The significance of facet joint cross-sectional area on magnetic resonance imaging in relationship to cervical degenerative spondylolisthesis

Background contextCharacteristic changes of the facet joints, including synovial cysts, facet joint hypertrophy, and facet joint effusions, on magnetic resonance imaging (MRI) and computed tomography have been associated with lumbar degenerative spondylolisthesis. The cervical facets have not been examined for associations with cervical degenerative spondylolisthesis similar to those seen in the lumbar spine.PurposeTo define abnormalities of the facet joints seen on supine MRI that correlate with cervical spondylolisthesis seen on upright radiographs.Study designRetrospective radiographic review of consecutive patients with a universally applied standard.Patient sampleA total of 204 consecutive patients from a single institution, with both an MRI and upright radiographs, were reviewed.Outcome measuresSagittal plane displacement on upright lateral radiographs was compared with MRI. The total area of the facet joint and the amount of facet joint asymmetry were measured on an axial MRI.MethodsThe data were analyzed to determine a significant association between the cervical degenerative spondylolisthesis and the following: facet joint asymmetry, increased total area of the facet joint, and age.ResultsDegenerative spondylolisthesis was seen in 26 patients at C3–C4 and in 27 patients at C4–C5. Upright radiographs identified significantly more degenerative spondylolisthesis than MRIs at levels C3–C4 and C4–C5, 26 versus 6 (p<.001) at C3–C4 and 27 versus 11 (p<.001) at C4–C5. Patients with degenerative spondylolisthesis were more likely to be older, have a larger total facet area, and more facet asymmetry at C3–C4 and C4–C5 (p<.05).ConclusionsSupine MRIs underestimate sagittal displacement compared with upright lateral radiographs. Asymmetric facet hypertrophy at C3–C4 and C4–C5 is associated with degenerative spondylolisthesis on upright lateral films even in the absence of anterolisthesis on supine MRIs.     

Successful treatment of cervical myelopathy with minimal morbidity by circumferential decompression and fusion

Circumferential cervical decompression and fusion (CCDF) is an important technique for treating patients with severe cervical myelopathy. While circumferential cervical decompression and fusion may provide improved spinal cord decompression and stability compared to unilateral techniques, it is commonly associated with increased morbidity and mortality. We performed a retrospective analysis of patients undergoing CCDF at the University of California, San Francisco (UCSF) between January 2003 and December 2004. We identified 53 patients and reviewed their medical records to determine the effectiveness of CCDF for improving myelopathy, pain, and neurological function. Degree of fusion, functional anatomic alignment, and stability were also assessed. Operative morbidity and mortality were measured. The most common causes of cervical myelopathy, instability, or deformity were degenerative disease (57%) and traumatic injury (34%). Approximately one-fifth of patients had a prior fusion performed elsewhere and presented with fusion failure or adjacent-level degeneration. Postoperatively, all patients had stable (22.6%) or improved (77.4%) Nurick grades. The average preoperative and postoperative Nurick grades were 2.1 ± 1.9 and 0.4 ± 0.9, respectively. Pain improved in 85% of patients. All patients had radiographic evidence of fusion at last follow-up. The most common complication was transient dysphagia. Our average clinical follow-up was 27.5 ± 9.5 months. We present an extensive series of patients and demonstrate that cervical myelopathy can successfully be treated with CCDF with minimal operative morbidity. CCDF may provide more extensive decompression of the spinal cord and may be more structurally stable. Concerns regarding operation-associated morbidity should not strongly influence whether CCDF is performed.     

Treatment of multilevel cervical spondylotic myeloradiculopathy with posterior decompression and fusion with lateral mass plate fixation and local bone graft

This is a retrospective review of 32 patients with multilevel cervical myelopathy treated by laminectomy and lateral mass plate fusion. The prognosis of surgically treated myelopathy is evaluated as well as prognostic factors for recovery of myelopathy. Diagnoses included cervical spondylosis or ossification of the posterior longitudinal ligament. Final follow-up was at 15.2 months (mean) postoperatively. Myelopathy was graded preoperatively and postoperatively by the system of Nurick. All patients had preoperative radiographs and magnetic resonance imaging (MRI). The presence of abnormal T2-weighted MRI signal (myelomalacia) was noted. Postoperative studies included flexion-extension radiographs to assess fusion and MRI to evaluate decompression of neural elements and resolution of myelomalacia. Severity of preoperative Nurick myelopathy, presence of myelomalacia, and age were evaluated as potential prognostic indicators for surgically treated myelopathy. Mean Nurick score improved from 2.6 (range 1-4) to 1.8 (range 0-3) postoperatively (p < 0.0001). Twenty-two patients (71%) had improvement in Nurick grade of at least one point, and nine showed no improvement. No patients had deterioration of Nurick grade. Preoperative myelomalacia was noted in 15 (47%) patients, and all 15 had residual myelomalacia postoperatively. Severe myelopathy, age, and myelomalacia had no prognostic value for improvement of myelopathy. Complications included pseudarthrosis (3%), wound infection (9%), and transient C5 palsy (6%). This study demonstrates excellent outcomes from laminectomy and fusion in multilevel cervical myelopathy. A high rate of improvement of myelopathy was observed, neurologic deterioration did not occur, and complication rates were low. Severe myelopathy and myelomalacia on preoperative MRI had no prognostic value.     

Anterolisthesis and retrolisthesis of the cervical spine in cervical spondylotic myelopathy in the elderly

Background Degenerative spondylolisthesis of the cervical spine has received insufficient attention in contrast to that of the lumbar spine. The authors analyzed the functional significance of anterior and posterior degenerative spondylolisthesis (anterolisthesis and retrolisthesis) of the cervical spine to elucidate its role in the development of cervical spondylotic myelopathy (CSM) in the elderly. Methods A total of 79 patients aged 65 or older who eventually had surgical treatment for CSM were evaluated radiographically. Results Altogether, 24 patients (30%) had displacement of 3.5 mm or more (severe spondylolisthesis group), 31 had displacement of 2.0–3.4 mm (moderate spondylolisthesis group), and 24 had less than 2.0 mm displacement (mild spondylolisthesis group). The severe spondylolisthesis group consisted of 14 patients with anterolisthesis (anterolisthesis group) and 10 patients with retrolisthesis (retrolisthesis group). Patients with severe spondylolisthesis had a high incidence (93%) of degenerative spondylolisthesis at C3/4 or C4/5 and significantly greater cervical mobility than those with mild spondylolisthesis. The anterolisthesis group, but not the retrolisthesis group, had a significantly wider spinal canal than the mild spondylolisthesis group, although the degree of horizontal displacement and cervical mobility did not differ significantly between the anterolisthesis and retrolisthesis groups. Severe cord compression seen on T1-weighted magnetic resonance imaging (MRI) scans and high-intensity spinal cord signals seen on T2-weighted MRI scans corresponded significantly to the levels of the spondylolisthesis. Conclusions Degenerative spondylolisthesis is not a rare radiographic finding in elderly patients with CSM, which tends to cause intense cord compression that is seen on MRI scans. Greater mobility of the upper cervical segments may be a compensatory reaction for advanced disc degeneration of the lower cervical segments, leading to the development of degenerative spondylolisthesis. With a similar degree of displacement, anterolisthesis tends to have a greater impact on the development of CSM than retrolisthesis.     

Surgical treatment of cervical spondylotic myelopathy with anterior compression: a review of 67 cases

OBJECT: In patients with cervical spondylotic myelopathy (CSM), ventral disease and loss of cervical lordosis are considered to be relative indications for anterior surgery. However, anterior decompression and fusion operations may be associated with an increased risk of swallowing difficulty and an increased risk of nonunion when extensive decompression is performed. The authors reviewed cases involving patients with CSM treated via an anterior approach, paying special attention to neurological outcome, fusion rates, and complications. METHODS: Retrospectively, 67 cases involving consecutive patients with CSM requiring an anterior decompression were reviewed: 46 patients underwent anterior surgery only (1-to3-level anterior cervical discectomy and fusion [ACDF] or 1-level corpectomy), and 21 patients who required > 3-level ACDF or > or = 2-level corpectomy underwent anterior surgery supplemented by a posterior instrumented fusion procedure. RESULTS: Postoperative improvement in Nurick grade was seen in 43 (93%) of 46 patients undergoing anterior decompression and fusion alone (p < 0.001) and in 17 (81%) of 21 patients undergoing anterior decompression and fusion with supplemental posterior fusion (p = 0.0015). The overall complication rate for this series was 25.4%. Interestingly, the overall complication rate was similar for both the lone anterior surgery and combined anterior-posterior groups, but the incidence of adjacent-segment disease was greater in the lone anterior surgery group. CONCLUSIONS: Significant improvement in Nurick grade can be achieved in patients who undergo anterior surgery for cervical myelopathy for primarily ventral disease or loss of cervical lordosis. In selected high-risk patients who undergo multilevel ventral decompression, supplemental posterior fixation and arthrodesis allows for low rates of construct failure with acceptable added morbidity.     

Facet cysts in the subaxial cervical spine: Case series focused on radiological and histopathological findings with a scoping review

BackgroundFacet cysts in the subaxial cervical spine are a relatively rare cause of neuropathy. This case series aimed to investigate the radiological and histopathological features and surgical results of these lesions, and provide possible mechanisms of cyst development.MethodsThirteen subaxial cervical facet cysts in 12 patients were diagnosed on the basis of magnetic resonance imaging and computed tomography with facet arthrography. Surgical outcomes were evaluated according to the Japanese Orthopaedic Association scores for cervical myelopathy, or Tanaka's scores for cervical radiculopathy. These results were presented in combination with a scoping review of the literature.ResultsSeven cysts were found in the posteromedial region, and six in the posterolateral portion of the spinal canal. Computed tomography revealed degeneration of all involved facet joints. All patients underwent decompression, and the mean recovery rates of Japanese Orthopaedic Association scores and Tanaka's scores were 57.1% and 87.5%, respectively. Histopathologically, all cysts were continuous with the degenerated ligamentum flavum. In the scoping review, the patients' mean age was 65.1 years. The cysts were distributed as follows: 3.6% at C2–3, 10.7% at C3–4, 14.3% at C4–5, 5.4% at C5–6, 7.1% at C6–7, and 58.9% at C7–T1. The presenting symptoms were myelopathy (49.4%) and radiculopathy (50.0%). Radiologically, 55% and 45% of the cysts were of the posteromedial and posterolateral types. Of the patients, 76.9% underwent decompression only, and 23.1% had concomitant fusion. Cyst recurrence was not observed in the mean follow-up period of 15.1 months.ConclusionsThe pathogenesis of cysts is closely related to degenerative changes in the facet joint and ligamentum flavum, and rupture in degenerated ligaments can develop into a cavity, which contributes to cyst formation. The scoping review suggests that cyst resection generally results in positive outcomes without recurrence in either decompression alone or concomitant fusion.     

Ossification of the posterior longitudinal ligament. Results of anterior cervical decompression and arthrodesis in sixty-one North American patients

BACKGROUND: Ossification of the posterior longitudinal ligament is commonly associated with cervical myelopathy. Surgical treatment is a matter of controversy. We report on a series of patients who were managed with anterior cervical decompression and arthrodesis for the treatment of cervical myelopathy associated with ossification of the posterior longitudinal ligament. METHODS: We retrospectively reviewed the records for all sixty-five patients who had been managed with anterior decompression and arthrodesis for the treatment of cervical ossification of the posterior longitudinal ligament and associated neurologic compression from 1982 to 2001. Sixty-one patients (thirty-nine men and twenty-two women) were followed for at least two years (or until the time of death). The average number of vertebrae resected was 2.2. The average duration of follow-up for the sixty surviving patients was four years (range, two years to fifteen years and four months). The preoperative, six-week postoperative, and final follow-up clinical status (including neurological function as assessed with the Nurick grading system) was recorded for each patient. RESULTS: Fifty-six of the sixty-one patients had neurological improvement, with an average improvement of 1.5 Nurick grades at the time of the final follow-up. Eight patients had absent dura at the time of surgery and, of these, five had development of a cerebrospinal fluid fistula. Eight patients had development of new neurological signs and/or symptoms in the upper extremity postoperatively. Eight patients required reoperation because of a painful pseudarthrosis (one patient), strut-graft dislodgment (three), cerebrospinal fluid leakage (three), or compression of a nerve root caudad to the area of the original procedure (one). One patient died as the result of cardiac arrest on the third postoperative day. Fifty-eight patients had an osseous fusion, one had an asymptomatic nonunion, and one had a symptomatic pseudarthrosis that was treated with revision surgery. CONCLUSIONS: Anterior decompression and arthrodesis is an effective way to achieve pain relief and neurological improvement in North American patients of non-Asian descent who have cervical myelopathy associated with ossification of the posterior longitudinal ligament. The risk of durocutaneous fistula, graft dislodgment, and postoperative neurological symptoms appears to be high in patients with cervical myelopathy associated with this condition.     

颈椎前路Zephir钢板治疗脊髓型颈椎病临床疗效分析

目的探讨颈椎前路Zephir钢板系统治疗脊髓型颈椎病的临床疗效。方法对43例脊髓型颈椎病患者行颈前路减压、椎体间自体髂骨植骨融合或颈椎椎间融合器（钛网或Cage）融合、Zephir钢板内固定术,术后随访0．5—3年。结果临床结果按JOA颈椎病疗效判定标准评定,优16例,良19例,有效7例,无效1例,恶化0例。优良率为81．39％,平均植骨融合时间为12周,植骨融合率为100％。结论Zephir钢板治疗脊髓型颈椎病安全有效,提高了植骨融合率,临床疗效满意。     

老年人脊髓型颈椎病的特点及手术治疗

目的 探讨老年人脊髓型颈椎病的临床特点及手术方法。方法 对26例60－81岁老年人脊髓型颈椎病患者行颈前路开槽式减压，24例取自体髂骨移植，并行带锁钢板内固定，2例用Cage内充填减压椎体之松质骨植入。结果 23例获随访，平均随访时间为24.6个月，植骨融合率为100％，术后椎间高度及颈椎生理曲度维持良好，临床疗效优良率73％。结论 老年患者由于全身多器官功能退化，颈部骨质退变，临床表现复杂，多节段发病，诊断及治疗都存在一定的难度，只要选择适当，高龄并非手术禁忌症。     

颈前路减压支撑融合钢板内固定术治疗脊髓型颈椎病

目的 探讨颈前路减压、椎体间植骨支撑融合或颈椎椎间融合器（钛网或Cage）支撑融合、钢板内固定术治疗脊髓型颈椎病的临床方法及疗效。方法 回顾分析66例脊髓型颈椎病患者行颈前路减压后,分别采取骼骨植骨支撑融合、颈椎间融合器（钛网或Cage）植入支撑融合,钢板内固定术,随访时间平均32个月,采用Zdeblick影像学判定椎体间融合的标准,贾连顺的评定法评定术后临床疗效。结果 在颈前路减压、钢板内固定术治疗脊髓型颈椎病方法中,自体骼骨植骨融合优良率87．5％,供区并发症12．1％,椎间盘退变椎问高度丢失7．6％;颈椎间融合器支撑融合优良率96．1％,无供区并发症和椎问盘退变椎间高度丢失。结论 颈前路减压、椎体间植骨融合或颈椎间融合器支撑融合、钢板内固定术治疗脊髓型颈椎病临床疗效满意。钢板内固定术后颈椎即刻稳定;植骨融合手术操作简单,费用少,但存在供区并发症、椎问高度丢失;椎间融合器融合稳定、牢固,椎间高度丢失少,后者疗效优于前者。     

Spinal cord injury in cervical spinal stenosis by minor trauma

BackgroundThe size of the spinal canal is a factor that contributes to the neurologic deficits associated with cervical OPLL and CSM. We investigate the development of neurologic deterioration after minor trauma and the clinical results of decompressive surgery in cervical spinal stenosis retrospectively.MethodWe treated 200 cases (98 cervical OPLLs and 102 CSMs) of cervical spinal stenosis for 8 years. There were 63 (33.5%) minor trauma cases to the cervical spine in 200 patients. Of these 63 patients, 18 developed myelopathy, 13 showed deterioration of preexisting myelopathy, and no neurologic change was observed in 32 patients. The neurologic status was assessed by the JOA score. The patients were divided into 2 groups according to the residual cervical spinal canal diameter: group I (<10 mm cervical spinal canal) and group II (≥10 mm cervical spinal canal).ResultsNeurologic outcome depended on the diameter of the residual spinal canal; 22 of the 25 patients in group I developed neurologic deterioration, whereas that occurred in 8 of the 38 patients in group II (P < .05). After surgical decompression, 8 patients in group I and 30 patients in group II came out with an improved JOA score of more than 50% (P < .05).ConclusionEven indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal. It may be beneficial to check lateral radiograph of the cervical spine as a screening tool for early detection of cervical spinal stenosis especially in Asian people older than 40 years.     

显微镜下减压融合术治疗脊髓型颈椎病

目的:探讨显微镜下颈前路减压融合术治疗脊髓型颈椎病的疗效。方法:2005年2月至2010年3月,在显微镜辅助下经颈前路减压融合术治疗脊髓型颈椎病21例,男13例,女8例;年龄32～71岁,平均51.5岁;病程6个月～3年,平均12.5个月。手术操作:在显微镜下应用高速磨钻等工具进行减压操作,脊髓充分减压后取自体髂骨植骨融合加内固定。对手术前后JOA颈椎病评分进行比较并评价其疗效。结果:21例患者均获随访,时间18～24个月,平均20个月。患者脊髓神经功能均有不同程度提高,JOA评分由术前9.26±1.72增加至术后的13.64±1.38(t=2.452,P=0.000)。根据JOA评分评定疗效:优12例,良7例,一般2例。结论:显微镜下颈前路减压融合术具有操作精细、减压充分等优点,治疗脊髓型颈椎病安全、有效。     

Degenerative spondylolisthesis of the cervical spine — symptoms and surgical strategies depending on disease progress

Background Degenerative spondylolisthesis of the cervical spine is rare. Patients show signs of progredient myelopathy, radiculopathy and pain. Treatment strategies include ventral, dorsal and combined fusion techniques with or without repositioning and decompression.Methods In this study, we present 16 patients with degenerative cervical spondylolisthesis. The leading symptom was severe myelopathy in 8 patients, radiculomyelopathy in 5 patients and neck pain in 3 patients. However, neck pain was the initial symptom in all the patients and decreased when neurological symptoms became more evident. Radiographic examinations included plain radiography, MRI, CT, myelography and lateral tomography.Results Spondylolisthesis was located five times at level C3/4, C4/5 and C5/6. In three cases spondylolisthesis was located at level C7/T1. There were two patients with spondylolisthesis on two levels. Instability could be demonstrated by flexion/extension radiography in five cases. Patients were divided into three groups according to a newly introduced classification system. The surgical approach corresponded to this classification. In ten patients the spondylolisthesis could be corrected by extension and positioning, so discectomy and fusion on one or two levels with cage, plate and screws was sufficient. In five cases a corpectomy was necessary due to severe spondylosis. In one case a combined approach with dorsal decompression and release followed by ventral fusion was applied due to additional dorsal spinal cord compression. The follow-up period was 6–52 months. After surgery, none of the patients showed any signs of neurological deterioration. In all cases, a stable fusion was achieved with no signs of instability on flexion/extension radiographs. Neurological improvement was seen in 6 of 8 patients with myelopathy and 4 of 5 patients with radiculomyelopathy. The others showed stable disease. Pain relief was seen in all patients who complained of pain preoperatively.Conclusion The aims of treatment for cervical spondylolisthesis are spinal cord decompression (ventral, dorsal or both), correction and fusion. The used procedure should depend on the severity of the cervical deformity, degree and side of the spinal cord compression, and the possibility of correction by extension and positioning.     

Effects of cervical arthrodesis and arthroplasty on neck response during a simulated frontal automobile collision

Background contextWhereas arthrodesis is the most common surgical intervention for the treatment of symptomatic cervical degenerative disc disease, arthroplasty has become increasingly more popular over the past decade. Although literature exists comparing the effects of anterior cervical discectomy and fusion and cervical total disc replacement (CTDR) on neck kinematics and loading, the vast majority of these studies apply only quasi-static, noninjurious loading conditions to a segment of the cervical spine.PurposeThe objective of this study was to investigate the effects of arthrodesis and arthroplasty on biomechanical neck response during a simulated frontal automobile collision with air bag deployment.Study designThis study used a full-body, 50th percentile seated male finite element (FE) model to evaluate neck response during a dynamic impact event. The cervical spine was modified to simulate either an arthrodesis or arthroplasty procedure at C5–C6.MethodsFive simulations of a belted driver, subjected to a 13.3 m/s ΔV frontal impact with air bag deployment, were run in LS-DYNA with the Global Human Body Models Consortium full-body FE model. The first simulation used the original model, with no modifications to the neck, whereas the remaining four were modified to represent either interbody arthrodesis or arthroplasty of C5–C6. Cross-sectional forces and moments at the C5 and C6 cervical levels of the neck, along with interbody and facet forces between C5 and C6, were reported.ResultsAdjacent-level, cross-sectional neck loading was maintained in all simulations without exceeding any established injury thresholds. Interbody compression was greatest for the CTDRs, and interbody tension occurred only in the fused and nonmodified spines. Some interbody separation occurred between the superior and inferior components of the CTDRs during flexion-induced tension of the cervical spine, increasing the facet loads.ConclusionsThis study evaluated the effects of C5–C6 cervical arthrodesis and arthroplasty on neck response during a simulated frontal automobile impact. Although cervical arthrodesis and arthroplasty at C5–C6 did not appear to significantly alter the adjacent-level, cross-sectional neck responses during a simulated frontal automobile impact, key differences were noted in the interbody and facet loading.     

脊髓型颈椎病前路手术的神经学评价和疗效影响因素

[目的]探讨脊髓型颈椎病神经学评价标准和疗效影响因素。[方法]对21例脊髓型颈椎病的患者术前和术后实施Nurick分级法、JOA评分以及我国的40分评估法，并评价各种方法的优缺点。对影响神经学功能恢复的可能因素加以分析。[结果]平均随访11个月，术后Nurick颈椎病脊髓功能分型提高2～3级。JOA评分提高1～6分；我国的40分法提高7—12分。影响脊髓型颈椎病的手术技术因素有：椎体后缘骨赘切除不全、颈椎生理弧度恢复不良、椎体高度撑开不足或术后的过度丢失。[结论]Nurick分类允许更严格的比较，对某些脊髓病并不适合；JOA评分方法简便、有效，能较为全面地反映脊髓型颈椎病脊髓功能的改变；40分评定方法评价较为客观，但较为繁琐。椎体后缘骨赘切除不全和椎体高度撑开不足与手术疗效关系最为密切。     

Surgical stabilization of the cervical spine. A comparative analysis of anterior and posterior spine fusions

Two hundred twenty-two cervical spine stabilization procedures in 212 patients are reviewed. In 114 posterior cervical fusions, 88 anterior fusions, and ten combined procedures, no deaths occurred. Surgical complication rates were similar, but more severe complications were noted with anterior cervical fusions, including tracheoesophageal problems and transient neurologic loss. Six cases of graft dislodgement requiring reoperation also occurred. In long-term follow-up evaluations, 36 anterior fusion patients developed progressive kyphotic deformity averaging 22 degrees between surgery and the time solid fusion was obtained. Degenerative changes above and below the fusion mass were detected in 36 of 59 patients treated by anterior surgery. Posterior cervical fusion patients were noted to have no significant late change in alignment, and degenerative changes were infrequent. However, 73 of 98 patients had significant extension of fusion mass beyond the originally intended levels of stabilization. Because anterior cervical spine fusion was associated with significant complications of graft dislodgement and tracheoesophageal trauma, as well as postsurgical progressive deformity, the authors recommend posterior wiring and fusion as the procedure of choice to treat cervical spine instability and permit halo-free postsurgical rehabilitation. When anterior neural decompression and fusion is necessary, concomitant posterior wiring and fusion or halo vest immobilization may be necessary to maintain reduction and prevent kyphotic angulation, because posterior ligamentous disruption is not always grossly evident on radiographic examination.     

Open-door laminoplasty with suture anchor fixation for cervical myelopathy in ossification of the posterior longitudinal ligament

Expansive laminoplasty was developed to achieve posterior spinal cord decompression while preserving cervical spine stability. In the classic Hirabayashi procedure, the lamina door is tethered open by sutures between the spinous process and facet capsule or paravertebral muscle. The authors present a modified technique, which enhances secure fixation and prevents restenosis owing to hinge closure. Twenty-seven patients (7 females, 20 males) with cervical myelopathy secondary to ossification of the posterior longitudinal ligament were enrolled. Each patient underwent unilateral open-door laminoplasty with suture anchor fixation. Tying and fixation of the sutures onto the holed lateral mass screws was used instead of the conventional method. Radiography, magnetic resonance imaging, and computed tomography scanning were used for imaging studies. The Nurick score was used to assess myelopathy severity, whereas the Japanese Orthopedic Association score was adopted to compare clinical outcome before and after surgery. Mean follow-up period was 38 months (range, 18 to 60). Ten patients had 5 levels of decompression (C3-7), and 17 patients had 4 (C3-6, 12 patients; C4-7, 5 patients). All patients experienced functional improvement of at least 1 Nurick score after surgery. The Japanese Orthopedic Association score increased significantly from 7.5+/-3.2 before surgery to 13.2+/-1.6 at final follow-up. Postoperative radiography and computed tomography scan demonstrated significantly increased sagittal diameter and canal expansion. No neurologic deterioration owing to hinge reclosure or major surgery-related complications were observed. In conclusion, unilateral open-door laminoplasty with suture anchor fixation effectively maintains expansion of the spinal canal and resists closure while preserving alignment and stability. This modified technique has a low complication rate and provides marked functional improvement in patients with cervical myelopathy owing to ossification of the posterior longitudinal ligament.     

Circumferential cervical surgery for spondylostenosis with kyphosis in two patients with athetoid cerebral palsy.

BACKGROUND: Patients with athetoid cerebral palsy may develop severe degenerative changes in the cervical spine decades earlier than their normal counterparts due to abnormal cervical motion. METHODS: Two patients, 48 and 52 years of age, presented with moderate to severe myelopathy (Nurick Grades IV and V). MR and 3-dimensional CT studies demonstrated severe spondylostenosis with kyphosis in both patients. This necessitated multilevel anterior corpectomy with fusion (C2-C7, C3-C7) using fibula and iliac crest autograft and Orion plating, followed by posterior wiring, fusion using Songer cables, and halo placement. RESULTS: Postoperatively, both patients improved, demonstrating only mild or mild to moderate (Nurick Grades II and III) residual myelopathy. Although both fused posteriorly within 3.5 months, the patient with the fibula graft developed a fracture of the anterior C7 body with mild anterior graft migration, and inferior plate extrusion into the C7-T1 interspace. However, because he has remained asymptomatic for 9 months postoperatively, without dysphagia, removal of the plate has not yet been necessary. CONCLUSIONS: Patients with athetoid cerebral palsy should undergo early prospective cervical evaluations looking for impending cord compromise. When surgery is indicated, circumferential surgery offers the maximal degree of cord decompression and stabilization with the highest rate of fusion.     

The relationship between preoperative cervical alignment and postoperative spinal cord drift after decompressive laminectomy and arthrodesis for cervical spondylotic myelopathy

BackgroundCervical spondylotic myelopathy represents a debilitating disorder, often resulting in significant neurological impairment over time. Cervical laminectomy has enjoyed a successful track record in the surgical management of these patients. Little is understood regarding the significance of postdecompressive migration of the spinal cord in relation to patient outcome.MethodsPreoperative and postoperative cervical spine MRIs of 28 patients who underwent cervical laminectomy and fusion for the treatment of CSM were reviewed. Radiographic parameters including preoperative cervical alignment, LDI, space available at the level cepahlad/caudad to the decompression, percent spinal cord expansion at the radiographically most compressed level, and spinal cord drift to the midpoint of the spinal cord were measured and subsequently analyzed for statistical correlation. The recovery rate based on the mJOA score was calculated for each patient and analyzed for correlation with spinal cord drift.ResultsThe Cobb angle C2-7, cervical spinal angle, and CCI represented tightly correlated measures of cervical alignment. The preoperative cervical alignment did not statistically correlate with postoperative spinal cord drift. No statistical correlation was revealed between postdecompressive spinal cord drift and recovery rate.ConclusionsPreoperative cervical alignment does not statistically correlate with postoperative spinal cord drift in patients undergoing multisegmental decompressive laminectomy and fusion for CSM. The observation of significant posterior shifting of the spinal cord in the context of straight or kyphotic preoperative alignment suggests that posterior decompression and arthrodesis represent a viable option in the surgical management of patients with CSM with nonlordotic preoperative alignment.