene Selkov, Jr., M.S. (n) Chicago, IL Jonathan Silverstein, M.D. (n) Chicago, IL Terrance D. Peabody, M.D. (n) Chicago, IL (Presented by Jaime Rice, M.D., Chicago, IL [n])
BACKGROUND: As a part of the ACGME Outcomes Project, Program Directors are required to assess residents and fellows in a formative and summative fashion. We discuss the use of a web based platform, the Surgical Training and Assessment Tool (STAT), in measuring competency.
METHODS: We identified 117 common orthopedic procedures. Surgical knowledge, skill, and independence and the key technical maneuvers of these procedures were defined, organized into a system of hierarchical, expandable menus, and loaded into a secure, web based catalog. Both trainees and attendings electronically submitted evaluations of the trainee’s performance, along with an overall grade and optional general comments.
RESULTS: Over the first 10 months of use in a single university based orthopedic surgery residency program, a hand fellowship, and an orthopedic oncology fellowship, 1,805 assessments (803 attending, 1,002 trainee) were recorded. The median time for completion of the assessments (from login to submission) was 76.5 seconds. In a multiple linear regression model, skill, knowledge, and independence assessments were found to be significant contributors to the overall grade (r 2 = 0.7, p<0.001). There was agreement between raters. The difference in average overall grades by trainees (7.59 = “B ”) and attendings (9.26 = “B+”) was statistically significant (p<0.001).
CONCLUSIONS: STAT is a useful tool for assessing competency in orthopedic surgery residency and fellowship programs. Formative feedback enhances communication, facilitates reflection and improvement, and clarifies objectives while providing program directors with essential information by which to measure the educational effectiveness of a program and judge the evolving competency of the trainee.
99. Improvement in Musculoskeletal Function Following Bariatric Surgery *Michael F. Iossi, M.D. (n) Dayton, OH Emmanuel Konstantakos, M.D. (n) Dayton, OH Donovan Teel, II, M.D. (n) Dayton, OH Richard Sherwood, Ph.D. (n) Dayton, OH Richard T. Laughlin, M.D. (n) Dayton, OH Dana Duren, Ph.D. (n) Dayton, OH
INTRODUCTION: Obesity has a strong association with hip and knee osteoarthritis and need for total joint arthroplasty (TJA). Weight reduction (bariatric) surgery is an effective method of achieving acute weight loss. While the impact of bariatric surgery on general medical conditions (e.g., type 2 diabetes) is well documented, few studies focus on physical functional outcomes following bariatric surgery.
MATERIALS AND METHODS: Fifty one women aged 20 74 undergoing the Roux en Y gastric bypass procedure were followed prospectively for six months. Height, weight, and waist circumference were recorded preoperatively and at three and six months postoperatively. Additionally, to track changes in musculoskeletal and physical function, the Timed Get Up and Go Test (TGUG) and SF 36 and Short Musculoskeletal Function Assessment (SMFA) questionnaires were administered.
RESULTS: Overall, patients had significant weight loss and functional improvement during this study. Presently, 76% of patients have completed the six month follow up, with a mean weight loss of 34.8 kg (27.2%) and mean TGUG improvement of 2.3 seconds (18.2%). SMFA and SF 36 also showed improvement in all components with weight loss. Because of known age effects in TGUG, associations between parameters were analyzed by age group. The strongest correlation was seen in patients aged 30 to 40 (r=0.74, p<0.5).
DISCUSSION: Bariatric surgery results in weight loss and reduction of long term risks for osteoarthritis and TJA, but also acutely improves musculoskeletal function in morbidly obese patients. Additionally, for patients with clinical osteoarthritis pursuing TJA, bariatric surgery may serve as an adjunct for improving global functional outcome, and enhancing the rehabilitation potential in this patient population. 100. Hand Rubbing with Aqueous Alcohol Solution Following Traditional Surgical Hand Scrubbing: A Comparison of Microbial Hand Counts *Roger K. Owens, II, M.D. (n) Louisville, KY Peter J. Buecker, M.D. (n) Louisville, KY
BACKGROUND: Several scrubless solutions have made their way into the operating room in recent years. There are no studies evaluating microbial hand counts following use of aqueous alcohol solution after a traditional surgical scrub.
METHODS: Seventeen resident and attending physicians and operating room surgical personnel were prospectively enrolled into the IRB approved study. Bacterial cultures were taken from each subject’s hand prior to scrub, following a five minute scrub with chlorhexidine, and then after rubbing their hands with aqueous alcohol solution. Bacterial species were isolated and measured in colony forming units (CFU).
RESULTS: Fourteen of 17 subjects (82.4%) had bacterial growth on baseline cultures with an average CFU of 236.5 ± 318.5. Coagulase negative staphylococcus was the predominant microorganism (76.5%). Other bacteria isolated were Neisseria flavescnens, bacillus species, and corynebacterium species. All cultures were negative following both the five minute chlorhexidine scrub and rubbing with aqueous alcohol solution.
CONCLUSIONS: Hand rubbing with aqueous alcohol solution appears unnecessary immediately following a five minute scrub with a chlorhexidine brush. Future studies to help further evaluate the issue may include obtaining cultures and colony count comparisons between soap and alcohol scrub groups one hour after the initial scrub and/or at the outset of the second case, as this is where alcohol scrubs are most commonly used. MAOA BREAKOUT SESSION #8 TUMOR/BASIC SCIENCE/EDUCATION April 24, 2009
101. Sub Iliacus Approach for Periacetabular Biopsy Peter J. Buecker, M.D. (n) Louisville, KY *David Chen, M.D. (n) Louisville, KY
INTRODUCTION: Current approaches for surgical biopsy of periacetabular lesions of the pelvis are often extensive and potentially morbid. A less invasive method for biopsy of such lesions with minimal risk of tumor contamination would seem beneficial. We describe two clinical cases and present cadaveric dissection data on such an approach.
METHODS: We dissected four whole body fresh tissue pelves through the first window of the ilioinguinal approach. Using the intersection of two radiographic lines for positioning, we made a small corticotomy in the ilium and passed an angled curette anteriorly, superiorly, and posteriorly to the acetabulum. The size and intrapelvic position of the corticotomy was recorded. Radiographic accessibility of all desired periacetabular loci was confirmed with extensive cadaveric dissection.
RESULTS: All eight iliac corticotomies were able to access all desired periacetabular locations. The mean size of the incision was 7 cm and the corticotomy was 2.0 x 1.7 cm. Its position averaged 20 mm posterior to the anterior inferior iliac spine (AIIS) on the line connecting the AIIS to the anterior border of the sacroiliac joint, and averaged 47 mm inferior to the anterior superior iliac spine (ASIS). Two patients are presented who underwent biopsy in this fashion. Both were fully ambulatory without assistive device and were discharged home on the first postoperative day.
CONCLUSION: The first window of the ilioinguinal approach to the acetabulum provides a familiar approach where the surgeon can use radiographic lines to find a safe corticotomy position to biopsy periacetabular lesions with less associated morbidity and potential tumor contamination than previously described biopsy approaches. 102. Diagnosis of Intramuscular Hemangioma: MRI Is Not Enough *Peter J. Buecker, M.D. (n) Louisville, KY
OBJECTIVE: To identify the frequency with which intramuscular hemangioma (IH) was omitted from consideration in differential diagnosis on MRI in histopathologically proven cases.
METHODS: Retrospective review of a consecutive series of biopsy proven cases of IH. Comparison of differentials made by musculoskeletal (MS) versus non specialist radiologists and interpretation with and without contrast enhancement was made. Review of diagnosis by clinician with clinical exam in addition to MRI was also evaluated.
RESULTS: Twenty one cases were identified. 7/10 scans reported by MS radiologists included IH in the reported differential versus 5/11 by non specialist radiologists. 9/15 reports correctly included IH after contrast enhancement compared with 0/6 without. Clinical evaluation resulted in 19/21 correct diagnoses. One patient clinically diagnosed with IH was proven to be incorrect after biopsy.
CONCLUSION: IH should be considered in differentials of enigmatic soft tissue masses. Contrast enhancement appears to aid in their identification. Clinical evaluation is essential to the ultimate diagnosis of intramuscular hemangioma. Therefore, open communication must exist between the radiologist and ordering clinician.
103. ♦Porous Tantalum Acetabular Implants in Patients with Periacetabular Tumors Undergoing Total Hip Arthroplasty *Fazel A. Khan, M.D. (n) Rochester, MN Michiro Yanagisawa, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN Franklin H. Sim, M.D. (n) Rochester, MN
BACKGROUND: Acetabular reconstruction in patients with periacetabular tumors undergoing total hip arthroplasty (THA) may be challenging due to bone loss and prior irradiation. Porous tantalum acetabular implants have performed well in other scenarios involving bone loss and irradiation. We hypothesized that such implants might also be successful for periacetabular tumors.
METHODS: A joint registry search identified 16 patients with periacetabular tumors who underwent THA with porous tantalum implants with minimum two year follow up (for surviving patients). Acetabular reconstruction followed tumor curettage and consisted of an uncemented porous tantalum shell. When required for mechanical stability, additional screws, porous tantalum augments, pelvic plate, and/or a cup cage construct was added. Clinical and radiographic results were reviewed.
RESULTS: 14/16 patients underwent primary THA. 14/16 patients had prior periacetabular irradiation. Mean survival was 2.4 years. Mean follow up length for all patients was 20.8 months. There were 4 Class I, 3 Class II, and 7 Class III Harrington defects. Revision cases included 1 Type 2 and 1 Type 4 AAOS defects. Acetabular reconstruction consisted of cup only (4 cases), cup plus plate (1), cup plus cage (5), cup plus augment plus plate (1), cup plus augment (4), and cup plus augment plus cage (1). At latest follow up, pain was improved in 10 patients, unchanged in 3 (3 unknown); ambulation was improved in 10 patients, unchanged in 2, worsened in 1 (3 unknown); mean Harris Hip Score improved from 41 to 82. Radiographs demonstrated no cases of loosening and no progression of radiolucent lines.
CONCLUSION: At short term follow up, porous tantalum acetabular implants, appropriately augmented to achieve sound initial mechanical stability, appear effective in patients with periacetabular tumors undergoing THA. Longer term data is needed. 104. Massive Pigmented Villonodular Synovitis of the Knee *Trevor R. Banka, M.D. (n) Detroit, MI Michael P. Mott, M.D. (n) Detroit, MI Theodore W. Parsons, M.D. (n) Detroit, MI Theodore Mayer, M.D. (n) Detroit, MI Marnix Van Holsbeeck, M.D. (n) Detroit, MI
Patients with massive PVNS about the knee (defined as presence of significant intra and extra articular tumor extension in both the anterior and posterior compartments and bone erosions) were identified. Swelling, pain, palpable masses, and limited range of motion were common presenting complaints. MRI was used to define the extent of the disease and map the course of the neurovascular bundle.
Histologically, sheets of eosinophilic tumor cells were noted with granular cytoplasm and vesicular nuclei. All had significant hemosiderin deposition, foamy histocytes, and tendon invasion. One patient had active disease exhibiting a great number of foamy histocytes, fibroblast proliferation, and necrosis. A second had a burned out form with dense fibrous tissue and few giant cells. The third had a malignant form with variable numbers of neutrophils, mature plasma cells, and scattered lymphocytes without notable areas of necrosis. Clinically, this patient had ongoing systemic issues with malaise and anemia.
Treatment consisted of open, anterior, and posterior staged synovectomies combined with a total knee arthroplasty in a patient with end stage arthritis. The patient with malignant PVNS diagnosed after TKA performed elsewhere underwent an above the knee amputation. All patients noted considerable improvement of symptoms (subjective pain relief) with resolution of anemia and malaise when present.
Massive PVNS of the knee appears to result from neglected disease and may present with both intra and extra articular involvement as well as significant degenerative changes about the knee. Definitive biopsy in these patients seems prudent to correctly diagnose the rare malignant form of the disease and afford the potential for appropriate intervention. 105. A Study In Vivo of the Effects of a Static Compressive Load on the Proximal Tibial Physis in Rabbits *Andrew Bries, M.D. (n) Akron, OH Dennis S. Weiner, M.D. (n) Akron, OH Mark J. Adamczyk, M.D. (n) Akron, OH Michael J. Askew, Ph.D. (n) Akron, OH Walter Horton, Jr., Ph.D. (n) Rootstown, OH William Landis, Ph.D. (n) Rootstown, OH
INTRODUCTION: Many pediatric disorders are directly related to abnormalities of the growth plate and its response to environmental influences. This study intends to define biochemical and other responses of the growth plate to compression, that is, the Heuter Volkman principle, at the cellular level.
METHODS: Static compressive loads (10 and 30N) were applied for 2 or 6 weeks across proximal tibial physes of 12 week old female New Zealand white rabbits (n = 24). The contralateral hind leg in all rabbits underwent a sham surgery with no load to serve as an internal control. Harvested physes were divided into portions for histology, immuno histochemistry, and quantitative gene expression.
RESULTS: No histological changes were found after two weeks of physeal compression. After six weeks of compression, physes had shorter, disorganized chondrocyte columns in the proliferative and hypertrophic zones compared to controls and literature reports. Evaluation of immunohistochemistry and gene expression for aggrecan, types II and X collagen, and apoptosis markers is ongoing in additional work.
DISCUSSION/CONCLUSION: This study will help determine if increased compressive forces at a physis cause changes in matrix constituents critical to cartilage biochemistry and structure and leading to greater insight and understanding of growth plate physiology. 106. Advanced Bone Regeneration Using an Injectable CaSO 4/CaPO 4 TCP Composite Compared to Autogenous Bone Graft Substitute in a Canine Model Robert M. Urban, B.A. Chicago, IL (a,b,e Wright Medical Technology) Thomas M. Turner, Ph.D. Chicago, IL (a,b,e Wright Medical Technology) *Deborah J. Hall, B.S. (n) Chicago, IL Erica L. Dahlmeier, B.S. (n) Chicago, IL Nozomu Inoue, M.D. (n) Chicago, IL Steven Gitelis, M.D. (n) Chicago, IL
HYPOTHESIS: CaSO 4/CaPO 4 TCP composite bone graft substitute results in a greater amount and strength of regenerated bone compared to cancellous autograft in a canine critical sized bone defect.
METHODS: Twenty dogs had a contained medullary defect created axially in the proximal humerus. In ten dogs, the defect was treated with CaSO 4/CaPO 4 TCP composite bone graft substitute (PRO DENSE, Wright Medical) and studied for 13 weeks (N=5) and 26 weeks (N=5). In the other ten dogs, the defect was treated with autograft bone and followed for 13 weeks. An additional ten unoperated humeri were used to establish the morphological and mechanical properties of normal canine bone in the region of the experimental defect.
PROCEDURES: The area fraction, ultimate compressive stress, and modulus of elasticity of bone in the treated defects and in the comparable region of normal humeri were quantified using histomorphometric and mechanical methods. The results were analyzed using the Mann Whitney test.
RESULTS: Radiographically, the bone graft substitute was evident at 6 and 13 weeks, and a small amount persisted after 26 weeks. At 13 weeks, the amount, strength, and stiffness of regenerated bone in the defects were several fold greater (p=0.005) using CaSO 4/CaPO 4 TCP graft compared to defects treated with cancellous autograft bone and several fold greater (p=0.009) compared to normal bone. However, there was no difference in the modulus of elasticity. Although the compressive stress was still greater (p=0.047) at 26 weeks for defects treated with the composite bone graft substitute compared to normal bone, the regenerated bone had remodelled to a normal cancellous architecture.
SIGNIFICANCE OF FINDINGS: CaSO 4/CaPO 4 TCP graft produced a several fold greater amount and strength of regenerated bone than autologous bone graft at 13 weeks. This synthetic bone graft substitute holds promise for non load bearing applications where dense, strong bone formation at earlier time points would be advantageous, potentially resulting in quicker return to activity. 107. Metaphyseal Fracture Strength as a Better Measure of Bone Quality in Osteoporosis Qian Xu, M.S. (n) Louisville, KY *Michael J. Voor, Ph.D. Louisville, KY (a Pradama, Inc.) Kevyn Merten, Ph.D. Louisville, KY (e Pradama, Inc.) Kathleen Hamilton, B.S. (n) Louisville, KY Sheena Duncan, M.S. (n) Louisville, KY Kendra Stone, M.S. (n) Louisville, KY Jeff Falcone, Ph.D. (n) Louisville, KY William M. Pierce, Ph.D. Louisville, KY (d Pradama, Inc.)
To study three common treatments to prevent bone loss in osteoporosis, an ovariectomized rat model was used to evaluate bone quality. The hypothesis was that new test methods which focus on the metaphyseal bone are more sensitive to important group differences.
Forty one female Sprague Dawley rats (5.5 months old) were used. Seven groups were based on treatment and time of sacrifice: sham control (SHAM)(W5&11), OVX control (OVX)(W5&11), OVX+Alendronate (ALEN)(W11), OVX+17 Ethinyl Estradiol (E2)(W11), and OVX+Teriparatide (PTH)(W11). Starting five weeks after OVX, drugs were given three times per week for six weeks.
Left femora were tested to failure in three point bending. Right femoral density was measured using Archimedes’ method of underwater weight. Left tibiae were trimmed and an indentation test was performed by advancing a flat tipped cylindrical post (1.5 mm diameter) axially into the proximal metaphysis. The right tibiae were tested in three point bending using a test fixture that produced a metaphyseal fracture pattern. Density and strength were analyzed by ANOVA and post hoc t tests.
Femoral three point bending did not show any significant differences between any groups (p=0.26). Archimedes’ density showed a significant difference between SHAM and OVX at 11 weeks (p<0.01), but the difference was only 4.2%. Indentation tests showed multiple significant differences; with PTH providing a 50% increase over OVX (p<0.05). The metaphyseal bending test showed significant increases (over OVX 5W) for ALEN and PTH of 42% (p<0.01) and 87% (p<0.005) respectively.
Density and three point bending strength of rat femora were unable to show much difference, if any, between SHAM, OVX, or the three drug treatment groups. However, when cancellous bone indentation and metaphyseal three point bending tests were used, significant differences were seen, with PTH and ALEN outperforming E2. Thus, a more sensitive measure of bone quality can be made when the focus is the metaphysis (site of most fragility fractures) where cancellous bone architecture dominates.
108. A Prospective Functional and CT Analysis of a Calcium Sulfate/Calcium Phosphate Composite Graft in Proximal Tibial Fractures William M. Ricci, M.D. St. Louis, MO (a,c,e Wright Medical Technology) J. Tracy Watson, M.D. St. Louis, MO (a,c,e Wright Medical Technology) Joseph Borrelli, M.D. Dallas, TX (a,c,e Wright Medical Technology) Robert Choplin, M.D. Indianapolis, IN (a,c,e Wright Medical Technology) Scott Persohn, LRTRCT Indianapolis, IN (a,c,e Wright Medical Technology) Timothy Weber, M.D. Indianapolis, IN (a,c,e Wright Medical Technology) *Christiaan Mamczak, D.O. St. Louis, MO (a,c,e Wright Medical Technology) Rena White Arlington, TN (a,c,e Wright Medical Technology)
INTRODUCTION: The efficacy of various graft materials to resist progressive collapse and to support subchondral bone, as well as the quality and quantity of bone regeneration, remains largely unstudied in the tibia. The purpose of the present study is to evaluate a new composite graft material with respect to its ability to resist collapse and promote bone growth.
MATERIALS AND METHODS: Twenty six patients with unilateral tibial plateau fractures were enrolled in a prospective multicenter single cohort study. The protocol included ORIF and defect augmentation with a composite bone graft substitute. Patients underwent CT scanning in the immediate postoperative period and at 12 weeks. Functional outcome was assessed using the SMFA scores. CT analysis quantified maintenance of reduction and density of the graft.
RESULTS: Thirteen of the 26 enrolled patients were followed at 12 weeks based on their time out from surgery, with none lost to follow up. Maximum depression and fracture gap measurement did not change from the immediate postoperative scan. Mean maximum depression for all seven patients was 1 mm. Density measures showed the material approximating that of bone at 964 Hounsfield units. SMFA scores improved from 44.27 at baseline to 36.54.
CONCLUSIONS: Histologic studies in animals with this material have shown more new bone versus autograft at 13 weeks. This pilot study is aimed at determining whether initial results support the laboratory conclusion. CT evaluation showed the material retains perioperative reduction, while postoperative approximation of the material’s density to bone suggests regeneration. 109. A Novel Titanium Foam for Orthopedic Load Bearing Applications David D. Waddell, M.D. Shreveport, LA (a,e Genzyme Biosurgery Corp.; a,c,e Wright Medical Technology) Dirk Scholvin, M.S. Arlington, TN (e Wright Medical Technology) Richard Obert, M.S. Arlington, TN (e Wright Medical Technology) Jon Moseley, Ph.D. Arlington, TN (e Wright Medical Technology) Mike Carroll, B.S. Arlington, TN (e Wright Medical Technology) Robert M. Urban, B.A. Chicago, IL (a Wright Medical Technology) Thomas M. Turner, Ph.D. Chicago, IL (a Wright Medical Technology) Debra J. Hall, B.S. Chicago, IL (a Wright Medical Technology) (Presented by J. David Blaha, M.D., Ann Arbor, MI)
BACKGROUND: A novel 60 70% open porous titanium material was developed to serve as a scaffold for bone ingrowth in load bearing orthopedic applications.
METHODS: In order to evaluate this material, tests were conducted to determine the mechanical properties, chemical composition, adherence to a titanium alloy substrate, and in vivo performance in metaphyseal and transcortical canine models.
RESULTS: Ultimate compressive and flexural strength was shown to be dependent on porosity, with compressive strength reaching 79 93 MPa at ~70% porosity and 141 MPa at 64% porosity. The compressive modulus ranged from 2.5 GPa to 3.8 GPa. Flexural strength of samples near 70% porosity was in excess of 100 MPa. Abrasion resistance of the porous titanium coating per FDA guidance was found to be equivalent to that of porous bead coatings while exceeding the abrasion resistance of titanium plasma spray coatings. The coefficient of friction of the titanium foam was higher than that of porous bead coatings and equivalent to that of plasma spray coatings. Both lap shear and tensile pull off tests of porous titanium coated Ti6Al4V substrates resulted in adhesive tape failures greater than 40 MPa, exceeding the minimum strength requirement of 20 MPa set by the FDA. Elemental composition of the porous titanium was shown to be equivalent to that of porous titanium bead coatings. The canine studies showed rapid bone ingrowth and integration of the porous titanium specimens in both trabecular and cortical bone .
CONCLUSIONS: The extensive testing performed on this new porous titanium implant material has shown that it is an excellent choice for both orthopedic implant coatings and stand alone implants. 110. Implementation and Impact of a Medical Team Training Program in the Veterans Health Administration *Brian T. Carney, M.D. (n) White River Junction, VT Julia Neily, R.N. (n) White River Junction, VT Peter D. Mills, Ph.D. (n) White River Junction, VT
BACKGROUND: To improve staff communication and patient outcomes, the Veterans Health Administration (VHA) is conducting Medical Team Training (MTT). The program consists of: facility preparation by conference calls starting two months before a Learning Session, formation of a facility implementation team, training at an all day Learning Session, performance of project(s) by the facility to include briefings and debriefings in the operating room, and follow up interviews for one year after the Learning Session. The purpose of this study was to review the initial results of these interviews.
METHODS: Interviews of the first 23 facilities to complete the MTT program were reviewed. A semi structured quarterly interview template was used to generate a summary report. Facility implementation and impact from 90 interview summaries was classified by consensus of three reviewers.
RESULTS: One year after the LS, all except one facility were implementing briefings and debriefings to some degree; 26% had done so for “all cases in all services”. The self reported final impact of the program on patients and staff was highest in facilities that were briefing/ debriefing "all cases in all services". Improved safety was reported by 61% of facilities; 10 avoided an undesirable event. Improved teamwork was reported by 91% of facilities; 10 improved staff communication. Improved quality was reported by 91% of facilities; 16 changed a process of care. Improved efficiency was reported by 96% of facilities; 21 improved equipment utilization.
CONCLUSIONS: Higher impact of the program on patients and staff was reported with higher implementation. Facilities reported improvements in safety, teamwork, quality, and efficiency. 111. Functional Outcomes Assessment of Patient Care as a Tool for Resident Education *Marc F. Swiontkowski, M.D. (n) Minneapolis, MN Julie Agel (n) Minneapolis, MN
PURPOSE: Residency experience should provide an opportunity to learn the impact of treatment on patient function. Use of a validated HRQOL instrument will familiarize residents with the process of patient outcomes assessment which will be useful in future MOC and P4P efforts.
METHODOLOGY: G4 orthopedic surgery residents approached 20 patients prior to operative treatment of their musculoskeletal condition to complete a Short Form Musculoskeletal Assessment. This validated 46 item questionnaire allowed patients to document their function. At three months, patients were mailed a follow up questionnaire to document their short term functional change.
RESULTS: Over four years, 19 residents handed out 335 questionnaires. The majority of patients were from a VA Hospital, the most common diagnoses were degenerative joint disease of the hip or knee or carpal tunnel syndrome. Fifty six percent of the patients returned their second questionnaire. SMFA scores for the three largest patient population groups were: Baseline SMFA Postop SMFA Hip Arthritis 47 35 Knee Arthritis 40 30 Carpal Tunnel 42 42
CONCLUSIONS: Residents often do not see the patients over the long term recovery process. These questionnaires were returned to the treating resident to give them a sense of the quality of short term recovery for a small group of patients. The results are reported to individual residents along with aggregate data in an annual grand rounds format. The discussions which follow regarding the relative improvement of groups of patients with similar diagnoses, as well as individual patients have been revealing. Residents have appreciated the experience, learned how medical comorbidity has a large impact on functional outcome, lower extremity conditions have greater group related functional impact than upper extremity conditions due to weight bearing/mobility issues and the lack of contralateral extremity adaptability for specific functions. The exercise requires setting up a system to support the collection of data forms and patient contact for the post intervention functional assessment. 112. Safety Attitudes of Surgical Teams Are Associated with Gender and Profession *Brian T. Carney, M.D. (n) White River Junction, VT Julia Neily, R.N. (n) White River Junction, VT Peter D. Mills, Ph.D. (n) White River Junction, VT
BACKGROUND: Achieving a culture of safety is believed to be an important mechanism for improving patient safety. The Safety Attitudes Questionnaire (SAQ) measures provider perceptions of patient safety culture across six domains; higher scores denote more positive perceptions. While professional differences on the SAQ have been explored, gender differences have not.
METHODS: The SAQ was completed by 187 surgical care providers at nine VA Medical Facilities immediately before a medical team training learning session.
RESULTS: Anesthesia providers had a better understanding of the effects of stress on performance than both surgeons and nurses. Nurses had lower perceptions of working conditions than surgeons. When compared to males, females had lower perceptions of teamwork climate, job satisfaction, management, and working conditions. In regression modeling, female gender independently contributed to lower perceptions of job satisfaction, management, and working conditions.
CONCLUSION: Prior to beginning patient safety oriented team training, we found profession and gender related differences in patient safety attitudes within surgical teams. Educational efforts designed to enhance patient safety should be designed so that they address such differences. MAOA BREAKOUT SESSION #9 JOINT REPLACEMENT April 24, 2009
113. Total Knee Replacement for Osteoarthritis in Patients 55 Years of Age and Under: Are We Doing as Well with Modular Components? *Andrew Odland, B.S. (n) Iowa City, IA John J. Callaghan, M.D. Iowa City, IA (c,e DePuy) Steve S. Liu, M.D. (n) Iowa City, IA
BACKGROUND: Encouraging mid term results have been reported in younger patients (under age 55) with osteoarthritis who undergo total knee arthroplasty. Most of these studies have been performed with non modular tibial components. The purpose of this study was to evaluate the minimum 10 year follow up of total knee arthroplasty performed in patients 55 years of age and under using modular tibial components with polyethylene that was sterilized with gamma irradiation in air.
METHODS: Fifty nine patients (69 knees) with osteoarthritis underwent primary total knee arthroplasty using posterior cruciate retaining (20%) or posterior cruciate substituting (80%) components which had modular tibial trays between 1990 and 1998 by a single surgeon. Patients were evaluated clinically for need of revision and by obtaining SF 12 and WOMAC outcome scores as well as UCLA and Tegner activity scores. Radiographs were evaluated for loosening and osteolysis.
RESULTS: At minimum ten year follow up, 10 patients (12 knees) were deceased and 41 patients (57 knees) were living. Minimum 10 year radiographs were obtained on 70% of patients. Seven knees were revised for aseptic loosening (2) or osteolysis (5). Four other knees demonstrated radiographic evidence of osteolysis on minimum ten year radiographs. Sixty percent of patients were still performing moderate labor or sports activities.
CONCLUSION: At minimum ten year follow up of modular total knee replacement in this active young population, 7 knees (10.1%) required a revision for aseptic loosening (2, 2.8%) or osteolysis (5, 7.3%). This is higher than the prevalence reported for total knee replacement using monolithic tibial components in patients 55 years of age or younger. It is this population where differences in design and materials may demonstrate differences in clinical results and radiographic long term durability.
114. Projection of the Cost of Implant Surveillance After Total Joint Arthroplasty in the United States Saju Rajan, B.S. (n) St. Louis, MO Amanda Schutz, Ph.D. (n) St. Louis, MO *John C. Clohisy, M.D. St. Louis, MO (a Wright Medical Technology)
INTRODUCTION: There is a projected major increase in the need for total joint replacement over the next three decades. Nevertheless, routine clinical follow up protocols have not been established, and the cost of implant surveillance is not well known. The purpose of this study was to project the cost of providing implant surveillance for THA and TKA patients in the US healthcare system.
METHODS: The cost of a follow up visit after TKA or THA was approximated by establishing the amount allowable by Medicare. This information was combined with predictions of total hip and knee replacements until 2030 to project the aggregate cost of long term follow up. An expected mortality rate of 3.5% was assumed for these estimates. Projected costs (in 2008 dollars) were calculated based on patients following up annually and every other year.
RESULTS: The Medicare allowable cost of a follow up visit after TKA was $107.88 and after THA was $112.29. If follow up is performed annually, the average cost per year until 2030 to provide follow up care after TKA will be $1.75 billion (in 2008 dollars). THA follow up cost would average $570 million per year until 2030. Collectively, TKA and THA follow up would cost $2.32 billion per year. Performing follow up every two years would cost $870 million per year (TKA) and $285 million per year (THA), respectively.
CONCLUSIONS: These results illustrate the magnitude of the cost to conduct routine surveillance of hip and knee implants. These data suggest that cost effective arthroplasty surveillance programs need to be developed. 115. Treatment of Acute Hematogenous Infection in Total Joint Arthroplasty Jeffrey K. Burns, M.D. (n) Chicago, IL *Beau S. Konigsberg, M.D. (n) Omaha, NE Craig J. Della Valle, M.D. Chicago, IL (a,b,c,e Zimmer; b Smith & Nephew, Stryker) Richard A. Berger, M.D. Chicago, IL (a Smith & Nephew; a,c,e Zimmer) Aaron G. Rosenberg, M.D. Chicago, IL (a,c,d Zimmer)
INTRODUCTION: Infection is a devastating complication following joint replacement. There is minimal information presently available to assist the practicing orthopedic surgeon in appropriate management. The goal of this study is to review our experience with treating acute hematogenous infections.
METHODS: We identified 36 patients (37 joints; 19 knees, 18 hips) with an acute hematogenous infection following joint replacement. Inclusion criteria mandated that the patients had to be a minimum of six months postoperative (to avoid including acute post operative infections), have well fixed components, systemic signs of infection, or an obvious hematogenous source. All patients were treated with irrigation and debridement with exchange of the modular components followed by six weeks of intravenous antibiotics and a variable course of oral antibiotics. Minimum follow up was two years. Success was defined as component retention at two years.
RESULTS: At two year follow up, eight patients had died (22% of the cohort), seven with their implants retained. Of the 28 living patients, 24 (86%) retained their components at an average follow up of 43 months (range 26 82). The average duration of symptoms before surgical debridement was 5.3 days (range 1 28). The average time between index arthroplasty and surgical debridement was 52 months (range 6 182). The average HHS/KSS for those with retained implants was 83.1 (range 55 97.9) at most recent follow up.
DISCUSSION: Irrigation and debridement for the treatment of an acute hematogenous infection was associated with implant retention in the majority of patients (86%). The mortality rate among this subset of patients was strikingly high at two years. 116. Four to Six Year Follow Up of Primary Total Hip Arthroplasty Using a Contemporary Titanium Tapered Stem *Arun Reddy, B.S. (n) Iowa City, IA David Hennessy, B.S. (n) Iowa City, IA John J. Callaghan, M.D. Iowa City, IA (c,e DePuy) Peter Bracha, B.S. (n) Iowa City, IA Steve S. Liu, M.D. (n) Iowa City, IA Devon D. Goetz, M.D. (n) West Des Moines, IA
BACKGROUND: Tapered cementless femoral components have been utilized in the total hip arthroplasty construct using either porous surfaces or grit blasted surfaces for bone ingrowth or on growth for close to 20 years. It has only been recent, the last 5 10 years, that these stems have gained tremendous popularity in the United States. The purpose of this study was to evaluate the 4 6 year follow up of our initial experience using a contemporary tapered, proximally porous coated titanium femoral component.
METHODS: Eighty six patients underwent 100 total hip replacements using a contemporary tapered titanium proximally coated femoral component (Summit, DePuy, Warsaw, IN) and a Pinnacle (DePuy, Warsaw, IN) acetabular component. Average age at the time of surgery was 60.4 years (range 25 90). Patients were prospectively followed for 4 6 years or until death. Patients were evaluated clinically for need of revision and using SF 12 and Harris Hip ratings. Radiographs were evaluated for femoral loosening and osteolysis.
RESULTS: At 4 6 year follow up, no hips have been revised for femoral or acetabular loosening. One hip required revision for dislocation. Minimum four year radiographs demonstrate bony ingrowth of all femoral components. There is no evidence of osteolysis on radiographs (crosslinked polyethylene was used in all cases). One patient complains of significant thigh pain.
CONCLUSION: At 4 6 year follow up, this contemporary titanium tapered femoral component has performed well with all stems obtaining bony ingrowth and no revisions for aseptic loosening. These results encourage us to continue using cementless tapered stems. 117. Predicting Patient Discharge Disposition in the United States Following Total Joint Arthroplasty *Sara Lyn Miniaci, B.S. Cleveland, OH (a Arthrex; a,c,e Arthrosurface; a Breg; a DJ Ortho; a,e Stryker; c Tenet, Zimmer) Alison K. Klika, M.S. (n) Cleveland, OH Trevor G. Murray, M.D. (n) Cleveland, OH Brian Wells, M.D. (n) Cleveland, OH Michael W. Kattan, M.D. (n) Cleveland, OH Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew, Zimmer; a,b,e Stryker; c Exactech; c,e SS White, Wright Medical Technology; e Otismed)
INTRODUCTION: Appropriate discharge planning can reduce length of stay and improve patient satisfaction after total joint arthroplasty (TJA). We have developed and reported on our model, named the Predicting Location after Arthroplasty Nomogram (PLAN), used to preoperatively predict discharge disposition following TJA. The purpose of this study was to externally validate this model, using data collected from one large academic center and two community based hospitals, all within a single health system in the United States.
METHODS: Using the CPT frequency report available through our Operating Room Information System (ORIS), all surgeries for CPT codes 27447 (primary TKA), 27130 (primary THA), 27134 and 27137 (revision THA), 27486 and 27487 (revision TKA), and bilateral TKA were reviewed from May 1, 2007, to April 30, 2008. The first ten cases of each type of procedure were chosen to review (50 cases at each institution). The PLAN was applied to each patient and a predicted discharge disposition was determined and compared to the actual discharge disposition. Discrimination was quantified using the concordance index, which represents the ability of the model to accurately assign a higher risk to the patient not discharged home for every possible discordant pair of patients.
RESULTS: The calculated concordance index for the external validation sample was 0.861 (95% confidence interval 0.797 – 0.914). The accuracy of the development sample was similar, with a calculated concordance index of 0.867 (95% confidence interval 0.840 0.895).
DISCUSSION: The PLAN, with a concordance index of 0.861 and excellent calibration calculated by external validation, appears to be accurate and may be a useful tool to more efficiently plan a patient’s discharge and effectively counsel patients regarding expectations for their discharge following total joint arthroplasty. 118. Inter and Intra Observer Variability of Preop Navigation – A Cadaveric Validation Study *David K. DeBoer, M.D. Nashville, TN (a,e Wright Medical Technology) C. Lowry Barnes, M.D. (n) Little Rock, AR J. David Blaha, M.D. (n) Ann Arbor, MI Brad L. Pennenberg, M.D. (n) Beverly Hills, CA Richard Obert, B.S. (n) Nashville, TN Paul Stemnenski, B.S. (n) Nashville, TN
INTRODUCTION: Computer navigation repeatability is often cited as a benefit over standard instrumented methods in Total Knee Arthroplasty (TKA). Initial capital cost and added OR time are two drawbacks for computer assisted tracking systems. An alternative approach is to preoperatively prepare a patient specific alignment guide based on CT or MRI data. The repeatability of such guides has not been studied to date. This experiment attempts to quantify the inter and intra observer repeatability of guide placement and deviation relative to the planned orientation.
METHODS: A CT scan of a cadaver lower extremity was obtained and converted to a 3D solid computer model. A virtual total knee replacement was performed on the femur and a custom alignment guide was created that uniquely positioned the femoral component in the virtually determined orientation. The specimen was placed in a surgical rig and infra red (IR) markers were attached to the femur and registered on a motion tracking system. Placement and registration of the guide was performed by four orthopedic surgeons, in rotation, a total of 16 times. Variation of the guide position was calculated between each trial.
RESULTS: Angular variation between all trials was 1.18° ± 1.20° in flexion and 0.5° ± 0.74° in varus/valgus. Intra observer variation was between 0.10° and 1.22°. Rotational placement of the guide was 1.75° ± 1.37°. Intra observer variation was less than 2.53°.
DISCUSSION: The results obtained by this study indicate the positional and rotational position of a custom pin placement guide is repeatable. The precision exceeded 1° in all but one case for rotational alignment and the accuracy was better than 3°. With the ability to accurately determine landmarks on a computer model of the bone, the accuracy and repeatability of the guide position would be expected to exceed 3° more frequently than traditional instrumentation. 119. Complications Associated with Early Anticoagulation in Total Joint Arthroplasty Patients Diagnosed with Venous Thromboembolic Disease *Ryan W. Patterson, M.D. (n) Cleveland, OH Nicholas Papakonstantinou, M.D. (n) Cleveland, OH Mark I. Froimson, M.D. (n) Cleveland, OH
BACKGROUND: Venous thromboembolism (VTE) in total joint arthroplasty (TJA) patients is associated with significant morbidity and mortality. However, treatment with anticoagulation (AC) is associated with a high rate of complications. We reviewed TJA patients who were treated for VTE in the early postoperative period (mean of 2.3 days after surgery).
METHODS: A retrospective review of 829 patients who underwent hip or knee TJA over a one year period was performed. Twenty nine patients diagnosed with a VTE were identified for an incidence of 3.5%.
RESULTS: Treatment of VTE began at a mean of 2.3 days after surgery (range 0 6 days) and consisted of heparin drip in 23 (79%) patients, Lovenox in 4 (14%), and IVC filter without full AC in 2 (7%); all were transitioned to Coumadin. The most common complication was anemia: 48% and 14% had a hemoglobin less than 8 and 7 g/dL, respectively. All had overt bleeding (Bleeding index [BI] > 2) with mean BI=9.7 and received a mean of 4.4 units of packed red blood cells (PRBCs). Starting AC within three days of surgery was associated with receiving 2.6 units more PRBCs (p=0.01). Ten (34%) and 13 (45%) had a supratherapeutic INR and PTT, respectively. Wound hematoma occurred in 9 (31%), cellulitis in 4 (14%), wound drainage in 14 (48%), and 3 (10%) underwent re operation. Other bleeding complications included a superior gluteal hemorrhage requiring embolization, retroperitoneal hemorrhage, and vaginal and bladder bleeding. There was one death related to acute renal failure and retroperitoneal hemorrhage (began heparin drip on POD#2). VTE patients who received heparin had an additional 2.8 days longer length of stay (p=0.09). Wound infection was significantly associated with bleeding (p=0.05).
DISCUSSION: Treatment of VTE at a mean of 2.3 days postoperative had a high incidence of complications related to bleeding in TJA patients. This resulted in an increased risk of infection, length of stay, transfusions, and re operation. 120. ♦Novel Treatment of Failed Two Stage Revision for Periprosthetic MRSA Sepsis Corey Montgomery, M.D. (n) Little Rock, AR *Richard P. Evans, M.D. (n) Little Rock, AR
INTRODUCTION: MRSA incidence, resistance, and treatment failure rates continue to climb. Treatment of failed Vancomycin treatment of two stage reconstruction for periprosthetic MRSA sepsis remains very limited. Successful treatment of six cases of failed MRSA periprosthetic total hip and knee infections treatment are reported.
MATERIALS AND METHODS: Five total hip and one total knee periprosthetic MRSA total joint infections underwent two stage reconstruction using articulating Daptomycin/Tobramycin impregnated PMMA spacer and six weeks of 6 mg/kg IV Daptomycin. Five of these six cases had previously failed two stage reconstruction using Vancomycin impregnated PMMA spacers plus six weeks of intravenous Vancomycin. Three were mixed gram negative infections and concurrently treated with gram negative coverage antibiotics.
RESULTS: Five out of six patients had clearance of MRSA infection with an average follow up of one year.
CONCLUSION: Daptomycin may provide an alternative treatment protocol for two stage treatment of MRSA periprosthetic joint infections. 121. ♦Compression Strength and Porosity of Manufactured Single Antibiotic Loaded Cement Vacuum Mixed with Vancomycin *Hugh S. Brock, M.D. (n) Kansas City, KS Patrick G. Moodie, M.S. (n) Kansas City, KS Jamey L. Iverson, B.S. (n) Kansas City, KS Kelly J. Hendricks, M.D. (n) Kansas City, KS Terence McIff, M.D. (n) Kansas City, KS
INTRODUCTION: High doses of antibiotics are commonly mixed with bone cement for use during septic arthroplasty revision surgery. Antibiotics are detrimental to the strength of cement through an unknown mechanism whereas vacuum mixing has a beneficial effect by decreasing porosity. We hypothesized that the compression strength of manufactured single antibiotic cement decreases when vacuum mixed with increasing amounts of Vancomycin due to an increase in porosity.
METHODS: Samples were made by vacuum mixing incremental amounts of Vancomycin (2, 4, 6, and 8 g) with two manufactured single antibiotic cements, Palacos R + 0.5 g of Gentamicin (PRG) and Simplex P + 1 g Tobraymicin (SPT). They were then analyzed for pores with computed tomography before being tested on a materials testing machine to determine their compression strength. Additional samples were then fractured and surfaces analyzed for microporosity using scanning electron microscopy and for surface roughness by profilometry.
RESULTS: The ultimate compression strength (UCS) of PRG and SPT correlated negatively with increasing amounts of Vancomycin. At least 8 g could be added to PRG (UCS = 75.04 ± 3.32 MPa) and no more that 6 g to SPT (UCS = 82.67 ± 3.29 MPa) in order to maintain an UCS above the International Organization for Standardization (ISO) minimum standard (70 MPa) (p < 0.05). Porosity did not correlate with Vancomycin concentration, but surface roughness trended toward a direct relationship.
DISCUSSION: Our finding that antibiotics have a detrimental effect on the compression strength of manufactured single antibiotic cement is consistent with the literature; however, this effect is diminished compared to previous research employing hand mixing techniques. The detrimental effect antibiotics have on the compression strength of cement is not due to an increase in porosity. Greater surface roughness with higher Vancomycin concentrations could represent an interference with cement polymerization, explaining the decrease in strength.
122. Decreased Dislocation After Revision THA with Larger Femoral Head Size and Posterior Capsular Repair *Arthur L. Malkani, M.D. (n) Louisville, KY Matthew T. Hummel, M.D. (n) Louisville, KY Madhusudhan R. Yakkanti, M.D. (n) Louisville, KY Dale L. Baker (n) Louisville, KY
INTRODUCTION: Purpose of this paper is to determine if posterior capsular repair and use of larger femoral head size lead to decreased incidence of dislocation following revision THA.
METHODS: 242 consecutive revision THAs were performed between 2000 and 2005. Two cohorts were examined. Group I consisted of 132 consecutive revision THAs using posterior approach. Group I received 28 mm femoral head without repair of posterior capsule. Group II consisted of 110 consecutive revision THAs. Group II received 32 mm revision femoral head and underwent posterior capsular repair. Cohorts were compared with respect to several surgical parameters (EBL, OR time) as well as Harris hip scores, complications, and incidence of dislocation. Each patient had minimum of 12 months follow up.
RESULTS: There were no statistically significant differences found between the groups with respect to Harris Hip Scores, surgical EBL, OR time, and total complications. The only statistically significant finding occurred in dislocation incidence. Group I had a total of 14 dislocations or an incidence of 10.6%. Group II had a total of 3 hip dislocations for an incidence of 2.7% which was a statistically significant decrease from Group I (p<0.05).
DISCUSSION AND CONCLUSION: Posterior capsular repair has shown to decrease dislocation rate in primary THA. Revision THA has historically higher dislocation rate from secondary to multiple factors. Based on our review, use of larger femoral heads coupled with secure repair of remaining posterior capsular tissue has proven to decrease incidence of hip dislocation in revision surgeries .
123. Acetabular Cup Malalignment After Total Hip Resurfacing Arthroplasty: A Case for Elective Revision? *Matthew C. Mai, M.D. (n) Springfield, IL Joseph C. Milbrandt, Ph.D. (n) Springfield, IL D. Gordon Allan, M.D. (n) Springfield, IL
We present here the clinical course and explore the management decisions for a patient who underwent metal on metal (MOM) hip resurfacing arthroplasty, developed progressively elevated serum metal ion levels, and subsequently required revision of the failed prosthesis.
CASE AND FINDINGS: 49 year old female with avascular necrosis of the left hip that underwent resurfacing arthroplasty with a Cormet 2000 device in September 2002. She was incidentally enrolled in a study monitoring trace metal levels in patients undergoing hip arthroplasty. The resurfacing procedure was uneventful. However, postoperative evaluation revealed the acetabular cup position to be in an abducted and excessively anteverted position. Postoperative, the patient showed clear evidence of a significant reduction in pain and marked improvements in gait, range of motion assessments, and activities of daily living.
Serum trace metal analysis revealed progressively increasing serum cobalt (Co) and chromium (Cr) levels (microg/L); 37.9 and 13.9, respectively at six months to 62.8 and 27.2 at one year to 120.2 and 37.6 at two years. Year 2 Co levels were more than 400 times that observed in controls without implants (Co=0.28, Cr=0.32) and more than the 40 times the level observed in the typical patient with a Cormet 2000 device (Co=2.6 and Cr=3.7). Her creatinine clearance was 80 mL/min.
During the course of follow up, elective revision was considered due to the acetabular malalignment and elevated metal ion levels, but not performed since the patient was doing well clinically. Subsequently, 4.5 years after the resurfacing procedure the resurfaced joint acetabular component failed and a traditional total hip arthroplasty revision was performed.
CONCLUSIONS: This report explores factors useful in assessing the need for elective revision prior to failure under conditions such as poor cup position. In addition, is there benefit to monitoring of serum ion levels in these cases and could those results be taken into consideration when surgeons contemplate elective revisions to prevent later catastrophic failure? 124. Timing of Symptomatic Pulmonary Emboli Following Total Hip and Total Knee Arthroplasty *Neel P. Jain, M.D. (n) Chicago, IL S. David Stulberg, M.D. (n) Chicago, IL Tracie Jacobsen, B.S. (n) Chicago, IL
INTRODUCTION: The focus of deep vein thrombosis (DVT) prophylaxis following total joint arthroplasty has shifted in recent years to the reduction of symptomatic pulmonary emboli (PE). The relative infrequency and presumed delayed occurrence of these events has led many to suggest that the risks of more frequent early postoperative complications of treatment, especially bleeding, be weighed against the benefits of thromboembolic prophylaxis. The purpose of this study was to determine the timing and risk factors associated with the development of symptomatic PE following total hip arthroplasty (THA) and total knee arthroplasty (TKA).
METHODS: A retrospective analysis was performed of all patients diagnosed with a symptomatic pulmonary embolism following THA and TKA performed from January 2004 to March 2008. The records of 58 patients (out of approximately 3,000 operated upon by 7 surgeons) were examined. All patients were managed and treated by an anti coagulation dosing service. Helical CT Scans were used to make the diagnosis of PE.
RESULTS: 48 of the 58 patients (83%) were women. 33 patients (57%) had unilateral TKA, 14 (24%) had bilateral TKA, and 11 (19%) had THA. The average patient age was 65 (range: 44 88). The PE were diagnosed an average of 4 days (range: 1 46) following surgery. 56 of the 58 patients (97%) were diagnosed by the sixth postoperative day. The average INR at the time of diagnosis was 1.7 (range: 1.0 3.0). There were two mortalities (3%), both of which occurred within the first two postoperative days.
CONCLUSIONS: The PE in this study occurred predominantly in women undergoing TKA. There appears to be an urgent need to develop an effective prophylaxis program aimed at preventing PE in the early postoperative period and to identify patients at risk of these PE. MAOA BREAKOUT SESSION #10 PEDIATRICS/EDUCATION April 24, 2009
125. Effect of Direct Pars Repair in Adolescents with Spondylolysis on Adjacent Disk Morphology *Brian D. Kleiber, M.D. (n) Omaha, NE John W. McClellan, III, M.D. (n) Omaha, NE Kay Ryshon, M.S. (n) Omaha, NE Sarah Stamm, PA C (n) Omaha, NE
BACKGROUND CONTEXT: Spondylolysis is a unilateral or bilateral defect in the pars interarticularis, which results from acute trauma or repetitive microtrauma. Incidence in adults is estimated at 6% with onset most commonly in adolescence. It has been shown that spondylolysis induces motion changes in the affected lumbar level and the adjacent level above. Mechanically this may predispose one to disc degeneration. MRI imaging in one long term (45 year) study of patients with spondylolysis showed evidence of disc degeneration in nearly all patients. Direct repair of the pars interarticularis has been shown to normalize adjacent level motion and disc stresses.
PURPOSE: To show that pars repair spares the intervertebral disc and is associated with good clinical outcomes.
STUDY DESIGN/SETTING: Review of eight consecutive patients that underwent unilateral or bilateral pars repair by a single board certified orthopedic spine surgeon in private group practice between August of 2000 and January of 2007.
METHODS: Study candidates were identified by chart review. All patients had had symptomatic spondylolysis identified by computed tomography. Additionally, SPECT scans were obtained to determine if the lesion was active. Healing of the defect was confirmed with CT imaging. Patients who gave consent for the investigation were asked to return for follow up lumbar MRI studies. These scans were interpreted by an independent board certified radiologist. Clinical outcome was determined from chart review of subjective pain and return to sport/work.
RESULTS: The patients consisted of 5 males and 3 females with an age range of 13 to 19 (mean 16 ±6) at symptom onset. Four patients had bilateral defects and 4 had unilateral defects for a total of 12 defects. Average age at time of surgery was 17+1 (range 14 to 20). Patients were followed clinically post surgery for an average of 17 months. CT scans obtained during clinical follow up confirmed healing of 10 out of 12 (83%) treated pars defects. During the clinical follow up, 100% of patients were able to return to sports or work. One patient reported continued intermittent lumbar pain, the remaining patients reported no pain. Follow up MRI was obtained at an average of 50 months (range 10 to 88 months) from surgery and disc degeneration was classified according to the system outlined by Pfirrmann, et al. Preoperative MRI studies showed one Grade I disc and 7 Grade II. Only one of eight patients showed progressive disc degeneration on follow up MRI (1 with Grade I, 6 with Grade II, and 1 with Grade IV).
CONCLUSIONS: In this group of patients who underwent pars repair, clinical outcomes were good and disc morphology was largely preserved. 126. Analysis of 342 Consecutive Operative Pediatric Supracondylar Humeral Fractures *Shelley M. Oliver, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: The purpose of this study was to analyze the results of operatively treated pediatric supracondylar humeral fractures (PSHF).
METHODS: From March 2002 to September 2007, all operatively treated PSHF were retrospectively analyzed.
RESULTS: 342 total fractures with 171 males and 171 females were documented. The mechanism of injury was not significantly different in terms of gender or etiology. Associated injuries were 2 polytrauma, 2 traumatic brain injuries, 5 open injuries, and 19 (5.3%) brachial artery injuries. Sixteen (4.7%) children had ipsilateral fractures. Twenty seven (7.9%) children had associated traumatic neural injuries (14 anterior interosseous, 6 ulnar, 3 posterior interosseous, and 4 multiple). Timing of surgery was < 8 hours (140, 41%) and ≥ 8 hours (202, 59%). Type of surgery was closed reduction percutaneous pinning (CRPP) in 321 (94%) or open reduction internal fixation (ORIF) in 21 (6.1%). Pinning technique was lateral (78, 23%) or crossed (264, 77%). Complications were 5 malunion, 1 compartmental syndrome, 9 pin tract infection, 3 iatrogenic neural injury (all with crossed pins), 4 symptomatic scars, and 6 brachial artery occlusion. All 9 pin tract infections occurred in patients with pin removal at an average of 5 weeks compared to 4.2 weeks in patients without infection and 7 of 9 occurred in Medicaid patients, but was not affected by geographic distance from clinic. Range of motion averaged 148°. Unplanned secondary surgeries were 3 conversions to ORIF, 1 revision CRPP, 3 debridements, 1 exploration of brachial artery, 1 migrated pin removal, and 1 cheloid excision.
CONCLUSIONS: PSHF are common injuries that require precise stable reductions whether performed percutaneous or open with lateral or crossed pins. Even though no difference in quality of reduction was noted with crossed versus lateral pins, crossed pins can still result in transient iatrogenic nerve injury. Pin tract infections occurred when pins remained greater than five weeks and in lower socioeconomic class patients. 127. The Use of the Reconstruction Plate in Tibial Osteotomies in Children *Adam C. Schaaf, M.D. (n) Akron, OH Dennis S. Weiner, M.D. (n) Akron, OH Todd F. Ritzman, M.D. (n) Akron, OH Melanie A. Morscher, B.S. (n) Akron, OH
INTRODUCTION: External fixation and cross pin fixation appear to be the two most commonly used forms of fixation after a tibial osteotomy in children described in the literature. The purpose of this study is to describe our experience using a properly bent and contoured reconstruction plate for mismatched surfaces after tibial osteotomy.
METHODS: A retrospective review of all tibial osteotomy surgeries in children performed by a single surgeon using a reconstruction plate for internal fixation was performed from March 2000 to January 2008. A low fibular osteotomy and high tibial osteotomy that required contouring and shaping of the plate was performed in all cases. All cases were reinforced with a long leg cast. A total of 48 cases were included in our study.
RESULTS: A properly bent and contoured reconstruction plate was utilized effectively and conformed well to the mismatched surfaces after tibial osteotomy, usually valgus combined with external derotation. No deep infection, malunions, or nonunions were encountered. Additionally, no neurovascular complications occurred, including compartment syndrome.
DISCUSSION/CONCLUSION: The reconstruction plate in this study may be less strong than the standard compression plate, but it is very malleable and can be contoured to fit in nearly every direction to accommodate mismatched appositional surfaces. It has been successfully used in 48 consecutive cases of tibial osteotomy in children without complication. 128. Results and Complications of Rigid Antegrade Nailing of Adolescent Femoral Diaphyseal Fractures *John C. Tanner, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: The purpose of this study was to evaluate results and complications of rigid antegrade femoral nailing (RAFN) of adolescent femoral diaphyseal fractures.
METHODS: Forty one consecutive patients treated between May 1, 2002, and February 1, 2007, for adolescent (ages 12 18 years old with open physes) femoral diaphyseal femoral fractures with RAFN were retrospectively analyzed. RAFN with a standard piriformis start nail, a standard piriformis start nail inserted through the trochanter, or trochanteric femoral nail was inserted for all femoral diaphyseal fractures.
RESULTS: Average age was 16.4 years (range 12 18) with 24 males and 11 females. Thirty patients (73.2%) were polytrauma and 7 were open (17.1%). All fractures were associated with motor vehicle or pedestrian etiology. Average BMI was 24.2 (range 17 38). Winquist classification was: 0 (1, 2.4%), 1 (21, 51.2%), 2 (6, 14.6%), 3 (7, 17.1%), or 4 (6, 14.6%). AO/OTA classification was: A2 (1, 2.4%), A3 (11, 26.8%), B2 (21, 51.2%), B3 (4, 9.8%), C1 (1, 2.4%), or C2 (3, 7.3%). RAFN was performed with a standard AFN via piriformis start (28/41, 68.3%), standard AFN via a trochanteric start (5/41, 12.2%), or trochanteric AFN (8/41, 19.5%). Time to callus formation was 100% (41/41) at 6 weeks, and time to healing was 100% (41/41) at 12 weeks. Complications were LLD (1, 8 mm), nonunion (1), malunion (2, varus and BMI, r=0.99, p<0.001), HO (7, Brooker I). No infections, AVN, trochanteric arrest, or neck valgus were recorded. Eleven (26.8%) had nail removals and two had prominent screw removals.
CONCLUSIONS: Rigid antegrade femoral nailing for femoral diaphyseal fractures in adolescents with open physes can be performed safely with high healing rates and low complications. The type of nail or start site did not affect the results. Obesity (BMI) was associated with varus malunions. 129. Glenohumeral Dysplasia Changes After Tendon Transfer Surgery in Children with Birth Brachial Plexus Injuries Ann E. Van Heest, M.D. (n) Minneapolis, MN *Colleen E. Glisson, M.D. (n) Minneapolis, MN Hanley Ma, B.S. (n) Minneapolis, MN
HYPOTHESIS: Children with glenohumeral dysplasia secondary to birth brachial plexopathy treated with tendon transfer surgery at a younger age will show greater radiographic improvement than those treated at an older age.
METHODS: Twenty six children were treated with latissimus dorsi and teres major tendon transfer and pectoralis major muscle lengthening. Pre and postoperative CT scan measurements of glenoid version, % humeral head coverage, and classification as dislocated, subluxed, or normal positioning, were performed on 26 children at an average follow up of 17 months (10 46 months). Average age at surgery was 44 months (10 134 months). Two age groups were compared: 24 months or less at the time of surgery (n=11); and greater than 2 years (n=15). Concomitant surgical techniques were also evaluated.
RESULTS: For the 11 children treated 24 months of age or less, % humeral head coverage averaged 13% preoperatively and postoperatively 42%; glenoid version averaged –25° pre operatively and postoperatively 14 degrees; and preoperatively 5 shoulders were dislocated, 5 subluxed, 1 normal, while postoperatively 0 shoulders were dislocated, 2 subluxed, and 9 normally positioned. For the 15 children treated at greater than 2 years of age, % humeral head coverage averaged 30% preoperatively and postoperatively 33%; glenoid version averaged – 17° preoperatively and postoperatively –16°; and preoperatively 2 shoulders were dislocated, 6 subluxed, 7 normal, while postoperatively 2 shoulders were dislocated, 5 subluxed, and 8 normally positioned. Concomitant surgical procedures (site of tendon transfer insertion, fixation method, tendon lengthening, open reduction) did not have an effect except for open reduction.
SUMMARY: Eleven children treated at 24 months of age or less had significant improvement in the CT scan radiographic measurements of glenohumeral dysplasia, while 15 children treated at greater than 2 years of age did not. The effect of age had greater correlation with improvement than open reduction. Surgical treatment of glenohumeral dysplasia is recommended at less than 2 years of age. 130. Traumatic Separation of the Distal Humeral Physis Sustained at Delivery *F. Stig Jacobsen, M.D. (n) Marshfield, WI Goran Hansson, M.D. (n) Gothenburg, Sweden Johan Naathorst Westgelt, M.D. (n) Gothenburg, Sweden
INTRODUCTION: Fracture dislocation of the distal humeral physis is a rare fracture usually seen after birth trauma or child abuse. Treatment recommendations are controversial ranging from closed reduction to open reduction and pinning. The orthopedic literature also notes a secondary varus deformity in up to one third of cases. The purpose of this study is to define the complications and treatment in fracture sustained after birth injury.
MATERIAL AND METHODS: Six patients presented with severely displaced distal humeral fractures after difficult deliveries, which is the largest series published. Only three out of six were referred with the correct diagnosis. MRI, ultrasound, or arthrogram were further done in five of six patients. Four patients presented late and were casted in flexion and pronation while the other two had closed reduction and casting which did not seem to correct the deformity.
RESULTS: At follow up (1 18 years), all patients had a normal range of motion and five of the six had a normal carrying angle. One patient with only one year follow up had 10° of varus deformity.
CONCLUSION: Casting seems to be sufficient treatment even in fractures with significant displacement. 131. Ischial Spine Projection Reveals a High Rate of Acetabular Retroversion in Perthes Disease *A. Noelle Larson, M.D. (n) Rochester, MN Rafael J. Sierra, M.D. (n) Rochester, MN Anthony A. Stans, M.D. (n) Rochester, MN
INTRODUCTION: Acetabular retroversion has been seen in patients with sequelae of LCP disease. The lack of ossification of the anterior and posterior acetabular walls makes assessment of the "crossover sign" difficult in the very young patient. The prominence of the ischial spine sign (PRIS) has been shown to correlate well with the crossover sign. We hypothesize that the PRIS sign is indicative of retroversion and will be highly positive in the young patient with LCP disease.
METHODS: The AP pelvic radiographs of 204 patients with a diagnosis of LCP disease who presented between 1998 and 2008 were reviewed. Non standardized radiographs and those that had bony anatomy obscured were excluded. Only patients < 20 years old without prior pelvic or femoral osteotomy were included. Radiographs of 32 patients with 34 affected hips were included.
RESULTS: A positive PRIS was noted in 29 of the 34 hips on the affected side. PRIS sign was not visible under the age of five years and correlated well with the crossover sign once the rim ossified in the skeletally mature patient.
DISCUSSION AND CONCLUSION: We show acetabular retroversion as evidenced by a positive PRIS in nearly 9 out of 10 patients with LCP. It is uncertain if this is a cause or a sequela of the disease. These findings support a mechanical etiology for LCP disease and also imply that a pelvic osteotomy that allows three dimensional correction of the acetabular fragment (version) would be better suited for management of the Perthes hip. 132. Unstable SCFE: A Systematic Review of Treatments and Results Saju Rajan, B.S. (n) St. Louis, MO Ira Zaltz, M.D. (n) Royal Oak, MI Amanda Schutz, Ph.D. (n) St. Louis, MO *John C. Clohisy, M.D. St. Louis, MO (a Wright Medical Technology)
INTRODUCTION: Since the description of safe surgical hip dislocation and the epiphyseal vascular flap, the traditional treatment of unstable SCFE is subject to question. The purpose of this study was to perform a systematic review of the literature to determine the level of clinical evidence regarding treatment of the unstable SCFE. Particular attention was given to the incidence of femoral head osteonecrosis.
METHODS: A literature search was performed using identical keywords (unstable slipped femoral epiphysis; limits: English) in four medical literature database search engines (Pubmed, EMBASE, OVID, ISI Web of Science). Fifty eight citations were identified and 15 met the criteria for inclusion in our study: greater than ten patients with an unstable SCFE and a minimum two year clinical follow up.
RESULTS: All studies were Level IV retrospective case series with inclusion, treatment, and diagnostic biases. Clinical and radiographic treatment endpoints varied widely. Collectively, 356 patients with unstable SCFE were identified. Treatment methods included: immediate single or multiple pinning with and without reductions, preoperative traction, bone peg epiphysiodesis, spica cast immobilization, delayed single or multiple pinning with and without manipulation. Eighty hips (22.5%) were identified with osteonecrosis of the femoral head. The incidence of this complication ranged from 0 58% in these studies.
CONCLUSION: Current evidence regarding the treatment of unstable SCFE is Level IV, outcome measures are not standardized and the complication of femoral head osteonecrosis occurs in 22.5% of hips. Multicenter, prospective studies are necessary to compare current treatment methodologies, and to identify etiologies and risk factors for osteonecrosis. 133. Novel Use of Locking Plate for Femoral Osteotomy Fixation in Severe Coxa Vara Secondary to Fibrous Dysplasia in Pediatric Patients Trevor R. Banka, M.D. (n) Detroit, MI *Michael P. Mott, M.D. (n) Detroit, MI James F. Mooney, M.D. (n) Charleston, SC Theodore W. Parsons, M.D. (n) Detroit, MI Marnix Van Holsbeeck, M.D. (n) Detroit, MI
Significant coxa vara is particularly debilitating secondary to the imposed altered biomechanics of gait. Management typically involves proximal femoral osteotomy in an attempt to restore the mechanical and anatomic axes of the femur to a more normal state. When coxa vara presents in patients with fibrous dysplasia, additional concerns arise due to the poor bone quality of the involved femur available for fixation. This paper describes the novel use of a standard, but custom contoured, locking plate in achieving and maintaining fixation of a proximal femoral osteotomy for coxa vara in patients with fibrous dysplasia.
Two patients with polyostotic fibrous dysplasia (one with McCunne Albright) and significant proximal femoral (shepard’s crook) deformities were identified. Fixation into the proximal femur was made, followed by osteotomy and subsequent fixation to the distal shaft. Fixation consisted of a single Synthes 4.5 mm locking plate. Both patients went on to heal uneventfully, and resumed full weight bearing with improved motion and gait. To date, no fractures adjacent to the plate have been noted, and there has been no evidence of recurrent deformity.
Osteotomy fixation in young people with fibrous dysplasia is complicated not only by multiplanar deformity, but also by limited area for fixation and poor bone quality. The fixed position and multiple number of proximal screws which can be varied in length to comply with the anatomic confines, as well as the contourability of the plate, confer distinct advantages in performing an osteotomy fixation in dysplastic bone. This method appears to offer another option for potentially successful management of these complex deformities. 134. Periacetabular Osteotomy Augmentation with Osteochondroplasty of the Femoral Head Neck Junction John C. Clohisy, M.D. (n) St. Louis, MO Murat Pekmezci, M.D. (n) St. Louis, MO *Nader A. Nassif, M.D. (n) St. Louis, MO Eunice Selena, M.S. (n) St. Louis, MO Perry L. Schoenecker, M.D. (n) St. Louis, MO
INTRODUCTION: Secondary femoroacetabular impingement (FAI) is a known complication of acetabular reorientation. A precise acetabular correction combined with recontouring of the femoral head neck junction theoretically minimizes the risk of secondary impingement. There is very limited information regarding the efficacy of this technique. The purpose of this study is to report the results of combined PAO and osteochondroplasty of the femoral head neck junction in patients with acetabular dysplasia and impingement abnormalities of the proximal femur.
METHODS: Fifty consecutive patients treated with a combined PAO and open osteochondroplasty were evaluated retrospectively. There were 35 females, the average age was 28.9 years, and all patients were followed a minimum of one year. All patients had symptomatic acetabular dysplasia and were judged to be at risk for secondary FAI due to an abnormal femoral head neck junction. Standard radiographic, clinical, and complication data was analyzed.
RESULTS: The mean Harris hip score improved from 65.4 to 88.1 at follow up (p<0.001). Eighty eight percent of patients reported good/excellent results. Radiographically, the mean Tonnis angle improved 15.4°, lateral CE angle 15.8°, anterior CE angle 17.0°, and femoral head medialization 5.4 mm (all, p<0.001). The mean head neck offset improved 5.5 mm, head neck offset ratio 0.09, and the alpha angle 19.1° (all, p<0.001). There were no femoral neck fractures or other major complications. Two patients required a second procedure for symptomatic labral tears. There were no reoperations for FAI.
CONCLUSION: Periacetabular osteotomy combined with femoral head neck junction osteochondroplasty is a safe, efficacious technique for the treatment of symptomatic hip dysplasia. 135. Do Men Outperform Women During Orthopedic Residency Training? *Kate S. Pico, M.D. (n) Minneapolis, MN Terence J. Gioe, M.D. (n) Minneapolis, MN Ann Van Heest, M.D. (n) Minneapolis, MN Penny Tatman, MPH, MT (ASCP) (n) St. Paul, MN
PURPOSE: Orthopedic surgery residency continues to have the lowest percentage of women (11%) of all primary surgical specialties. To examine prevailing attitudes, we compared the performance of male and female orthopedic residents, hypothesizing that the performance of men and women would not differ significantly.
METHODS: We prospectively gathered data on 82 residents (66 male, 16 female) with graduation years of 1999 2011. Residents were compared on the basis of their Orthopaedic In Training Exam (OITE) scores, American Board of Orthopaedic Surgery (ABOS) results, and a comprehensive eight category electronic faculty evaluation measure (E*Value TM ) that rates resident performance in every category on each rotation on a 1 5 scale.
RESULTS: Males and females had no significant differences in their E*Value TM scores in any of the eight categories measured (medical knowledge, patient care, behaviors, technical, communication, practice based, systems based, overall competence). Males and females had no significant difference in their mean OITE scores for year two of residency; however, men had higher mean scores at year 3 (64.7 vs. 60.9; p=.04), year 4 (70.2 vs. 66.1; p=.004), and year 5 (73.0 vs. 69.4; p=.009). The mean percent correct for ABOS Part 1 score was not significantly different for men and women (76.3% vs. 74.8%; p=.33). All resident graduates that had taken ABOS Part 1 had passed; however, the percentage of men that took more than one attempt to pass Part 1 was significantly lower statistically than women (7% vs. 33%; p=.05). No difference was seen in Part 2 pass attempts.
CONCLUSIONS: In our program, male and female residents were seen as equally competent physicians as graded by comprehensive faculty evaluations. However, men outperformed women on OITE measures in years 3 5. Further study is needed to explain why women remain underrepresented in orthopedic surgery. 136. Impact of the 80 Hour Work Week on Surgical Exposure and National In Training Exam Scores in an Orthopedic Residency Program *John M. Froelich, M.D. (n) Springfield, IL Joseph C. Milbrandt, Ph.D. (n) Springfield, IL D. Gordon Allan, M.D. (n) Springfield, IL
INTRODUCTION: It has been proposed that the introduction of the 80 hour work week on July 1, 2003, would lead to a reduction in the number of surgical cases performed by residents each year. The current study was designed to examine the impact of the introduction of the 80 hour week on the number of surgical cases performed by PGY2 – PGY5 orthopedic residents and on an objective measure of resident knowledge level, Orthopaedic In Training Exam (OITE) scores.
METHODS: Data was collected from the ACGME national database for the three academic years prior to and after July 1, 2003. We compared the number of CPT surgical procedure codes logged by all residents in each PGY year prior to and the three years immediately following implementation of the 80 hour work week. The average raw OITE scores for each class obtained during the same time period was also evaluated and compared. Data were reported as the mean ± standard deviation (SD). Independent t tests were used to compare means between groups.
RESULTS: No statistical difference was noted in the number of surgical procedure codes logged prior to or after institution of the 80 hour week for PGY years 2, 4, and 5. There was an increase in the average number of CPT codes logged in the PGY 3 year after 2003, (457.6 versus 578.7, p=0.02). No statistically significant difference in the raw OITE scores was observed for our orthopedic residents, nor was there a statistical difference in the national average scores over the same time period.
CONCLUSION: The current study attempted to quantify the impact of recent work hour regulations on the number of procedures performed by residents and their performance on a nationally standardized knowledge based exam. A statistical difference was noted in the PGY 3 year only, suggesting more surgical exposure after implementation of the 80 hour limit. There was no difference noted in average raw OITE scores for our program or nationally. These data suggest that the impact of the 80 hour work week was not significantly detrimental to these two program component measures. Further investigation is warranted with a larger sample number. 137. Can the Resident Selection Process Predict Performance? *Jacqueline A. Geissler, M.D. (n) Minneapolis, MN Terence J. Gioe, M.D. (n) Minneapolis, MN Ann Van Heest, M.D. (n) Minneapolis, MN Penny Tatman, MPH, MT (ASCP) (n) St. Paul, MN
INTRODUCTION: Can an orthopedic residency program stratify applicants in an order predictive of future resident and post resident performance? Our program utilizes a rigorous group consensus model for resident selection that involves 20 faculty for two days. We hypothesized that higher ranking applicants would perform better than those ranked lower using multiple measures of resident performance.
METHODS: Records of 82 residents who matriculated to our program between 1994 and 2006 were reviewed. Resident performance was compared within the following ranking groups: applicants ranked in the top 12 versus those ranked 13 25, a narrower subset (≤ 5 versus ≥ 15), residents obtained through the match versus those obtained outside the match, and those ranked by the current group consensus model versus earlier methods. Resident performance was measured by a comprehensive eight core competency electronic faculty evaluation measure (E*Value TM ), OITE scores, and the ABOS Parts I and II exam results.
RESULTS: Residents ranked in the top five were rated higher in all eight faculty E*Value TM core competencies compared to other residents, regardless of ranking method (p<0.04). Those applicants ranked in the top 12 were rated higher in the core competencies areas of communication (p =0.009), practice based scores (p = 0.008), and system based scores (p = 0.05) than residents who were ranked below 12. Residents who were ranked by the group consensus model had higher OITE scores in years 2, 3, and 5 (p ≤ .04) than residents who were ranked with an earlier method. No significant differences were noted in ABOS Part I or Part II exam results.
DISCUSSION: Our current rigorous group consensus ranking system predictably identifies orthopedic resident candidates who will receive the best ratings for ACGME resident core competencies as measured by E*Value faculty evaluations. The group consensus ranking system appears more reliable in this regard than earlier ranking methodology. MAOA THIRD PLENARY SESSION April 25, 2009
138. Temporal and Spatial Relationships of Collagen I and II After Direct Midsubstance Tendon Injury *R. Michael Greiwe, M.D. (n) Cincinnati, OH Christopher Frede (n) Cincinnati, OH Kumar Chokalingham (n) Cincinnati, OH Dave Butler, Ph.D. (n) Cincinnati, OH Keith Kenter, M.D. (n) Cincinnati, OH
Musculoskeletal tendon injury results in significant patient morbidity and high health care costs. The genetic expression of collagen I and II in healing of tendon and ligament has not been well developed in the literature. By mixing the technologic advances in genetics and molecular biology, we hope to create a road map for improved constructs in tissue engineering. Specifically, we contrasted the temporal and spatial relationship of normal tendon and injured tendon col 1 and col 2 gene expression after creating a midsubstance tendon defect.
MATERIALS AND METHODS: Forty two 10 week old subjects were chosen for the study. We bred doubly transgenic mice to express a fluorescent color prior to expression of collagen I and II. The patellar tendon surgery was modeled after the Soslowsky patellar tendon injury model. Twelve mice were used to evaluate col 1 and col 2 gene expression and 12 as age matched controls. Nine subjects each were chosen for biomechanical evaluation at four weeks and six weeks. The data was then analyzed for statistical significance using a chi squared analysis.
RESULTS: Results of the fluorescent analysis that collagen I gene expression is present at one week, and increases by the two week mark, has decreased by four weeks. Col 1 gene expression is significantly elevated around the tissue defect. There was no obvious col 2 expression within the healing tendon tissues. Biomechanical data showed inferior repairs at the four and six week mark versus normal tendon.
CONCLUSIONS: We were able to document an increased expression of col 1 at two weeks diminishing by four weeks. For the first time, collagen 1 gene expression was documented in relation to its locale in the tendon. We further document the inferiority of the natural repair process at four and six weeks with biomechanical testing. In the future, utilization of this repair model may allow researchers to develop a roadmap for tissue engineering or tissue therapy that closely mimics normal tissue repair. 139. Biomechanical Comparison of Distal Locking Screws for Distal Tibia Fracture Intramedullary Nailing *Brennen L. Lucas, M.D. Wichita, KS (a Synthes) Bruce R. Buhr, M.D. Wichita, KS (a Synthes) Alexander C. M. Chong, MSAE, MSME Wichita, KS (a Synthes) Paul H. Wooley, Ph.D. Wichita, KS (a Synthes)
Treatment of diaphyseal tibia fractures with intramedullary tibial nailing is widely accepted and has been expanded to distal metaphyseal fractures. Newer generation tibial nails provide several distal interlocking screw options. Two medial to lateral screws and two perpendicular distal interlocking screws have been shown to be similar in fixation stability. A case series compared three distal interlocking screws to two distal interlocking screws in vivo and found no malunion, but without explanation as to how the number and/or orientation of those screws were chosen. Our objective was to define which screw configuration is most biomechanically stable for intramedullary nailing of distal tibia fractures.
A preliminary experiment was performed with four different screw configurations: (I) one medial to lateral and one oblique, (II) two medial to lateral, (III) one medial to lateral and one anterior to posterior, and (IV) one medial to lateral, one anterior to posterior and one oblique in simulated distal tibiae with a simulated distal metaphyseal fracture. The two most stable configurations were tested using a simulated distal cadaveric tibiae metaphyseal fracture.
Significant differences were attributable to distal screw orientation for intramedullary nailing of distal tibia fractures. Configurations II and IV were more stable than the other two configurations. No statistically significant differences were detected in construct stability in all modes of testing between Configurations II and IV.
When choosing intramedullary fixation for treatment of distal tibia metaphyseal fractures, two medial to lateral screws provide the necessary stability for satisfactory fixation. This saves operative and fluoroscopy time, and may be economically advantageous compared to three distal locking screws and/or an oblique screw. 140. Manufacturer Recall of Total Joint Components: The Joint Registry Process *Kristofer A. Kimber, M.D. (n) Minneapolis, MN Jonathan H. Biebl, M.D. (n) St. Paul, MN Terence J. Gioe, M.D. (n) Minneapolis, MN Penny Tatman, MPH, MT (ASCP) (n) St. Paul, MN Kathleen Killeen, B.S. (n) St. Paul, MN
INTRODUCTION: More than 80,000 hip and knee arthroplasty components are presently marketed in the U.S. Implant recalls are an infrequent but challenging process for the companies, surgeons, and hospitals involved. We hypothesized that a joint registry could both efficiently identify patients that had received recalled implants, and compare their survival to registry norms.
MATERIALS AND METHODS: The experience in a large community based joint registry with two recalled pressfit acetabular shells (Cup A and Cup B) was reviewed. We identified 193 recalled Cup A implants and 39 recalled Cup B implants. Analysis of recalled implant survival versus all non recalled shells (n= 3632) was performed for revision reasons of aseptic loosening, failure of bone ingrowth, or mechanical failure only. Variables considered included gender, age, year of index procedure, cup size, and number of screws compared against the variable of interest (recall) and the outcome of interest (revision for pertinent reason).
RESULTS: Cup A recalled implants had a higher cumulative revision rate (CRR) of 2.4% versus 1.7% in all non recalled implants (p< 0.001). Cup B recalled implants had a CRR of 20.1% versus 1.7% in all non recalled implants (p< 0.001). After controlling for the potential confounders noted, Cup A recalled implants had a 21 times (95% CI 3.5 129.2, p=0.001) greater risk of revision compared to all non recalled implants. Cup B recalled implants had a 74 times (95% CI 26.2 208.5, p <0.001) greater risk of revision compared to all non recalled implants. Identifying the patients who had the recalled implants, noting the revised cases, and notifying surgeons took approximately two hours of registry staff time.
DISCUSSION: The recalled implants failed at significantly higher rates than non recalled implants of similar design. A joint registry can efficiently communicate recall information and failure rates to surgeons. 141. Retrospective Review of Tibiofibular Fusions as a Salvage Procedure for Chronic Syndesmotic Injuries *Gregory H. Dairyko, M.D. (n) Chicago, IL Kirstina M. Olson, M.D. (n) Chicago, IL Brian C. Toolan, M.D. (n) Chicago, IL
BACKGROUND: Previous authors have demonstrated that failure to stabilize syndesmotic injuries associated with ankle fractures lead to poor functional outcomes. The treatment of these chronic deformities remains unclear. This retrospective study investigated the radiographic and clinical outcomes of these injuries treated with tibiofibular syndesmotic fusions as a salvage procedure.
METHODS: The initial and most recent postoperative radiographs of ten ankle syndesmotic fusions were examined by three observers. Six radiographic parameters of ankle and syndesmotic radiographic measurements were evaluated. AOFAS scores preoperatively and postoperatively were compared. The results were analyzed using paired student’s t test and chi squared analyses (p<0.05).
RESULTS: The average age of the ten patients, with a mean follow up of 41 months (range 29 54 months), was 54 years (range 40 63 years). The average total AOFAS score significantly improved from 37 (range 16 62) to 85 (range 70 100). The pain subset of the AOFAS score significantly improved (p<0.001). The average medial clear space, talo crural angle, and talar tilt significantly improved from 5.87 mm to 2.58 mm, 6.3° to 8.7°, and 9.2° to 5.9°, respectively. There was no clinically relevant progression of arthritis based on the Kellgren score. Two patients underwent removal of hardware and one underwent an ankle arthroscopy. All patients reported they would repeat the surgery. None of the patients have necessitated an ankle fusion.
CONCLUSIONS: Radiographic and clinic parameters in this retrospective series have shown promising early outcomes. Based on these findings, we conclude that a salvage procedure with a tibiofibular fusion is a viable alternative to ankle arthrodesis for a chronically, unstable ankle. 142. Anti Interleukin 8 Therapy Inhibits Tumor Induced Osteolysis and Tumor Progression *Corey Montgomery, M.D. (n) Little Rock, AR Larry Suva, Ph.D. (n) Little Rock, AR Richard W. Nicholas, Jr., M.D. (n) Little Rock, AR Dana Gaddy, Ph.D. (n) Little Rock, AR
INTRODUCTION: Skeletal metastases connote a dramatic change in the prognosis for the patient and significantly increases the morbidity associated with disease. A variety of tumor cells including breast and prostate secrete interleukin 8 (IL 8), and we have shown that IL 8 directly stimulates osteoclast formation in vitro , independent of any requirement for RANKL. We hypothesized that IL 8 may be responsible for the extensive osteolysis induced by breast cancer cells colonizing bone.
MATERIALS AND METHOD: To examine the effect of tumor derived IL 8 in vivo, IL 8 expressing human breast cancer cells (MDA MET) were injected into the tibia of nude mice. After tumor formation (approximately seven days), 20 animals were treated daily with a monoclonal antibody directed against human IL 8 and 20 were not treated. Mice were sacrificed and tibiae evaluated radiologically and histologically.
RESULTS: All control mice developed large osteolytic lesions. In the IL 8 antibody treated group, small tumor foci with no demonstrable osteolysis were observed in only two mice; no mice developed osteolytic tumors. The total area of osteolytic lesions and tumor burden was significantly lower in mice treated with IL 8 antibody compared with control.
DISCUSSION: The efficacy of anti IL 8 antibody provides a strong rationale for the utility of anti IL 8 therapy in the inhibition of tumor growth in bone, and suggests a novel therapeutic opportunity for the treatment of bone metastasis. 143. ORIF versus Partial Patellectomy for Acute Fractures of the Patella: Effects on Knee Extensor Torque Output and Gait Mechanics *Michael T. Archdeacon, M.D. Cincinnati, OH (a,e Stryker) Taylor Aronhalt, M.S. (n) Cincinnati, OH Samuel C. Wordeman, B.S. (n) Cincinnati, OH Timothy Hewett, Ph.D. (n) Cincinnati, OH
OBJECTIVE: To determine the functional strength and gait adaptations utilized by patients with patellar fractures repaired by partial patellectomy or ORIF. We hypothesized that no difference would be observed in thigh strength or gait biomechanics for ORIF subjects in side to side comparisons or to normal controls while partial patellectomy subjects would show side to side strength deficits and altered gait biomechanics.
METHODS: Standard clinical evaluation including extensor lag, ROM and manual muscle testing, isometric knee dynamometer torque in extension and flexion, knee and hip kinematics (flexion angles), and knee and hip kinetics (external flexion moments) were assessed for patella fracture subjects treated with partial patellectomy or ORIF and for a normal, uninjured control group.
RESULTS: Subjects: mean age: 42.8 ± 15.7 years, mean height: 172.5 ± 7.6 cm, mean mass: 83.4 ± 21.1 kg, mean time from surgery: 35.8 ± 20.0 months. Subjects were considered normal from standard clinical evaluations. For isometric extensor torque, there existed a mean side to side deficit for all fractures of 22% (p=0.005) on the involved leg. This was driven by the partial patellectomies alone due to their 20% deficit (p=0.050) while there was no significant deficit for ORIF subjects. Compared to controls, partial patellectomies alone were 38% weaker in extension (p=0.014) while ORIF subjects were not different. During gait, partial patellectomies saw decreased knee flexion angles (9.5°, p=0.03) compared to controls (15.6°) while ORIF subjects had increased knee flexion angles (26.8°, p=0.006).
CONCLUSIONS: By excising a significant fragment of the patella during partial patellectomy, the effectiveness of the extensor mechanism is drastically reduced, showing long term functional impairments in both quadriceps strength and gait while fractures repaired by open reduction internal fixation regain symmetric strength and gait patterns that are not different from uninjured controls. MAOA BREAKOUT SESSION #11 TOTAL KNEE REPLACEMENT April 25, 2009
144. Patient Reported Knee Society Scales and Radiographs Alone Predict Failure of Total Knee Arthroplasty *Patrick M. Morgan, M.D. (n) Minneapolis, MN David Hightower, M.D. (n) Minneapolis, MN Terence J. Gioe, M.D. (n) Minneapolis, MN
The demand for total knee arthroplasty (TKA) performed in the United States is predicted to increase 673% over the next 20 years. Given the resources required, physician office visits for all well functioning implants may be impractical. We hypothesized that a combination of trends in patient reported Knee Society (AKS) pain and function scores and serial radiographs would predict selected mechanisms of TKA failure.
AKS scores and radiographs of 53 revision TKAs from a prospectively followed cohort of 1,100 total knees performed at our institution. Patients were categorized as either requiring acute revision (fracture, component failure, acute infection) or as non acute (implant loosening, progressive osteolysis, pain). Patient reported Knee Society scales were analyzed. Radiographs from two years prior to revision were screened for complete radiolucent lines, progressive osteolysis, gross malpositioning, fracture, or component fracture.
Prior to revision, the non acute group (30 knees) showed a 45% decrease in AKS Pain score and (p<0.001) and a 33% reduction in AKS Function score (p<0.001). In no case was a non acute knee revised without a decrease in the patient reported AKS scales, concerning radiographs, or both. Similar AKS score changes were not seen in knees revised for acute causes (p>0.05).
These findings suggest that routine physician examination of the well functioning total knee may not be required for the routine monitoring over time. Instead, these data suggest that remote patient monitoring via a patient reported outcome score and telemedicine radiographs may be appropriate for routine surveillance of the well functioning total knee. 145. Hybrid Stem Fixation in Revision Total Knee Arthroplasty: Results at Average Five Year Follow Up *Alexander Sah, M.D. (n) Fremont, CA Craig J. Della Valle, M.D. Chicago, IL (a,b,c,e Zimmer; b Smith & Nephew, Stryker) Richard A. Berger, M.D. Chicago, IL (a Smith & Nephew; a,c,e Zimmer) Aaron G. Rosenberg, M.D. Chicago, IL (a,c,d Zimmer)
INTRODUCTION: The optimal method of prosthetic fixation in revision total knee arthroplasty (TKA) remains controversial. Hybrid fixation, components inserted with metaphyseal cementation, and press fit diaphyseal stems have potential benefits including ease of insertion, improved alignment, and easier removal when compared to a fully cemented stem. Few studies report the results of this method of fixation in revision TKA. The purpose of this study is to report our experience with stemmed revision femoral and tibial components inserted with a hybrid fixation technique.
METHODS: Eight eight consecutive revision TKAs in 83 patients were performed using hybrid stem fixation and evaluated at an average of five years postoperatively. Revision was performed for aseptic loosening in 36 patients, infection in 25, instability in 8, osteolysis in 7, malalignment in 6, and stiffness in 6. The cohort consisted of 52 women and 31 men with an average age of 69 years (range, 40 to 90 years). Tibial offset stems were used in 64 of 88 (73%) cases and femoral offset stems used in 26 of 88 (30%) of cases.
RESULTS: At an average of 60 months (range, 24 to 126 months), the mean preoperative knee society pain score improved from 46 to 85 points and the mean function score improved from 48 to 68 points (p<0.01 for both). Nine knees (10%) were re revised during the follow up period; two for deep infection requiring component removal, four debridements for acute infection, one each for tibial and femoral aseptic loosening, and one for periprosthetic fracture. No implant was radiographically loose, although partial radiolucent lines were seen in 17 knees (19%). Transient end of stem pain was reported in two knees.
CONCLUSION: Hybrid stemmed component fixation provides durable results in revision TKA at an average of five years postoperatively. This method of fixation has a low rate, 2%, of failure secondary to aseptic loosening. 146. Gender, Age, and BMI Predict Severe Functional Limitation Two and Five Years Post TKA Jasvinder A. Singh, M.D. Minneapolis, MN (a DePuy, Stryker, and Zimmer) Megan O’Byrne, M.D. (n) Rochester, MN *David G. Lewallen, M.D. (n) Rochester, MN
OBJECTIVE: Investigate whether gender, age, and BMI predict severe functional limitation (SFL) post TKA.
METHODS: Patients who underwent primary or revision TKA responded to questionnaires two or five years post TKA. SFL was defined as severe limitation in >=1 activity: walking, going up/down stairs, and rising from a chair. Multivariable logistic regression analyzed predictors of SFL, adjusting for diagnosis, implant, comorbidity, distance from medical center, and ASA score odds ratios are presented.
RESULTS: Response rates were 48 65%. SFL was reported by 6.8% at two years and 10% at five years post primary TKA; 17.8% at two years and 21.6% at five years post revision TKA. Female gender, age≥81 and BMI≥40 significantly predicted higher odds of SFL in both primary and revision TKAs at both time points (table).
TABLE: Multivariable adjusted odds ratios of SFL; p<0.05 marked with *. Prim. TKA 2yr Prim. TKA 5yr Rev. TKA 2yr Rev. TKA 5yr Female (ref, male) 3.0* 2.0* 2.9* 2.6* Age, 61 70 (ref, <60) 1.1 1.2 0.6 0.9 Age 71 80 2.4* 2.8* 1.2 1.8 Age >=81 7.6* 4.8* 2.5* 4.8* BMI, 25 29.9 (ref,<24.9) 1.2 0.9 1.0 0.9 30 39.9 1.6* 1.2 1.3 0.9 >=40 3.0* 2.0* 2.7* 2.5*
CONCLUSIONS: Significant independent association of female gender, age over 80 and BMI ≥40 with SFL, can help the surgeons better inform their patients of the risk of SFL. 147. The Impact of Topical Thrombin JMI on Loss of Hemoglobin in Total Knee Arthroplasty: Consecutive Case Series with a Single Surgeon Phillip J. Lewandowski, M.D. (n) Akron, OH *Ian M. Gradisar, M.D. (n) Akron, OH Leann M. Speering, M.S. (n) Akron, OH Michael J. Askew, Ph.D. (n) Akron, OH David R. DiNuoscio, B.S. (n) Rootstown, OH
INTRODUCTION: Preoperative autologous blood donation for total joint arthroplasty surgery is decreasing. The use of intraoperative wound coagulants coupled with better operative techniques have decreased the amount of blood loss. Decreasing postoperative wound hemorrhage may reduce morbidity, length of hospital stay, number of transfusions, postoperative infections, and returns to the operating room.
Reports on the use of Thrombin JMI ® (King Pharmaceuticals) to control intraoperative bleeding in spine surgery are few. English reports on its use in total joint arthroplasties are even less.
A large comparative clinical study on the effects of thrombin in total knee arthroplasty (TKA) has not been reported. Therefore, we intend to quantitate the outcomes of TKA patients that received intraoperative Thrombin versus TKA patients without. We hypothesize an equivalent loss of hemoglobin between the two treatment groups.
METHODS: This retrospective outcomes study is IRB approved. Our Investigational group includes up to 220 TKAs that received topical thrombin. Our control group is a comparative group of up to 220 TKAs without thrombin. Data collection includes: demographics, pre and postoperative Hgb levels, change in Hgb, transfusion rates, return to the operating room, and length of hospital stay.
RESULTS: The statistical analysis will be conducted using the PC SAS statistical analysis software package. Preliminary analyses of the data indicate the majority of patients are female (70%) with an average age of 64 years old; there are no differences in gender or age between treatment groups (n=96). There appears to be equivalent rates of postoperative transfusions between groups. Average length of hospital stay is 3.5 days. Return visits to the operating room are low in both groups.
DISCUSSION/CONCLUSION: To our knowledge, this is the largest review of the use of topical thrombin in total joints. As the use of intraoperative coagulant therapies becomes more prevalent, their clinical benefit must be weighed against the cost analysis and their effectiveness. 148. Revision Total Knee Arthroplasty with Uncemented Modular Fluted Stems *Michael A. Masini, M.D. (n) Ann Arbor, MI Arthur L. Malkani, M.D. (n) Louisville, KY Madhusudhan R. Yakkanti, M.D. (n) Louisville, KY Dale Baker (n) Louisville, KY
INTRODUCTION: The purpose of this study is to report our results of revision knee arthroplasty with uncemented intramedullary stems using an offset which provides independent and optimum placement of the tibial and femoral component.
METHODS: 119 patients undergoing revision knee arthroplasty with an average age of 67 years (range, 47 87 years) were retrospectively reviewed. Average follow up was 44 months (36 70 months). In all patients, a hybrid technique was utilized where the tibial tray of the femoral component was cemented into the metaphysis with a press fit fluted intramedullary stem. Patients were evaluated clinically using the Knee Society Pain and Function Scores.
RESULTS: Average preoperative Knee Society Pain Score was 39 points which improved to 68 points (p<0.05). Average Knee Society Function Score was 58 points which improved to 79 points (p<0.05). A majority of patients utilized an 80 mm stem with varying diameters. Average stem diameter was 16.8 mm. There were a total of 58 tibial offsets utilized and 28 femoral offsets utilized. The tibial offsets varied from 4 mm 8 mm. There were three failures requiring revision, 1 for infection, 1 instability, and 1 for periprosthetic fracture.
DISCUSSION AND CONCLUSION: Results of this study using a hybrid technique for revision total knee arthroplasty demonstrated excellent clinical results. Using an offset provided independent press fit stem fixation allowing rigid cortical contact with the fluted stem. Long term results made it necessary to see if the hybrid technique achieves results similar to cemented stem fixation. 149. Evaluation of the Effect of Cement Viscosity on Cement Mantle in Total Knee Arthroplasty *D. Gordon Allan, M.D. Springfield, IL (a Zimmer) Brian S. Kern, M.D. (n) Springfield, IL Manish Paliwal, M.D. (n) Ewing, NJ Joseph C. Milbrandt, Ph.D. (n) Springfield, IL
INTRODUCTION: Aseptic loosening of the tibial implant remains one of the major reasons of failure in total knee arthroplasty (TKA). Cement viscosity at the time of application to the bone is of great importance to ensure a long term success of the arthroplasty. Currently, there are a number of cements available with a wide range of viscosities and set times. High viscosity faster setting cements may significantly reduce operating room times. However, the concern is that this positive feature may be at the expense of decreased penetration into the bone, and hence reduced stability of the construct.
METHODS: Four cement types (DePuy II [DePuy Inc., Warsaw, IN], Endurance [DePuy Inc., Warsaw, IN], Simplex P [Stryker Corp., Kalamazoo, MI], and Palacos [Zimmer, Inc., Warsaw, IN]) were compared and evaluated during TKA using surrogate tibiae. Depth of cement penetration in seven zones as advised by the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation System were evaluated.
RESULTS: On radiographic analysis of the implanted surrogate tibiae, it was found that Simplex had the maximum cumulative penetration (19.2 mm) in seven zones in Mediolateral view, and 12.7 mm in three zones in anteroposterior view, though statistically insignificant (two tailed P = 0.2626). In zone six, the difference was statistically significant when comparing Simplex with Palacos (11 mm vs. 4.6 mm, two tailed P value = 0.0350), somewhat significant with DePuy 2 (11 mm vs. 6 mm, two tailed P value = 0.08), but the difference was not significant when compared with Endurance (11 mm vs. 10 mm, two tailed P value = 0.6345). In Zone 5, the difference was statistically significant with Simplex vs. Endurance (0.33 mm vs. 2.17 mm, P = 0.028), and with Simplex vs. DePuy 2 (0.33 mm vs. 2.17 mm, P = 0.012).
CONCLUSIONS: The lack of penetration in Zone 6 may result in reduced shear strength. This study enhances the understanding of the relation between cement viscosities and cement penetration into cancellous bone in TKA. 150. Kinematic Comparison of Normal and Replaced Knees in an Open Chain Isometric Extension Model *C. Lowry Barnes, M.D. Little Rock, AR (a,c,e Wright Medical Technology) J. David Blaha, M.D. (n) Ann Arbor, MI David K. DeBoer, M.D. (n) Nashville, TN Richard Obert, M.S. (n) Arlington, TN Paul Stemniski, M.S. (n) Arlington, TN Michael Carroll, B.S. (n) Arlington, TN
INTRODUCTION: An open chain model was used to compare differences in kinematics during isometric extension between normal and knees replaced with a tricompartmental prosthesis.
METHODS: Ten cadavers legs were skeletonized while preserving the knee joint capsule, quadriceps, and hamstring tendons. CT scans of the extremity were converted to CAD models that precisely related the bone surfaces to motion analysis markers. The limbs were mounted in a custom open chain extremity rig. Force was applied at the quadriceps tendon to extend the extremity. Three dimensional kinematic data of the isometric extension motion of the knee were recorded using a motion capture camera system and combined with CAD models of the extremity to evaluate joint kinematics through virtual animations, contact points, and kinematic profiles. After collecting data on normal knee kinematics, each specimen underwent total knee replacement with commercially available implants.
RESULTS: Tibiofemoral contact points for the normal knee indicate stable behavior on the medial compartment and progressive posterior motion of contact on the lateral side with increasing flexion. Kinematic profiles for normal knees were consistent in shape among all specimens. Contact point data after knee replacement was consistent with the behavior of the normal knee. Replaced knee kinematic profiles varied from normal, but were consistent across specimens.
CONCLUSION: In this open chain model, both normal and replaced knees indicate a stable medial side and free motion on the lateral side. The replaced knees closely approximate the surface kinematics of normal knees. Variation in kinematic profiles between the normal and replaced knees are partially attributed to surgical alignment correction. 151. Psychological Factors – Affecting Outcomes After Primary TKA *Jasvinder A. Singh, M.D. Minneapolis, MN (a DePuy, Stryker, and Zimmer) Robert C. Colligan, M.D. (n) Rochester, MN Megan O’Byrne, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN
OBJECTIVE: Seligman’s theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favorable health outcomes. It is already known that depression is associated with poorer arthroplasty outcomes. We investigated the association between pessimism and the prevalence of self reported knee pain two and five years post primary TKA.
METHODS: We identified 894 primary TKA surgeries from 1993 2005 in which the patients responded to follow up questionnaires two or five years post surgery. Scores from the Optimism Pessimism (PSM) scale from the Minnesota Multiphasic Personality Inventory (MMPI) completed by a subset of TKA patients a median of 16.1 years before their TKA as a part of clinical care were obtained for 783 primary TKA surgeries with two year surveys and 443 primary TKA surgeries with five year surveys. We examined the association of the PSM score as a categorical and also as a continuous variable with the prevalence of TKA pain at two and five years using logistic regression. (p<0.05 was considered significant).
RESULTS: PSM was significantly associated with moderate severe pain at two years post primary TKA: a one unit increase in PSM had an Odds Ratio (OR) (95% Confidence Interval [CI]) of 1.03 (1.00, 1.05). At five years post TKA, the OR (95% CI) was 1.03 (1.00, 1.07); both were statistically significant (p = 0.02 and 0.05, respectively). Those categorized as pessimists (T scores > 60) were also more likely to experience moderate severe pain at two years post primary TKA (OR: 1.73; 95% CI: (1.08, 2.78); p=0.02).
CONCLUSIONS: A pessimistic explanatory psychological style was associated with increased severity of self reported pain two and five years post TKA. 152. Short Term Mechanical and Subjective Outcomes of Total Knee Arthroplasty *Craig R. Mahoney, M.D. (n) West Des Moines, IA Vassilios Vardaxis, Ph.D. (n) Des Moines, IA David McEowen (n) Des Moines, IA Jake Stotts (n) Des Moines, IA
INTRODUCTION: Total knee arthroplasty (TKA) aims to alleviate pain and improve function in patients with osteoarthritis (OA). While TKA patients are able to ambulate with less pain after the surgery, their locomotion characteristics seem to persist. The purpose of this study was to assess the changes and the relationship between psychometric and functional parameters before and after TKA.
METHODS: Gait analysis and psychometric data (SF 36 questionnaire) was collected on 8 controls and 10 TKA patients’ pre and three months post surgery. Gait functional characteristics (stride length, velocity, and sagittal and frontal plane moments at the knee) and psychometric variables (SF 36: physical function, role physical, bodily pain, and social function) were assessed. A two by two mixed ANOVA design was used (group x time).
RESULTS: Improvements found in step length and velocities for the TKA group were not significant (p≤ .05). There were significant interactions in all psychometric measures (p≤ .05). The knee abduction moment was significantly reduced after surgery for the TKA group (p≤ .05). No significant correlations between the psychometric and gait variables were found.
DISCUSSION: Our data suggest psychometric and functional improvements at three months post surgery; however, there is no direct relationship between patients’ view of their health and the magnitude of the knee joint loading. The post surgery gait data indicate that full rehabilitation has not been achieved at three months. 153. Does Participation in Non Recommended Sports Impact Total Knee Arthroplasty Durability? Sebastien Parratte, M.D. (n) Marseille, France Diane L. Dahm, M.D. (n) Rochester, MN Michael J. Stuart, M.D. Rochester, MN (a,e Stryker) Mark W. Pagnano, M.D. (n) Rochester, MN *Daniel J. Berry, M.D. Rochester, MN (a,c DePuy; a Stryker, Zimmer)
IINTRODUCTION: Recent studies report some sports participation after TKA is common, but the effect on prosthesis durability of not recommended sports according to the Knee Society (KS) definition is unknown. This study compares TKA mechanical failure rates in patients involved in not recommended sports with matched patients involved in low or moderate activities.
MATERIALS: From 1,500 primary modern condylar posterior cruciate substituting TKA of one design, 218 patients were identified by self completed questionnaire as practicing a non recommended (KS criteria) sport. This sport group was matched by age, gender, and BMI to patients not practicing non recommended sports (control group). 535 patients (420 men, 115 women; mean age 68±8 years; mean BMI 30±5 Kg/m 2) were included. Clinical and radiologic evaluation was performed using KS clinical and roentgenographic scores and multivariate analysis was performed using a Cox model.
RESULTS: At 7.5 ± 2 years, mean KS Knee scores were: control group 92, sport group 94; KS function scores: control group 85 and sport group 92 (both p<0.0001). The raw revision rate for mechanical failure (loosening, wear, or periprosthetic fracture) was 8.5% in the sport group and 11% in the control group (p=0.52/RR=0.82). In the multivariate Cox model, adjusting for all variables significant in univariate analysis, the sport group had a 10% increased risk of mechanical failure compared to the control group (Hazard ratio: 1.10, p=0.85). None of the survivorship differences between groups in univariate or multivariate analysis were statistically significant.
DISCUSSION: At a mean follow up time of 7.5 years after modern condylar TKA in 218 patients, no significant differences in implant durability could be demonstrated between those involved in not recommended sports activities compared to matched controls. Longer follow up may still reveal survivorship differences. 154. Patellofemoral Arthroplasty versus Total Knee Arthroplasty for Isolated Patellofemoral Osteoarthritis *Diane L. Dahm, M.D. (n) Rochester, MN Walid Al Rayashi, B.S. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN Bruce A. Levy, M.D. (n) Rochester, MN
INTRODUCTION: A paucity of comparison data exists between patellofemoral arthroplasty (PFA) and total knee arthroplasty (TKA) for patients with isolated patellofemoral arthritis. The purpose of this study was to compare outcomes of PFA and TKA in this patient population.
METHODOLOGY: We identified all patients at our institution who underwent PFA or TKA between January 2003 and December 2005. Isolated patellofemoral disease was confirmed via preoperative radiographs demonstrating Kellgren scores ≤ 2 and Iwano scores > 2. Preoperative and postoperative Knee Society Scores (KSS), Tegner, and UCLA scores were obtained. Linear regression was used to analyze the effects of independent variables.
RESULTS: We identified 23 PFA patients and 22 TKA patients. There were 5 males and 33 females. Mean age was 60 years and 69 years respectively (p = 0.01). Mean follow up was 29 months (24 49) and 27 months (24–33) respectively. Mean postoperative KSS knee scores were 89 and 90 in the PFA and TKA cohorts respectively. Mean KSS function scores were 84 and 73 respectively. Mean Tegner scores were 4.3 and 2.6 respectively (p < 0.0001). Mean UCLA scores were 6.6 and 4.2 respectively (p < 0.0001). Mean blood loss was 117 cc and 197 cc among the PFA and TKA patients respectively (p = 0.03). Mean hospital stay was 3.3 days and 4.4 days respectively (p = 0.001). There were no statistically significant differences with numbers available for gender, race, mean BMI, or smoking status. Linear regression showed that blood loss, hospital stay, and outcomes were not affected by age as an independent variable. No significant complications occurred in the PFA group. There was one DVT in the TKA group.
CONCLUSION: Patellofemoral arthroplasty yields clinical outcomes comparable to TKA for isolated patellofemoral arthritis. Mean blood loss was less, and hospital stay was shorter for PFA patients. 155. Accurate Intraoperative Assessment of Knee Deformity is a Useful Predictor of Postoperative Outcome Ritesh R. Shah, M.D. (n) Chicago, IL *S. David Stulberg, M.D. (n) Chicago, IL Mark A. Yaffe, M.D. (n) Chicago, IL Susan B. Gall, B.S. (n) Chicago, IL Nicholas Palmese, M.S. (n) Chicago, IL
INTRODUCTION: Implant longevity, pain relief, and function are related to the accuracy with which total knee arthroplasty achieve precise, reliable implant and limb alignment. Numerous studies have demonstrated that the use computer assisted techniques is associated with improved limb and implant alignment and fewer outliers. CAS is also a powerful and accurate intraoperative measurement tool. The purpose of this study was to determine if navigation measurements performed intraoperatively helped predict postoperative outcomes.
METHODS: Sixty seven consecutive image free computer assisted total knee arthroplasties were performed. Intraoperative measurements of pre surgical limb alignment and knee range of motion were obtained using the navigation system. Postoperative measurements and knee society function scores were obtained at four to six weeks and two year follow up. The intra operative computer data were electronically transferred to the post surgical outcome measurement tool. The intraoperative data were then statistically compared to specific outcome measurements, including range of motion, mechanical axis, and coronal deformity.
RESULTS: Patients with intraoperative pre surgical mechanical axis deviations greater than 10° demonstrated decreased one month postoperative function scores when compared to all patients receiving computer assisted total knee arthroplasties and when compared to patients with pre surgical mechanical axis deviations of less than 10°. Patients with pre surgically measured valgus deformities greater than 10° had decreased functional and knee scores when compared to all patients receiving computer assisted total knee arthroplasties. Patients with pre surgical range of motion greater than 133° demonstrated higher one month postoperative knee scores and range of motion.
CONCLUSIONS: Accurate intraoperative assessment of alignment and range of motion using a navigation system is useful in anticipating postoperative outcomes, especially with the extremes of alignment deformities. MAOA BREAKOUT SESSION #12 SHOULDER/ELBOW April 25, 2009
156. The Effect of Instrument Size on Rotator Cuff Stitch Strength Brent A. Ponce, M.D. (n) Birmingham, AL *Chad D. Hosemann, III, M.D. (n) Birmingham, AL Parthasarathy Raghava, M.S. (n) Birmingham, AL Alan W. Eberhardt, Ph.D. (n) Birmingham, AL
INTRODUCTION: The tissue suture interface is the weakest aspect of a rotator cuff repair. Hence, it is critical to identify techniques to increase stitch strength and improve healing rates. Differences in the tissue penetrating geometries of arthroscopic devices used in rotator cuff repairs may affect stitch strength. The purpose of this study was to evaluate the impact of tissue penetrator size and shape on stitch holding strength.
METHODS: 192 sheep infraspinatus tendon grafts were used to test three tissue penetrating devices: small circular, mid sized circular, and large rectangular. With each device, four different stitches, a simple, mattress, modified Mason Allen (MMA), and massive cuff (MAC), were placed (n=48). Each graft was cyclically loaded using a Materials Testing System and then loaded to failure. A mixed model multivariate regression model was used to test the effect of device and suture type on peak to peak displacement, cyclic elongation, and load to failure.
RESULTS: The average load to failure (LTF) using the smallest circular penetrating device was 112N, versus 95.3N and 91.0N for the other devices (p = 0.0008). Stitch type remained the most important predictor of LTF: simple 48N, mattress 68N, MMA 130N, and MAC 152N (p<0.02 for all).
DISCUSSION AND CONCLUSION: The strength of rotator cuff stitches was significantly affected by the different sized tissue penetrating instruments. However, the critical factor in the strength of a stitch remains the type of stitch placed. 157. Scapula Fractures in Reverse Total Shoulder Arthroplasty Lynn A. Crosby, M.D. Dayton, OH (c Exactech) *J. Adam Hamilton, M.D. (n) Dayton, OH
BACKGROUND: Modern reverse total shoulder arthroplasty (RTSA) implants have been developed to address pathologies in rotator cuff deficient shoulders. As their use becomes more common, the nature of this procedure’s complications and how these complications should be managed continues to evolve. Fractures of the scapula following RTSA have been described, but no specific classification schemes or formal treatment recommendations exist.
METHODS: The available medical records of 400 consecutive patients treated with RTSA by a single surgeon over a 4.5 year period were reviewed, and all scapula fractures were identified. Analysis of these fractures revealed three discrete patterns. Small avulsion fractures of the anterior acromion were classified as Type I fractures; fractures through the anterior acromion just posterior to the acromioclavicular joint were classified as Type II fractures; fractures of the posterior acromion or scapular spine were classified as Type III fractures.
RESULTS: Eight patients in 400 (2.0%) treated with RTSA were found to have Type I fractures visible on the first follow up radiographs; none of these patients had any further surgical intervention for treatment of these fractures. Ten patients (2.5%) developed Type II fractures at a mean of 10.8 months following RTSA; most of these fractures were managed surgically. Four patients (1.0%) developed Type III fractures at a mean of 10.3 months following surgery; all of these fractures were treated with surgical fixation.
CONCLUSION: Scapula fracture is a relatively common complication of RTSA. Type I fractures can be observed with predictably good results. Type II fractures are effectively treated with acromioclavicular joint resection if stable, but open reduction internal fixation and acromioclavicular joint resection should be considered if the fracture is unstable. Type III fractures are best treated with open reduction internal fixation.
158. Two Incision versus One Incision Repair for Distal Biceps Tendon Rupture: A Cadaveric Study of Footprint Reconstruction Syed A. Hasan, M.D. (n) Little Rock, AR Carl L. Cordell, M.D. (n) Little Rock, AR William R. Hogue, B.S. (n) Little Rock, AR Russell B. Rauls, M.D. (n) Little Rock, AR Mark S. Bailey, Jr., M.D. (n) Little Rock, AR
INTRODUCTION: A distal biceps tendon rupture is repaired either through a single anterior incision or a two incision technique. The purpose of this study was to test our hypothesis that a superior anatomic repair can be achieved using the two incision technique because it allows for enhanced exposure of the bicipital tuberosity.
METHODS: Twenty cadaveric arms were randomly assigned to one of two groups: one incision (Group I) or two incision (Group 2). The biceps tendons of the ten cadavers in Group 1 were exposed through a single anterior incision. The radial tuberosity was palpated with the arm placed in 90° of supination. A 2 mm guide pin was centered in the tuberosity to serve as a guide for reaming a 7.5 mm bone tunnel. For the ten cadavers of Group 2, the posterior approach was performed, again centering a 2 mm guide pin on the tuberosity. Each radius was harvested with the biceps tendon insertion intact. The average footprint of each tendon was determined using a computerized 3D digitizer. The software allowed us to create a virtual bone tunnel, 7.5 mm in diameter, centered on the 2 mm drill hole, to simulate the repair site. The percentage of the virtual drill hole within the original footprint was then determined.
RESULTS: The average area of the virtual repair within the original tendon footprint was 73.4% for the posterior approach, while for the anterior approach it was only 9.7%. There was a statically significant difference (p= <0.001) in the median values of footprint covered between the two types of repair.
CONCLUSION: The two incision technique results in a significantly improved anatomical repair of the biceps tendon to the original insertion site. The one incision repair results in lateralization of the repair which, although not tested, could result in decreased strength of supination. Clinical studies directly comparing the two techniques with regards to the strength of supination after repair may be helpful to further elucidate patient outcomes. 159. Functional Outcomes and Radiographic Appearance of Single versus Double Row Rotator Cuff Repair William T. Pennington, M.D. Milwaukee, WI (c,e Arthrex) *David J. Gibbons, M.D. (n) Milwaukee, WI Brian A. Bartz, P.A. (n) Milwaukee, WI Jonathon Klinger, B.S. (n) Milwaukee, WI
INTRODUCTION: Double row transosseous arthroscopic rotator cuff repair (ARCR) techniques are thought to theoretically provide an improved repair by providing increased contact area and pressure of the repaired tendinous cuff to the native footprint while also increasing repair strength. This study aims to compare the double row fixation to single row fixation of simple over horizontal configuration (the arthroscopic Mason Allen equivalent).
METHODS: A prospective, non randomized assessment of 132 ARCR patients included 78 patients with single row repair and 54 with double row repair. All patients were evaluated with VAS, UCLA, and ASES scores, and for planes of active motion and dynomometric strength. Scores and measurements were obtained preoperatively and at 3, 6, 12, and 24 months postoperatively. MRI was used to evaluate healing in both groups at 12 months postoperatively.
RESULTS: No statistically significant difference was observed in functional outcomes between groups in all parameters from preoperative values. However, postoperative VAS, UCLA, ASES scores, and strength measurements were slightly better in the single row group, while ROM measurements were slightly better in the double row group. Patient satisfaction was 91% in the single row repair group and 92% in the double row repair group. MRI showed significantly improved healing rate with double row repair compared to single row repair.
CONCLUSION: Our results suggest that single row repair with an arthroscopic Mason Allen configuration provides comparable clinical results to that obtained with the double row repair type. However, radiographic healing is significantly improved in the double row repairs. 160. Shoulder Arthroplasty in Morbidly Obese Patients Christopher J. Linberg, M.D. (n) MacDill AFB, FL John W. Sperling, M.D. (n) Rochester, MN Cathy D. Schleck, B.S. (n) Rochester, MN *Robert H. Cofield, M.D. (n) Rochester, MN
BACKGROUND: Currently, there is no information on shoulder arthroplasty in obese patients. The purpose of this study was to determine the complications, results, and failure rate of shoulder arthroplasty in morbidly obese patients.
METHODS: Between 1994 and 2005, 45 shoulder arthroplasties were performed for osteoarthritis in patients with a BMI greater than 40. Forty one shoulders were followed for a minimum of two years (mean, 55 months) or until revision.
RESULTS: Shoulder arthroplasty in morbidly obese patients was associated with significant improvement in pain and range of motion (p ≤ 0.001). The average operative time was 220 minutes. Four required anteromedial approaches. There was one intraoperative humeral shaft fracture and two small anterior deltoid avulsions. Five patients required overnight ICU monitoring postoperatively. One shoulder developed a superficial infection resolving with oral antibiotics while one patient had wound healing difficulty requiring dressing changes. Five shoulders underwent revision arthroplasty. Two revisions were for deep periprosthetic infection. One hemiarthroplasty was revised for glenoid arthritis. One shoulder was revised for posterior instability. One shoulder was revised to a reverse prosthesis for glenoid loosening after a rotator cuff tear. The Kaplan Meier estimate for survival free of revision was 70.2% at ten years .
CONCLUSION: Shoulder arthroplasty in the morbidly obese is associated with long term improvement in pain and function. However, there seems to be an increased complexity in performing shoulder arthroplasty in this unique patient population. They seem to have an increased need of an extensile approach and their revision rate seems to be increased. Along with this, they also have a higher utilization of resources. 161. Mini Open Rotator Cuff Tear Repair without Acromioplasty in Patients 65 and Older Works Too *Michael J. Carlson, M.D. (n) Omaha, NE Junfeng Sun, Ph.D. (n) Omaha, NE Erica M. Burns, M.D. (n) Omaha, NE Jonathon Cotton, M.D. (n) Omaha, NE Edward V. Fehringer, M.D. (n) Omaha, NE
INTRODUCTION: Increased age is associated with increased cuff tear prevalence. Yet, it is unclear whether repairable tears in those > 65 heal and how those shoulders function compared to untreated shoulders. The purpose of this study was to assess cuff re tear prevalence and shoulder scores in those > 65 following mini open repair without acromioplasty and compare them with 200 untreated, aged shoulders.
MATERIALS AND METHODS: Group I included 54 cuffs repaired in patients > 65 with a mini open technique without acromioplasty. Participants completed the Simple Shoulder Test (SST), a Constant Score, and a rotator cuff ultrasound at a minimum 12 months postoperative. Group II included 200 untreated shoulders in volunteers > 65 that underwent the same functional and ultrasound evaluation.
RESULTS: Forty two of 54 shoulders were studied 12 61 months postoperative; 9 cuffs had re torn. Those without re tears had higher SST (p=0.01) and Constant (p=0.001) scores than those with re tears. Shoulders with untreated tears had significantly worse SST (p<0.001) and Constant (p<0.0001) scores than those with healed repairs; however, those untreated tears were in patients that were significantly older. Shoulders with healed repairs had no difference in SST (p=0.64) or Constant scores (p=0.61) when compared with those untreated shoulders without tears.
DISCUSSION AND CONCLUSION: Cuff re tear prevalence was 21% following mini open repair without acromioplasty in patients > 65. Those with healed repairs had better scores than those that did not, and they had better scores than those with untreated tears. Those with healed repairs had comparable function to untreated shoulders without tears.
SUMMARY: Mini open cuff repair without acromioplasty in patients > 65 healed in 79%. If healed, shoulder scores were better than untreated shoulders with tears and equal to untreated shoulders without tears. 162. Clinical Outcomes of Shoulder Patients with Greater Tuberosity Cysts on MRI *Michael A. Herbenick, M.D. (n) Dayton, OH Brandi Hartley, B.S. (n) Dayton, OH Lynn A. Crosby, M.D. (n) Dayton, OH
INTRODUCTION: Subchondral cystic changes are commonly visualized within the greater tuberosity of the humerus when utilizing MRI. These cysts have been associated with rotator cuff pathology, chronic acromial impingement, or even a normal variant. Although many scholars have examined these cyst like lesions and their impact on common orthopedic problems; no study has investigated the impact of these cystic changes in the patients’ clinical outcome including operative and non operative treatments.
MATERIALS: A retrospective review of 294 patient shoulder MRIs over the last five years in one orthopedic practice was analyzed for subchondral cystic changes. Location, size, and evidence of any rotator cuff tear, if present, were documented. These patients were further analyzed according to treatments received and clinical outcomes.
RESULTS: Cystic changes were noted in 116 patients, which accounts for 39.5% of the study population. Anterior cysts were related to chronic impingement and rotator cuff tears. Posterior cysts, while largely thought to be part of normal patient anatomy, also had an association with rotator cuff tears.
CONCLUSION: Patients with anterior subchondral cystic changes may require operative intervention at a higher rate. Patient outcomes may be affected with presentation of cystic changes in the greater tuberosity. 163. A Biomechanical Comparison of Three Double Row Rotator Cuff Repair Techniques Samuel S. Koo, M.D. (n) San Antonio, TX *Todd C. Moen, M.D. (n) Chicago, IL Gordon W. Nuber, M.D. (n) Chicago, IL Jason L. Koh, M.D. Chicago, IL (e Arthrex)
INTRODUCTION: The objective was to compare the load to failure properties of two arthroscopic and one open double row fixation techniques.
METHODS: Three double row stitch configurations in 30 sheep shoulders were performed and tested. A materials testing machine was used to pretension the specimen and then loaded to failure under displacement control at 1 mm/sec. Stiffness, yield load, and ultimate load were measured and compared.
RESULTS: The load to failure for the open Mason Allen technique was 421 N +/ 116N. The load to failure for the arthroscopic Mason Allen technique was 387 N +/ 74N. The load to failure for the standard double row was 409 N +/ 132 N. No significant differences were found between the suture techniques in the ultimate load to failure, yield load, or stiffness.
CONCLUSION: In this in vitro cadaveric sheep study, we found no significant differences between the three double row suture techniques in the ultimate load to failure. 164. Integrity and Strength of the Subscapularis After Total Shoulder Arthroplasty *Jeffrey D. Jackson, M.D. (n) Rochester, MN Scott P. Steinmann, M.D. (n) Rochester, MN Akin Cil, M.D. (n) Rochester, MN Sheri Merten, M.D. (n) Rochester, MN
INTRODUCTION: Relatively little information is available on healing the subscapularis repair after total shoulder arthroplasty (TSA). The purpose of this study was to document the subscapularis healing rate after subscapularis tenotomy by use of ultrasound and correlate healing to physical examination findings and shoulder internal rotation strength.
METHODS: Fifteen consecutive patients who underwent TSA due to unilateral osteoarthritis were evaluated after a minimum of one year follow up with ultrasound, physical examination, and internal rotation strength testing. At surgery, the subscapularis tendon was cut 1 cm medial to its insertion and then repaired at the end of the procedure with 8 to 10 braided, non absorbable sutures in a figure of eight fashion.
RESULTS: All patients were satisfied with the results of surgery. Out of 15 shoulders, 7 had a complete tear of the repaired subscapularis tendon by ultrasound. Lift off test and abdominal compression test correlated poorly with the ultrasonographic condition of the subscapularis. There were three false negative and five false positive results. Subscapularis tear after arthroplasty resulted in a significant weakness of isometric (p=0.006) and isokinetic (p=0.004) internal rotation strength and a worse DASH score (p=0.04) compared to shoulders with an intact subscapularis. Intact subscapularis after TSA did not result in significantly different isometric (p=0.208) and isokinetic (p=0.233) internal rotation strength compared to the normal shoulder. No patient demonstrated anterior subluxation on examination or by radiograph.
CONCLUSIONS: Subscapularis tear after total TSA is a common problem which cannot be diagnosed reliably by physical examination or radiographs. Failure to heal the subscapularis tenotomy is probably more common than has been previously reported based on only physical examination testing. 165. Incidence of Symptomatic Opus Anchor Failure in Mini Open Rotator Cuff Repairs Michael A. Herbenick, M.D. (n) Dayton, OH *Jonathan Chae, B.S. (n) Dayton, OH Lynn A. Crosby, M.D. (n) Dayton, OH
INTRODUCTION: There is a high incidence of rotator cuff repair failures in the US. Suture anchor pullout is one mode of failure for rotator cuff repair. The purpose of this study was to evaluate risk factors for OPUS suture anchor pullout used for rotator cuff repair.
METHODS: This was a retrospective, case controlled study. 273 cases of rotator cuff repair were reviewed. Age, gender, medical co morbidities, smoking history, length of time until failure was recognized, number of anchors used, duration of symptoms prior to surgery, other concurrent procedures during rotator cuff repair, acromial morphology, history of trauma prior to surgery, history of trauma after surgery, injections prior to surgery, and NSAID use prior to surgery were all evaluated in this study. Postoperatively, patients were followed up for a minimum of one year.
RESULTS: Of the 273 cases reviewed, there were 170 cases with documented use of OPUS anchors. Follow up documentation showed 30 rotator cuff repair failures using the OPUS anchor system. Of these 30 failures, 7 were secondary to OPUS anchor pullout.
CONCLUSIONS: OPUS anchor pullout is one mode of failure for rotator cuff repair using the OPUS suture anchor system. Symptomatic re tear rates for all rotator cuff repairs with the OPUS system is 18%. Symptomatic failure of the OPUS anchor system occurred in 4% of patients. Our study suggests that there may be an association between age and bony pullout of the OPUS anchor. 166. Comparison of Open versus Percutaneous Plating of Proximal Humerus Fractures B. Matthew Hicks, M.D. (n) Fort Wayne, IN Justin P. Colanese, M.D. (n) Fort Wayne, IN *Jeffrey S. Staron, M.D. (n) Fort Wayne, IN
BACKGROUND: The percutaneous plating technique provides indirect proximal humeral fracture reduction with minimal soft tissue exposure when compared with open direct plating. Any advantages of the percutaneous plating technique over the standard open reduction method were examined.
METHODS: Twenty patients treated percutaneously and 20 treated by open reduction for two and three part humerus fractures by a single primary surgeon over a five year period were evaluated by retrospective chart review. Evaluation parameters included estimated surgical blood loss and time, time to radiographic healing, adverse events, secondary interventions, and functional outcomes via the DASH (disabilities of arm, shoulder, hand) survey.
RESULTS: The percutaneous method yielded an average surgical blood loss of 73 mL compared with 111 mL for open. DASH outcome measures revealed a mean score of 39.5 for patients treated percutaneously, while those treated by open fixation had a mean score of 41.2. Comparison of time to radiographic healing showed an average of 124 days when treated percutaneously and 149 days when treated open.
CONCLUSIONS: Mean surgical blood loss and radiographic healing time favored the percutaneous plating method. The percutaneous technique yielded statistically similar functional outcomes to the open reduction internal fixation method, with minimal scarring and soft tissue damage. 167. Clinical Presentation of Patients with Symptomatic Anterior Hip Impingement *John C. Clohisy, M.D. (n) St. Louis, MO Evan R. Knaus, D.O. (n) St. Louis, MO Devyani M. Hunt, M.D. (n) St. Louis, MO Gail E. Pashos, MPH, MT (ASCP) (n) St. Louis, MO Marcie Harris Hayes (n) St. Louis, MO Heidi Prather, D.O. (n) St. Louis, MO
INTRODUCTION: Femoroacetabular impingement (FAI) has become an increasingly recognized etiology of labrochondral disease and secondary osteoarthritis. Nevertheless, there is limited information regarding the clinical syndrome associated with FAI.
PURPOSE: The purpose of this study was to determine the clinical history, functional status, activity status, and physical examination findings that characterize symptomatic FAI.
METHODS: Fifty one consecutive patients (52 hips) with symptomatic FAI were evaluated prospectively. Comprehensive evaluation of the clinical history, physical exam, and previous treatments was performed. Patients completed demographic and validated hip questionnaires including the Baecke, SF 12, Modified Harris Hip, and UCLA activity score.
RESULTS: The average patient age was 35 years and 57% were male. Symptom onset was most commonly insidious (68%) and activity related groin pain was the predominant complaint (88%). The mean time from symptom onset to definitive diagnosis was 3.1 years. Patients were evaluated by an average 3.9 healthcare providers prior to diagnosis and inaccurate diagnoses were common. Seventeen percent of the patients had surgical intervention at another anatomic site without resolution of symptoms. On examination, 92% of the hips were painful with the anterior impingement test. Hip flexion and internal rotation in flexion were limited to an average 97° and 9°, respectively. The patient cohort was relatively active with major restrictions of function, activity, and overall health.
CONCLUSION: These data underscore the concept that enhanced awareness of the clinical syndrome associated with FAI will result in more timely diagnosis and treatment. 168. Results of Hip Arthroplasty in Patients that Sustain Iatrogenic Punctures of the Labrum John S. Badylak, M.D. (n) Madison, WI James S. Keene, M.D. (n) Madison, WI *Matthew J. White, M.D. (n) Madison, WI
INTRODUCTION: Although iatrogenic labral punctures are estimated to occur in 18% of hip arthroscopies, the consequences of these punctures have not been documented. This study examined this issue by comparing the results of 50 patients that had iatrogenic labral punctures (ILP) with those of 50 patients that did not have labral punctures (NLP) during their hip arthroscopy.
MATERIAL AND METHODS: From a database of 250 patients who had their hip arthroscopy performed by the senior author, 50 patients with ILPs were identified. ILPs were recorded on each patient’s “hip sheet” at the time of their arthroscopy. The results of hip arthroscopy in these patients were compared to those of 50 demographically matched patients with similar arthroscopic procedures selected from the remaining 200 patients that did not have labral punctures (NLP). All hips included in this study were examined by the senior author and assessed with Byrd's 100 point modified Harris hip scoring system prior to arthroscopy, and at 3, 6, and 12 months after surgery .
RESULTS: The average age of the 50 ILP and 50 NLP patients was 42 and 39 years, respectively, and the preoperative scores of both groups averaged 35 points. Average joint distraction was 13 mm (range 9 18 mm) and 15 mm (range 10 19 mm) in the ILP and NLP patients, respectively. At arthroscopy, 34% of the ILP and 20% of the NLP patients were found to have osteoarthritis and 90% of the ILP and NLP patients had debridement of labral tears. In all ILP patients, the cannula that punctured the labrum was repositioned immediately following the establishment of the anterior portal. After surgery, the two groups had improvement of their hip pain and had six week scores that averaged 69 and 73 points, respectively. At six months, their scores averaged 80 and 81 points, and after 12 months, the scores averaged 84 and 86 points in the ILP and NLP patients, respectively. At all follow up intervals, there were no significant differences between the scores of the two groups (p > 0.05).
CONCLUSINS: Iatrogenic labral punctures did not affect the short term (> 1 year) outcomes of patients who sustained these injuries at the time of their hip arthroscopy. 169. Nerve Injury After Periacetabular Osteotomy (PAO): A Multicenter Study *Rafael J. Sierra, M.D. (n) Rochester, MN John C. Clohisy, M.D. (n) St. Louis, MO Paul Beaule, M.D. (n) Ottawa, Ontario, Canada Perry L. Schoenecker, M.D. (n) St. Louis, MO Young Jo Kim, M.D. (n) Boston, MA Robert T. Trousdale, M.D. (n) Rochester, MN
INTRODUCTION: The prevalence, factors predisposing to, and outcome of nerve injuries after PAO is not well known. Our objective was to report the prevalence of nerve injury after PAO with special emphasis on patient and surgical related factors.
MATERIALS AND METHODS: 1,468 PAO performed at four institutions between 1991 and 2007 were reviewed. Twenty seven patients developed nerve injuries (1.9%). There were 21 patients with an average age of 24 (range 13 to 53). The underlying diagnosis was dysplasia in 16, post Perthes in 2, epiphyseal dysplasia in 1, retroversion in 1, and neuromuscular dysplasia in 7. Five patients had previous surgery, and three patients had concomitant procedures. Intraoperative nerve monitoring was used for all cases.
RESULTS: Sciatic nerve or its peroneal division was injured in 16, femoral in 8, and combined sciatic/femoral in 1. The deficit was motor only in 2, sensory only in 6, and combined in 17. Exploration and neurolysis was performed in four cases. The average time to recovery or plateau of deficit was 9 months (average 2 days to 24 months). Femoral nerve motor function improved in all cases. Eight sciatic nerve injuries had permanent deficits (seven motor and one sensory).
DISCUSSION: Femoral motor deficit improved in all patients. This nerve is at risk with medial retraction of the psoas in anticipation of the pubic osteotomy. The sciatic nerve is at risk during the ischial cut, bone removal from posterior column, or from extremity lengthening. Motor function recovers fully in only half of these injuries. 170. Osteoarthritis Associated with Femoroacetabular Impingement – Nonsurgical Treatment Reduces Pain and Improves Function Hany El Rashidy, M.D. (n) Chicago, IL Victoria Brander, M.D. (n) Chicago, IL Mahesh Polavarapu, B.S. (n) Chicago, IL Angela Adams, B.S. (n) Chicago, IL Michelle Chambers, B.S. (n) Chicago, IL *S. David Stulberg, M.D. (n) Chicago, IL
Femoracetabular impingement deformities are believed to be a common cause of early hip osteoarthritis. Surgery focuses on reducing pain and improving motion or attempting to reduce osteoarthritis progression through structural realignment. However, there is no evidence that surgery alters the natural history of arthritis associated with FAI. Similarly, there are no studies describing the outcomes of nonsurgical treatment of this condition.
METHODOLOGY: Patients with moderate, painful osteoarthritis associated with FAI were enrolled in a nonsurgical treatment program. They underwent three fluoroscopically guided intra articular hylan GF injections and customized exercise. Patients were evaluated before treatment and after three months. Main outcomes were visual numeric pain score (VAS), adverse events, walking distance, range of motion, and satisfaction. Radiographs were evaluated for degree of osteoarthritis and impingement (CAM or Pincer) deformities.
RESULTS: In these 40 hip joints with moderate osteoarthritis, 43% had only CAM deformities, 43% combined CAM/Pincer lesions, and 13% Pincer only lesions. Seventy percent of patients were male, mean age 53 years. Average pre treatment VAS scores were: rest 35.3, walk 62.8, and night 43.6. Mean pain scores at three months were 23.9 at rest, 48.4 during walking, and 25.9 at night; all improvements were statically significant (p<0.05). Eighty percent of patients reported that they were satisfied/very satisfied with the results. Two patients reported pain after injection: one at the injection site and one reported hip pain after the second injection, which resolved without treatment.
CONCLUSIONS: Intra articular hylan GF 20 injections with customized exercise safely and effectively reduces pain and improves function in moderate hip osteoarthritis associated with FAI deformities. A prospective randomized trial comparing surgical to nonsurgical therapy is warranted. 171. Results of Hip Arthroplasty and Labral Debridement in Patients with Femoroacetabular Impingement *Matthew J. White, M.D. (n) Madison, WI James J. McCarthy, M.D. (n) Madison, WI James S. Keene, M.D. (n) Madison, WI Mark E. Flanum, M.D. (n) Madison, WI
INTRODUCTION: Untreated femoroacetabular impingement (FAI) has been promoted as a cause of poor results after arthroscopic debridement of labral tears. This study compares the functional results of patients with FAI to those of patients without FAI who at the time of their hip arthroscopy only had treatment of their intra articular lesions.
MATERIAL AND METHODS: The preoperative radiographs and magnetic resonance arthrograms (MRAs) of 150 consecutive patients who had their preoperative imaging completed at our institution, their hip arthroscopy performed by the senior author, and a minimum follow up of one year following their surgery were examined for abnormal alpha and center edge angles (CEA). From these measurements, 42 patients with FAI (alpha angle > 55° or CEA > 40°) were identified. Results of hip arthroscopy in these patients were compared to 42 demographically matched patients that were selected from the remaining 120 patients that did not have radiographic evidence of FAI. All 84 hips included in this study were examined by the senior author and assessed with Byrd's 100 point modified Harris hip scoring system (HHS) prior to arthroscopy, and at 3, 6, and 12 months after surgery.
RESULTS: The average age of the patients with and without FAI was 39 and 41 years, and their preoperative HHS averaged 41 and 45 points, respectively. Prior to surgery, all 84 patients had anterior hip pain with prolonged sitting and pain with flexion and internal rotation of their hip. Three months after surgery, the scores averaged 85 and 86 points and at 12 months, the scores averaged 91 and 90 points for patients with and without FAI, respectively. At all of the follow up intervals, there were no significant differences between the scores of the two groups (p > 0.05).
CONCLUSIONS: Femoroacetabular impingement that was evident on preoperative radiographs and MRAs did not affect the outcomes of patients who at the time of their hip arthroscopy only had treatment of their intra articular lesions. 172. Results of Hip Arthroscopy in Patients with Gluteus Medius Tendon Tears David M. Marcu, M.D. (n) Madison, WI James S. Keene, M.D. (n) Madison, WI *Brian J. Ludwig, M.D. (n) Madison, WI Donna G. Blankenbaker, M.D. (n) Madison, WI Arthur A. DeSmet, M.D. (n) Madison, WI
INTRODUCTION: When an MRI or MR arthrogram of the hip documents a labral tear and a gluteus medius tendon (GMT) tear in a patient with hip pain, a question that arises is what should be done about the GMT tear. Arthroscopic repair of GMT tears has been advocated as an adjunct to hip arthroscopy for the treatment of hip pain. To date, the indications for this procedure and the outcomes of patients who have had hip arthroscopy without repair of their GMT tears have not been delineated. This study compares the results of 30 patients with and 30 patients without GMT tears who at the time of their hip arthroscopy only had treatment of their intra articular lesions.
METHODS: Preoperative magnetic resonance arthrograms (MRAs) of 150 patients who had their imaging completed at our institution and their hip arthroscopy performed by the senior author, were reviewed by two musculoskeletal radiologists who were looking for GMT tears. From this review, 30 patients with full thickness GMT tears (0.6 to 1.8 cm in length) were identified. Results of hip arthroscopy in these patients were compared to those of 30 demographically matched patients without GMT tears. All 60 hips were assessed with Byrd's 100 point modified Harris hip scoring system prior to arthroscopy, and at 3, 6, and 12 months after surgery.
RESULTS: Average preoperative scores of patients with tendon tears (GMT patients) and the patients without tears (GWT patients) were 41 and 46 points, respectively. Prior to surgery, all 60 patients had anterior hip pain, and 20 patients (10 in each group) had pain and tenderness at the greater trochanter. Three months after surgery, none of the GMT or GWT patients had greater trochanteric pain, and their average hip scores were 85 and 88 points, respectively. At 6 months, the scores averaged 88 and 89 points, and after 12 months, the scores averaged 90 and 91 points. At all follow up intervals, there were no significant differences between the scores of the two groups (p>0.05).
CONCLUSIONS: Gluteus medius tendon tears, evident on preoperative MRAs, did not affect the outcomes of patients who at the time of their hip arthroscopy only had treatment of their intra articular lesions. 173. Osseous Remodeling After Femoral Head Neck Junction Osteochondroplasty for Hip Impingement Disorders Murat Pekmezci, M.D. (n) St. Louis, MO *Nader A. Nassif, M.D. (n) St. Louis, MO Gail Pashos, B.S. (n) St. Louis, MO Perry L. Schoenecker, M.D. (n) St. Louis, MO John C. Clohisy, M.D. (n) St. Louis, MO
INTRODUCTION: Femoral head neck junction recontouring is utilized to correct femoracetabular impingement abnormalities. The biologic remodeling of the osteochondroplasty site has not been well described. The purpose of this study was to evaluate the radiographic healing and remodeling of femoral head neck junction osteochondroplasties.
METHODS: One hundred twenty two patients (130 hips) who had an open osteochondroplasty procedure by a single surgeon were retrospectively reviewed at an average 19 months (range, 12 52). The average age was 33 years. Femoral head neck offset (HNO), head neck offset ratio (HNOR), and alpha angle (AA) were analyzed. Features of osseous remodeling, deformity recurrence, and procedure complications were recorded.
RESULTS: On frog lateral views, the mean HNO improved 5.9 mm, HNOR improved 0.12, and the AA improved 25° (all, p<0.001). For the cross table lateral views, the mean HNO improved 4.1 mm, mean HNOR 0.08, and the mean AA 22.2° (all, p<0.001). Partial or complete corticalization was observed in 62% of cross table lateral and 78% of frog leg lateral views. Less than 25% had regrowth at the osteochondroplasty site. Minor heterotropic bone formation was observed in 16.4% of patients. Clinical outcomes were evaluated on 105 hips. The mean Harris hip score improved from 63.1 to 83.3 (p<0.001) with 91% of the patients experiencing overall improvement in their scores. No femoral neck fractures were observed.
DISCUSSION/CONCLUSION: This study demonstrates the correction obtained with femoral head neck junction osteochondroplasty is maintained over the short term, and radiographic remodeling of the area indicates early signs of recorticalization in the majority of the patients. 174. Multi Center Study for Incidence of DVT and Pulmonary Embolism After Periacetabular Osteotomy John C. Clohisy, M.D. (n) St. Louis, MO Perry L. Schoenecker, M.D. (n) St. Louis, MO *Rafael J. Sierra, M.D. (n) Rochester, MN Robert T. Trousdale, M.D. (n) Rochester, MN Paul Beaule, M.D. (n) Ottawa, Ontario, Canada Young Jo Kim, M.D. (n) Boston, MA Michael Millis, M.D. (n) Boston, MA
INTRODUCTION: Patients with hip dysplasia undergoing major orthopedic surgeries are at risk of deep vein thrombosis (DVT). The objective of this study was to determine the incidence of DVT and pulmonary embolism (PE) in those patients who had undergone an elective peri acetabular osteotomy (PAO).
METHODS: Data was collected from four different centers between January 1996 and April 2008. 729 patients are included: 180 (26%) were male and 506 (74%) female; average age 25 years (range 15.4 56.5); average BMI 22.1 (18 42). DVT prophylaxis was for Center A: Coumadin and calf pumps for three weeks and ASA for three weeks before 2000 and ASA for six weeks after 2000. Center B: ASA and calf pump for six weeks. Center C: LMWH for three weeks; Center D Coumadin for three weeks. DVTs were diagnosed with duplex ultrasound and PEs with chest CT.
RESULTS: Out of the 729 patients, 6 (0.82%) had DVT (5 females, 1 male) and 3 (0.41%) had a PE (2 males, 1 female). Five DVTs were below the knee and one in the common femoral vein. The mean age of patients with DVT was 38.5 (range 27 44) and BMI 26.4 (range 22 31).
CONCLUSION: The overall incidence of DVT after major pelvic osteotomy is lower than for other types of elective hip surgery such as hip replacement which is probably due to the relative younger age, supine position, and minimal extremity manipulation associated with the PAO. Because no major complications were associated with the prophylaxis, all patients undergoing PAO receive DVT prophylaxis, although no standardized protocol has been established.
175. Periacetabular Osteotomy for the Treatment of Acetabular Dysplasia: A Systematic Review of the Literature *John C. Clohisy, M.D. (n) St. Louis, MO Amanda J. Schutz, Ph.D. (n) St. Louis, MO Lauren St. John, B.S. (n) St. Louis, MO Perry L. Schoenecker, M.D. (n) St. Louis, MO Rick W. Wright, M.D. (n) St. Louis, MO
INTRODUCTION: The periacetabular osteotomy (PAO) is commonly utilized as a surgical treatment for symptomatic acetabular dysplasia. However, the strength of clinical evidence to support this procedure has not been critically reviewed. The purpose of this study was to perform a systematic literature review to analyze the level of evidence regarding the PAO, and to assess the efficacy of this procedure.
METHODS: We searched Medline, CINAHL (Cumulative Index to Nursing & Allied Health), PubMed, EMBASE, and the Cochrane Library for articles published between January 1950 and August 2007. Inclusion criteria included English language and human participants. Database search terms included: “hip dysplasia”, “periacetabular osteotomy”, “Bernese osteotomy”, and “Ganz osteotomy.” Exclusion criteria included surgical technique descriptions, lack of minimum two year follow up, and lack of reporting radiographic or clinical results. The searches identified 112 studies and 13 of these met our criteria.
RESULTS: The 13 studies included a total of 667 hips, and 12 were Level IV evidence in the form of retrospective case series. Good to excellent results were reported in 54% to 89% of hips at mid term follow up. Radiographic deformity correction was consistent. Fair and poor clinical results were associated with more advanced preoperative osteoarthritis. The procedure was commonly associated with reduced hip flexion motion postoperatively.
CONCLUSION: The current level of evidence to support the clinical efficacy of the PAO is modest (Level IV). These data suggest that continued clinical investigation is needed to better define patient selection criteria for surgery, to refine surgical techniques, and to optimize clinical results. 176. Total Hip Arthroplasty After Periacetabular Osteotomy: A Multi Center Retrospective Review *Michael J. Taunton, M.D. (n) Rochester, MN Louis Stryker, M.D. (n) Rochester, MN Rafael J. Sierra, M.D. (n) Rochester, MN John C. Clohisy, M.D. (n) St. Louis, MO Michael Millis, M.D. (n) Boston, MA Young Jo Kim, M.D. (n) Boston, MA Robert T. Trousdale, M.D. (n) Rochester, MN
INTRODUCTION: The Bernese periacetabular osteotomy (PAO) may be an effective treatment for patients with an underlying acetabular deformity that can be corrected to a position of a stable, congruent hip joint. However, a subset of patients goes on to develop end stage arthritis.
METHODS: The computerized databases of the authors’ institutions were used to identify all PAOs that subsequently underwent total hip arthroplasty (THA), with a minimum of two years of clinical and radiographic follow up. The operative reports, x rays, and clinical notes were reviewed to correlate clinical factors.
RESULTS: There were a total of 787 PAOs performed at the authors’ institutions. Average clinical follow up from PAO was 7.9 years. Average clinical follow up from THA was 3.3 years. The average age at PAO was 33.6 years. The average pre PAO Harris Hip Score (HHS) was 57; the average post PAO HHS was 70. There were 34 patients that subsequently underwent THA. The average time between PAO and THA was 5.6 years. The average post THA HHS was 87.5. Four patients had a complication after their THA. There was superficial wound drainage in two. There were dislocations in two patients, both of which underwent revision.
DISCUSSION AND CONCLUSION: The rate of failure of PAO to THA was 4.3% in this study. The revision rate after THA was 4.7%. The difficulty of the THA was perceived to be greater, with longer operative times. Surgeons aware of the risk of failure of PAO and the increased difficulty of THA after PAO may take measures to improve patient outcome. 177. Single Surgeon Learning Curve for Total Hip Resurfacing *Ryan M. Nunley, M.D. St. Louis, MO (a Smith & Nephew) Jinjun Zhu, M.D. (n) St. Louis, MO Robert L. Barrack, M.D. St. Louis, MO (a Smith & Nephew)
Total hip resurfacing has recently gained popularity in North America, but many orthopedic surgeons have not had formal training with this technically demanding procedure. The purpose of this study was to determine the learning curve associated with hip resurfacing.
We retrospectively reviewed the first 150 total hip resurfacing cases performed by a single surgeon at a high volume, university referral hospital from June 2006 to January 2007. Demographic data, radiographic measurements, and adverse events were recorded for all patients. No patient was lost to follow up.
Mean age was 50.2 years (range, 33 81 years) and mean body mass index was 27.9 kg/m 2 (range, 20.1 39.5 kg/m 2). There were no femoral neck fractures, no lateral femoral neck notches, and no patient required revision surgery. There was one patient with peroneal nerve palsy (second patient in this series), and one hip dislocation at one year after surgery (#17 in series) treated with closed reduction and no further episodes. Nine hips in the first 25 cases had femoral component placed into relative varus compared to the preoperative femoral neck shaft angle. Varus malpositioning of the femoral component steadily improved over the series, but it was not until the last 25 patients (of 150) that femoral stem malpositioning was avoided. Acetabular inclination greater than 50° occurred in 19 hips of the first 100 case, but only 4 times in the last 50 cases.
Although the complication rate is low in this series, total hip resurfacing should be approached with caution by surgeons unfamiliar with this technically demanding procedure. 178. Posterior Column Plating and an Uncemented Cup for Pelvic Discontinuity in Revision THA *Harold W. Rees, M.D. (n) Oak Park, IL Daniel J. Berry, M.D. Rochester, MN (a,c DePuy; a Stryker, Zimmer) David G. Lewallen, M.D. Rochester, MN (a,b,c,e Zimmer)
INTRODUCTION: The purpose of this study was to evaluate the outcome of pelvic discontinuity treated with posterior column plating and an uncemented acetabular component in a large series of patients.
METHODS: From a single institution registry of 11,097 revision THAs, all patients who had pelvic discontinuity treated solely with reconstruction plating and an uncemented cup fixed with screws were identified. Sixty two hips met the inclusion criteria. Two patients died and two patients were lost to follow up, leaving 58 hips in 55 patients (mean age 62 years; 6 men, 49 women) in the study cohort. Mean follow up was 3.7 years (range 2 15).
RESULTS: Harris hip scores improved from average 39 preoperatively to 74 postoperatively, and 46 patients had no or slight pain at latest evaluation. Final follow up radiographs were available for 50 hips at average follow up of 3.9 years. Eight cups migrated and 16 discontinuities were not healed at latest follow up. Thirty three hips had both a stable cup and definitely or probably healed discontinuity. Eleven of the 16 hips with an unhealed discontinuity had a stable cup fixed to the superior hemipelvis. Eight of the 16 hips with an unhealed discontinuity reported slight or no pain. Only one patient was re revised for cup loosening and no hips were reoperated for unhealed discontinuity. Complications included 4 infections and 2 dislocations, all of which required revision. There were no sciatic nerve injuries.
DISCUSSION: Posterior column plating and an uncemented porous acetabular cup led to pelvic healing in 68% of hips, and a stable cup in 84% of hips. Complications were not infrequent. 179. Repair versus Reconstruction of Posteromedial and Posterolateral Corners in the Multiligament Injured Knee Bruce A. Levy, M.D. (n) Rochester, MN *Diane L. Dahm, M.D. (n) Rochester, MN Diego A. Herrera, M.D. (n) Rochester, MN Peter B. MacDonald, M.D. (n) Rochester, MN Khaled A Dajani, M.D. (n) Rochester, MN Michael J. Stuart, M.D. (n) Rochester, MN
INTRODUCTION: The purpose of this study was to compare the clinical and functional outcomes of a consecutive series of knee dislocation patients who underwent acute repair of collateral ligaments, followed by anterior and posterior cruciate ligament reconstruction (ACL/PCL), with those who had single stage reconstruction of all ligaments.
METHODOLOGY: All patients with evidence/presumption of knee dislocation treated by a single surgeon, identified in our prospective database were included. Between February 2004 and May 2005, patients were treated with acute repair of the posteromedial corner (PMC) and/or posterolateral corner (PLC), followed by ACL/PCL reconstructions. Between May 2005 and February 2007, patients were treated with single stage multiligament knee reconstruction. All patients followed a standard rehabilitation protocol. International Knee Documentation Committee (IKDC) subjective scores and Lysholm scores as well as clinical data were documented.
RESULTS: Forty two knees in 41 consecutive patients were identified. Group A consisted of 18 acute repairs in 14 patients of the PLC (11) and/or PMC (7), followed by ACL/PCL reconstructions. Mean follow up was 31 months (range 13 42). Group B consisted of 31 reconstructions in 27 patients of the PLC (23) and/or PMC (8), at the time of ACL/PCL reconstructions. Mean follow up was 18 months (range 12 to 30). Five of the 11 PLC (45%) repairs and 1 of the 23 PLC (4%) reconstructions failed (p<0.008). Two of the 7 PMC (29%) repairs and 1 of the 8 PMC (13%) reconstructions failed (p=0.57). Following revision reconstructions in both groups, no significant differences were noted for mean IKDC subjective scores (77 vs. 70, p=0.33) and mean Lysholm scores (86 vs. 80, p=0.19).
CONCLUSION: Our series demonstrated a statistically significant higher rate of failure for repair of the PLC, compared to reconstruction. No significant difference was found between PMC repair and reconstruction. We caution against the use of primary PLC repair in the setting of multiligament knee injury. 180. Effect of ACL Reconstruction and Meniscectomy on Length of Career in National Football League Athletes: A Case Control Study *Corey S. Gill, M.D. (n) St. Louis, MO Stephen Lyman, Ph.D. (n) New York, NY Ronnie P. Barnes, M.D. (n) New York, NY Scott A. Rodeo, M.D. (n) New York, NY Russell F. Warren, M.D. (n) New York, NY Robert H. Brophy, M.D. (n) St. Louis, MO
INTRODUCTION: Meniscal and anterior cruciate ligament injuries are common in college football athletes. The effect of meniscectomy and/or ACL surgery during college on the length of an athlete’s career in the National Football League has not been well examined. The purpose of the current study was to test the hypothesis that athletes with a history of meniscectomy or ACL surgery prior to the NFL combine would have a shorter career than matched controls.
METHODS: A database containing the injury history and career NFL statistics of athletes from 1987 2000 was used to match athletes with a history of meniscectomy and/or ACL surgery to controls without previous surgeries. Athletes were matched by position, year drafted, round drafted, and additional injury history. Outcome measures included games played, games started, and years played.
RESULTS: A total of 54 athletes with a history of meniscectomy, 29 with a history of ACL reconstruction, and 11 with a history of both ACL reconstruction and meniscectomy were identified and matched to controls. A history of isolated meniscectomy significantly reduced the length of career in terms of years (5.6 vs. 7.0, p = 0.03) and games played (62 vs. 85, p=0.02) compared to controls. Isolated ACL surgery did not significantly reduce the length of career in years or number of games played. Athletes with a history of both ACL reconstruction and meniscectomy had a shorter career in terms of games started (7.9 vs. 35.1, p<0.01), games played (41 vs. 63, p=0.07), and years in the league (4.0 vs. 5.8, p=0.08) compared to athletes with a history of either surgery alone.
CONCLUSIONS: Meniscectomy, but not ACL reconstruction, shortens the expected career of a professional football player. A combination of ACL reconstruction and meniscectomy may be more detrimental to an athlete’s durability than either surgery alone. Clinically, a better understanding of the natural history of ACL and/or meniscus injury in elite athletes may lead to improvements in surgical treatment and rehabilitation after these injuries. 181. Outcome Analysis of Arthroscopic Posterior Labral Repair in Athletes *Mark J. Sytsma, M.D. (n) Milwaukee, WI William T. Pennington, M.D. (n) Milwaukee, WI Brian A. Bartz, P.A. (n) Milwaukee, WI Jonathan Klinger, B.S. (n) Milwaukee, WI
PURPOSE: To evaluate the incidence, surgical treatment, and prognosis of posterior labral tears associated with athletes with respect to satisfaction, functional outcome analysis, and return to sport.
METHODS: Seventy five consecutive patients injured in athletics were treated surgically during the two year period of 2005 2006 for labral pathologies. Twenty seven of these (36%) were treated for posterior labral tears. The primary mechanisms of injury were from direct trauma to the posterior labrum in contact athletics and repetitive overhead athletic activity leading to microinstability lesions. These patients, aged 15 43 years old (mean: 21), underwent arthroscopic repair of posterior labral tears. All patients were evaluated with ASES, UCLA, Constant Score, VAS, and for planes of active motion and dynamometric strength. Scores and measurements were obtained preoperatively, and 3, 6, 12, and 24 months postoperatively. Outcomes and results were analyzed for statistical significance.
RESULTS: A 93% patient satisfaction rate was observed for arthroscopic posterior labral repairs at two years postoperatively. At 24 months postoperatively, statistically significant improvement was observed in all outcome parameters from preoperative values. Return to sport was achieved in 25 of 27 patients.
DISCUSSION/CONCLUSION: Surgical treatment of posterior labral pathologies is predictably effective in returning athletes to previous athletic activities as demonstrated by the significant functional improvement in this subset of patients as well as the overall high level of ability to return to pre injury level of function. 182. Outcomes of ACL Reconstruction with Concomitant Inflammatory Arthritis *Nicholas L. Strasser, M.D. (n) Rochester, MN Jay P. Shah, B.S. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN Bruce A. Levy, M.D. (n) Rochester, MN Michael J. Stuart, M.D. (n) Rochester, MN Diane L. Dahm, M.D. (n) Rochester, MN
INTRODUCTION: The outcome of patients with inflammatory arthritis (IA) undergoing anterior cruciate ligament (ACL) reconstruction has not been previously reported. The purpose of our study was to compare the outcomes of ACL reconstruction in patients with and without inflammatory arthritis.
METHODS: The records of all patients at our institution who underwent ACL reconstruction between 1980 and 2006 were reviewed. Inclusion criteria were primary ACL reconstruction, prior or concurrent diagnosis of an IA, and ≥ 2 years potential follow up. Patients with a history of multi ligamentous injury were excluded. These patients were matched on the basis of gender, age (± 6 years), and year of surgery, with a cohort of patients without IA, who also underwent ACL reconstruction. Clinical and functional outcomes were assessed utilizing pre and postoperative physical exam, IKDC, Lysholm, Tegner, and UCLA scores.
RESULTS: We identified 17 knees in 14 patients with IA, and a matched control group of 15 knees in 15 patients without IA that underwent primary ACL reconstruction. Three patients were lost to follow up in the IA group. Mean age at the time of surgery was 35 years (range 20 54) and 39 years (range 25–60) in the IA and control groups respectively. Mean follow up was 146 months (range 27–344) and 120 months (range 25–248) in each group respectively. There was no statistically significant difference between the two groups with respect to mean knee flexion, extension, Lachman, and pivot shift testing. There was a statistically significant difference between the IA and control cohorts for mean postoperative IKDC subjective (67 vs. 87, p = 0.006), Lysholm (76 vs. 95, p = 0.013), Tegner (2.5 vs. 5.2, p = 0.004), and UCLA (5.2 vs. 82, p = 0.013) scores. There were no graft failures requiring revision reconstruction in either group.
CONCLUSION: We found that the presence of an inflammatory arthritis negatively affected final IKDC, Lysholm, Tegner, and UCLA scores in patients that underwent ACL reconstruction when compared to a matched cohort without inflammatory arthritis. 183. Arthroscopic Repair of Meniscal Tears with Concomitant ACL Reconstruction in Patients 18 Years and Younger *Ryan T. Pitts, M.D. (n) Rochester, MN Jay P. Shah, B.S. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN Aaron J. Krych, M.D. (n) Rochester, MN Bruce A. Levy, M.D. (n) Rochester, MN Michael J. Stuart, M.D. (n) Rochester, MN Diane L. Dahm, M.D. (n) Rochester, MN
PURPOSE: The purpose of our study is to report the results of patients under the age of 18 who underwent arthroscopic meniscal repair in the setting of concomitant ACL reconstruction.
METHODS: We reviewed the records of all patients at our institution aged ≤ 18 years who underwent arthroscopic meniscal repair with concomitant ACL reconstruction from January 1990 to January 2005. Patients with dual stage operations and/or a history of multiligamentous injury were excluded. Pre and postoperative clinical and radiographic records were reviewed. Functional outcome was assessed using Tegner and IKDC subjective scores.
RESULTS: One hundred fifteen patients met inclusion criteria. Fifteen patients were lost to follow up; thus, 101 knees in 100 patients were available for review. Mean age was 16 years (range 13 18), and mean follow up was 8 years (range 2 19). Eighty knees were reconstructed with bone patellar tendon bone (BPTB) autografts, 19 with hamstring autografts, and 2 with BPTB allografts. There were 65 simple, 20 bucket handle, and 16 complex meniscal tears with clinical healing rates of 83%, 70%, and 75% respectively. Twenty one menisci (21% overall) failed initial repair at a mean of 17 months (range 3 61) postoperatively and underwent repeat arthroscopic surgery (16 meniscectomies, 5 revision repairs). Young age (p=0.03) and male gender (p=0.02) was associated with an increased rate of failure. ACL graft failure rate requiring revision was 6.7%. Mean pre and postoperative IKDC scores were 39 (range 23 72) and 90 (range 33 100) respectively. UCLA activity scores averaged 8.5 pre injury, 4.3 post injury, and 8.3 postoperatively.
CONCLUSIONS: This study demonstrated satisfactory rates of clinical healing and functional outcomes of meniscal repairs performed in conjunction with ACL reconstruction. 184. Can Surgeons Predict Outcome Following Meniscectomy? *Elizabeth R. Cohen, B.S. (n) Akron, OH John P. Albright, M.D. (n) Iowa City, IA Jingzhen Yang, Ph.D. (n) Iowa City, IA Annunziato S. Amendola, M.D. (n) Iowa City, IA Brian R. Wolf, M.D. (n) Iowa City, IA
BACKGROUND: Patients rely on their orthopedic surgeon to provide an accurate set of expectations with regard to return to activities of daily living, work, and recreational and competitive activities following meniscectomy. Up to this point, no study has examined the ability of surgeons to provide accurate predictions of patient outcome following meniscectomy.
OBJECTIVES: Determine the ability of surgeons to predict outcome following meniscectomy and identify which factors influence a surgeon’s score most significantly.
METHODS: Sixty two adults were prospectively studied. Data collected include demographic information and surgical observations, documented on a modified MOON form. Surgeons provided a predicted outcome score following surgery. Patient outcome was measured by IKDC. Kappa measure was used to evaluate inter observer agreement based on 11 identical case reports. Adjusting for age and gender, univariate analysis was completed. A model was created by multivariable linear regression to explain the factors which most strongly influence a surgeon’s outcome score.
RESULTS: Surgeon score was not significantly associated with IKDC score (p=0.2839). Highest grade of chondromalacia observed at time of surgery (p=0.0019) and patient’s psychological affect (p=0.047) were found to be most significantly associated with the surgeon prediction. Patient age (p=0.14), gender (p=0.5), and BMI (p=0.11) were not significantly associated with surgeon score. The mean kappa correlation measuring inter observer surgeon agreement was 0.725.
DISCUSSION: Although surgeons are making similar predictions, they are unable to accurately predict patient outcome. This has implications in providing accurate postoperative information to a patient’s family and providing appropriate follow up to the patient. 185. A Biomechanical Evaluation of a Novel, Self Cinching Stitch for Shoulder Arthroscopy, the Lasso Loop Stitch *Brent A. Ponce, M.D. Birmingham, AL (a DePuy Mitek) Chad D. Hosemann, III, M.D. (n) Birmingham, AL Parthasarathy Raghava, M.S. (n) Birmingham, AL John M. Tokish, M.D. (n) Colorado Springs, CO Alan W. Eberhardt, Ph.D. (n) Birmingham, AL Laurent Lafosse, M.D. (n) Annecy, France
INTRODUCTION: The weakest aspect of a rotator cuff repair remains the tissue suture interface. Improved stitch techniques may help reduce the number of implants without compromising repair construct strength. A novel stitch, the lasso loop, has been clinically used with success, but has not been biomechanically evaluated. The lasso loop stitch is a technically simple stitch where the mid portion of a suture is passed through the tissue creating a loop through which the free suture end is passed to create a self cinching stitch. The purpose of this study was to evaluate the biomechanical properties of the lasso loop in comparison to other common stitches used in shoulder surgery: namely the simple, mattress, Modified Mason Allen (MMA), and massive cuff (MAC) stitches.
METHODS: Forty sheep infraspinatus tendon grafts were equally divided among the five stitches. Each graft was cyclically loaded and then loaded to failure. Peak to peak displacement, cyclic elongation, and load to failure were measured. A one way analysis of variance was performed with a significance level of alpha=0.05.
RESULTS: The lasso loop (42.9 ±15.2N) had 44% higher load to failure than the simple stitch (29.8 ±27.5N) though the difference was not statistically significant (p>0.05). No difference was found between the mattress (44.9 ±23.2N) and lasso loop stitch (p>0.05). Both MAC (139.6 ±45.1N) and MMA (100.1 ±52.3N) had significantly higher load to failure than the lasso loop stitch (p <0.05).
CONCLUSION: The lasso loop stitch exhibits better properties than a simple stitch and similar properties to a mattress stitch. It is a simple arthroscopic stitch that holds great potential for addressing common pathology in shoulder arthroscopy. 186. Contact Pressure Properties of Osteochondral Defects of the Knee: The Effect of Non Vertical Walls Katherine J. Coyner, M.D. (n) Royal Oak, MI Scott Ensminger, B.S. (n) Royal Oak, MI *Sean Matuszak, M.D. (n) Royal Oak, MI Jacob Miller, B.S. (n) Royal Oak, MI Adam Steinman, B.S. (n) Royal Oak, MI Joseph H. Guettler, M.D. (n) Royal Oak, MI Kenneth A. Jurist, M.D. (n) Royal Oak, MI
OBJECTIVE: To compare the mechanical behavior and load transmission of full thickness osteochondral defects of articular cartilage in human knee cadaveric specimens. In addition, the change in behavior was measured after a cylindrical lesion of known dimension was converted to a conical shaped defect with beveled walls. Also, it was determined what part of the lesion size is more critical: the outer diameter or the inner diameter in relation to load transmission.
METHODS: Ten knee specimens were mounted in an MTS. Tekscan sensors were placed in the medial and lateral compartments. Dynamic pressure readings were recorded throughout the loading and holding phases. Readings were recorded for vertical walled (cylindrical shape) and beveled lesions (conical shape with base of cone 2 mm greater than apex) as size ranged from 6 16 mm. The distance from the center of the defect to the locus of peak pressure in each compartment was calculated.
RESULTS: An important comparison is the difference in center to peak pressure distance between well shouldered and beveled defects when using outer diameter as a metric (e.g., 10 mm beveled with 12 mm outer diameter vs. 12 mm well shouldered). In the lateral condyle, 4 out of the 6 test pairs showed an increased distance from well shouldered to beveled lesions, with an average distance of 0.2174 mm. In the medial condyle, 5 out of 6 test pairs showed an increased distance from well shouldered to beveled lesions, with an average distance of 0.5231 mm. Beveled lesions were observed to act more like well shouldered lesions of a larger size (10 mm beveled acted more like a 12 mm well shouldered). This comparison demonstrated in beveled lesions the more critical value was the outer diameter.
CONCLUSION: The outer diameter of beveled defects in knee articular cartilage is a better predictor of pressure distribution on surrounding cartilage than the inner diameter. Beveled lesions more accurately reflect the native in vivo state when treating articular cartilage lesions of the knee. These lesions should be evaluated and treated based on their outer diameter measurement, to avoid underestimating their true size and mechanical behaviors. 187. ACL Tibial Spine Avulsion Treatment and Outcomes *Darlene M. Guse, B.S. (n) Rochester, MN Jay P. Shah, B.S. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN Bruce A. Levy, M.D. (n) Rochester, MN Michael J. Stuart, M.D. (n) Rochester, MN Diane L. Dahm, M.D. (n) Rochester, MN
INTRODUCTION: Tibial spine avulsion fractures occur at the tibial insertion site of the anterior cruciate ligament (ACL). Treatment options for displaced fractures include suture or screw fixation of the avulsed fragment. We present the functional outcomes of a retrospective patient series treated for ACL tibial spine avulsion with either suture or screw fixation.
METHODS: Between 1980 and 2005, we identified patients who underwent surgical management of a tibial spine avulsion fracture. Pre and postoperative radiographic data, and pre and postoperative Tegner, UCLA, Lysholm, and International Knee Documentation Committee (IKDC) subjective scores were documented.
RESULTS: Twenty two patients met our inclusion criteria and were available for follow up at a mean of 87 months. Mean age was 17 years (range 7 to 39). Fifteen patients were treated with suture repair and seven patients with screw fixation. Fracture pattern was comminuted in 13 patients and simple in 9. All 22 knees had a preoperative Kellgren score of 0. Preoperative Lachman was documented in 16 knees (1 with 0, 5 with 1+, 8 with 2+, 2 with 3+) and postoperatively in 20 knees (16 with 0, 3 with 1+, 1 with 2+). The following improved significantly (p<0.0001) after surgery: mean knee total arc of motion (75° preoperative vs. 134° postoperative), Tegner (1.1 preoperative vs. 6.3 postoperative), UCLA (3.1 preoperative vs. 8.9 postoperative), Lysholm (43 preoperative vs. 90 postoperative), and subjective IKDC (45 preoperative vs. 93 postoperative) scores. Functional outcomes were not significantly associated with fixation method, presence of comminution, anatomic fracture reduction, or length of postoperative immobilization. Increasing age had a negative effect on Lysholm scores, IKDC, and Tegner scores. No patient required late ACL reconstruction for persistent instability.
CONCLUSION: Patients undergoing surgical management of tibial spine avulsion fractures had satisfactory clinical and functional outcomes regardless of fixation method used. Increasing age was a negative predictor of outcome in these injuries. 188. Outcomes Following Medial Patellofemoral Ligament Reconstruction with Hamstrings Allograft for Patella Instability *Ryan M. Arnold, M.D. (n) Omaha, NE David E. Brown, M.D. (n) Omaha, NE
INTRODUCTION: Treatment for patella dislocation or subluxation has included numerous surgical realignment and reconstruction procedures. Biomechanical studies have demonstrated the medial patellofemoral ligament to be the primary soft tissue restraint to lateral displacement of the patella. Few studies exist evaluating results of reconstruction of the ligament. The purpose of this study was to assess the functional and radiographic outcomes of medial patellofemoral ligament reconstruction for patella instability.
METHODS: Fifty eight knees with traumatic or recurrent patella instability were treated by two surgeons with medial patellofemoral ligament reconstruction using a hamstrings allograft were evaluated with physical examination, preoperative and postoperative radiographs, Kujala score, and KOOS score at a minimum of 12 months postoperative.
RESULTS: Twenty three knees were evaluated at a mean of 31 months postoperative. The remaining knees were unavailable for follow up. Mean sulcus angle was 146 preoperative and 141 postoperative. Mean congruent angle was 4° preoperative and 1.4° postoperative. Mean Kujala score was 72. Mean KOOS scores were: pain 82, symptoms 77, ADLs 91, sports 64, and quality of life 55. Mean postoperative range of motion was from full extension to 135° of flexion. Three patients had a positive apprehension sign; one patient underwent revision and continues to dislocate.
DISCUSSION AND CONCLUSION: Medial patellofemoral ligament reconstruction with hamstrings allograft for patella instability provides excellent prevention of dislocation, good pain relief, and functionality with daily activities, but patients struggle with sporting activities and overall quality of life. 189. Single Soft Tissue Graft Reconstruction of the Fibular Collateral Ligament and Posterolateral Corner Bruce A. Levy, M.D. (n) Rochester, MN *Steve J. Schechinger, M.D. (n) Minneapolis, MN Khaled A. Dajani, M.D. (n) Rochester, MN Diego A. Herrera, M.D. (n) Rochester, MN Robert G. Marx, M.D. (n) New York, NY
INTRODUCTION: The purpose of this study is to present the functional and clinical outcomes of a consecutive series of patients who underwent fibular collateral ligament (FCL) and posterolateral corner reconstruction (PLC) utilizing a single soft tissue allograft construct.
METHODS: Patients were identified through prospective sports medicine databases at two academic institutions. Only patients who had undergone FCL and PLC reconstruction (as opposed to repair) were included. All patients underwent identical surgical technique by two surgeons, and followed a standard postoperative rehabilitation protocol. Functional and clinical outcomes were assessed utilizing physical exam, Lysholm scores, and International Knee Documentation Committee (IKDC) subjective scores.
RESULTS: Eighteen knees in 18 patients were identified, with minimum two year follow up. There were 14 males and 4 females. Average age was 31 years (range 19 to 61). Mean clinical follow up was 30 months (range 24 to 75). Mean IKDC subjective score was 74 (range 33 to 99), and mean Lysholm score was 83 (range 46 to 100). Average knee range of motion was full extension to 119° of flexion (range 80° to 150°). Complications included stiffness requiring manipulation in three patients, and painful hardware requiring removal in two patients. No patients have required revision reconstruction to date. Four patients (22%) had residual laxity, predominately to varus stress post reconstruction.
CONCLUSIONS: Numerous posterolateral corner techniques have been reported in the literature with varying degrees of success. We describe a novel technique that takes into account the main static posterolateral corner stabilizers (popliteofibular ligament, fibular collateral ligament, and posterolateral capsule) which has not been previously reported. Our series demonstrated satisfactory clinical and functional outcomes. 190. Gapping of Meniscus Tears Sutured at Multiple Spacing Increments: A Bovine Cadaveric Model *Timothy L. Miller, M.D. (n) Columbus, OH David C. Flanigan, M.D. (n) Columbus, OH Joshua Harris, M.D. (n) Columbus, OH Justin Hepker, B.S. (n) Columbus, OH Erin Hutter, M.S. (n) Columbus, OH Robert Siston, Ph.D. (n) Columbus, OH
BACKGROUND: Repair of a torn meniscus is a common procedure in the realm of Sports Medicine orthopedic surgery. Few quality studies have addressed the question of what distance between sutures best stabilizes the repaired tissue and prevents gapping of the tear.
PURPOSE: To evaluate the amount of circumferential gapping that occurs with stressing of bovine meniscus tears repaired with 2 0 fiberwire sutures spaced at varied distances.
OBJECTIVE: To determine the ideal spacing increment of 2 0 fiberwire sutures for repair of complete longitudinal meniscus tears to prevent gapping.
METHODS AND MEAUREMENTS: In a biomechanics lab, full thickness longitudinal tears were created in 30 bovine cadaveric menisci. The tears were repaired with 2 0 fiberwire sutures spaced at 10 mm, 8 mm, 6 mm, 5 mm, 4 mm, and 3 mm increments in respective specimens. Five menisci of each spacing distance were stressed at a rate of 12.5 mm/minute to a maximum load of 70 20 Newtons in a custom built hydraulic displacement machine called the Instron. Gap distance of the tears was then measured and recorded for specimens of each spacing group.
RESULTS: Preliminary results of stressing the repaired menisci are currently pending completion.
CONCLUSION: Stress testing of repaired bovine cadaveric meniscus tears is currently underway. When results are completed and analyzed, an ideal suture spacing distance may be determined to allow for maximum biomechanical strength of the repair, maximum healing potential, and prevention of gapping. In time, it is hoped that these results may be applied to a human model. 191. Unicortical Locking Screws Provide Comparable Rigidity to Standard Screws in Clavicle Fixation Curtis W. Hartman, M.D. (n) Omaha, NE Hani Haider, Ph.D. (n) Omaha, NE Nicholas C. Branting, B.S. (n) Omaha, NE *Matthew A. Mormino, M.D. (n) Omaha, NE Edward V. Fehringer, M.D. (n) Omaha, NE
Mid shaft clavicle fracture fixation carries the risk of neurovascular injury. No reports exist concerning the utilization of a potentially safer method using locked unicortical fixation. The purpose of this study was to perform a biomechanical comparison of clavicle fracture fixation constructs with unicortical locked screws and standard bicortical screws.
Ten 4 th generation composite clavicles with transverse mid shaft osteotomies were randomly divided between two groups. Each osteotomy was reduced and fixed with a 2 nd generation eight hole 3.5 mm locking pelvic reconstruction plate on the superior surface with either bicortical compression screws (Group 1) or unicortical locking screws (Group 2). All specimens were tested on a 4 axis servohydraulic testing frame in three modes: axial rotation, anterior/posterior bending, and cephalad/caudad bending.
Mean construct stiffness for AP bending was 1.255 ± 0.058 Nm/deg and 1.442 ± 0.065 Nm/deg for groups 1 and 2, respectively (p=0.0013). Mean construct stiffness for axial rotation was 0.701 ± 0.08 Nm/deg and 0.726 ± 0.03 Nm/deg for groups 1 and 2, respectively (p=0.581). Mean construct stiffness for cephalad bending was 0.889 ± 0.064 Nm/deg and 0.880 ± 0.044 Nm/deg for groups 1 and 2, respectively (p=0.807). Mean construct stiffness for caudal bending was 2.523 ± 0.29 Nm/deg and 2.774 ± 0.25 Nm/deg for groups 1 and 2, respectively (p=0.182).
Bicortical fixation did not provide greater rigidity than unicortical locking fixation. In AP bending, unicortical locking fixation provided greater rigidity. Unicortical locking screw fixation provides comparable rigidity to standard bicortical screws in composite clavicle osteotomy fixation. 192. Locked Intramedullary Nailing of Two Part Surgical Neck Proximal Humeral Fractures Armodios M. Hatzidakis, M.D. (n) Denver, CO Robert J. Nowinski, D.O. (n) Newark, OH Duane Fenton, P.A. (n) Denver, CO *Michael J. Shevlin, M.D. (n) Omaha, NE Edward V. Fehringer, M.D. (n) Omaha, NE
INTRODUCTION: Intramedullary nailing (IMN) of proximal humerus fractures with unlocked proximal fixation has been associated with complications and variable outcomes. The purpose of this study is to report our experience with IMN and locked proximal fixation for two part surgical neck fractures.
METHODS: Forty nine patients with 49 Neer two part surgical neck fractures were treated with IMN and locked proximal fixation by three surgeons. An articular entry point was utilized for device insertion. Outcomes were quantified with Constant scores and standard radiographs.
RESULTS: Ten patients were lost to follow up, six due to deaths unrelated to the procedures. Thirty nine patients (29 female) with a mean age of 64 years were followed for at least 12 months (mean=20; range=12 48 months). All fractures healed primarily. Mean follow up Constant Score was 71 (SD=12, range 37 88) with a mean age adjusted Constant score of 97% (range=60 119%). Average Constant pain score was 13 (SD=2.2). Mean forward flexion was 134° (SD=23°). All but one fracture healed with a neck shaft angle greater than or equal to 125°. Five patients had additional surgery after fracture healing (hardware removal, manipulation, and heterotopic bone removal). Dynamic distal interlocking was associated with controlled settling of the fracture site in all patients in whom it was employed (12/12).
DISCUSSION AND CONCLUSION: Intramedullary nailing of two part surgical neck proximal humerus fractures with locked proximal fixation leads to predictable fracture healing and favorable outcomes. An articular entry point may allow less rotator cuff insertion injury and, therefore, improve results. 193. Complications of Acute Mid Shaft Clavicle Fractures Stabilized with a Rockwood Intramedullary Clavicle Pin Christopher D. Mudd, M.D. (n) St. Louis, MO *Kevin Quigley, M.D. (n) St. Louis, MO Lyndon B. Gross, M.D. (n) Chesterfield, MO
BACKGROUND: Mid shaft clavicle fractures have historically been treated non operatively; however, recent data suggest that the rates of nonunion and functional deficits are higher than previously thought with nonoperative management. Intramedullary clavicle fixation has emerged as a potential alternative to plate fixation. Previous studies of the safety and efficacy of intramedullary clavicle fixation have shown mixed results. In this study, we retrospectively evaluate the outcome of patients treated acutely with open intramedullary nailing of the clavicle with a Rockwood pin.
METHODS: We retrospectively identified 18 patients (14 male and 4 female with a mean age of 31 years) who sustained an acute closed mid shaft fracture of the clavicle and underwent open primary fixation with a Rockwood pin, from 2004 through 2007. The clinical and radiographic records of these patients were reviewed with emphasis on incidence of complications and time to union. Descriptive statistics were used to time to union, soft tissue complications, time to pin removal, and maintenance of reduction.
RESULTS: Fifteen (83%) of the patients achieved union in a mean of 12.9 weeks. Two non unions and one delayed union occurred requiring two of these patients to undergo repeat operations. The overall complication rate was 56%, with 50% of the patients experiencing a soft tissue complication and 28% experiencing a complication related to fracture healing. Complications included nonunion, posterior pain, superficial and deep infections, premature removal of the pin, and loss of reduction. Four of the fractures lost reduction, with a mean loss of length of 0.55 cm in these four patients.
CONCLUSIONS: Although the use of a Rockwood pin remains an option for fixation of simple mid shaft clavicle fractures, careful patient selection and excellent surgical technique are necessary as nonunion is an important complication to consider when using this device. Additionally, the patient must be cautioned that this implant has a high rate of soft tissue irritation and infection which may necessitate premature removal. 194. Antibiotic Nail Placement for Infected Unstable Long Bone Nonunions Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Matthew R. Karek, B.S. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI *Terrance J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: Open long bone fractures have high rates of nonunions and infections causing a treatment dilemma. Treatment requires nail removal to rid the infection and nail insertion to stabilize the fracture .
METHODS: Over a five year period, 2002 2007, 19 consecutive patients were treated with an intramedullary antibiotic (IABX) nail for infected unstable long bone nonunions. A retrospective evaluation of parameters was performed.
RESULTS: Ten male and 9 female patients with an average age of 45 years (range 17 71) were analyzed. The long bone fractures were 13 tibia and 6 femoral fractures. Initially, 63.2% (12/19) were open fractures and 52.9% were polytrauma. 57.9% (11/19) acute fractures were initially treated with a nail. 36.8% (7/19) were debrided before initiating IABX nail insertion. 26.3% (5/19) failed antibiotic bead insertion. 31.6% infections were refractory to all prior attempts of infection eradication. Culture results revealed methicillin resistant Staphylococcus aureus (5), Streptococcus (3), methicillin sensitive Staphylococcus aureus (2), Enterobacter (2), Pseudomonas aeruginosa (1), Serratia marcescens (1), Aspirgillus (1), and diphthroids (1). Infections were isolated bacteria (15), two bacterium (3), and three bacterium (1). Average IABX insertion duration was 16.4 days (range 2 49). No IABX nail complications (breakage, removal problems) were noted. Postoperative antibiotics were given orally (n=2), intravenous (n=9), or none (n=8). Eleven nonunions did not require any stimulus to heal while 2/19 required iliac crest bone graft and 7/19 bone morphogenetic protein for segmental defects. All nonunions were eventually treated with a stainless steel nail and were treated until union.
CONCLUSIONS: In this population, temporary intramedullary antibiotic nail insertion removes intramedullary infection, stabilizes the nonunion, and prepares the environment for definitive long bone nailing. 195. Duration of Antibiotic Prophylaxis and Clinical Outcome in Patients Following Major Orthopedic Trauma Clifford B. Jones, M.D. (n) Grand Rapids, MI *Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Benjamin C. Mgboh (n) Grand Rapids, MI Karen J. McAllen (n) Grand Rapids, MI Wayne E. Vander Kolk, M.D. (n) Grand Rapids, MI Jeffrey F. Barletta, M.D. (n) Grand Rapids, MI
INTRODUCTION: Eastern Association for the Surgery of Trauma Guidelines (EAST G) for antibiotic use following major orthopedic trauma recommend 24 hour duration of prophylaxis following wound closure, or 72 hours post injury, whichever occurs first. The goals of this study were to measure EAST G compliance, compare EAST G compliance versus noncompliance infection rates, compare antibiotic related complication rates, and identify infection associated risk factors.
METHODS: All patients ≥ 18 years of age with documentation of a Type III open fracture were retrospectively identified using the Institutional Trauma Registry from June 2003 to December 2006.
RESULTS: One hundred consecutive patients were evaluated. Demographics were similar between groups. Compliance with the EAST G was noted in 14% of patients. Infection rates were similar between the EAST G compliant and EAST G noncompliant groups (p=0.726). Antibiotic related complications did not differ (p= 0.367). Antibiotic costs were significantly lower in the EAST G compliant group ($109.94 vs. $340.38, p<0.001). Patients that required mechanical ventilation, had a pelvic fracture, had a higher ISS, received more blood transfusions, and had more operations were more likely to have an infection (p<0.001). Neither EAST G compliance (infection, 16% vs. no infection, 14%, p=0.726) nor duration of prophylaxis (infection, 6 [1 25] days vs. no infection, 4 [1 33] days, p=0.513) were associated with an infection. Units of blood transfused, the need for mechanical ventilation, the number of operations required and presence of a pelvic fracture were significant risk factors for infection predicting 40.5% of the variance for infection rates with the units of blood transfused and the need for mechanical ventilation accounting for 34.5% (F=16.13, p<.001).
CONCLUSIONS: EAST G compliance was poor. Antibiotic duration exceeding these guidelines did not lower infection rates, but significantly increased costs; thus, prolonged antibiotic prophylaxis should be discouraged. Blood transfusions and mechanical ventilation are strong predictors for infection. 196. Evaluation of Popliteal Artery Injury with Locked Lateral Plating of the Tibial Plateau *Michael S. Dee, M.D. (n) Omaha, NE John Sojka, M.D. (n) Kansas City, KS Miguel Daccarett, M.D. (n) Omaha, NE Matthew A. Mormino, M.D. (n) Omaha, NE
INTRODUCTION: Due to the proximity of the popliteal artery in the popliteal fossa, there is risk of artery injury when plating the tibial plateau. We studied the possibility of popliteal artery damage increasing as one places a fixed trajectory lateral proximal tibia locking plate with posterior plate lift off and or anterior plate translation from the ideal position.
MATERIALS/METHODS: Utilizing six cadaver specimens, the lateral surgical approach for placing a lateral proximal tibia locking plate was utilized. A Synthes 3.5 mm and a Synthes 4.5 mm proximal tibia lateral locking plate were studied. Screw trajectory was recorded along with proximity of the distal screw tip to the popliteal artery with plate locked in the straight lateral position. A 3 mm shim was placed to mimic posterior plate lift off. The amount of posterior medial screw tip rotation was recorded along with whether or not the screw tip contacted or injured the tibial artery. This same exercise was repeated with a 6 mm shim. The plate was then translated 5 mm anterior. This was followed by placement of a 3 mm shim and then 6 mm shim.
RESULTS: The artery was injured in 0/6 specimens using the 3.5 mm plate in all plate positions which were straight lateral (SL), SL with 3 mm posterior lift off (LO), and with SL and 6 mm LO, followed by 5 mm anterior translation (AT), 5 mm AT with 3 mm LO and then 5 mm AT and 6 mm LO. (2/6 with 5 mm AT and 6 mm LO had intimate artery contact). The artery was injured in 6/6 using the 4.5 mm plate in the 5 mm AT 6 mm LO position, 5/6 with 5 mm AT and 3 mm LO, 2/6 with 5 mm AT, 4/6 with SL and 6 mm LO, 2/6 with SL and 3 mm LO and 0/6 with SL.
CONCLUSION: The Synthes 3.5 mm proximal tibia lateral locking plate must be translated 5 mm and have 6 mm posterior lift off to put the popliteal artery at risk. The 4.5 plate, however, can put the artery at risk with as little as 3 mm posterior lift off in the intended lateral position or with 5 mm anterior translation with no posterior lift off. 197. Dislocation After Total Hip Arthroplasty Performed for Displaced Femoral Neck Fracture Abraham J. Cass (n) Rochester, MN *Joseph R. Cass, M.D. (n) Rochester, MN Bernard F. Morrey, M.D. (n) Rochester, MN
HYPOTHESIS: Over the past five years, there has been increased interest in the use of total hip arthroplasty (THA) for treatment of femoral neck fractures (FNF). Studies have quoted dislocation rates as high as 22% when THA is done for a FNF. A prior study from this institution (1969 1981) found a 10% dislocation rate. Subsequent to that time period, surgeons began to recognize and deal with some of the factors associated with postoperative instability. It is hypothesized that with a better understanding of the mechanisms that dislocation rates will be reduced.
METHODS AND MATERIALS: All arthroplasties performed at this institution for any reason since 1969 are entered into a computerized database. The period of 1984 2006 was selected for review. The charts and radiographs for each patient who underwent THA for a displaced FNF (OTA 31B) were reviewed and the data analyzed. Patient factors, surgical approach, capsular repair, head size, acetabular orientation, and leg length were assessed.
RESULTS: Thirty two patients underwent THA for a displaced FNF. One died intraoperatively, leaving 31 for review. One arthroplasty dislocated, for a rate of 3.2%. The average age of the patients was 74, (range 61 94). Average follow up was 6 years (range 1 16). No patient was lost to follow up. Of the surviving patients, those with follow up less than five years had their arthroplasty performed less than five years ago. The approach was anterolateral in 30 and posterior in 1. The head sizes were 22 mm (1), 26 mm (8), 28 mm (15), and 32 mm (7).
CONCLUSION: The risk of dislocation at this institution decreased from 10% to 3.2%, approaching that found after primary THA for osteoarthrosis.
SIGNIFICANCE: This study, with its 100% follow up rate, has demonstrated that by adhering to several known principles, it is possible to markedly decrease the risk of dislocation after THA in this population. 198. Baseball Bat Orthopedic Related Trauma: Outcomes Analysis Pablo R. Pazmiño, M.D. (n) Los Angeles, CA *Brian G. Larkin, M.D. (n) Detroit, MI J. Tracy Watson, M.D. (n) St. Louis, MO Djolbas Kuldjanov, M.D. (n) St. Louis, MO
INTRODUCTION: Few reports in the literature have focused on the orthopedic related fractures sustained from baseball bat related traumas. The current literature demonstrates that baseball bats have become a popular weapon in urban assault. Past studies have focused on neurosurgical aspects surrounding these traumas. These studies have already shown that the impact sustained from a baseball bat is 25% more than a 9 mm bullet, with up to three times its potential force (8,000 lbs). As a result, these injuries were often thought to be associated with severe soft tissue compromise.
METHODS: From 2001 2006, 143 patients who sustained baseball bat related trauma, fractures, and soft tissue injuries in our medical center were followed for subsequent sequelae. These patients were either directly seen by our orthopedic department, emergency room physicians, or found on a hospital trauma systems search afterwards.
RESULTS: Upper extremity injuries accounted for 32.2% of the cases, lower extremity injuries were found in 17.9% of the patients, and 83.2% sustained other or concomitant associated injuries. The ulna was found to be the most commonly fractured bone. Nonoperative treatment was indicated in 81.8% of patients, whereas surgical treatment including open reduction internal fixation was only indicated in 18.2% of the patients. Operative irrigation and debridement was performed for 13.7% of Grades I, II, and III open fractures prior to definitive treatment. Compartment syndrome and subsequent operative fasciotomies accounted for only 5.6% of all patients. Loss of consciousness occurred in 36.4% of patients. Males represent 93% of bat related trauma recipients. African Americans (76.2%) represent the ethnic group with the highest incidence who sustained bat related injuries in our urban trauma center. Warmest months correlated with higher incidences of assault (45.5%).
DISCUSSION AND CONCLUSION: These results suggest that while baseball bat related orthopedic trauma causes significant bony and soft tissue injuries it is not associated with the previously thought increase in soft tissue complications, surgical procedures, compartment syndromes, or subsequent fasciotomies. 199. Planned Delayed Transfer of Complex Pelvic/Acetabular Fractures from a Level III to a Level I Trauma Center Michael T. Archdeacon, M.D. Cincinnati, OH (e Stryker) Anthony Borzotta, M.D. (n) Cincinnati, OH John D. Wyrick, M.D. (n) Cincinnati, OH Jay Johannigman, M.D. (n) Cincinnati, OH *T. Toan Le, M.D. Cincinnati, OH (e Stryker)
INTRODUCTION: Regionalized Level I orthopedic management of complex pelvic fractures is normative, but scheduling delays after immediate transfer consume valuable bed days. We reviewed an evolving process of deliberately staging the transfer of such patients from a Level III to an adult Level I center. We hypothesized that planned, delayed transfer of patients with complex acetabular fractures would reduce preoperative bed utilization at the Level I center without compromising patient safety.
METHODS: Retrospective analysis of trauma registry (CDM, Conifer, CO), hospital and office records of 109 patients with any pelvic fracture seen at a Level III center from June 2002 to July 2007. Demographics, injury character, and payer of retained and transferred patients were compared to outcomes: length of stay (Level I preoperative and hospital LOS for both centers) and safety (mortality, new injury, diagnoses).
RESULTS: Only 3 of 82 retained patients had pelvic repairs, the rest having nonoperative sacral or iliac fractures. Twenty five of 27 transferred patients required acetabular repairs. Deaths were unrelated to pelvic injury. No major injuries were missed at the Level III.
CONCLUSIONS: With system maturation and growing confidence between centers, initial stabilization and care at a Level III center with staged transfer for repair of complex pelvic fractures steadily and safely reduced preoperative and total length of stay at the Level I.
RETAINED TRANSFER Number 82 27 Male 43 (52.4%) 19 (70.3%) Age X +/ SD 46.2+18.8 50 +18.2 ISS X +/ SD 13 + 9.9 9 + 5.1 Died 2 (2.4%) 1 (3.7%) Level III LOS (days) 3.7 + 2.6 2.1 + 1.8 Hypotension in ED 15 (18.3%) 3 (11.1%) OR trips all causes 26 (31.7%) 3 (10.3%) ORIF Pelvis 3 (3.7%) 25 (92.6%) PAYER Insurer 40 (48.8%) 9 (33.3%) Government 15 (18.3%) 5 (18.5%) Workman's 5 (6.1%) 1 (3.7%) Self 22 (26.8%) 12 (44.4%)
200. “Relaxation” of the Symphyseal Hardware: Loss of Fixation After Plating of the Anterior Pelvis is More Common Than You Think Michael T. Archdeacon, M.D. Cincinnati, OH (a,e Stryker) Cory A. Collinge, M.D. Fort Worth, TX (e Biomet, Smith & Nephew) *Elizabeth Dulaney Cripe, B.S. (n) Cincinnati, OH
PURPOSE: The purpose of this study was to evaluate the incidence of failure of fixation or relaxation of the symphysis pubis after plate fixation in a consecutive series of pelvic ring disruptions. Our null hypothesis stated: No significant loss of fixation in pubic symphysis plating would be observed between immediate postoperative period and final follow up.
METHODS: We evaluated 102 pelvic injury patients treated with anterior symphyseal plating in an IRB approved, retrospective study. Inclusion criteria consisted of all patients with Tile B or Tile C injuries treated by one of two pelvic surgeons with pubic symphysis plating from 1999 2006. Radiographs were analyzed preoperatively, immediately postoperatively, and at latest follow up (minimum six months), and measurement of the symphysis pubis was determined and compared between these time points. Screw loosening and plate failure, as well as other complications, were noted.
RESULTS: A minimum 6 month clinical follow up (range 6 55 months) was obtained for 56 (55%) of the patients. The null hypothesis that there would be no significant loss of fixation in pubic symphysis plating between the immediate postoperative period and final follow up was rejected. There were two cases where the symphysis widened to >10 mm (11 and 21 mm) and these were considered true failures of fixation. There was screw loosening in 26 patients and plate failure in 3 others resulting in mild symphyseal widening (3 5 mm) in 29 (52%) of the patients. On immediate postoperative radiographs, the symphysis pubis width measured 4.6 mm (range 2.5 6 mm) while final follow up radiographs measured 7.8 mm (range 3 21 mm), representing a 42% change in symphyseal width (P<0.05).
CONCLUSION AND SIGNIFICANCE: This study demonstrated a high incidence of lost fixation after pubic symphysis plating, although changes in alignment were mild in the vast majority of cases. This phenomenon likely represents relaxation of the implants as motion is restored to the articulations of the pelvis, but patients should be counseled regarding this possibility. 201. Comparison of Two Skin Closure Techniques in Acetabular Fracture Patients: Preliminary Results of a Prospective, Randomized Trial *Christopher D. Mudd, M.D. St. Louis, MO (a Stryker) Berton R. Moed, M.D. St. Louis, MO (a Stryker)
BACKGROUND: Wound complications, such as persistent drainage and deep infection, have been reported for the posterior exposure to the acetabulum. We hypothesize that closure of the skin with a running subcutaneous suture then sealed with Dermabond will result in lower rates of infection and wound drainage, as well as improved cosmesis, when compared to the standard closure using staples.
METHODS: Patients requiring the Kocher Langenbeck (or equivalent) posterior exposure were randomized into two groups: closure of skin with staples versus subcutaneous absorbable suture with Dermabond. Closed suction drains were inserted in all patients. The fluid collected from the drains, signs of infection, and times to drain removal, wound dry, and drain holes dry were recorded, as were multiple patient variables. A vacuum sponge was placed on wounds or drain holes having persistent drainage. Patients were followed for a minimum of six months postoperative.
RESULTS: Preliminary results were analyzed after enrolling 51 patients of a planned 150 patient study. Two deep infections occurred in the staple group versus none in the Dermabond group (p=.09). A vacuum sponge was required on 6 incisions in the staples group versus 4 incisions in the Dermabond group and required on the drain holes in 3 in the staples group versus 11 using Dermabond. These findings were not statistically different, nor were those comparing times to drain removal, wound dry, and drain holes dry, BMI, age, and days to hospital discharge. However, wound cosmesis was subjectively superior in the Dermabond group.
CONCLUSIONS: Closure with subcutaneous absorbable sutures and Dermabond has no disadvantages, has the potential to provide a decreased infection rate, and provides more pleasing cosmetic results when compared to staples as the gold standard. However, this study remains ongoing, and it is quite possible that greater patient numbers will provide alternative findings. 202. Hybrid Plate Fixation for Both Bone Forearm Fractures *Nikola M. Dobrasevic, M.D. (n) Grand Rapids, MI Clifford B. Jones, M.D. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI James R. Ringler, M.D. (n) Grand Rapids, MI
INTRODUCTION: The purpose of this study was to evaluate the utilization of hybrid plate fixation (2.7 mm DCP ulnar and 3.5 DCP radial) of both bone diaphyseal forearm fractures.
METHODS: Thirty three consecutive patients with both bone forearm fractures were treated with hybrid plate fixation between July 2002 and November 2006 and identified for retrospective analysis. Plating for both bone diaphyseal forearm fractures was accomplished with 2.7 mm DCP for ulnar and 3.5 mm DCP for radial components. Fracture type, tobacco, length of plate, healing, plate prominence, and complications were measured.
RESULTS: Thirty consecutive patients with 33 both bone forearm fractures had an average age of 31 (range 16 69). BMI averaged 26 (range 17 55). Eleven (33%) were smokers. All were the result of blunt trauma. AO/OTA classification was A3 (12, 36.5%), B3 (18, 54.5%), and C3 (3, 9.1%). Twelve (36.4%) fractures were open. No bone graft was utilized. Ulnar DC plate and radial DC plate lengths averaged 9 holes (range 6 12, 35% 10 hole) and 8 holes (range 6 10, 55% 8 hole), respectively. Average forearm range of motion measurement was pronation of 86°, supination of 84°, wrist dorsiflexion of 74°, and palmar flexion of 62°. Distal ulnar plate irritation and removal occurred in one patient (3%). One (3%) closed A3 fracture in a smoking patient treated with an eight hole 2.7 DCP resulted in a nonunion, but was successfully treated with repeat compression plating. No infections, malunions, or fixation failures occurred.
CONCLUSIONS: Hybrid plate fixation of both bone forearm fractures allows for multiple screw fixation in comminuted fractures, results in stable fixation especially with longer plates, and has minimal complications. 203. Orthopedic Trauma Service Utilization – Is There More Than What Meets the Eye? *Mr. Ulfin Rethnam (n) Rhyl, United Kingdom Rajam Yesupalan (n) Rhyl, United Kingdom Mr. Nigel Clay (n) Rhyl, United Kingdom
BACKGROUND: Proper utilization of trauma services can have a significant impact on patient outcome. Delays leading to postponement of trauma surgeries can result in poor outcome especially in the elderly. We analyze the factors influencing poor trauma service utilization and its impact.
METHODS: This retrospective study included all orthopedic trauma patients who required surgical intervention over a four week period. Data was collated on time scale for the trauma patient through their journey from the ward to the trauma theatre. Any delays and subsequent postponements were assessed and reasons analyzed.
RESULTS: There were 192 admissions relating to trauma during the study period with 158 proposed surgical procedures. There was a delayed start to the trauma theatre list by >30 min in 53.6% of days. A surgeon was available to start the list on time in 75% of days. The mean delays were as follows: ward delay 20.12 min (Range 7–86 min), theatre reception – 12.1 min (Range 0–50 min), anesthesia – 20.6 min (Range 1–75 min), and delay between consecutive patients – 5.3 min (Range 0–95 min). Most delays were in the ward due to re shuffling of list, pending investigations, patients not kept ready, and lack of communication between the medical personnel. The delays resulted in postponement of 55 surgical procedures.
CONCLUSION: Trauma services should be managed appropriately to improve patient care. Our study identified a deficiency in the utilization of available trauma services. A thorough planning with good communication between all members of the trauma team would improve the quality of trauma care.
MAOA POSTER PRESENTATIONS – 2009 ANNUAL MEETING #1 48
TRAUMA
1. The Correlation of Measurable Serum Markers of Inflammation with Lung Levels Following Orthopedic Trauma *Benjamin W. Sears, M.D. (n) Maywood, IL Michael D. Stover, M.D. (n) Maywood, IL Kristen Lauing, B.S. (n) Maywood, IL Ryan Himes, B.S. (n) Maywood, IL Michelle Morgan, B.S. (n) Maywood, IL Elizabeth Favre, B.S. (n) Maywood, IL John J. Callaci, Ph.D. (n) Maywood, IL
INTRODUCTION: Evaluation of the inflammatory status in trauma patients is becoming increasingly recognized as an important adjunct for guiding post injury clinical decisions. This largely because surgical intervention contributes to the magnitude of the inflammatory response, and an ill timed procedure in a physiologically imbalanced patient may contribute to inflammatory associated organ injury. Correlating easily measurable serum and pulmonary inflammatory markers may be a useful tool in assessing timing for appropriate surgical intervention.
METHODS: Eighty five (85) Sprague Dawley rats underwent either a sham operation or bilateral femoral intramedullary pinning and mid diaphyseal closed fracture via blunt guillotine. Animals were euthanized at time of injury, 6 hours, 24 hours, 48 hours, and 72 hours after injury. Serum and lung tissue were collected and 24 inflammatory markers were analyzed by commercial available immunoassay.
RESULTS: Bilateral femur fracture significantly increased serum markers of inflammation including IL 2, IL 6, IL 10, GM CSF, GRO/KC, MCP 1, and WBC. Femur fracture also significantly increased lung levels of IL 1a and GRO/KC. Significantly elevated serum levels of GRO/KC at six hours were significantly associated with elevated lung levels at six hours. Significant increase in serum levels of IL 6 at 6 hours demonstrated a trend towards increased lung levels at 24 and 72 hours post injury.
DISCUSSION: Orthopedic trauma results in the elevation of clinically measurable serum and lung markers of inflammation. Significantly elevated serum levels of GRO/KC were associated with significantly increased lung levels, and a significantly increased serum IL 6 level was associated with a trend towards elevated lung levels. Thus, elevated serum levels of GRO/KC correlate with increased lung levels at six hours after injury, and may be a sensitive measure of lung inflammation following trauma. 2. The Influence of Alcohol Binge on Serum and Lung Markers of the Immuno Inflammatory Response Following Orthopedic Trauma *Benjamin W. Sears, M.D. (n) Maywood, IL Michael D. Stover, M.D. (n) Maywood, IL Kristen Lauing, B.S. (n) Maywood, IL Ryan Himes, B.S. (n) Maywood, IL Michelle Morgan, B.S. (n) Maywood, IL Elizabeth Favre, B.S. (n) Maywood, IL John J. Callaci, Ph.D. (n) Maywood, IL
INTRODUCTION: Alcohol intoxication, present in 25 40% of trauma patients with orthopedic injuries, is a well known risk factor for metabolic bone disease, delayed fracture healing, and a known modulator of the immuno inflammatory pathway. However, the significance of ethanol intoxication on the clinical evaluation of the inflammatory response following orthopedic trauma is currently not well understood. In the present study, we examine the influence of orthopedic trauma and alcohol binge on measurable serum and lung markers of inflammation.
METHODS: Eighty five (85) Sprague Dawley rats were administered either saline or alcohol in binge fashion for three days, followed by a either a sham operation or bilateral femoral intramedullary pinning and mid diaphyseal closed fracture via blunt guillotine. Animals were euthanized at various time points after injury. Serum and lung tissue were collected, and 24 inflammatory markers were analyzed by commercial immunoassay.
RESULTS: Bilateral femur fracture significantly increased serum markers of inflammation including IL 2, IL 6, IL 10, GM CSF, GRO/KC, MCP 1, and WBC. Alcohol binge resulted in significant depression of post injury serum levels of IL 6, IL 2, IL 10, CRP, and WBC. However, alcohol binge significantly increased lung levels of the proinflammatory markers IL 6 at 6 hours, and IL 1b, IL 2 and MIP 1a at 48 hours following injury compared to controls.
DISCUSSION: These results indicate that acute alcohol intake is associated with depressed levels of serum inflammatory markers following orthopedic trauma; however, lung levels of the proinflammatory markers IL 6, IL 1b, IL 2 and MIP 1a were found to be significantly elevated after injury compared to controls. These findings should be taken into account when evaluating the inflammatory response in intoxicated trauma patients with orthopedic injuries. SPINE
3. The Effect of Malreduction on the Strength of Iliosacral Screw Fixation in Transforaminal Sacral Fractures *Jason P. Young, M.D. (n) Maywood, IL Michael D. Stover, M.D. (n) Maywood, IL Mark C. Reilly, M.D. (n) Newark, NJ Avinash Patwardhan, Ph.D. (n) Maywood, IL Robert Havey, B.S. (n) Maywood, IL Braden McIntosh, B.S. (n) Maywood, IL
OBJECTIVE: To determine the relationship between transforaminal fracture malreduction and resultant strength of iliosacral screw fixation in a biomechanic cadaveric fracture model.
DESIGN: Fourteen cadaveric pelves were cleaned of all soft tissues maintaining all important ligamentous structures. All specimens underwent dual energy x ray absorptiometry analysis for bone mineral density. Each specimen was loaded into a servohydraulic test system in the anatomic position with load transmission ipsilateral to the fracture site. Each specimen was cyclically loaded (175 365N) without fracture to determine intact stiffness. Simulated transforaminal sacral fractures were created in each pelvis (OTA Type 61 C1.3,a 2). Fractures were then fixed using navigation for standardization with two iliosacral lag screws; anatomically reduced in five specimens, cranially malreduced 5 millimeters in three specimens, cranially malreduced 10 millimeters in three specimens, and cranially malreduced 15 millimeters in three specimens. Each pelvis was then cyclically loaded (175 365N). Stiffness and motion data were determined using the servohydraulic test system and the Optotrak 3020.
OUTCOME MEASURES: Macroscopic failure as well as load versus displacement was measured for each specimen both before and after fracture fixation to determine return to intact stiffness. During the loading process, three dimensional motion data was constructed using a twelve point optical tracking system.
RESULTS: Anatomically reduced transforaminal sacral fractures have increased stiffness as compared with the malreduced fractures. Four of the five anatomically reduced specimens were loaded cyclically to 500 cycles where as none of the malreduced specimens were able to cycle beyond 100 cycles. The majority of malreduced specimens failed macroscopically in the first ten cycles.
CONCLUSION: The results of this cadaveric biomechanical study indicate that malreduction of transforaminal sacral fractures results in a less mechanically sound fixation construct than after an anatomic reduction. MISCELLANEOUS
4. Effect of Acetominophen, Ibuprofen, and Celexcoxib on Human Chondrocyte Production of Matrix Metalloproteinase 1 Mihir Patel, M.D. (n) Selden, NY *Philip J. Lahey, M.D. (n) Brooklyn, NY Ashish Patel, M.D. (n) Brooklyn, NY Theresa Jacob, M.D. (n) Brooklyn, NY Jack Choueka, M.D. (n) Brooklyn, NY
INTRODUCTION: Matrix metalloproteinase subtype 1 is expressed in osteoarthritic cartilage, with the number of chondrocytes synthesizing MMP 1 increased in the early phases of disease. The purpose of this study is to evaluate the effects of commonly prescribed medications for the treatment of OA (acetaminophen, ibuprofen, and celecoxib) on the chondrocyte production of this enzyme.
METHODS: Normal human chondrocytes (commercially obtained) were cultured in 75 cm² flasks at 37°C and 5% CO2. Approximately 1x 10 6 cells/mL were plated per well in a 24 well plate. Cells were exposed, in physiologic concentrations, to either acetaminophen (1mM), ibuprofen (170 M), celecoxib (10 M), or only media (control) for 24 and 48 hour incubation periods. ELISA Kits for MMP 1 were used with optical density analysis performed with commercially available software.
RESULTS: After a 24 hour incubation period the concentrations of MMP 1 were: Control = 2.29±0.45 ng/mL, Acetaminophen = 2.15±.09 ng/mL, Ibuprofen = 0.97±.15 ng/mL, and Celecoxib = 3.02±0.45 ng/mL. After a 48 hour incubation period, the concentrations of MMP 1 were: Control = 2.82±0.16 ng/mL, Acetaminophen = 0.77±0.10 ng/mL, Ibuprofen = 1.39±0.08 ng/mL, and Celecoxib = 3.25±0.36 ng/mL.
DISCUSSION: Since increased MMP 1 activity correlates with the progression of osteoarthritis, drugs that can reduce the concentrations of the enzyme could potentially aid in decreasing the progression of disease. Acetominophen and ibuprofen displayed the ability to decrease production of the enzymes at certain time points. Celecoxib did not alter MMP 1 levels after 24 or 48 hours. Further study is warranted to investigate the risk/benefit ratio of these drugs. 5. Medical Tourism: A Competitive Reality? Junaid Makda, M.D. (n) Philadelphia, PA *Khalid M. Yousuf, M.D. (n) Oklahoma City, OK Kenneth Kearns, M.D. (n) Philadelphia, PA Hasan Kakli, B.S. (n) Philadelphia, PA Javad Parvizi, M.D. (n) Philadelphia, PA
OBJECTIVE: Rising healthcare costs, a growing number of underinsured/uninsured, and the need for an affordable solution have brought traveling abroad for healthcare to the forefront. Traveling to another country to obtain healthcare appears to be gaining popularity with an increasing number of patients seeking surgical care abroad. The purpose of this study was to evaluate patient knowledge and interests in medical tourism, discuss the economic implications of international healthcare, and the potential medical legal risk as it applies to total joint arthroplasty.
METHODS: A 31 question survey was administered to 100 patients with complaints of hip and knee pain. The survey evaluated the patient’s socioeconomic background, insurance status, and knowledge and potential interests in medical tourism.
RESULTS: The average age was 59.5 years. The majority (97 patients) had insurance and most (71 patients) had a type of co payment. Among the cohort surveyed, only 26 patients were familiar with the term medical tourism. If given the option by the insurance company to have the surgery performed abroad, two patients would elect to have the surgery overseas. If offered a financial incentive, six patients would want the surgery performed overseas. If the insurance company denied the procedure, 42 would pay out of pocket to have the surgery in the U.S., 19 patients would have the surgery in another country for less than half the cost, and 25 would forego the procedure. Only five patients were interested in medical tourism as a surgical option after the survey.
CONCLUSION: The majority of the surveyed patients showed little to no interest in having their surgery performed overseas. Concerns of infection, unfamiliarity with the surgeon/hospital, dealing with potential complications, lack of physician follow up, and time away from family may be some of the reasons why patients may be apprehensive about having surgery overseas. The enormous demands on our healthcare system are leading insurance companies to explore medical tourism as a cost effective alternative. The impact of medical tourism on orthopedic surgeons in the U.S. goes beyond losing potential patients. 6. Short Musculoskeletal Function Assessment: Defining Reference Values *Jessica C. McMichael, M.D. (n) St. Louis, MO Berton R. Moed, M.D. (n) St. Louis, MO
INTRODUCTION: The Short Musculoskeletal Function Assessment (SMFA) is a self report health status questionnaire used by orthopedic surgeons to monitor outcomes of orthopedic interventions. The SMFA’s utility is limited by a lack of published reference values. While a set of reference values has been collected by the University of Minnesota (UMN), this data may not accurately represent the normal population. The goal of this study was to define reference values for the SMFA in Missouri, and identify differences, regional or otherwise, that may exist from the UMN data.
MATERIALS AND METHODS: A telemarketing campaign was conducted through the U.S. mail to recruit random healthy subjects to complete the SMFA. The study area included a 100 mile radius around St. Louis, Missouri. Stratification criteria included: age 18 35, 36 55, 56 89, ethnic background, zip code, and BMI. The returned surveys were scored according to standard instructions. We compare our results to those reported by the University of Minnesota.
RESULTS: Fifteen hundred calls were made, yielding 71 returned surveys. The mean (std. dev.) scores for the six indices of the SMFA were: Daily Activities 13.21 (19.02), Emotion 20.02 (15.95), Arm/Hand 6.93 (15.01), Mobility 16.75 (17.66), Function 11.90 (11.87), and Bother 18.84 (18.40). The values obtained from our random healthy subjects were similar to those reported by the UMN.
CONCLUSIONS: Our results support the UMN SMFA data collection methodology and indicate that there are no significant regional differences. Our reference values or those reported by UMN may be useful to orthopedic surgeons who use the SMFA to monitor outcomes of orthopedic interventions. 7. The Effects of Screw Orientation in Osteoporotic Bone; a Comparison with Locked Plating *Scott W. Zehnder, M.D. St. Louis, MO (b Synthes) Aki S. Puryear, M.D. (n) St. Louis, MO J. Gary Bledsoe, M.D. (n) St. Louis, MO
OBJECTIVE: We hypothesize that convergently placed screws in a synthetic severely osteoporotic plate bone model offer superior construct stability over screws placed in a traditional manner. Furthermore, this stability rivals that of locking screws.
METHODS: Forty plate bone constructs were assembled and divided into four groups of ten. Perpendicularly placed screws were placed in one group, convergently placed crossing screws were placed in a second group, an oblique end screw was placed in a third group, and a fourth group utilized perpendicularly placed locking screws in a locking plate. All test subjects were mounted and tested in statically loaded cantilever bending to the point of failure. Stiffness, initial load to failure, and maximal load tolerated were all analyzed.
RESULTS: All three groups with nonlocked plates demonstrated similar failure patterns and load to failure. Locking constructs demonstrated a distinctly different failure pattern and demonstrated microfailure at smaller (although not significant) loads than the nonlocking constructs. The group with an oblique end screw was significantly less stiff than the other three groups; however, this did not have any effect on failure.
CONCLUSIONS: In a severely osteoporotic model, failure in cantilever bending at low forces will take place regardless of fixation methods used, in some cases at smaller loads in locking constructs. The mechanism of failure is different in locked constructs compared to traditional constructs. Furthermore, the added benefit of oblique screw placement observed in healthy bone is not observed in osteoporotic bone. 8. Injury Patterns of Couples in Motorcycle Collisions: Who Takes the Hit? Joshua M. Murphy, M.D. (n) Louisville, KY Jacob M. Lantry, M.D. (n) Louisville, KY *Craig S. Roberts, M.D. (n) Louisville, KY John A. Nyland (n) Louisville, KY
INTRODUCTION: Although there have been several reports on motorcyclist injury patterns, to our knowledge there is limited data on the injury patterns of individuals riding on the same motorcycle. The purpose of this study was to identify orthopedic injury patterns in driver passenger motorcycle accident victims presenting to a level one trauma center.
METHODS: We performed an institutional review board approved retrospective review of a level one trauma center registry and medical records from 1993 to 2006. Once subjects were identified, drivers and passengers presenting within 24 hours of each other were cross checked to verify that they were on the same motorcycle. Twenty one couples that met this criteria were identified out of 91 cases.
RESULTS: Nineteen of the 21 pairs (90.5%) included a male driver with a female passenger. The incidence of a positive toxicology screen was 57% for the driver and 33% for the passenger. There was no significant difference in incidence of head injury between driver and passengers or helmet usage. There was an increased incidence of head injuries in those drivers and passengers not wearing a helmet compared with those wearing a helmet. Mean hospital stay and mean GCS were found to be similar for both driver and passenger. A statistically significant difference was found in incidence of scapula fractures in drivers as compared to passengers.
CONCLUSION: Greater emphasis should be placed on ruling out scapula fractures among drivers in driver passenger motorcycle accidents. Identified differences enable prospective research of the true significance of scapula fractures to patient quality of life. 9. Mouthguard Utilization Among Minor Ice Hockey Players *Ferhang Raaii, M.D. (n) Southfield, MI Rahul Vaidya, M.D. (n) Detroit, MI David C. Markel, M.D. (n) Southfield, MI
INTRODUCTION: Previous studies in the pediatric sports literature have not delineated the factors that predict the use of mouthguards or the epidemiology of cerebral concussion among youth hockey players. We performed a multi center descriptive epidemiological study to determine whether a player’s age and type of mouthguard predict mouthguard utilization, and ultimately reveal the likelihood of sustaining a cerebral concussion.
METHODS: Standardized written surveys addressing a variety of questions pertaining to the patterns of mouthguard utilization were completed on a voluntary basis by 180 minor ice hockey players, aged 9 to 13, under the supervision of their coaches. Chi square tests were performed to measure differences between categorical variables. One way analysis of variance (ANOVA) tests were used to determine if age had a significant effect on a player’s behavior with respect to mouthguard wear. Post hoc Student Newman Keuls (SNK) analysis was carried out in conjunction with the ANOVA tests.
RESULTS: Subjects who owned custom made mouthguards were most likely to wear them, followed in sequence by owners of boil and bite and stock type models. Regardless of mouthguard variety, the rate of compliance was low, with only 31.7% of respondents wearing them at every game and only 51.1% wearing them during every practice. Younger players wore mouthguards more consistently than their older teammates, especially during sanctioned practice sessions. This effect was strong enough to overcome the higher proportion of older players who owned custom made mouthguards. No link could be established between averting concussions and mouthguard utilization, despite a concussion prevalence of 17.8% (32 players) within this cohort.
CONCLUSIONS: Injury prevention strategies must integrate an evidence based culture of safety via the following avenues: (1) adoption of stricter rules of play, (2) vigorous enforcement of the existing regulations, (3) education regarding the potential for catastrophic injuries, and (4) consistent utilization of protective equipment. HIP
10. Factors Affecting Bony Impingement in Total Hip Arthroplasty *William B. Kurtz, M.D. (n) Nashville, TN Stephen Murphy, M.D. (n) Boston, MA
INTRODUCTION: This study evaluates the variables affecting bony impingement in total hip arthroplasty including acetabular component offset and height, femoral component offset, height and anteversion, and osteophyte removal.
METHODS: The ROM of ten osteoarthritic hips undergoing THA was modeled using pelvic CT scans and the HipNav software (CASurgica, Pittsburgh). Maximum flexion, extension and internal and external rotation between 110° of flexion to 40° extension were determined for every component variation. Variations in acetabular offset and height and femoral offset and height were made in 2 mm increments and femoral anteversion was changed in 5° increments. The ROM with osteophytes removed was also determined. The ROM before bony impingement was compared to the ROM before component impingement and the native hip ROM.
RESULTS: Every millimeter of decreased acetabular offset and increased acetabular height decreased the maximum internal rotation by 2° and 1.6°, respectively. This decreased ROM was not fully recoverable with a comparable increase in femoral offset or height or aggressive osteophyte removal. The maximum internal rotation is greatly dependent on the amount of hip flexion; the maximum external rotation is less dependent on the amount of hip flexion. An increase in bony impingement and decrease in component impingement is seen with a large head:neck ratio and a decrease in acetabular offset. The ROM before bony impingement in a hip replacement is greater than the ROM in a native hip.
CONCLUSIONS: Acetabular component positioning is more important on hip ROM than femoral component positioning. Bony impingement with internal rotation is more sensitive to the degrees of hip flexion than bony impingement with external rotation. The increased ROM before component impingement with a large femoral head is negated if the acetabular offset is decreased because ROM is limited by bony impingement. The Ranawat combined anteversion technique is valid for component impingement but not bony impingement. 11. Early Experience with a Novel Non Metallic Cable in Primary and Revision Total Hip Arthroplasty *Nicholas Ting, B.S. (n) Chicago, IL Glenn D. Wera, M.D. (n) Chicago, IL Craig J. Della Valle, M.D. Chicago, IL (a Smith & Nephew, Stryker; a,b,e Zimmer)
INTRODUCTION: Cables are frequently utilized by surgeons in the course of primary and revision total hip arthroplasty (THA). Most of these devices are made from metal, which provides excellent strength, however fretting can occur which can damage the bearing surface leading to accelerated wear. The purpose of this study was to report an early experience with the use of a non metallic cable.
METHODS: A double stranded cable made from a nylon core covered by a polyethylene sheath was utilized in 30 consecutive cases. The cable was utilized to repair an extended trochanteric osteotomy (ETO) in 22 cases, to manage an intraoperative fracture in 4, a post operative periprosthetic fracture in 2, and to apply a strut graft in 2. An average of 3.0 cables were used (range 1 6). Patients were followed prospectively for a minimum of 3 months postoperatively (range 3 to 17 months) to specifically identify any complications associated with their use and the rate of healing of the associated fractures or osteotomies.
RESULTS: There were two complications directly related to the use of the cables including one nonunion of an ETO that led to recurrent dislocation and the need for repeat fixation. A second patient sustained a fracture of an ETO secondary to a technical error in cable placement at the base of the greater trochanter; the fracture healed without operative treatment.
CONCLUSION: Initial experience with this novel non metallic cable shows adequate fixation strength to allow for healing with an acceptable rate of device related complications. 12. Late Salvage of Failed Open Reduction and Internal Fixation of Posterior Wall Fractures of the Acetabulum Berton R. Moed, M.D. (n) St. Louis, MO *D. Brian Dean, M.D. (n) St. Louis, MO
A fracture of the posterior wall is the most common pattern seen in acetabular fractures. Unfortunately, there are instances in which surgical repair is unsuccessful due to technical error, re injury, patient noncompliance, or other factors. The purpose of this study was to review the outcome of late revision surgery in a series of patients with posterior wall fractures having recurrent hip instability following failed initial open reduction and internal fixation. Three females and one male were included in the study, all of whom presented with a unilateral, elementary fracture/dislocation of the posterior wall sustained initially during a motor vehicle crash. The four patients were referred for recurrent hip instability and were subsequently treated by a revision open reduction and internal fixation performed 3 weeks or more (range 3 weeks to 9 months) after the original injury. Three of the four patients eventually required total hip arthroplasty after revision open reduction and internal fixation surgery was preformed. Two of these three patients required total hip arthroplasty within 18 months of revision surgery. Both, over 50 years of age, had experienced catastrophic early hip re dislocation associated with femoral head pathology following the initial surgery. One patient continues to ambulate without assistance or pain on her native hip 18 years after the revision surgery. Patients are likely to experience poor clinical outcome, ultimately requiring total hip arthroplasty, when salvage procedures are delayed by more than three weeks. In older patients, particularly if there is concomitant damage to the femoral head, late revision fracture fixation surgery may be ill advised, and total hip arthroplasty may be the most appropriate secondary surgery. However, late revision fracture fixation surgery may provide young, active patients years of satisfactory function before total hip arthroplasty is required. 13. ♦Revision of Hip Resurfacing Arthroplasty Robert J. Gillespie, M.D. (n) Cleveland, OH *Glenn D. Wera, M.D. (n) Chicago, IL Carter Petty (n) Boston, MA Mathew J. Kraay, M.D. (n) Cleveland, OH William J. Petersilge, M.D. (n) Cleveland, OH Victor M. Goldberg, M.D. Cleveland, OH (a,b,c,e Wright Medical Technology, Zimmer)
INTRODUCTION: The purpose of this study was to evaluate the radiographic parameters and clinical results of converting failed hip resurfacing arthroplasty to total hip arthroplasty. We hypothesized that there could be a mismatch between stem placement and native hip orientation associated with failed hip resurfacing. Clinically, we compare the results of revised cases to successful hip resurfacing arthroplasty.
METHODS: We performed 92 metal on metal hip resurfacing arthroplasties, of which 8 were converted to total hip arthroplasty. The average duration of follow up was 51 months. Using prospective SF 12 and Harris Hip Scores, the clinical outcomes of these patients were compared to 50 patients who had uncomplicated metal on metal hip resurfacing. In addition, radiographic neck shaft, stem shaft, and stem lateral angles were compared.
RESULTS: There was no significant difference between the two groups in regard to the Harris Hip Scores or the SF 12 scores. All cases demonstrated significant improvement at follow up. There was one periprosthetic infection after revision; otherwise, there were no additional complications. Radiographically, a valgus neck shaft angle (p<0.03) and an increased lateral stem shaft angle (p<0.023) were both associated with failure of hip resurfacing arthroplasty. There was a trend toward higher neck lateral angles in the revised group (p<0.08). The divergence between native hip and stem shaft angles was not significant.
DISCUSSION: Conversion of aseptic failure of a hip resurfacing to a conventional total hip arthroplasty leads to similar clinical outcomes to patients undergoing an uncomplicated hip resurfacing. Excessively valgus femora may be inappropriate for hip resurfacing arthroplasty. 14. Revision THA Using a Modular Femoral Implant in Paprosky Type III and IV Femoral Bone Loss *Arthur L. Malkani, M.D. (n) Louisville, KY Frederick F. Jaffe, M.D. (n) New York, NY Kirby Hitt, M.D. (n) Temple, TX John R. Schurman, II, M.D. (n) Wichita, KS
INTRODUCTION: Paprosky Type IIIA, IIIB, and IV femoral defects can create a challenging problem. The purpose of this review was to review the clinical and radiographic results of patients undergoing femoral component revision with a modular femoral implant with significant defects.
METHODS: Twenty seven patients with Paprosky Type IIIA, IIIB, and IV defects were identified from a prospective multicenter study. There were 16 males and 11 females with an average age of 66 years (range 43 85). Fifteen patients had one prior surgery, and the rest had two or greater number of procedures. The minimum follow up was two years.
RESULTS: The mean preoperative Harris Hip Score was 43 points which improved to 83 points at two years. The average blood loss was 1,400 cc. The average operative time was 186 minutes. Current leg length achieved in 85% of the patients. There were no cases of femoral component loosening. There were three dislocations and six intraoperative fractures. The overall complication rate leading to any type of reoperation was 25%.
DISCUSSION AND CONCLUSION: Despite excellent results with respect to achieving leg length, offset, and implant stability using a modular femoral implant, complication rate still remains high in this difficult group of patients with Paprosky Type IIIA, IIIB, and IV femoral defects undergoing revision hip arthroplasty. Greater attention needs to be paid to minimize the complication rate in this patient population. 15. The Learning Curve for Adopting Total Hip Resurfacing Among Hip Specialists *Ryan M. Nunley, M.D. St. Louis, MO (a Smith & Nephew) C. Andy Engh, M.D. (n) Alexandria, VA Peter J. Brooks, M.D. (n) Cleveland, OH John Rogerson, M.D. (n) Madison, WI Stephen J. Raterman, M.D. (n) Tampa, FL Robert L. Barrack, M.D. St. Louis, MO (a Smith & Nephew)
Total hip resurfacing is more challenging than traditional total hip arthroplasty and until recently has not been routinely performed in North America. This study reviewed the initial radiographic results from high volume, experienced hip specialists, who now routinely perform hip resurfacing to determine the learning curve.
One blinded examiner retrospectively measured the preoperative and postoperative radiographs for 623 consecutive hips (592 patients) with hip resurfacings performed by five surgeons across the United States from June 2006 to January 2008 without computer assistance. Each surgeon had at least his first 100 cases reviewed. Demographic data and adverse events were recorded for all patients.
Mean age was 49.7 years (range, 31 81 years) and there were 131 females (22.1%) and 461 males (77.8%). The diagnosis was osteoarthritis in 560 hips (89.8%), dysplasia in 43 hips (6.9%), avascular necrosis in 13 hips (2.1%), and other in 7 hips (1.1%). There were two hips with femoral neck fracture (0.32%) requiring reoperation; two dislocations (0.32%) treated with closed reduction and no further episodes; and one peroneal nerve palsy. Relative varus malpositioning of the femoral stem occurred in 94 hips (15.1%) and acetabular component malpositioning (inclination angle greater than 50°) occurred in 56 patients (8.9%). For all surgeons, while component positioning improved with experience, malpositioning still occurred in 7 15% of each surgeon’s last 25 hip resurfacings.
This multicenter hip resurfacing study shows a low early complication rate but frequent component malpositioning. Results suggest improved instrumentation and/or computer assistance may be advisable to improve component placement. 16. Iliopsoas Tendonitis Following Total Hip Arthroplasty Treated with Selective Steroid Injections *Ryan M. Nunley, M.D. (n) St. Louis, MO Joyce P. Wilson, M.D. (n) St. Louis, MO Louis Gilula, M.D. (n) St. Louis, MO William J. Maloney, M.D. (n) Palo Alto, CA John C. Clohisy, M.D. (n) St. Louis, MO Robert L. Barrack, M.D. (n) St. Louis, MO
Iliopsoas tendonitis is uncommon following total hip arthroplasty (THA). Treatment options are varied in the literature. The purpose of this study was to determine the effectiveness of fluoroscopically assisted iliopsoas bursa injections in patients with iliopsoas tendonitis following THA.
We retrospectively reviewed 19 patients with THA who were diagnosed with iliopsoas tendonitis by physical examination (persistent groin pain triggered by active hip flexion, hip flexion against resistance, and passive hyperextension), had no evidence of component failure, and negative work up for occult infection. All were referred to a musculoskeletal radiologist for fluoroscopic injection of the iliopsoas bursa. Prior to injection, each patient filled out a pain assessment questionnaire, which was reviewed by the radiologist before and after the procedure. Telephone questionnaire was administered (average 29.3 months) after the final injection to determine the patient’s functional status.
Average modified Harris Hip Score improved from 61.2 pre injection to 82.3 post injection (p<0.001), but nine patients (47%) required a second injection at an average of 8.9 months after the first injection. Ultimately, five patients (31.6%) had to undergo an additional surgical procedure (two iliopsoas lengthening and three revision THAs) to address the underlying cause of the iliopsoas irritation. Of the remaining 14 patients, only 1 patient had persistent symptoms requiring continued medical treatment.
Iliopsoas tendonitis is uncommon following THA, but should be considered in the differential diagnosis for patients presenting with groin pain. Fluoroscopic injection of the iliopsoas bursa can give good pain relief and should be considered part of the treatment algorithm before surgical intervention. 17. Pain and Function with Mini Incision Total Hip Arthroplasty versus Conventional Incision Hip Resurfacing *Ryan M. Nunley, M.D. (n) St. Louis, MO Elizabeth Zhou, M.D. (n) St. Louis, MO Scott Kaiser, M.D. (n) San Francisco, CA John C. Clohisy, M.D. (n) St. Louis, MO Robert L. Barrack, M.D. (n) St. Louis, MO
Minimally invasive total hip arthroplasty (THA) is believed to benefit from reduced soft tissue trauma resulting in less pain, more rapid rehabilitation, and earlier hospital discharge. The surgical technique utilized for total hip resurfacing favors a longer, more conventional hip. The purpose of this study was to determine if differences exist in pain and functional recovery between mini incision THA and hip resurfacing.
We retrospectively reviewed records for 246 consecutive patients, primary THA or total hip resurfacing, at our institution from March 2005 to December 2007. We identified 50 patients who had a total hip arthroplasty performed through a posterior mini incision (10+2 cm) that were age and gender matched to 101 patients who had a total hip resurfacing performed through a traditional long incision (20+5 cm). Data collected included: patient demographics, duration of surgery, estimated blood loss, transfusion requirements, drain output, pain scores, narcotic requirements converted to morphine equivalents, distance ambulated, and time to discharge.
The average hospital stay was 59.8+12.4 hours in the mini incision group and 67.5.4+15.1 hours in the hip resurfacing group (p=0.0021). Patients with the mini incision had less surgical time (p=0.0001), less blood loss (p=0.012), less pain each postoperative day (p=0.039), and less pain at discharge (p=0.0076). However, the distance walked each postoperative day favored the hip resurfacing group (p=0.023). Total narcotic requirements standardized to morphine equivalents favored the mini incision group but was not significant (p=0.073).
Mini incision THA has better early pain control and earlier discharge to home compared to total hip resurfacing, but hip resurfacing has better ambulation in the early postoperative period. 18. Outcome of Prosthetic Hip Infections with Resistant Organisms at a Tertiary Care Center Jason Cochran, D.O. (n) Okemos, MI Trevor G. Murray, M.D. (n) Cleveland, OH Robert Molloy, M.D. (n) Cleveland, OH *Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew, TissueLink, Zimmer; a,b,e Stryker; c Exactech; c,e SS White, Wright Medical Technology; e Otismed) Viktor E. Krebs, M.D. Cleveland, OH (a,b,e Stryker, TissueLink; b,e Shukla Medical)
BACKGROUND: Recent literature has highlighted the economic and social burden that results secondary to infected total hip arthroplasty (THA). The economic cost of an infection is significantly higher than the direct medical costs associated with revision THA for aseptic loosening. Revision procedures for infection are associated with longer operative time, more blood loss, and a higher number of complications compared with revisions for aseptic loosening or primary THA. The purpose of this study was to test the hypothesis that infections with resistant organisms have a much higher failure rate than what is described in the literature.
METHODS: A retrospective single center study was conducted to evaluate patients that underwent resection arthroplasty for a prosthetic hip infection. We included all patients with resistant organisms infected from the dates of 1995 to 2005. Treatment was considered a failure if a two stage procedure failed to clear the infection and required repeat excision arthroplasty.
RESULTS: The cohort consisted of 56 patients who had a prosthetic hip infection with a resistant organism. Follow up averaged 44 months with a minimum of 12 months (range, 12 130 months). Forty five patients went on to re implantation. Only 29 of the 45 patients had a successful two stage revision procedure. Although 35% of these patients had a re infection, only 13% became re infected with the same organism. Of the repeat infections, ten infections were from different organisms and six were the same as the initial infection. Only 3 of the 16 failed procedures went on to a successful second two stage procedure.
CONCLUSIONS: Others have discouraged the re implantation of a prosthetic joint involving resistant organisms. This study highlights the importance of considering the virulence of infecting organisms when treating prosthetic hip infections. We feel with aggressive surgical debridement we can reproducibly treat these infections. 19. Effect of Age and Gender on Serum Titanium Levels Following Hip Arthroplasty Using Highly Modular Versus Nonmodular Prosthesis *Bradley W. Dyrstad, M.D. (n) Springfield, IL B. K. Parsley, M.D. (n) Springfield, IL Joseph C. Milbrandt, M.D. (n) Springfield, IL D. Gordon Allan, M.D. (n) Springfield, IL
INTRODUCTION: Total hip arthroplasty performed using modular stem prostheses allow for intraoperative flexibility, easing the reconstruction procedure and potentially improving the performance of the implant. However, any benefit may be offset by evidence suggesting increased wear at modular junctions could result in greater systemic exposure to titanium ions than nonmodular devices. The purpose of this study is to explore whether the observed differences in titanium levels between modular and nonmodular prostheses is influenced by age and gender.
METHODS: Serum samples were collected annually in patients receiving a one piece, nonmodular (Versys) or a three piece, modular (Acumatch) stem. Student’s t test was used to compare ion levels in two groups based on gender. Spearman correlation was used to examine correlations between ion levels and patient age. Titanium (Ti) levels were measured using high resolution inductively coupled plasma mass spectroscopy by a technician blinded to the patient groups.
RESULTS: Overall, median Ti level was significantly higher in the Acumatch group (3.25 micrograms/L) when compared to patients receiving the Versys (2.42) device (p=0.0022). In the Acumatch group, the median Ti level observed was significantly higher in females (3.8) when compared to males (2.85) (p=0.0076). However, no gender difference was observed in the Versys group (p=0.67). A correlation between age and serum Ti levels was observed in the Acumatch group (p=0.024), but not in the patients receiving the Versys implant.
CONCLUSION: The clinical significance of the degree of serum Ti level elevation is still not known. The observed gender differences seen with the Acumatch device could be attributed to differences in component size, composition, and/or articulating surface wear patterns. In addition, the differences could be attributed to changes in the metal ion clearance and/or compartmentalization. Future projects must be designed to confirm the observed gender patterns and attempt to explain why Ti levels are elevated with age and why this increase appears to be selective to the Acumatch device.
20. Percutaneously Assisted Total Hip Arthroplasty – Early Outcomes of a Novel Soft Tissue Sparing Approach Brad L. Penenberg, M.D. Beverly Hills, CA (a,c,e Wright Medical Technology) Joseph Isaacson, M.D. Los Angeles, CA (a,c,e Wright Medical Technology) Eugene P. Schoch, III, M.D. Austin, TX (a,c,e Wright Medical Technology) *Jonette Hodge, R.N. Arlington, TN (e Wright Medical Technology)
INTRODUCTION: Several so called “minimally invasive” approaches to total hip arthroplasty have been introduced by surgeons during the last ten years. The goal of such an approach is improvement in early clinical outcomes that allow patients to return to work/activity sooner than would be otherwise possible. The purpose of this prospective study was to determine the early outcomes of a novel percutaneously assisted approach.
MATERIALS AND METHODS: The Percutaneously Assisted Total Hip (PATH) instrumentation incorporated a lateral femoral portal through which acetabular preparation and component placement was done. In order to evaluate the early clinical outcomes of THA patients implanted with the PATH approach, 47 patients were prospectively enrolled and followed. Particular attention was given to outcomes at two and six weeks.
RESULTS: Demographics for age, BMI, preoperative Harris Hip Score, and WOMAC were 65 years, 27.7, 48.4, and 48.7, respectively. Skin incision averaged 8 cm, while blood loss averaged 200 ml, and operative time 77 minutes. Mean Harris Hip and WOMAC scores were 72.9/82.98 and 25.1/12.7 at two weeks/six weeks, respectively. All patients ceased narcotic medication by day 24 and all walking aids by day 35.
CONCLUSIONS: Soft tissue sparing approaches to THA are often associated with steep learning curves. The instrumentation associated with this technique has shown promise to reduce or eliminate this learning curve. Preliminary results of this study suggest a patient benefit with this technique, specifically in regard to return to activity and reduction in the need for pain medication. 21. Early Clinical Outcomes in THA Patients Implanted via Mini Posterior Approach versus Percutaneously Assisted Technique Brad L. Penenberg, M.D. Beverly Hills, CA (a,c Wright Medical Technology) Gregory N. Van Winkle, M.D. Menomonee Falls, WI (a,c Wright Medical Technology) Eugene P. Schoch, III, M.D. Austin, TX (a,c Wright Medical Technology) Joseph Isaacson, M.D. Los Angeles, CA (a,c Wright Medical Technology) *Joel Batts, B.S. Arlington, TN (e Wright Medical Technology)
INTRODUCTION: Several so called “minimally invasive” approaches to total hip arthroplasty have been introduced to and utilized by surgeons during the last ten years. The goal of such an approach is improvement in early clinical outcomes that allow patients to return to work/activity sooner than would be otherwise possible. The purpose of the present study was to compare a mini posterior approach to a novel percutaneously assisted approach, the latter utilizing a lateral portal for acetabular preparation and component placement.
MATERIALS AND METHODS: Fourteen case matched patients were implanted in mini posterior fashion (Group I) or using the novel approach (Group II) and prospectively followed under IRB oversight using HHS and WOMAC. Intraoperative blood loss and time on pain medication was also collected.
RESULTS: There were no significant differences between gender, preoperative HHS and WOMAC. There was a slightly shorter hospital stay and a nearly eight day reduction in postoperative time on pain medication in Group II versus Group I, respectively. While operative time did not vary, blood loss was 57 ml less in Group II. WOMAC and HHS at two weeks were significantly better in Group II patients (WOMAC=14.2 vs. 24.67, p=0.04 and HHS=80.3 vs. 56.5, p=0.01), suggesting faster return to activity and less pain.
CONCLUSIONS: Results of this study suggest a patient benefit using this novel instrumentation with respect to key early functional and quality of life measures versus mini posterior approach. A reduced need for pain medication in Group II may be indicative of the more conservative approach to acetabular preparation. KNEE
22. Arthroscopic Treatment of Patellar Clunk and Synovial Hyperplasia After Total Knee Arthroplasty Michael J. Stuart, M.D. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN *Diane L. Dahm, M.D. (n) Rochester, MN Bruce A. Levy, M.D. (n) Rochester, MN
INTRODUCTION: The patellar clunk syndrome is a well documented cause of intra articular mechanical symptoms following total knee arthroplasty (TKA). Patellofemoral synovial hyperplasia is a less well described syndrome that results from diffuse tissue proliferation proximal to the patella. Patients typically present with anterior knee pain and crepitus. Although arthroscopic debridement is the treatment of choice, there is currently a paucity of outcome data in the orthopedic literature. We present the functional results of arthroscopic treatment for patellar clunk syndrome and patellofemoral synovial hyperplasia after primary TKA.
METHODS: Between 1980 and 2006, 25 primary TKA patients at our institution underwent arthroscopic surgery for either patellar clunk syndrome (15 knees) or patellofemoral synovial hyperplasia (10 knees). Pre and postoperative Knee Society Scores (KSS) and range of motion (ROM) were calculated. Patients completed a survey regarding pain, crepitus, and the ability to perform daily tasks (i.e., chair rising, stair climbing) before and after surgery.
RESULTS: Mean patient age was 69 years at the time of arthroscopy. Mean follow up was 41 months after arthroscopy and no patients were lost to follow up. Postoperative KSS knee and function scores improved in both the patellar clunk (92 vs. 76 knee score, 79 vs. 71 function) and synovial hyperplasia (92 vs. 83 knee score, 79 vs. 70 function) patients. On a 10 point severity scale, patients with patellar clunk, on average, experienced less pain (1 vs. 5) and crepitus (0 vs. 6) after arthroscopy, than did the synovial hyperplasia cohort (3 vs. 6 pain, 1 vs. 7 crepitus). Mean knee ROM was similar before and after surgery for the patellar clunk (112° vs. 115°) and synovial hyperplasia (115° vs. 119°) patients.
CONCLUSION: Arthroscopic debridement of patellofemoral synovial hyperplasia and patellar clunk syndrome after total knee arthroplasty alleviates pain and crepitus, and also improves function in the activities of daily living. 23. Staged Protocol for Acute Knee Dislocation: The Role of Initial Spanning External Fixation Bruce A. Levy, M.D. (n) Rochester, MN Khaled A. Dajani, M.D. (n) Rochester, MN Diane L. Dahm, M.D. (n) Rochester, MN Jay P. Shah, B.S. (n) Rochester, MN Michael J. Stuart, M.D. (n) Rochester, MN
INTRODUCTION: The purpose of this study is to present a “staged protocol” for management of high energy knee dislocations. Clinical and functional outcomes of patients requiring initial spanning external fixation were compared with those placed in a hinged knee brace prior to ligament reconstruction.
METHODOLOGY: All patients with evidence/presumption of knee dislocation treated by a single surgeon were identified in our prospective trauma database. All patients followed our staged protocol: Stage 1 included examination under anesthesia, selective use of spanning external fixation, and DVT prophylaxis. Stage 2 included multiligament knee reconstruction. Indications for external fixation were vascular injury, gross instability, and inability to tolerate mobilization in a brace. Outcomes were assessed using physical exam, Lysholm, and International Knee Documentation Committee (IKDC) subjective scores. Multiple regression isolated variables affecting final outcomes.
RESULTS: Between 2004 and 2006, 44 knees in 41 consecutive patients were identified. Eleven knees (10 patients) underwent initial spanning external fixation prior to reconstruction. Thirty three knees (31 patients) were treated with a brace prior to reconstruction. There were no statistically significant differences between patient age (35 vs. 31 years, p=0.89), duration of follow up (27 vs. 24 months, p=0.65), mean IKDC scores (65 vs. 74, p=0.86), mean Lysholm scores (77 vs. 83, p=0.92), and need for manipulation (2 vs. 2 patients, p=0.27) between the two groups. Only maximum knee flexion differed significantly (102 vs. 133, p=0.02). Regression analysis demonstrated the application of spanning external fixation (as opposed to age, gender, mechanism of injury, number of ligaments involved) had a negative effect on final ROM.
CONCLUSION: Although higher final knee flexion was noted in the non spanned group, our staged protocol for high energy knee dislocation resulted in satisfactory clinical and functional outcomes regardless of whether initial spanning external fixation was used. 24. Pre and Postoperative Alignment Using an Alternative Navigation Method *David K. DeBoer, M.D. Nashville, TN (a,e Wright Medical Technology) C. Lowry Barnes, M.D. (n) Little Rock, AR J. David Blaha, M.D. (n) Ann Arbor, MI Mike Carroll, B.S. (n) Arlington, TN Rich Obert, B.S. (n) Arlington, TN Paul Stemnenski, B.S. (n) Arlington, TN
INTRODUCTION: Component alignment in total knee arthroplasty (TKA) is important for kinematic function and longevity of the prosthesis. Standard instrumentation is accepted to provide alignment to intended reference points within 3° in 75% of cases. Intraoperative navigation has been claimed to increase the probability of being within 3° of the target to 85 90%. We propose an alternative method using CT or MRI and custom pin placement guides to allow the surgeon to accurately achieve alignment without the cost and requirements for intra operative navigation.
METHODS: CT scans of four cadaver lower extremities were obtained and converted to solid models. Each extremity was virtually aligned and custom pin placement guides were created for the femur and tibia. The extremity was then registered to a motion tracking camera system. The joint capsule was opened through a traditional approach and the custom guides were placed on the distal femur and proximal tibia. The TKA was completed and the implant final positions were registered to the motion tracking system. Average deviations from planned component location in femoral AP position, rotation, and varus/valgus and tibial varus/valgus and slope were determined.
RESULTS: Deviation from planned component alignment averaged less than 3° on all specimens tested in this study. Component placement in the AP direction deviated from the planned position by an average of less than 3 mm.
DISCUSSION: This is an alternative method of navigation that has results consistent with the placement accuracy of both standard instrumentation and intraoperative navigation. The results indicate the methods employed in this study have the accuracy to implement a patient specific alignment during TKA. 25. Manipulations Following ADVANCE Knee Arthroplasty: Medial Pivot and Double High Designs *C. Lowry Barnes, M.D. Little Rock, AR (a,c,e Wright Medical Technology) Daniel Lincoln, B.S. (n) Little Rock, AR Becky Brewer, B.S. (n) Little Rock, AR
INTRODUCTION: The ADVANCE TKR (Wright Medical Technology, Memphis, TN) is designed with a more constrained medial side than lateral side in an effort to reproduce more normal kinematics. Both a medial pivot (pcl sacrificing) and double high (pcl retaining) insert is available. Because of perception that a kinematic conflict might arise and effect ROM, it may be important to evaluate for manipulation rate and response to manipulation.
MATERIALS/METHODS: 755 ADVANCE knees were performed by the senior author between September 2005 and April 2008. Sixty percent were DH, and 40% were MP. Rate of manipulation and response to manipulation were studied.
RESULTS: The overall manipulation rate was 4.1% (4.6% for DH and 3.3% for MP—no significant difference). The average flexion after manipulation was 108° for DH group and 100° for MP group (no significant difference). The improvement post manipulation was, however, significant (p=.03) with MP improvement of 19° and DH improvement of 35°. Overall, there was an improvement of 30°.
DISCUSSION: The rate of manipulation is similar to previously reported rates with similar indications (less than 75° flexion or patient request). Additionally, patients responded similarly to other groups of posterior stabilized or pcl retaining TKR groups.
CONCLUSION: Significant kinematic conflict does not exist with the ADVANCE MP or DH design. 26. Distal Femoral Sizing Comparisons Using Computed Tomography Archive *C. Lowry Barnes, M.D. Little Rock, AR (b,c,e Wright Medical Technology) David K. DeBoer, M.D. (n) Little Rock, AR J. David Blaha, M.D. (n) Ann Arbor, MI John Green, M.S. (n) Little Rock, AR Rich Obert, M.S. (n) Arlington, TN
BACKGROUND: Knee implants are available in a variety of sizes; however, recent studies indicate a need for “anthropometrically” accurate sizing systems. Traditional methods of obtaining sizing measurements require invasive procedures or cadaveric specimens. The purpose of this study was to collect anthropometric knee data from different ethnicities and demonstrate a capability to obtain otherwise difficult to measure in vivo dimensions.
METHODS: Eighty knee CT scans of individuals (45 patients) with known biometric data were converted to virtual models and oriented with an anatomical coordinate system. The models were then used to obtain AP (most prominent anterior and posterior condylar points), ML (at 10 mm distal resection), and condylar spacing measurements.
RESULTS: Mean values for all measurements were larger for males than females in both the overall population and within each ethnic group. Ethnic differences were observed in AP and condylar spacing measurements, but not in ML dimensions. Comparisons of males to females from different ethnic populations indicated several pairings in which the mean measurements for males of one ethnicity were equivalent to females from another.
CONCLUSIONS: While size appears to trend with gender, there is overlap in the populations, especially across ethnic groups which indicates gender is not the sole factor necessary to determine implant sizing. This study utilizes a “virtual surgery” method which allows the user to take measurements in a surgically pertinent coordinate system that are difficult to obtain by conventional means. The method provides additional value of having a readily accessible archive for future measurements. 27. Low Incidence of Postoperative Complications Due to Pin Placement in Computer Navigated Total Knee Replacement *Richard F. Owens, Jr., M.D. (n) Cincinnati, OH Michael L. Swank, M.D. Cincinnati, OH (a,e BrainLAB, DePuy)
Computer navigated joint replacement surgery using optical tracking systems require that tracking arrays are fixated to the patient’s bone. The arrays may be fixated by pins ranging in size from 3 5 mm with unicortical or bicortical fixation into the metaphyseal, meta diaphyseal junction or in the diaphysis. Recent reports of femoral or tibial fracture at the pin site, as well as a recent cadaveric study have raised concern about proper pin placement. In order to quantify the risks associated with pin placement, we reviewed the postoperative complications occurring in a single surgeon series of 984 consecutive primary total knee replacements.
All pins were placed using 2 4 mm pins connected by an array that separates the pins by 15 mm. Two femoral pins were placed into medial epicondyle (metaphyseal) and within the incision. Two tibial pins were placed 10 cm inferior to the tibial joint line in the diaphysis. All pins were placed unicortically with drilling stopped at the level of the second cortex. Patients were examined perioperatively and data were recorded prospectively in a computerized database.
There were no fractures associated with pin placement. Seventeen (1.7%) patients had minor pin related complications. There were no patients with complications associated with the femoral pins. Twelve patients had a superficial infection around the tibial pin sites which resolved with oral or topical antibiotics. None of the infections required re admission to the hospital or hardware removal. Five patients had minor complaints (bleeding, skin tear, low level pain) which resolved without further intervention.
This large single surgeon series showed no major complications and a low incidence of minor complications associated with pin placement. We believe that reference array pins may be safely placed during computer assisted total knee arthroplasty. 28. Intermediate Postoperative Outcomes in Computer Assisted Total Knee Arthroplasty: Evaluating 261 Initial Consecutive Cases *Taruna J. Madhav, M.D. (n) Cincinnati, OH Shannon L. Hiratzka, MPH, MT (ASCP) (n) Cincinnati, OH Michael L. Swank, M.D. Cincinnati, OH (a,e BrainLAB, DePuy)
INTRODUCTION: Computer assisted total knee arthroplasty has demonstrated variable outcomes in the literature. A learning curve for computer assisted surgery is recognized, and there may be different outcomes for cases performed initially during the learning phase. This study reports on a single surgeon’s experience with the initial 261 computer assisted total knee arthroplasties.
METHODS: A single experienced reconstructive surgeon performed computer assisted total knee arthroplasty utilizing either the BrainLAB or Ci intraoperative navigation system and either the LCS Complete Mobile Bearing Knee System (DePuy) or Sigma PFC Rotating Platform (DePuy). Preoperative and postoperative data was recorded prospectively (DePuy Captureware) of the initial 261 consecutive cases at minimum of one year follow up. SAS 9.1 was used to perform multivariate analyses of four consecutive groups of patients. Data was controlled for body mass index, age, sex, implant type, preoperative range of motion, preoperative function, and preoperative pain scores.
RESULTS: There was no statistically significant difference in the improvement of postoperative function (p=0.29) and pain scores (p=0.28) among the patients in the four groups at minimum one year follow up. There was a statistically significant difference in improvement of postoperative extension (p=0.0022) and flexion (p=0.0139) scores with subsequent surgeries; however, the range of improvement for the groups was not clinically significant (extension ranging from 1.97 to 5.92° gained in the four groups, and flexion loss of 0.67° to gain of 6.18° in the four groups).
SUMMARY: For an experienced surgeon incorporating computer assisted surgery into his/her total knee arthroplasty practice, there is no significant learning curve in regards to intermediate term outcomes. Patients have similar intermediate outcomes whether performed earlier in that surgeon’s experience or later. At one year, there is no significant difference in patients’ postoperative improvement in function, pain score, knee flexion, and knee extension. 29. Computer Assisted Navigation Software Advancements Improve the Accuracy of Total Knee Arthroplasty *Ryan G. Molli, D.O. (n) Southfield, MI Kevin C. Anderson, M.D.(n) Manistee, MI Knute C. Buehler, M.D. Bend, OR (e Stryker Orthopaedics) David C. Markel, M.D. Southfield, MI (e Stryker Orthopaedics)
INTRODUCTION: We have previously published our findings on the success of computer assisted navigation in total knee arthroplasty. The purpose of this study was to evaluate the effectiveness of software advancements as well as surgeon experience in improving total knee prosthetic positioning and limb alignment.
METHODS: A single total joint fellowship trained surgeon performed total knee arthroplasty on 315 patients using conventional techniques (51 patients) or with assistance from Stryker computer navigation software version 2.0 (116 patients) or 3.1 (148 patients). Pre and post operative x ray measurements were taken and analyzed to compare limb and component alignment.
RESULTS: Our previous work demonstrated a statistically significant improvement (P<0.02) in limb alignment (±3° of biomechanical neutral) for version 2.0 software (93%) when compared to conventional techniques (82%). However, further improvement was seen with version 3.1 software (99%, P<0.03). Compared to the 2.0 software, tourniquet times were decreased for the 3.1 software (90 vs. 73 minutes, P<0.001). Furthermore, only the 3.1 software resulted in a statistically significant higher frequency of patients with the surgeon’s target tibial posterior slope of 3°± 2° when compared to the conventional techniques (80 vs. 59%, P<0.01).
DISCUSSION AND CONCLUSION: Several advances have been seen using computer assisted navigation. Improvements in the software, as well as the surgeon's experience, have allowed for more consistent postoperative mechanical axis and posterior tibial slope values, as well as shorter tourniquet times. Further research needs to be conducted to see if these factors will lead to improved patient function and/or prolonged prosthetic survival rates. 30. More Experienced Surgeons Select Larger Femoral Components in Total Knee Arthroplasty *Sumon Nandi, M.D. Cleveland, OH (b Stryker OITE Review Course) Mark I. Froimson, M.D. (n) Cleveland, OH Morgan H. Jones, M.D. (n) Cleveland, OH Boris Bershadsky, Ph.D. (n) Cleveland, OH
INTRODUCTION: Proper femoral component size selection is important for successful total knee arthroplasty (TKA) because it influences anterior femoral cortex notching and subsequent periprosthetic fracture risk, stability, range of motion, and patellar tracking. Ideally, femoral component size should be selected based on patients’ bone size and should not vary from surgeon to surgeon for patients with the same bone size. Nevertheless, surgeons’ preferences may impact their choice. We explore if systematic variations in femoral component size selection among surgeons exist and to what extent they are related to surgeons’ experience and training.
METHODS: The Operating Room Information System was queried for patients who underwent primary TKA (2003 2007, 13 surgeons) using two different knee systems (n1=1,388, n2=740). Comparison of surgeons’ femoral component size choices was performed for each knee system separately using a generalized linear model with femoral component size as the dependent variable and surgeons’ years in practice and adult reconstruction fellowship training as independent variables. Based on the literature, patients’ height, gender, weight, and age were selected to adjust for patient to patient variations in bone size.
RESULTS: Surgeon years in practice and adult reconstruction fellowship training were independent positive predictors of femoral component size in both samples (p=0.0001).
CONCLUSION: Our study demonstrates surgeon related variability in femoral component size selection for patients of a given height, gender, weight, and age (and presumably a given bone size). More experienced surgeons select larger femoral components. New surgical instruments and standardized training protocols may need to be developed to adjust for varying surgeon experience. With the degree of surgeon variability detected, within institution surgeon randomization may be a cost effective alternative to multi center clinical trials. Future work will focus on outcomes of surgeon related variations in femoral component size selection. 31. Pain Relief Following TKA Not Affected by Body Mass Index (BMI) *Jasvinder A. Singh, M.D. Minneapolis, MN (a DePuy, Stryker, Zimmer) Sherine E. Gabriel, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN
OBJECTIVE: High BMI is reportedly associated with poorer arthroplasty outcomes. We investigated the association between high preoperative BMI and prevalence of moderate severe knee pain post TKA.
METHODS: We identified a cohort of patients who underwent primary or revision TKA from 1993 2005 and responded to the follow up questionnaires two or five years post surgery. Multivariable logistic regression compared the odds of moderate severe knee pain by BMI category, adjusting for age, gender, diagnosis, comorbidity, implant type, distance from medical center, and ASA score; p<0.05 was considered significant.
RESULTS: Survey response ranged 48 65% (higher for two years). BMI was not associated with moderate severe pain at two or five years post primary TKA or post revision TKA (p>=0.18 for all) (see tables). Table . Multivariable adjusted Odds ratio (95% CI) of Moderate Severe Knee Pain post TKA by BMI (in kg/m2). Primary TKA 2 years Primary TKA 5 years <24.9 1.0 1.0 25 29.9 1.02 (0.74,1.39) 1.28 (0.84,1.94) 30 39.9 1.00 (0.73,1.37) 1.18 (0.78,1.78) ≥40 1.26 (0.83,1.91) 1.19 (0.66,2.14)
Revision TKA 2 years Revision TKA 5 years
<24.9 1.0 1.0 25 29.9 1.00 (0.64,1.56) 1.45 (0.81,2.59) 30 39.9 1.17 (0.76,1.81) 1.18 (0.78,2.43) ≥40 1.22 (0.68,2.17) 1.19 (0.77,4.02)
CONCLUSIONS: This study documents the lack of association of BMI with moderate severe pain in both primary and revision TKA. Similar pain outcomes should reassure both patients and surgeons that BMI does not impact pain outcomes post TKA. 32. Systematic Review of Total Knee Arthroplasty (TKA) in Patients 55 Years or Younger *John C. Clohisy, M.D. St. Louis, MO (a Wright Medical Technology) Selena Eunice (n) St. Louis, MO Amanda Schutz, Ph.D. (n) St. Louis, MO
BACKGROUND: TKA is commonly utilized as a surgical treatment in the elderly population for end stage knee disease and is now more commonly utilized for younger patients ( ≤ 55 years). Yet there is limited information on the efficacy of TKA in young patients. Therefore, the purpose of this study was to perform a systematic review of the literature to identify and summarize the studies that report the clinical outcomes of TKA in patients ≤ 55 years.
METHODS: A literature search within Ovid, Embase, and Pubmed using key terms: total knee arthroplasty and age ≤ 55 years, produced 76 relevant articles related to this topic. Eight articles met our inclusion criteria of patient age ≤ 55 years, radiographic data presented, and minimum two year follow up.
RESULTS: The remaining eight studies (399 total knees) produced Level III and IV evidence retrospectively. Good to excellent knee score results reported in ≥ 82% at midterm follow up, implant survivorship rates at ≥ 84.5% (follow up 4.56 18 years), and knee lysis/wear evident between a 7 13 year postoperative time frame.
CONCLUSION: Total knee arthroplasty is an effective procedure in patients ≤ 55 years; clinical evidence (level III and IV) supports favorable outcomes within this population, but efficacy is limited by survivorship. 33. Can Total Knee Arthroplasty Implant Size be as Accurately Predicted by Height as by Templating? John H. Flint, M.D. (n) Iowa City, IA *Aaron M. O’Brien, B.S. (n) Iowa City, IA Richard C. Johnston, M.D. (n) Iowa City, IA John J. Callaghan, M.D. Iowa City, IA (c,e DePuy)
BACKGROUND: Total knee arthroplasty is a very common orthopedic procedure. Surgeons commonly perform either acetate or digital templating prior to surgery to anticipate needed implant sizes. Specht and Aslam both showed they could predict the final implant size with templating within one size 93% and 90% of the time, respectively. The purpose of this study was to investigate if body metrics, including height, could be used to predict final implant size as accurately as templating.
METHODS: Four hundred and thirty eight consecutive primary total knee arthroplasties from a single high volume arthroplasty surgeon using a single implant, DePuy PFC Sigma, were selected. The implant size as well as body metric data was obtained including height, weight, BMI, gender, and race. The 438 knees and accompanying data were randomly split into two groups. Using one half of the group, a model was built to predict the size of the final implant off of the selected body metrics. This was then repeated in reverse using the second group to derive the model. The accuracy of the models to predict the other group’s sizes was recorded. The models were then merged and applied to a second surgeon’s patients, using the same implant, to predict the final implant sizes. Additionally, the preoperative templating of the second surgeon was compared to the model’s predicted size of the body metrics.
RESULTS: The model derived could accurately predict both femoral and tibial implant sizes within one size 94% of the time using the metric of height alone for surgeon one. The model predicted final implant size accurately within one size 91% of the time for surgeon two while his personal templating was accurate within one size 89% of the time.
CONCLUSIONS: Final total knee implant size can be as accurately predicted using patient height alone as by templating for the DePuy PFC Sigma Knee System. 34. Radiographs Do Not Allow Accurate Measurement of Lower Extremity and Implant Alignment Following TKA *Todd C. Moen, M.D. (n) Chicago, IL S. David Stulberg, M.D. (n) Chicago, IL Mark A. Yaffe, M.D. (n) Chicago, IL
INTRODUCTION: The purpose of this study was to determine the accuracy of postoperative long standing radiographs in determining alignment following TKA by comparing them with alignment measured by an image free navigation system.
METHODS: Fifty two consecutive patients underwent TKA using an image free navigation system. The mechanical axis of the lower extremity was measured using the system immediately before and after implantation. The navigation based mechanical axis data was compared with long standing radiographs made at one year postoperatively.
RESULTS: The average postoperative coronal alignment measured with the navigation system was 0.56° varus +/ 1°. The average alignment measured with postoperative x rays was 1.9° valgus +/ 2.8°. The mean discrepancy between the navigated alignment and radiographic alignment was 2.7° +/ 1.8°. Fifteen patients (30%) that had a radiographic alignment greater than 3° from neutral had an alignment measured with the navigation system within 3° of neutral. Three patients that had a navigation based alignment greater than 3° from neutral had a radiographic alignment within 3° of neutral. Fourteen patients had a discrepancy between their radiographic and navigation based alignment of greater than 4°. Therefore, 32 patients (65%) had radiographs that gave assessments of alignment that were significantly different than that measured with navigation.
DISCUSSION: Standard postoperative radiographs are imprecise and do not have the inherent accuracy needed to function as the primary measurement tool of alignment following TKA. Factors such as a patient’s individual anatomy, patient positioning, and difficulty in identifying anatomic landmarks contribute to radiograph’s inaccuracy. 35. Alignment in Total Knee Arthroplasty: An Analysis of Variability of the Anatomic and Mechanical Axes of the Femur Mr. Nicholas Wegner (n) Chicago, IL S. David Stulberg, M.D. (n) Chicago, IL *Todd C. Moen, M.D. (n) Chicago, IL
INTRODUCTION: One of the most significant challenges in reconstructing a neutral mechanical axis in total knee arthroplasty (TKA) is establishing the orientation of the distal femoral cut. Although the relationship between the anatomic and mechanical axes of the femur has been extensively studied, it remains incompletely understood. The purpose of this study was to establish the variability in the relationship between the anatomic and mechanical axes of the femur.
METHODS: Under fluoroscopic guidance, a standard contemporary intramedullary alignment system was used to establish the anatomic axis in 29 cadaveric femurs. Using a standardized protocol, digital radiographs were made in the coronal and sagittal planes. The angle between the anatomic and mechanical axes of the femur was then measured digitally. A mathematical model was used to establish the variability of the intramedullary system in making the distal femoral cut.
RESULTS: The mean femoral anatomic axis was in 5.25 of valgus (+/ 1.02 ) relative to the mechanical axis of the femur in the coronal plane, and was in 1.62 of flexion (+/ 1.09) relative to the mechanical axis in the sagittal plane. With the intramedullary alignment system used in this study, 95% of distal femoral cuts will be within 2.46 of the mechanical axis in the coronal plane, and 3.08 in the sagittal plane.
DISCUSSION: This study established the variability between the anatomic and mechanical axes of the femur, as well as the expected variability from a currently used intramedullary alignment guide. This information has implications in the indications for computer assisted navigation systems. 36. Golf After Total Knee Arthroplasty: Do Patients Return to Walking the Course? *Jeffrey D. Jackson, M.D. (n) Rochester, MN Diane L. Dahm, M.D. (n) Rochester, MN Jay Smith, M.D. (n) Rochester, MN Stephen Wisniewski, M.D. (n) Rochester, MN Jeffrey R. Harrington, M.D. (n) Rochester, MN
BACKGROUND: Golf provides an opportunity for low impact exercise for nearly all age groups and is considered a recommended activity for total knee arthroplasty (TKA) patients. We hypothesized that TKA would afford patients increased ability to participate in and enjoy golf, allowing a large percentage to return to walking the golf course.
METHODS: Surveys were sent to 131 golfers who had undergone primary TKA from 1995 to 2000. The detailed survey included 33 questions specific to the patients’ golf performance, enjoyment of golf, frequency of participation, timing of return to play, presence of pain, use of a cart, and related golf specific issues.
RESULTS: We received and evaluated 93 responses (71%). Fifty seven percent reported they had returned to golf within six months following TKA. Eighty one percent of respondents reported golfing as frequently as or more frequently than before knee replacement. Notably, golfers reported less pain while golfing after TKA than before TKA (88% vs. 17%; p<0.0001), and 94% of respondents reported currently enjoying golf as much or more than prior to surgery. Despite these excellent results, 86% percent of patients reported using a golf cart rather than walking while playing golf.
CONCLUSIONS: In this population of golfers, total knee arthroplasty reliably relieved pain previously experienced while golfing, and increased or maintained this group’s enjoyment of playing golf. However, almost 90% of these patients reported using a cart while golfing. Further patient education is needed regarding the potential health benefits of walking during golf after TKA. 37. Outcome of Total Knee Arthroplasty when the Extensor Mechanism is Preserved *Michael J. Anderson, M.D. Mequon, WI (a,e Wright Medical Technology) Joseph Isaacson, M.D. Los Angeles, CA (a,e Wright Medical Technology) Brad L. Penenberg, M.D. Beverly Hills, CA (a,e Wright Medical Technology Eugene P. Schoch, III, M.D. Austin, TX (a,e Wright Medical Technology) Jonette Hodge, R.N. Arlington, TN (e Wright Medical Technology)
INTRODUCTION: Several so called “soft tissue sparing” approaches to total knee arthroplasty have been utilized over the last decade. The purpose of this prospective study was to determine the early outcomes using soft tissue sparing instrumentation that facilitated preservation of the extensor mechanism.
MATERIALS AND METHODS: Forty unilateral patients were enrolled at four sites and implanted using anterior rough cut instrumentation that had been modified to accommodate bone cuts through minimal soft tissue dissection. Detailed operative data was collected including blood loss, length of quadriceps split, and the extent of any tear in the quadriceps tendon or VMO. The Knee Society Score (KSS) and Oxford Score (OS) were collected at the six weeks visit to determine early outcome.
RESULTS: Demographics for age, BMI, preoperative KSS, and OS were 68 years, 29.5, 52, 38, respectively. Subvastus approach was taken in 62.5% of the cases, with the remainder being parapatellar. The quad tendon was split in 25% of the cases, with an average split length of 2.6 cm. Quad tendon and VMO tears occurred in only two cases, with lengths less than 0.5 cm. Mean improvement from baseline at six weeks was 31 points and 14 points for the KSS and OS, respectively. Parapatellar approach showed a greater KSS improvement from baseline than subvastus (p<0.05).
CONCLUSIONS: This soft tissue sparing approach provided preservation of the extensor mechanism, resulting in early postoperative improvement. The greater KSS improvement in patients having parapatellar approach may indicate that a more technically demanding subvastus approach may diminish the effect of soft tissue sparing. 38. Biomechanical Testing of Tibial Fixation Implants with Double Stranded Allografts Used in ACL Reconstruction Jeremy R. Child, B.S. (n) Columbus, OH Alan S. Litsky, M.D. (n) Columbus, OH *David C. Flanigan, M.D. (n) Columbus, OH
Various types of grafts and fixation techniques are used in anterior cruciate ligament (ACL) reconstruction surgery. Graft tibial fixation, in particular, has been the main site of clinical failure in the immediate postoperative period. This study used bovine tibiae and two stranded, human anterior tibialis tendon grafts to compare the stiffness and fixation strength of two tibia fixation devices, the Milagro Interference Screw™ (Milagro), and the Bio Intrafix Soft Tissue Tibial Fixation System™ (Bio Intrafix). Twelve constructs (six tibiae in each group) were pulled to failure in a materials testing apparatus while measuring stiffness and load to failure. Paired tendon grafts (one right and one left) were used in opposite groups to minimize graft differences between groups. All constructs tested failed by slippage of one or both ends of the anterior tibialis graft past the fixation device. There was no significant difference in the mean stiffness between the Bio Intrafix group (269.7 ± 42.0 N/mm) and the Milagro group (248.3 ± 48.3 N/mm). The mean load to failure for the Bio Intrafix group (1320.2 ± 272.3 N) was significantly larger than the Milagro group (942.7 ± 235.8 N) with a P < 0.05. Bio Intrafix, which is designed for a four stranded graft, provided better fixation than a traditional bioabsorbable interference screw in a two stranded graft. Bio Intrafix fixation provides superior fixation to the Milagro at one of the weakest links in ACL reconstruction surgery. HIP & KNEE
39. Implementation of a Rapid Recovery Program Following Total Joint Arthroplasty *Wael K. Barsoum, M.D. Cleveland, OH (a Smith & Nephew, TissueLink, Zimmer; a,b,e Stryker; c Exactech; c,e SS White, Wright Medical Technology; e Otismed) Aaron Toetz, B.S. (n) Cleveland, OH Lauren Boukis, B.S. (n) Cleveland, OH April Fehribach, B.S. (n) Cleveland, OH Marka Gehrig, B.S. (n) Cleveland, OH Mary K. Miladonis, Ph.D. (n) Cleveland, OH Alison K. Klika, M.S. (n) Cleveland, OH
INTRODUCTION: For many patients, satisfaction means a quicker discharge home and an accelerated return to daily routine. With this in mind, our postoperative care has focused on decreasing patients’ length of stay (LOS) and increasing their function at the time of discharge by utilizing a Rapid Recovery (RR) program, which emphasizes early and frequent mobilization. The purpose of this study is to determine if implementing RR in total joint arthroplasty (TJA) patients has an effect on the LOS, function, and pain during the early postoperative period.
METHODS: A retrospective chart review was conducted for total knee arthroplasty (TKA) and total hip arthroplasty (THA) surgeries between January 2005 August 2006 (traditional group) and September 2006 December 2007 (RR group). Data collected included patient demographics, LOS, visual analog scale pain, walking distance, and patient discharge disposition. Joint specific outcomes scores were also reviewed, including Harris Hip Scores and Knee Society Scores.
RESULTS: A total of 103 THA patients (73 traditional; 30 RR) and 116 TKA patients (62 traditional; 54 RR) were reviewed. Results indicate that by undergoing a RR protocol following THA, patients are able to ambulate farther (p<0.01), experience less pain (<0.01), and spend less time in the hospital (p=0.02). Patients treated with TKA and RR are able to ambulate farther (p=0.01), have less pain (<0.05), have decreased LOS (p=0.01) and are discharged directly home at an increased frequency as compared to those treated in a traditional fashion (p<0.01). Additionally, TKA patients have greater Knee Society function scores at four weeks postoperatively (p=0.01).
CONCLUSIONS: These data support the use of a RR approach following TJA. Potential benefits of this program include reduced hospital costs due to decreased LOS, a quicker return to function based on postoperative ambulation data, and increased patient satisfaction as patients are increasingly able to return home more quickly. 40. Midterm Follow Up Compliance for Routine Total Joint Arthroplasty Surveillance Saju Rajan, M.D. (n) St. Louis, MO Amanda Schutz, Ph.D. (n) St. Louis, MO Adeniran Adewale, B.S. (n) St. Louis, MO *John C. Clohisy, M.D. St. Louis, MO (a Wright Medical Technology)
INTRODUCTION: Periodic surveillance of patients with total hip (THA) or total knee (TKA) arthroplasties has been recommended to facilitate early diagnosis of implant failure. Nevertheless, there is limited information regarding the efficacy of patient follow up protocols. The purpose of this study was to examine the midterm follow up compliance of THA and TKA patients.
METHODS: A cohort of 559 patients treated with THA or TKA by one surgeon were analyzed retrospectively. 350 THAs (255 primary, 95 revisions) and 209 TKAs (148 primary and 61 revisions) were studied. Patients were instructed by the surgeon to return for midterm follow up (five years). A subgroup of 29 patients in a prospective, randomized trial were contacted for follow up appointments and served as a comparison group. Compliance rates were determined and examined for correlation with patient demographics, clinical history, surgical result, and patient satisfaction.
RESULTS: Midterm (five year) follow up compliance was 26% for patients treated with THA and TKA procedures. In contrast, the comparison group (contacted for follow up appointments) had a compliance rate of 93% (p<0.05). Compliance for hip and knee arthroplasties was 23% and 35%, respectively. A multivariate model in THA patients showed that younger patient age (p <0.05) and a revision procedure (p<0.05) correlate with improved follow up compliance. A multivariate model in TKA patients indicated no significant predictors.
CONCLUSION: Midterm follow up compliance in this cohort was poor with an average 26% of patients returning for evaluation. Improved methods of surveillance for total joint replacement patients need to be developed. 41. Hip and Knee Arthroplasty in Hypophosphatemic Rickets *A. Noelle Larson, M.D. (n) Rochester, MN Joaquin Sanchez Sotelo, M.D., Ph.D. (n) Rochester, MN Robert T. Trousdale, M.D. (n) Rochester, MN Mark W. Pagnano, M.D. (n) Rochester, MN Arlen D. Hanssen, M.D. (n) Rochester, MN David G. Lewallen, M.D. (n) Rochester, MN
INTRODUCTION: There is very limited published information about the technical aspects and outcome of lower extremity arthroplasty in hypophosphatemic rickets. Associated bowing deformities of the femur and tibia may require corrective osteotomies at the time of arthroplasty and may complicate implant positioning, alignment, and fixation. In addition, these patients are at risk for periprosthetic stress fractures, and the effect of rickets on bone ingrowth is largely unknown. The purpose of this study was to analyze the outcome of total knee and total hip arthroplasty in patients with underlying hypophosphatemic rickets.
METHODS: Between 1972 and 2006, eight total hip arthroplasties and five total knee arthroplasties were performed in seven patients with degenerative arthritis and bone deformity secondary to hypophosphatemic rickets. All patients were followed prospectively at regular intervals and their records and radiographs were reviewed to determine their outcome and complications. The mean age at the time of surgery was 49 years and the mean follow up time was 6.5 years (range, 2 to 13 years).
RESULTS: Corrective osteotomies were performed prior to the arthroplasty in five cases and at the time of the arthroplasty in two hips. One additional patient required a corrective femoral osteotomy to treat recurrent stress fractures after knee arthroplasty. Specialized implants were required in four hips. Stems were used in one knee arthroplasty and increased constraint was required to obtain stability in a second knee. The mean Harris hip score improved from 54 to 75 points after hip arthroplasty (p=0.03). The mean Knee Society pain and function scores improved from 46 to 95 points and from 51 to 75 points respectively (p=0.001). Only one hip required revision for femoral aseptic loosening 13 years postoperatively. Radiographic review at most recent follow up showed all other implants to be stable, although radiolucent lines were identified in one zone only around one tibial component and two acetabular components.
42. Primary Hip and Knee Replacement: “Are We All Operating on the Same Patients, Even at the Same Institution?” *Paul K. Herickhoff, M.D. (n) Iowa City, IA John J. Callaghan, M.D. Iowa City, IA (c,e DePuy) Michael R. O’Rourke, M.D. (n) Iowa City, IA Charles R. Clark, M.D. (n) Iowa City, IA J. Lawrence Marsh, M.D. (n) Iowa City, IA Nicolas O. Noiseux, M.D. (n) Iowa City, IA Richard C. Johnston, M.D. (n) Iowa City, IA
BACKGROUND: Patient referral patterns and indications for total joint arthroplasty may vary between physicians. The aim of this study was to compare the preoperative characteristics of patients undergoing primary total hip and knee arthroplasty between four orthopedic surgeons operating at a single academic institution from 2003 to 2007.
METHODS: 1,896 primary total hip and total knee replacements were performed by four surgeons between 2003 to 2007. Patient demographics to include sex, age, and BMI and pre operative outcome scores (SF 36 and WOMAC) were recorded. These parameters were compared amongst the four surgeons.
RESULTS: No differences were found between surgeons in preoperative SF 36, WOMAC function scores, education, smoking, and musculoskeletal comorbidities for total hip and knee arthroplasty patients. Three of the surgeons operated on a higher proportion of younger and heavier patients compared to the fourth surgeon. The largest difference between surgeons in mean age and BMI was 4.4 years and 3.3 kg/m2. Inconsistent differences were demonstrated in life orientation scores, drinking, occupation, systemic comorbidities and WOMAC pain and stiffness scores between the surgeons.
CONCLUSIONS: Validated measures of patient disability (SF 36 and WOMAC scores) were essentially the same between surgeons at our institution demonstrating relatively similar indications for surgery. However, there were some differences in age, sex (more males), and BMI distribution of patients amongst the four surgeons. In addition, surgeons at this institution operated on younger patients and more males when compared to national averages. LOWER EXTREMITY
43. Evaluation of Tibia Fracture Union with CT Scans and Plain Radiography Brian M. Curtin, M.D. (n) Louisville, KY Madhusudhan R. Yakkanti, M.D. (n) Louisville, KY *Craig S. Roberts, M.D. (n) Louisville, KY Steven D. Glassman, M.D. (n) Louisville, KY
INTRODUCTION: CT scans have been shown to be very sensitive in detecting nonunions. There is limited evidence comparing CT scans and plain radiography in the diagnosis of tibial nonunions. The purpose of this study was to evaluate the correlation between plain radiographs and CT scan interpretations in detecting tibia nonunion.
METHODS: Three to six month radiographs and CT scans of 13 patients who underwent intramedullary nail fixation or plate fixation for traumatic tibia fracture and went on to subsequent nonunion repair were reviewed. Also, an additional six radiographs of patients who underwent intramedullary nail fixation for tibia fracture that healed within three months clinically and radiographically were reviewed. Three orthopedic surgeons graded all radiographs and CT scans that were randomized in presentation order. Grading criteria were the same for all three. Fusion grades with bridging cortices parameters based on previously published criteria for extremity fractures and an overall assessment of union were assigned to each set of images. Technique used to obtain all x rays and CT scans was identical and performed at the same institution. Kappa coefficients for interobserver and intraobserver variability were calculated.
RESULTS: Kappa coefficients for nonunion/union on x ray and CT were 0.77 for all three evaluators. Kappa coefficients were also calculated for plus/minus one cortex for each evaluator and found to be 0.85, 0.77, and 0.77 with an overall value of 0.80.
CONCLUSIONS: CT evaluation of tibial shaft fracture nonunion is unlikely to provide conclusions different from those achieved through plain radiography. 44. Functional Outcomes of Operatively Treated Tibial Plateau Fractures *Clifford B. Jones, M.D. (n) Grand Rapids, MI Matthew R. Karek, B.S. (n) Grand Rapids, MI Debra L. Sietsema, Ph.D. (n) Grand Rapids, MI Terrence J. Endres, M.D. (n) Grand Rapids, MI
INTRODUCTION: The primary aim of this study was to determine musculoskeletal and general health outcomes over time after tibial plateau fracture surgical treatment.
METHODS: From October 1, 2000, and December 31, 2005, a prospective analysis of operatively treated tibial plateau fractures was performed. Patients prospectively completed postoperative 6, 12, and 24 month SF 36 and SMFA functional outcome measurements. A radiographic analysis, demographic data, mechanism of injury, injury pattern, and surgical technique was performed.
RESULTS: 201 tibial plateau fractures with a mean age of 45.5 years (18 89) and a BMI of 29.3 (17.4 49.6) were analyzed. 25 were open injuries. 79 patients were polytrauma. 51 were unicondylar, and 150 were bicondylar fractures. Complications were 21 deep infections (10.4%), 22 malunions (10.9%), 11 nonunions (5.5%), 45 post traumatic arthrosis (22%), 18 joint contractures (9.0%), and 33 prominent HW (16.4%). Unplanned secondary surgeries were 32 HW removal (21.4%), 4 revision ORIF (2.0%), and 5 knee arthroplasty (2.5%). A statistically significant difference was noted in daily activity and mobility at two years compared to six months (p<0.05). A statistically significant difference was noted between unicondylar and bicondylar fractures in daily activity at six months and two years and in mobility at two years.
CONCLUSIONS: Tibial plateau fractures require precise reduction and stable fixation of alignment and articular step off while avoiding complications. Functional outcome measurements improve up to two years postoperatively. Unicondylar fractures function better than bicondylar fractures. 45. Vancouver Type II and III Periprosthetic Femur Fractures Treated with Modular Femoral Implants *Arthur L. Malkani, M.D. (n) Louisville, KY Mehdi Jaffari, M.D. (n) Philadelphia, PA Javad Parvizi, M.D. (n) Philadelphia, PA Dale Baker (n) Louisville, KY
INTRODUCTION: The purpose of this study was to review our clinical results of Vancouver Type II and III periprosthetic femur fractures treated with modular femoral implants.
METHODS: This is a retrospective review of 60 patients with an average age of 75 years and a minimum two year follow up. There were 22 males and 38 females with an average BMI of 30. Twenty six patients had a Vancouver Type II periprosthetic fracture, and 34 patients had a Type III pattern. In 43 patients, a modular femoral implant design was utilized. In 17 patients, a modular mega prosthesis (tumor type) was utilized.
RESULTS: At latest review, 4 patients had died leaving 56 patients available for review. There were a total of five patients requiring re operation surgery in this group which included two for acetabular component revision, two for femoral component revision due to subsidence, one for femoral stem fracture, and one for dislocation. Due to fatigue fracture at the trunion of the stem, an earlier generation design implant was discontinued.
DISCUSSION AND CONCLUSION: Vancouver Type II and III periprosthetic fractures can be successfully treated with a modular femoral implant with independent fixation of the stem into the femoral diaphysis to provide fracture stability and restoration of leg length and offset using a modular proximal body. High stresses at the body stem junction have leg to fatigue failures in certain design implants leading to a second generation of modular femoral implants with improved biomechanical properties and good short term results. UPPER EXTREMITY
46. Thumb Carpometacarpal Suspension Arthroplasty Using Interference Screw Fixation: Surgical Technique and Clinical Results *Robert W. Wysocki, M.D. (n) Chicago, IL Mark S. Cohen, M.D. (n) Chicago, IL John J. Fernandez, M.D. (n) Chicago, IL
BACKGROUND: We describe the technique and clinical results of a new method for thumb carpometacarpal joint arthroplasty.
METHODS: Over 12 months, 29 consecutive carpometacarpal arthroplasties were performed using flexor carpi radialis transfer through a single incision with an interference screw rather than direct tendon to tendon suturing for fixation. The scaphoid to first metacarpal distance was measured on all postoperative films to assess settling. All patients were evaluated with serial x rays and at a minimum of one year with the DASH, a functional survey, and measurements of range of motion, grip strength and pinch strength in lateral key pinch, tip pinch, and tripod pinch using dynamometry.
RESULTS: Twenty eight patients (97%) were available for follow up at a mean of 19 months. No arthroplasties had required revision. The average length of procedure was 33 minutes. Radiographs revealed a mean postoperative scaphoid to first metacarpal distance of 5.8 mm, which decreased by a mean of 0.9 mm over the first three months, and an additional 0.6 mm at final follow up. Palmar abduction, radial abduction, and strength in grip and lateral key, tripod, and tip pinch did not differ between the affected and unaffected sides. The mean DASH score was 15, and mean VAS score was 1. All patients were able to return to their preoperative level of employment and 50% participate in vigorous recreational activity. When comparing outcomes based on gender, preoperative Eaton staging, and workman’s compensation cases, the VAS pain score was higher in males and workman’s compensation cases than females and non workman’s compensation cases, (p < 0.05).
CONCLUSIONS: Thumb carpometacarpal arthroplasty using interference screw fixation has demonstrated excellent clinical outcomes with no revisions in this series. We demonstrate operative times and radiographic settling rates that compare favorably to the existing literature utilizing other techniques. Males and workman’s compensation patients had poorer outcomes. 47. Reliability of Plain Radiographs and Fluoroscopy in Evaluating the Scapholunate Interval *Philip J. Lahey, M.D. (n) Brooklyn, NY Jack Choueka, M.D. (n) Brooklyn, NY
OBJECTIVE: Accurate radiographic measurement of the scapholunate interval is essential in the evaluation of wrist injuries. Radiographs with stress and contralateral views can be used to assess the presence of static and dynamic instability. However, fluoroscopy eliminates technician positioning and anatomical variations of the carpus as variables, and allows the clinician to position the wrist in a manner that maximizes the scapholunate interval. The purpose of this study is to quantitatively compare the use of radiographs and fluoroscopy in the assessment of the scapholunate interval.
METHODS: Thirty consecutive patients complaining of wrist pain were enrolled in the study. Postero anterior (PA) radiographs of both wrists, with and without grip views, were obtained in a manner described to maximize the scapholunate interval. Next, under fluoroscopy, the clinician dynamically manipulated the wrists to obtain the maximum scapholunate distance with and without patient grip. Fluoroscopic images were digitized for measurement and a radiographic ruler was used for reference.
RESULTS: Overlap of the scaphoid and lunate precluding measurement occurred in 12.5% (14 of 120) of all plain radiographs taken, while none of the fluoroscopic images showed any overlap. Of the wrists with fluoroscopic images that revealed a scapholunate space >2 mm, only 27.7% (5 of 18 wrists) had plain radiographs that also showed a scapholunate space >2 mm. There were no statistically significant differences in left to right and stress comparisons for both radiographs and fluoroscopy.
CONCLUSION: This study illustrates that fluoroscopy allows for a more reliable assessment of the scapholunate interval both in its ability to measure and maximize the scapholunate space. 48. Assessing Rotational Deformity of the Fifth Metacarpal *Philip J. Lahey, M.D. (n) Brooklyn, NY Mihir Patel, M.D. (n) Selden, NY Jack Choueka, M.D. (n) Brooklyn, NY
INTRODUCTION: Treatment of 5 th metacarpal or phalangeal fractures is guided by the degree of rotational deformity perceived in the digit and in comparison to the unaffected hand. Scissoring or overlap of the digits upon flexion is a useful clinical tool to predict functional impairment upon healing. The purpose of this study is to assess the variation of scissoring in the normal population and determine whether or not contralateral comparisons are reliable.
METHODS: Right and left 5 th digits of 50 normal individuals were photographed in extension and with finger flexion. The digital images were analyzed using software to assess scissoring as measured by the percentage of the nail covered by overlap in flexion. Paired t tests were used for statistical analysis.
RESULTS: The average fingernail overlap was 26.8% ± 20.5%, ranging from 0 to 70.9%. The average overlap on the left hand was significantly less 21.9% ± 18.5% as compared to 31.8% ± 21.5% on the right (p< 0.01). The average variation between hands in individuals was 17.4% (p<0.01).
CONCLUSION: Overlap or scissoring of the 5 th digit is common and varies widely in the normal population studied. Significant differences in left and right scissoring exists amongst individuals. The practitioner must be aware of these variations when recommending treatment based on clinical exam.
* = presenter
♦ The FDA has not cleared the drug and/or medical device for the use described in this presentation (i.e., the drug or medical deice is being discussed for an “off label” use).
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