<<

n Feature Article

Modified Plate-only Open-door Versus and Fusion for the Treatment of Cervical Stenotic Myelopathy

Lili Yang, MD; Yifei Gu, MD; Jueqian Shi, MD; Rui Gao, MD; Yang Liu, MD; Jun Li, MD; Wen Yuan, MD, PhD

abstract Full article available online at Healio.com/Orthopedics. Search: 20121217-23

The purpose of this study was to compare modified plate-only laminoplasty and lami- nectomy and fusion to confirm which of the 2 surgical modalities could achieve a better decompression outcome and whether a significant difference was found in postopera- tive complications. Clinical data were retrospectively reviewed for 141 patients with cervical stenotic myelopathy who underwent plate-only laminoplasty and laminectomy and fusion between November 2007 and June 2010. The extent of decompression was assessed by measuring the cross-sectional area of the dural sac and the distance of drift at the 3 most narrowed levels on T2-weighted magnetic resonance imaging. Clinical outcomes and complications were also recorded and compared. Significant en- largement of the dural sac area and spinal cord drift was achieved and well maintained in both groups, but the extent of decompression was greater in patients who underwent Figure: T2-weighted magnetic resonance image laminectomy and fusion; however, a greater decompression did not seem to produce a showing the extent of decompression assessed by better clinical outcome. No significant difference was observed in Japanese Orthopaedic measuring the cross-sectional area of the dural sac Association and Nurick scores between the 2 groups. Patients who underwent plate-only (arrow). laminoplasty showed a better improvement in Neck Dysfunction Index and visual ana- log scale scores. In addition, limited decompression, rigid reconstruction of the , and preservation of cervical mobility combined with preservation of the posterior structure resulted in a lower rate of postoperative C5 palsy and axial pain in the modified laminoplasty group. For this reason, modified laminoplasty may be a more viable option for patients with cervical stenotic myelopathy.

The authors are from the Department of Orthopedics (LY, YG, RG, YL, JL, WY) and the Department of Imageology (JS), Changzheng Hospital, Second Military Medical University, Shanghai, China. Drs Yang and Gu equally contributed to this work. The authors have no relevant financial relationships to disclose. This research was supported by the Natural Science Foundation of Shanghai Science and Technology Committee (11ZR1448400) and Innovation Program of Shanghai Municipal Education Commission (12ZZ079). Correspondence should be addressed to: Wen Yuan, MD, PhD, Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Rd, Shanghai 200003, China ([email protected]). doi: 10.3928/01477447-20121217-23

JANUARY 2013 | Volume 36 • Number 1 e79 n Feature Article

osterior cervical decompression, including laminectomy and lami- Pnoplasty, has been widely used in the treatment of progressive myelopa- thy caused by stenotic conditions such as multilevel , ossification of the posterior longitudinal , and developmental . Laminectomy has been a classic and standard treatment for cervical stenotic myelopathy for decades, whereas lami- noplasty was developed in the late 1970s in Japan as an alternative to laminecto- my, with satisfactory clinical outcomes reported by many studies.1-5 Despite 1A 1B presumed advantages, open-door lami- Figure 1: Transverse T2-weighed magnetic resonance image showing the extent of decompression assessed noplasty is not uniformly accepted com- by measuring the cross-sectional area of the dural sac (arrow) (A). The distance of spinal cord drift was as- pared with laminectomy and fusion due sessed from the posterior margin of the posterior longitudinal ligament to the anterior margin of the spinal cord (B). to several drawbacks, including reclosure problems, hinge fracture, and potential injuries to the nerve roots or the spinal compression at 3 or more cervical levels sia. A standard posterior exposure was cord by grafts at the open side.6-9 confirmed by . Exclusion cri- performed for both procedures. In the Controversy over laminoplasty still ex- teria were patients with severe cervical laminoplasty group, the interspinous liga- ists. Some recent studies reported good , fracture, segmental cervical in- ments were cut at the superior and inferior outcomes with plate-only open-door lami- stability, tumors, metabolic disorders, and ends of the target levels, with the supra- noplasty in patients with cervical spinal history of cervical spine surgery or com- spinous entirely preserved. At canal stenosis in which mini-plates were bined with anterior cervical spine proce- the open side, a full-thickness trough was used to reconstruct the spinal canal.10-13 dures. Twenty-two patients were lost to drilled at the junction of the lateral mass To the current authors’ knowledge, few follow-up. A total of 141 patients (106 and the lamina with a high-speed burr, studies compare this modified lamino- men and 35 women) with a mean age of and a partial-thickness trough was drilled plasty with laminectomy.14 The purpose 57.9768.17 years (range, 41-75 years) at at the hinge side. Because the ligamentum of the current study was to confirm which surgery were included in this study. This flavum was hypertrophic, causing double- of the 2 surgical modalities could achieve study was approved by the Committee on sided compression in most patients, it was a better decompression outcome and Ethics of Biomedical Research. removed with part of the cortical bone at whether a significant difference existed in The specific procedure was decided the open-side of the expanded levels. The postoperative complications between the by the surgeons. Patients with large ante- lamina was elevated from the open side 2 techniques. rior osteophytes, facet degeneration, and toward the hinge side for approximately the continuous type of ossification of the 8 to 10 mm and stabilized with 8 or 10 Materials and Methods posterior longitudinal ligament typically mm mini-plates and screws. Autologous Clinical data for patients who under- underwent laminectomy and fusion. The bone debris was embedded into the hinge went laminectomy with instrumented 141 patients were divided into 2 groups trough as a bone graft to stimulate fusion. fusion and modified open-door lamino- according to procedure: the plate-only No bone graft was used as a strut at the plasty at the authors’ institution between open-door laminoplasty group (75 pa- open side. November 2007 and June 2010 were tients) and the laminectomy and fusion In the laminectomy and fusion group, retrospectively reviewed. Inclusion crite- group (66 patients). All patients had a the supraspinous and interspinous liga- ria were patients whose clinical findings minimum 24-month follow-up. ments and the total lamina with the liga- were consistent with the diagnosis of mentum flavum of the target levels were progressive cervical stenotic myelopa- Surgical Technique removed completely with a high-speed thy that failed to respond to nonsurgi- The patients were placed in the prone drill and rongeur. Lateral mass screws and cal treatment and patients who had cord position while under general anesthe- rods were then fixed at the decompression

e80 ORTHOPEDICS | Healio.com/Orthopedics Cervical Stenotic Myelopathy | Yang et al

scribed by Ishihara.15 Range of motion (ROM) was determined using the Cobb method for C2-C7 in flexion and exten- sion (Figure 2). To evaluate the clinical outcome, the Japanese Orthopaedic Association and the Nurick scoring systems were used to as- sess the neurological status, and the Neck Dysfunction Index (NDI) scoring system was used to assess neck function. Axial symptoms were evaluated by the 10-point visual analog scale (VAS). Complications 2A 2B 2C including infection, hardware failure, ce- Figure 2: Lateral radiograph showing evaluation of the cervical curvature index (CCI) with the Ishihara rebrospinal fluid leakage, C5 palsy, ky- method: CCI5(a11a21a31a4)/A (A). Lateral flexion-extension radiographs showing evalutation of range of motion (ROM) as the sum of the C2-C7 Cobb angle: ROM5a1b (B, C). phosis (kyphosis angle was measured), and axial pain (defined as a VAS score of 3 or more at 6-month follow-up) were re-

Table 1 corded for both groups. Demographics and Surgical Parameters Results Demographics and Surgical Parameters Mean6SD Seventy-five patients (56 men and 19 Laminoplasty Laminectomy and Demographic/Parameter Group Fusion Group Test Value P women) with a mean age of 57.19 years (range, 42-72 years) underwent modified Age at operation, y 57.1967.33 56.9868.34 Z520.161 .872 plate-only laminoplasty. Sixty-six patients Age range, y 42-72 41-75 (49 men and 17 women) with a mean age No. of M/F 56/19 49/17 x25 .954 0.003 of 56.98 years (range, 41-75 years) under- No. of operative levels 4.3360.622 4.5360.728 Z521.769 .901 went laminectomy and fusion. A mean of Blood loss, mL 284.53649.52 310.91650.92 Z522.985 .003 4.33 and 4.53 vertebral levels were operated Operation time, min 145.07627.13 173.79629.18 Z525.426 .000 on in the laminoplasty group and the lami- nectomy and fusion group, respectively. No statistical difference in sex, age, or operative levels was found between the 2 groups. levels. Autologous laminectomy bone was sac at the 3 most narrowed levels on T2- Mean operative time was 145.076 used as a bone graft. weighted magnetic resonance imaging 27.13 minutes in the laminoplasty group Patient data, including age, sex, op- preoperatively, 6 months postoperatively, vs 173.79629.18 minutes in the laminec- erative levels, intraoperative blood loss, and at last follow-up. The improve- tomy and fusion group. Mean intraop- and operative time, were recorded. ment ratio of the cross-sectional area erative blood loss was 284.53649.52 mL Anteroposterior and lateral flexion and was [(postoperative area2preoperative in the laminoplasty group and 310.916 extension plain radiographs and magnetic area)4preoperative area]3100%. The 50.92 mL in the laminectomy and fusion resonance images were obtained pre- and spinal cord drift distance was assessed group. Patients in the laminoplasty group had postoperatively. Sagittal and coronal com- from the posterior margin of the poste- less blood loss and a shorter operative time. puted tomography was obtained preopera- rior longitudinal ligament to the anterior The differences were statistically significant tively to diagnose ossification of the pos- margin of the spinal cord. Preoperative (Table 1). terior longitudinal ligament. values were then subtracted from the Six months postoperatively, osse- postoperative values to provide the mea- Clinical and Radiological Outcomes ous fusion was confirmed by computed surement of spinal cord drift (Figure 1). Computed tomography scans at 6 tomography. The extent of decompres- Pre- and postoperative cervical lordosis months postoperatively showed that bone sion achieved was assessed by measur- was measured on lateral radiographs us- grafts were fused in 74 (98.67%) pa- ing the cross-sectional area of the dural ing the cervical curvature index, as de- tients in the laminoplasty group and 64

JANUARY 2013 | Volume 36 • Number 1 e81 n Feature Article

(96.97%) patients in the laminectomy and fusion group. Mean cross-sectional area Table 2 of the dural sac of the 3 most stenotic lev- Extent of Decompression Using els in patients was 121.51615.20 mm2 Modified Laminoplasty and Laminectomy preoperatively, 159.49616.04 mm2 at 6 months postoperatively, and Mean6SD 159.17615.81 mm2 at 24 months post- Laminoplasty Laminectomy and operatively in the laminoplasty group Extent of Decompression Group Fusion Group Test Value, Z P and 120.38613.99 mm2 preoperatively, Area of dural sac, mm2 182.07613.20 mm2 at 6 months post- Preop 121.51615.20 120.38613.99 20.264 .791 2 operatively, and 181.69612.45 mm at Postop 6 mo 159.49616.04 182.07613.20 27.363 .000 24 months postoperatively in the laminec- Postop 24 mo 159.17615.81 181.69612.45 27.466 .000 tomy and fusion group. The change rate of Increase in area, % 31.88611.85 52.68613.73 27.743 .000 the 2 groups was 31.88%611.85% in the Spinal cord drift, mm laminoplasty group vs 52.68%613.73% in the laminectomy and fusion group Postop 6 mo 1.1960.25 2.4560.55 210.185 .000 (P,.01). Mean spinal cord shift was Postop 24 mo 1.2060.26 2.4460.56 210.141 .000 1.1960.25 mm at 6 months postopera- Abbreviations: postop, postoperative; preop, preoperative. tively and 1.2060.26 mm at 24 months postoperatively in the laminoplasty group and 2.4560.55 mm at 6 months postop- eratively and 2.4460.56 mm at 24 months postoperatively in the laminectomy and fusion group (Table 2). The extent of spi- nal canal stenosis of the 2 groups was sim- ilar, and both groups achieved significant decompression. However, the extent of enlargement of the spinal canal and spinal cord drift in the laminectomy and fusion 3A 3B 3C 3D group was greater than that in the lami- noplasty group. Decompression was well maintained 2 years postoperatively in both groups (Figures 3, 4). Mean preoperative Japanese Ortho-paedic Association scores were 8.9161.23 and 8.6561.05 in the lami- noplasty and the laminectomy and fu- sion groups, respectively (P..05). Mean postoperative Japanese Orthopaedic 3E 3F 3G 3H Association scores were 13.5561.34 and Figure 3: Preoperative anteroposterior (A) and lateral (B) radiographs and sagittal (C) and axial (D) mag- 13.5961.08 in the laminoplasty and the netic resonance images (MRIs) of a 58-year-old woman who developed numbness in both hands and laminectomy and fusion groups, respec- weakness in her extremities for 3 years combined with unbalanced gait for 1 year showing that the spinal cord was compressed at C3-C7. Postoperative anteroposterior (E) and lateral (F) radiographs after 5-level tively (P..05). The recovery rates were laminoplasty with mini-plates showing that the posterior structures were well protected. Sagittal (G) and 57.29%615.43% and 58.87%613.36% axial (H) MRIs showing a 34% increase in area of the spinal canal and a 0.9 mm drift of the spinal cord in the laminoplasty and the laminec- was achieved. The patient’s Japanese Orthopaedic Association score improved from 7 preoperatively to tomy and fusion groups, respectively 14 postoperatively. (P..05). Mean preoperative Nurick scores were 2.4060.96 and 2.5260.93 in the laminoplasty and the laminectomy Mean postoperative Nurick scores were plasty and the laminectomy and fusion and fusion groups, respectively (P..05). 0.6560.71 and 0.6860.68 in the lamino- groups, respectively (P..05). Mean pre-

e82 ORTHOPEDICS | Healio.com/Orthopedics Cervical Stenotic Myelopathy | Yang et al

operative NDI scores were 34.1163.74 and 33.7463.50 in the laminoplasty and the laminectomy and fusion groups, re- spectively (P..05). Mean postopera- tive NDI scores were 14.6763.04 and 16.8064.54 in the laminoplasty and the laminectomy and fusion groups, respec- tively (P..05). Mean preoperative VAS scores were 2.8561.11 and 2.5961.25 4A 4B 4C 4D in the laminoplasty and the laminectomy and fusion groups, respectively (P..05). Mean postoperative VAS scores were 1.1161.18 and 2.1561.38 in the lami- noplasty and the laminectomy and fusion groups, respectively (P,.01). Although laminectomy and fusion achieved a greater extent of decompression and spinal cord shift than laminoplasty, the 4E 4F 4G 4H neurological function recovery was simi- lar in both groups, and the neck function Figure 4: Preoperative anteroposterior (A) and lateral (B) radiographs and sagittal (C) and axial (D) magnetic resonance images (MRIs) of a 52-year-old man who developed numbness and weakness in his extremities recovery was better in the laminoplasty for 5 years and had an unbalanced gait for 6 months showing that the spinal cord was compressed at C2- group (Table 3). C6. Postoperative anteroposterior (E) and lateral (F) radiographs after 5-level laminectomy with screw and The cervical curvature index was rod fixation showing that the posterior structures were partially destroyed. Sagittal (G) and axial (H) MRIs maintained in both groups, and no signifi- showing that a 42% increase in area of the spianl canal and a 2.1 mm drift of the spinal cord was achieved. The patient’s Japanese Orthopaedic Association score improved from 8 preoperatively to 13 postoperatively. cant difference existed in pre- and post- operative scores between the 2 groups. Preoperative ROM was similar in both Table 3 groups. However, a significantly greater Clinical Outcomes of Modified Laminoplasty and Laminectomy loss of ROM was observed in the laminec- tomy and fusion group (Table 4). Mean6SD Laminoplasty Laminectomy and Complications Score Group Fusion Group Test Value P No iatrogenic neurological dete- Fusion rate, % 98.67 96.97 x250.485 .486 rioration or surgery-related hardware JOA failure was observed in any patient. Cerebrospinal fluid leakage occurred in Preop 8.9161.23 8.6561.05 Z521.513 .130 1 patient in the laminoplasty group and Postop 13.5561.34 13.5961.08 Z520.213 .831 3 patients in the laminectomy and fusion Nurick group due to tight adhesion causing dural Preop 2.4060.96 2.5260.93 Z520.827 .408 tear intraoperatively. However, cerebro- Postop 0.6560.71 0.6860.68 Z520.324 .746 spinal fluid leakage usually stopped after NDI 3 to 5 days of conservative treatment us- Preop 34.1163.74 33.7463.50 Z520.342 .732 ing local pressure. Postop 14.6763.04 16.8064.54 Z522.556 .011 C5 palsy occurred in 3 and 11 patients VAS in the laminoplasty and the laminectomy and fusion groups, respectively (P,.05). Preop 2.8561.11 2.5961.25 Z521.575 .115 The C5 palsy rate in the laminoplasty Postop 1.1161.18 2.1561.38 Z524.716 .000 group was significantly higher than that Abbreviations: JOA, Japanese Orthopaedic Association; NDI, Neck Disability Index; postop, in the laminectomy and fusion group. postoperative; preop, preoperative; VAS, visual analog scale. Patients with C5 palsy showed a signifi-

JANUARY 2013 | Volume 36 • Number 1 e83 n Feature Article

cantly greater change in dural sac area and a greater spinal cord shift compared with those without C5 palsy in both groups (Table 5). Axial pain lasted for more than 6 months postoperatively in 9 and 23 pa- tients in the laminoplasty and the lami- nectomy and fusion groups, respectively (P,.05). Cervical lordosis was well maintained in all but 3 patients in the lam- inoplasty group who developed kyphosis (22°, 25°, and 212°, respectively) and 2 patients in the laminectomy and fusion group who developed kyphosis (24° and 5A 5B 211°, respectively). These patients were Figure 5: Lateral radiograph of 57-year-old man with cervical stenotic myelopathy showing that the preop- closely observed, and none developed se- erative C2-C7 cobb angle was 16°(A). Lateral radiograph 2 years postoperative showing that a 8° kyphosis rious clinical symptoms by last follow-up developed (B). However, no neurological deterioration occurred. (Figure 5). Restenosis, accompanied with neu- Table 4 rological symptoms, was observed in 1 Cervical Curve Index and Range of Motion patient in the laminoplasty group 3 years postoperatively. However, restenosis in Mean6SD this patient was not caused by surgery but Laminoplasty Laminectomy and Outcome Group Fusion Group Test Value, Z P rather was a result of natural progression of degeneration. An anterior revision op- CCI eration was performed. No restenosis was Preop 0.14860.055 0.14660.050 20.531 .596 observed in the laminectomy and fusion Postop 0.14260.059 0.13560.062 21.383 .167 group (Table 6). ROM, deg Preop 29.8866.43 31.5065.69 21.512 .130 Discussion Postop 24.9566.24 11.4765.69 29.400 .000 Many orthopedic surgeons prefer a Loss, % 15.82 63.03 29.946 .000 posterior cervical approach, including Abbreviations: CCI, cervical curve index; postop, postoperative; preop, preoperative; ROM, laminectomy and fusion or laminoplasty, range of motion. to treat cervical stenotic myelopathy. Both procedures have been proven safe and effective.1,4,5,16 The posterior cervical Table 5 approach achieves the therapeutic effect Correlations Between Postoperative C5 Palsy by direct and indirect decompression of and the Extent of Decompression the spinal cord. Direct decompression is achieved by removal or elevation of the Mean6SD posterior compressive bone and infolding Extent of Decompression With C5 Palsy Without C5 Palsy Test Value, Z P of the ligamentum flavum. Indirect de- Increase in area, % compression of the anterior aspect of the Laminoplasty group 54.2865.35 30.94611.12 22.201 .022 spinal cord is achieved by posterior drift of the spinal cord.17,18 It was previously Laminectomy and 68.53613.16 48.90611.38 22.757 .000 fusion group believed that whether a sufficient expan- Spinal cord drift, mm sion of the spinal canal with an effective spinal cord drift is achieved would direct- Laminoplasty group 1.7060.11 1.1760.24 23.983 .000 ly affect the outcome of these posterior Laminectomy and 3.2360.38 2.2860.44 24.566 .000 fusion group treatments.19

e84 ORTHOPEDICS | Healio.com/Orthopedics Cervical Stenotic Myelopathy | Yang et al

increase of more than 50% and a spinal Table 6 cord shift of more than 3 mm was neces- Complications sary.19 However, in the current study, lim- ited decompression with an approximate Group, No. (%) 30% increase seemed to provide enough Complication Laminoplasty Laminectomy and Fusion Test Value, x2 P space for the spinal cord to keep clear of C5 radiculopathy 3 (4) 11 (16.67) 5.216 .022 compression and achieve a satisfying neu- CSF leakage 1 (1.33) 3 (4.55) 1.314 .252 rological recovery. Kyphosis 3 (4) 2 (3.03) 0.097 .756 Maintaining expansion of the spinal canal is critical to successful posterior Wound infection 0 (0) 1 (1.52) 1.144 .285 decompression. Restenosis of the spinal Restenosis 1 (1.33) 0 (0) 0.574 .448 canal after conventional laminoplasty Axial pain 9 (12) 23 (34.8) 10.446 .001 caused by reclosure or so-called spring Abbreviation: CSF, cerebrospinal fluid. back due to a lack of rigid fixation, non- union at the hinge side, or a slotting into the spinous process by a nonabsorbable suture is frequently reported and con- In previous studies, the extent of de- al21 reported that the outcome of posterior sidered a main complication compared compression by laminoplasty or laminec- decompression surgery was not correlated with laminectomy and fusion.6,7 Although tomy and fusion has not been compared with the magnitude of postoperative back- several modified types of reconstruction effectively due to the lack of a measure- ward shifting of the spinal cord and that styles, including plate fixation combined ment available. Some recent studies used increased canal diameters were associated with bone grafts and ceramic spacers, the diameter or area of the spinal canal, in- with an increased incidence of postopera- have been used, the results are not satis- clination angle, and Pavlov ratio on com- tive complications, especially C5 palsy. factory, and the possibility of graft dis- puted tomography scans or radiographs to Postoperative spinal cord drift, which location leading to reclosure and injury assess enlargement of the spinal canal in may result in tethering of the nerve root, to the nerve root or spinal cord is also patients who undergo laminoplasty.11,20 has been confirmed to cause the develop- of concern.23 Although mini-plates used However, these measurements cannot be ment of C5 palsy and is considered a risk in modified laminoplasty cannot create a used in patients who undergo laminecto- factor.22 continuous osseous posterior arch, they my and fusion because the posterior arch In the current study, a greater increase provide a stronger support and better ini- has been completely removed. in the cross-sectional area of the spinal ca- tial stability for the expanded spinal ca- In the current study, the authors com- nal and spinal cord drift was observed in nal. Bone debris grafted at the hinge side pared the magnitude of decompression patients with C5 palsy in both the lami- promotes osseous fusion, which can help by measuring cross-sectional area of the noplasty and the laminectomy and fusion reconstruct a stable, rigid, and expansive dural sac and posterior shift of the spi- groups. In patients with C5 palsy who un- laminar arch and prevent reclosure. nal cord at the 3 most stenotic levels on derwent laminoplasty, greater inclination Axial symptoms, which are considered magnetic resonance imaging. The result angles with larger-sized mini-plates were one of the most common complictions of showed that the extent of enlargement of observed. Thus, strategies to reduce post- posterior cervical surgury, are defined as the dural sac cross-sectional area and pos- operative spinal cord drift may reduce the pain and stiffness over nuchal periscapu- terior drift of the spinal cord after modi- risk of C5 palsy. The preserved posterior lar and shoulder regions postoperative- fied laminoplasty was smaller than that arches in modified laminoplasty helped ly.24,25 Causes of axial symptoms have not after laminectomy and fusion. However, prevent the spinal cord from backward been fully clarified. According to previ- the greater enlargement of the spinal canal shifting, reducing the C5 palsy rate. In ad- ous studies, axial pain may be caused by and spinal cord drift did not result in a bet- dition, to prevent excessive decompression nuchal muscle injury, destruction of facet ter recovery rate in the laminectomy and and spinal cord drift, the authors limited , intraoperative nerve root dam- fusion group. The neurological recovery the extent of decompression during lami- age, or hinge-side nonunion.24-26 A high was similar in both groups. noplasty by limiting the inclination angle rate of postoperative axial pain has been Controversy exists over the relation- with appropriately sized mini-plates. reported with laminectomy and conven- ship between the extent of decompres- In previous research, to achieve an tional laminoplasty.27,28 In some articles, sion and neurological outcome. Hatta et optimal canal expansion, a canal area conventional laminoplasty was associated

JANUARY 2013 | Volume 36 • Number 1 e85 n Feature Article

with more postoperative axial pain, caus- laminoplasty, which is important to the modified laminoplasty may be a more ing a poorer quality of life compared with stability of the posterior column and has viable option for patients with cervical laminectomy.29 been reported to reduce the incidence of stenotic myelopathy. However, in the current study, less kyphosis. In addition, early excision may axial pain was observed in the lamino- promote functional recovery in patients References plasty group. That is because the modi- who undergo modified laminoplasty with 1. Ryken TC, Heary RF, Matz PG, et al. Cervical fied laminoplasty caused little damage rigid plate fixation. laminectomy for the treatment of cervical de- generative myelopathy. J Neurosurg Spine. to the posterior structure. Several studies Preoperative loss of lordosis may in- 2009; 11(2):142-149. have confirmed that preserving muscles crease the risk of postoperative kyphotic 2. Hirabayashi K, Watanabe K, Wakano K, Suzuki attached to the C2 or C7 spinous process deformity. However, according to recent N, Satomi K, Ishii Y. Expansive open-door lam- and reconstruction of semispinalis cer- studies, patients with servere preopera- inoplasty for cervical spinal stenotic myelopa- thy. Spine (Phila Pa 1976). 1983; 8(7):693-699. vical muscle insertion at the C2 spinous tive kyphosis were not suitable for lami- 3. Yang SC, Yu SW, Tu YK, Niu CC, Chen LH, process can prevent postoperative axial noplasty because a sufficient spinal cord Chen WJ. Open-door laminoplasty with su- pain.30-33 In most patients who underwent drift cannot be achieved.38 Through the ture anchor fixation for cervical myelopathy in ossification of the posterior longitudi- laminectomy and fusion, the total lamina preflex rods, laminectomy and fusion nal ligament. J Spinal Disord Tech. 2007; was removed, which can involve the C2 or could moderately remodel the cervical 20(7):492-498. C7 spinous process. However, in patients curvature, which cannot be done by lami- 4. Anderson PA, Matz PG, Groff MW, et al. who underwent modified laminoplasty, noplasty. Thus, preoperative kyphosis was Laminectomy and fusion for the treatment of cervical degenerative myelopathy. J the posterior structures, including the considered one of the relative contraindi- Neurosurg Spine. 2009; 11(2):150-156. spinous process, muscles, ligaments, and cations of laminoplasty. For that reason, 5. Matsumoto M, Chiba K, Toyama Y. Surgical facet , were properly preserved. The patients with preoperative kyphosis were treatment of ossification of the posterior lon- smaller inclination angle in laminoplasty excluded from the current study. gitudinal ligament and its outcomes: poste- rior surgery by laminoplasty. Spine (Phila Pa may create a milder disturbance to the 1976). 2012; 37(5):E303-E308. posterior structure. Conclusion 6. Wang HQ, Mak KC, Samartzis D, et al. Axial symptoms are strongly corre- The results of this study demonstrated “Spring-back” closure associated with open- lated with cervical ROM.34 Laminectomy that laminectomy and fusion can achieve door cervical laminoplasty. Spine J. 2011; 11(9):832-838. and fusion achieves intervetebral stability a greater extent of enlargement of the spi- 7. Lee DH, Park SA, Kim NH, et al. Laminar at the expense of losing a greater ROM, nal canal and spinal cord drift compared closure after classic Hirabayashi open-door which may cause stiffness and muscle at- with laminoplasty. However, a greater de- laminoplasty. Spine (Phila Pa 1976). 2011; 36(25):E1634-E1640. rophy. Plate-only fixation could provide compression extent did not achieve a bet- 8. Xia Y, Shen Q, Li H, Xu T. Influence of hinge initial stability and effectively maintain ter clinical outcome. The degree of neu- position on the effectiveness of expansive ROM. In addition, immediate stabil- rological functional recovery was similar open-door laminoplasty for cervical spondy- ity, ROM preservation, and less invasion in the laminectomy and fusion and the lotic myelopathy. J Spinal Disord Tech. 2011; 24(8):514-520. enable patients who undergo modified laminoplasty groups, and neck function 9. Seichi A, Hoshino Y, Kimura A, et al. laminoplasty to achieve early postopera- was worse in the laminectomy and fusion Neurological complications of cervical lami- tive exercises, preventing muscle atrophy group. noplasty for patients with ossification of the from occurring. Laminectomy and fusion and lamino- posterior longitudinal ligament—a multi- institutional retrospective study. Spine (Phila Posterior cervical surgery has been plasty could maintain spinal canal en- Pa 1976). 2011; 36(15):E998-E1003. reported to have a high rate of postopera- largement and lordotic alignment with a 10. Rhee JM, Register B, Hamasaki T, Franklin tive kyphosis due to the aggressiveness low rate of restenosis and kyphosis. B. Plate-only open door laminoplasty main- tains stable spinal canal expansion with high of posterior tissue resection, facet injury, Modified laminoplasty was associated rates of hinge union and no plate failures. and multilevel surgery.35-37 However, with a lower rate of postopertive C5 pal- Spine (Phila Pa 1976). 2011; 36(1):9-14. cervical lordosis was well maintained sy due to limited decompression. Rigid 11. Jiang JL, Li XL, Zhou XG, Lin H, Dong J. in most patients in both groups in the reconstruction of the spinal canal and Plate-only open-door laminoplasty with fu- sion for treatment of multilevel degenera- current study. Instrumented fusion is preservation of cervical mobility com- tive cervical disease. J Clin Neurosci. 2012; believed to be an effective method for bined with preservation of the bone 19(6):804-809. preventing postoperative kyphotic defor- structure and soft tissue, which is impor- 12. Jiang L, Chen W, Chen Q, Xu K, Wu Q, mity and stopping progression in those tant to the stability of the posterior col- Li F. Clinical application of a new plate fixation system in open-door laminoplasty. who underwent laminectomy. The bone umn, can effectively reduce postopera- Orthopedics. 2012; 35(2):e225-e231. structure and soft tissue are preserved in tive axial symptoms. For this reason,

e86 ORTHOPEDICS | Healio.com/Orthopedics Cervical Stenotic Myelopathy | Yang et al

13. Chen G, Luo Z, Nalajala B, Liu T, Yang H. 22. Radcliff KE, Limthongkul W, Kepler CK, et laminoplasty. Spine (Phila Pa 1976). 2008; Expansive open-door laminoplasty with tita- al. Cervical laminectomy width and spinal 33(14):E455-E459. Orthopedics nium miniplate versus sutures. . cord drift are risk factors for postoperative 32. Sakaura H, Hosono N, Mukai Y, Fujimori 2012; 35(4):e543-e548. C5 palsy [published online ahead of print T, Iwasaki M, Yoshikawa H. Preservation of J Spinal Disord Tech 14. Highsmith JM, Dhall SS, Haid RW Jr, et al. March 20, 2012]. . muscles attached to the C2 and C7 spinous Treatment of cervical stenotic myelopathy: 23. Goto T, Ohata K, Takami T, et al. processes rather than subaxial deep exten- a cost and outcome comparison of lamino- Hydroxyapatite laminar spacers and tita- sors reduces adverse effects after cervical plasty versus laminectomy and lateral mass nium miniplates in cervical laminoplasty. J laminoplasty. Spine (Phila Pa 1976). 2010; fusion. J Neurosurg Spine. 2011; 14(5):619- Neurosurg. 2002; 97(3 suppl):323-329. 35(16):E782-E786. 625. 24. Hosono N, Yonenobu K, Ono K. Neck and 33. Zhang P, Shen Y, Zhang YZ, Ding WY, Xu 15. Ishihara A. Roentgenographic studies on shoulder pain after laminoplasty. A notice- JX, Cao JM. Preserving the C7 spinous the normal pattern of the cervical curva- able complication. Spine (Phila Pa 1976). process in laminectomy combined with lat- ture. Nihon Seikeigeka Gakkai Zasshi. 1968; 1996; 21(17):1969-1973. eral mass screw to prevent axial symptom. J Orthop Sci 42(11):1033-1044. 25. Wang SJ, Jiang SD, Jiang LS, Dai LY. Axial . 2011; 16(5):492-497. 16. Chen Y, Guo Y, Chen D, Wang X, Lu X, Yuan pain after posterior cervical spine surgery: 34. Nordin M, Carragee EJ, Hogg-Johnson S, et W. Long-term outcome of laminectomy and a systematic review. Eur Spine J. 2011; al. Assessment of neck pain and its associ- instrumented fusion for cervical ossification 20(2):185-194. ated disorders: results of the Bone and Joint Int of the posterior longitudinal ligament. 26. Hirabayashi K, Satomi K. Operative pro- Decade 2000-2010 Task Force on Neck Pain Orthop Spine (Phila Pa . 2009; 33(4):1075-1080. cedure and results of expansive open-door and Its Associated Disorders. 1976) 17. Lee JY, Sharan A, Baron EM, et al. laminoplasty. Spine (Phila Pa 1976). 1988; . 2008; 33(4 suppl):S101-S122. Quantitative prediction of spinal cord drift 13(7):870-876. 35. Suda K, Abumi K, Ito M, Shono Y, Kaneda after cervical laminectomy and . 27. Ohnari H, Sasai K, Akagi S, Iida H, Takanori K, Fujiya M. Local kyphosis reduces surgical Spine (Phila Pa 1976) . 2006; 31(16):1795- S, Kato I. Investigation of axial symptoms af- outcomes of expansive open-door laminoplas- Spine 1798. ter cervical laminoplasty, using questionnaire ty for cervical spondylotic myelopathy. (Phila Pa 1976) 18. Yusof MI, Hassan E, Abdullah S. Predicted survey. Spine J. 2006; 6(3):221-227. . 2003; 28(12):1258-1262. cervical canal enlargement and effective cord 28. Cho CB, Chough CK, Oh JY, Park HK, Lee 36. Cho WS, Chung CK, Jahng TA, Kim HJ. decompression following expansive lami- KJ, Rha HK. Axial neck pain after cervical Post-laminectomy kyphosis in patients with noplasty using cervical magnetic resonance laminoplasty. J Korean Neurosurg Soc. 2010; cervical ossification of the posterior longitu- Surg Radiol Anat imaging. . 2011; 33(2):109- 47(2):107-111. dinal ligament: does it cause neurological de- 115. terioration? J Korean Neurosurg Soc. 2008; 29. Nurboja B, Kachramanoglou C, Choi D. 43(6):259-264. 19. Sodeyama T, Goto S, Mochizuki M, Cervical laminectomy vs laminoplasty: is Takahashi J, Moriya H. Effect of decompres- there a difference in outcome and postop- 37. Zdeblick TA, Abitbol JJ, Kunz DN, McCabe sion enlargement laminoplasty for posterior erative pain? Neurosurgery. 2012; 70(4):965- RP, Garfin S. Cervical stability after sequen- Spine (Phila Pa Spine (Phila Pa 1976) shifting of the spinal cord. 970. tial capsule resection. . 1976). 1999; 24(15):1527-1531. 1993; 18(14):2005-2008. 30. Kotani Y, Abumi K, Ito M, et al. Impact of 20. Pavlov H, Torg JS, Robie B, Jahre C. Cervical deep extensor muscle-preserving approach 38. Fujiyoshi T, Yamazaki M, Kawabe J, et al. A spinal stenosis: determination with verte- on clinical outcome of laminoplasty for cer- new concept for making decisions regarding Radiology bral body ratio method. . 1987; vical spondylotic myelopathy: comparative the surgical approach for cervical ossifica- 164(3):771-775. cohort study. Eur Spine J. 2012; 21(8):1536- tion of the posterior longitudinal ligament: Spine (Phila Pa 1976) 21. Hatta Y, Shiraishi T, Hase H, et al. Is posterior 1544. the K-line. . 2008; 33(26):E990-E993. spinal cord shifting by extensive posterior de- 31. Kato M, Nakamura H, Konishi S, et al. Effect compression clinically significant for multiseg- of preserving paraspinal muscles on post- Spine mental cervical spondylotic myelopathy? operative axial pain in the selective cervical (Phila Pa 1976). 2005; 30(21):2414-2419.

JANUARY 2013 | Volume 36 • Number 1 e87