Long-term results of double-door laminoplasty for cervical stenotic myelopathy

STUDY DESIGN: A retrospective study of the long-term results from double-door laminoplasty (Kurokawa's method) for patients with myelopathy caused by ossification of the posterior longitudinal ligament and cervical spondylosis was performed. OBJECTIVE: To know whether the short-term results from double-door laminoplasty were maintained over a 10-year period and, if not, the cause of late deterioration. SUMMARY OF BACKGROUND DATA: There are few long-term follow-up studies on the outcome of laminoplasty for cervical stenotic myelopathy. METHODS: In this study, 35 patients with cervical myelopathy caused by ossification of the posterior longitudinal ligament in the cervical spine and 25 patients with cervical spondylotic myelopathy, including 5 patients with athetoid cerebral palsy, underwent double-door laminoplasty from 1980 through 1988 and were followed over the next 10 years. The average follow-up period was 153 months (range, 120-200 months) in patients with ossification of the posterior longitudinal ligament and 156 months (range, 121-218 months) in patients with cervical spondylotic myelopathy. Neurologic deficits before and after surgery were assessed using a scoring system proposed by the Japanese Orthopedic Association (JOA score). Patients who showed late deterioration received further examination including computed tomography scan and magnetic resonance imaging of the cervical spine. RESULTS: In 32 of the patients with ossification of the posterior longitudinal ligament and 23 of the patients with cervical spondylotic myelopathy, myelopathy improved after surgery. The improvement of Japanese Orthopedic Association scores was maintained up to the final follow-up assessment in 26 of the patients with ossification of the posterior longitudinal ligament and 21 of the patients with cervical spondylotic myelopathy. Late neurologic deterioration occurred in 10 of the patients with ossification of the posterior longitudinal ligament an average of 8 years after surgery, and in 4 of the patients with cervical spondylotic myelopathy, including the 3 patients with athetoid cerebral palsy, an average of 11 years after surgery. The main causes of deterioration in patients with ossification of the posterior longitudinal ligament were a minor trauma in patients with residual cervical cord compression caused by ossification of the posterior longitudinal ligament and thoracic myelopathy resulting from ossification of the yellow ligament in the thoracic spine. CONCLUSIONS: The short-term results of laminoplasty for cervical stenotic myelopathy were maintained over 10years in 78% of the patients with ossification of the posterior longitudinal ligament, and in most of the patients with cervical spondylotic myelopathy, except those with athetoid cerebral palsy. Double-door laminoplasty is a reliable procedure for individuals with cervical stenotic myelopathy.     

Genetic study of ossification of the posterior longitudinal ligament in the cervical spine with human leukocyte antigen haplotype.

To evaluate the genetic background of ossification of the posterior longitudinal ligament, the relationship between the presence of absence of ossification and human leukocyte antigen haplotypes was studied in 33 families of patients with ossification of the posterior longitudinal ligament. The study revealed that human leukocyte antigen haplotypes formed certain types of clusters, and that some human leukocyte antigen haplotypes were very rare in the Japanese population, suggesting the involvement of human leukocyte antigen-linked factors in the pathogenesis of ossification of the posterior longitudinal ligament of the cervical spine. In the families of these patients, ossification of the posterior longitudinal ligament was demonstrated by radiography in 56% (10/18) of the siblings. Each of these siblings shared both human leukocyte antigen haplotypes with the patient. None of those who shared only one human leukocyte antigen haplotype with the patient had developed ossification of the posterior longitudinal ligament. From these findings, the presence of both pathogenic human leukocyte antigen haplotypes is considered to be necessary for the development of ossification of the posterior longitudinal ligament, and this genetic predisposition may be activated by multiple factors, including regressive degeneration due to aging and the environment.     

Long-term results of the anterior floating method for cervical myelopathy caused by ossification of the posterior longitudinal ligament

STUDY DESIGN: Results of the anterior floating method used to decompress ossification of the posterior longitudinal ligament were studied for an average postoperative interval of 13 years. OBJECTIVE: To investigate the long-term results of the anterior floating method used to manage ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: The anterior floating method is a technique that differs from the extirpation method used to manage ossification of the posterior longitudinal ligament. Reports of the long-term results from anterior decompression used to manage cervical ossification of the posterior longitudinal ligament are rare. METHODS: The anterior floating method was used to decompress cervical ossification of the posterior longitudinal ligament in 63 patients. These patients were followed for more than 10 years with neurologic evaluations using a scoring system proposed by the Japanese Orthopedic Association (JOA score). RESULTS: The recovery rate was 66.5% at 10 years and 59.3% at 13 years, the time of the final survey. Operative outcomes most closely reflected the preoperative duration and severity of myelopathy (JOA score) and the preoperative cross-sectional area of the spinal cord. There was no correlation with the canal narrowing ratio or the thickness of ossification of the posterior longitudinal ligament. Delayed deterioration was attributed to an original inadequate decompression and progression of ossification of the posterior longitudinal ligament outside the original operative field. There was no evidence of significant recurrent ossification of the posterior longitudinal ligament within the margins of prior decompression. CONCLUSIONS: The anterior floating method appears to yield adequate long-term outcomes when used to manage ossification of the posterior longitudinal ligament.     

Ossification of the posterior longitudinal ligament in vitamin D-resistant rickets: case report and review of the literature

STUDY DESIGN: A case report of cervical myelopathy caused by ossification of the posterior longitudinal ligament in a patient with vitamin D-resistant rickets is presented together with a review of literature. OBJECTIVE: To report the diagnosis of ossification of the posterior longitudinal ligament in a white woman with vitamin D-resistant rickets. SUMMARY OF BACKGROUND DATA: The association between ossification of the posterior longitudinal ligament and untreated vitamin D-resistant rickets has been reported in Japan, but infrequently in white populations. In whites, ossification of the posterior longitudinal ligament is closely associated with diffuse idiopathic skeletal hyperostosis. A clear association between ossification of the posterior longitudinal ligament and vitamin D-resistant rickets in white populations has not yet been established. METHODS: The medical record and imaging studies of a patient treated at the authors' institution for cervical myelopathy caused by ossification of the posterior longitudinal ligament in the setting of treated vitamin D-resistant rickets were reviewed. A Medline search of the medical literature between 1966-1999 was performed to identify pertinent studies and similar case reports. RESULTS: The occurrence of spinal stenosis in untreated adults with vitamin D-resistant rickets has been reported in all regions of the spine in Japanese patients. The association between ossification of the posterior longitudinal ligament and untreated vitamin D-resistant rickets was first reported in Japan, where ossification of the posterior longitudinal ligament is endemic. This association may be incidental, because reports on ossification of the posterior longitudinal ligament in whites are not as frequent as in Japanese, reflecting the higher prevalence of this condition in Japan. CONCLUSION: Ossification of the posterior longitudinal ligament and ossification of the posterior longitudinal ligament associated with deranged calcium or phosphate metabolism may be different pathologic entities sharing a common outcome. Adequate treatment of vitamin D-resistant rickets may not always prevent or reverse ossification of the posterior longitudinal ligament.     

Long-term results of tension-band laminoplasty for cervical stenotic myelopathy: a ten-year follow-up

We reviewed 75 patients (57 men and 18 women), who had undergone tension-band laminoplasty for cervical spondylotic myelopathy (42 patients) or compression myelopathy due to ossification of the posterior longitudinal ligament (33 patients) and had been followed for more than ten years. Clinical and functional results were estimated using the Japanese Orthopaedic Association score. The rate of recovery and the level of postoperative axial neck pain were also recorded. The pre- and post-operative alignment of the cervical spine (Ishihara curve index indicating lordosis of the cervical spine) and the range of movement (ROM) of the cervical spine were also measured. The mean rate of recovery of the Japanese Orthopaedic Association score at final follow-up was 52.1% (SD 24.6) and significant axial pain was reported by 19 patients (25.3%). Axial pain was reported more frequently in patients with ossification of the posterior longitudinal ligament than in those with cervical spondylotic myelopathy (p = 0.027). A kyphotic deformity was not seen post-operatively in any patient. The mean ROM decreased post-operatively from 32.8° (SD 12.3) to 16.2° (SD 12.3) (p < 0.001). The mean ROM ratio was 46.9% (SD 28.1) for all the patients. The mean ROM ratio was lower in patients with ossification of the posterior longitudinal ligament than in those with cervical spondylotic myelopathy (p < 0.001). Compared to those with cervical spondylotic myelopathy, patients with ossification of the posterior longitudinal ligament had less ROM and more post-operative axial neck pain.     

伴颈椎后纵韧带骨化的颈椎间盘突出症手术治疗

目的 探讨伴有颈椎后纵韧带骨化的颈椎间盘突出症的临床特点、手术方式及疗效.方法 对2003年6月至2008年6月间伴有后纵韧带骨化的颈椎间盘突出症患者26例进行回顾性分析,男16例,女10例;平均年龄45岁.均在诱因下起病或出现明显加重,病程较短.术前行颈椎X线、CT和MR检查,证实有1-3个节段的颈椎间盘突出,同时伴有多个(≥2个)节段的后纵韧带骨化.术前疼痛视觉模拟评分(visual analogue scale,VAS)4-7分.平均5.3分;日本骨科学会(Japanese Orthopedic Association,JOA)评分5～12分,平均9.3分.13例患者单纯经椎间隙摘除突出的间盘减压;11例接受椎体次全切除减压;2例一期经椎间隙摘除突出的间盘,二期后路椎板切除减压.结果 患者根性疼痛及肢体麻木无力、走路不稳症状明显改善,术后随访12-36个月(平均18个月),术后疼痛VAS评分平均2.5(1～4)分,JOA评分平均14.2(11～16)分,JOA评分改善率平均为63.2%.2例患者出现脑脊液漏,经对症处理后消失,无其他并发症出现.结论 既往无明显临床表现或临床症状较轻微的颈椎后纵韧带骨化患者可因颈椎间盘突出导致临床症状出现或加重.术前明确责任病灶,手术切除突出的椎间盘常可获得良好疗效.     

前路飘浮法治疗颈椎后纵韧带骨化症初步报告

目的 :对前路飘浮法治疗颈椎后纵韧带骨化症 (OPLL)手术疗效进行初步评析。方法 :对 16例颈椎O PLL患者行前路飘浮法治疗 ,其中连续型 3例 ,节段型 8例 ,混合型 3例 ,孤立型 2例 ;最长手术节段 3节 ;椎管狭窄率 3 0 %～ 70 %。所有患者均采用钛板、钛网行颈椎重建。术后对近期结果随访 ,并按日本矫形外科协会 (JOA)评分系统评分。结果 :平均随访时间 6个月 ,平均恢复率为 68 2 %。无脑脊液漏、神经损伤等并发症发生。颈椎融合良好。结论 :前路飘浮法适合于大多数OPLL患者 ;新型颈椎内固定系统扩大了前路OPLL手术适应证     

Unusual appearance of an en plaque meningioma of the cervical spinal canal. A case report and literature review

STUDY DESIGN: A case report of a patient with cervical spinal cord and nerve root compression caused by a meningioma en plaque together with calcification of the posterior longitudinal ligament is presented,with a review of the literature. OBJECTIVE: To present the diagnosis of a calcified dural meningioma en plaque, with extradural extension into the ligamentum flavum, in a woman with cervical myelopathy and neuropathy. SUMMARY OF BACKGROUND DATA: This case demonstrates that the cervical spine can be involved in dural meningioma en plaque with calcifications, in a manner mimicking ossification of the ligamentum flavum, which has never been previously reported. METHODS: A patient presenting with cervical cord and nerve root compression caused by ossification of the posterior longitudinal ligament and a concurrent calcified dural meningioma en plaque was treated surgically and has made a gradual recovery. Imaging studies,surgical findings, and histopathologic evaluation were analyzed to support the diagnosis. RESULTS: At surgery, ossification of the posterior longitudinal ligament was noted, along with a calcified lesion involving the posterior cervical dura and the adjacent ligamentum flavum. A calcified meningioma was diagnosed by histopathologic examination of the dural-based lesion. CONCLUSION: Although previously not described, the diagnosis of calcified dural meningioma en plaque should be considered in all patients presenting with spinal cord and/or nerve root compression,even at cervical levels. Although ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum are more common etiologies of partially circumferential spinal calcification, dural-based meningiomas with extension into the surrounding ligaments demand early recognition because they can be associated with a poorer prognosis.     

Surgical strategy for ossification of the posterior longitudinal ligament in the cervical spine

Ossification of the posterior longitudinal ligament is a common cause of cervical myelopathy, and controversy remains regarding surgical options. Between January 2004 and December 2007, a total of 164 patients with ossification of the posterior longitudinal ligament in the cervical spine who underwent surgical treatment at the authors' institution were included in this study. The choice of surgical option was based on pathological extent and cervical alignment. Short-segment pathology was treated via the anterior approach and long-segment pathology via the posterior approach. When the posterior approach was selected, laminoplasty was performed for the patients with cervical lordosis and laminectomy with fusion for those with cervical kyphosis. Consequently, anterior corpectomy and fusion was performed in 91 patients, laminoplasty in 41 patients, and laminectomy and instrumented fusion in 32 patients. The Japanese Orthopedic Association scoring system was used to evaluate patients' neurological status, and related complications were also recorded. Clinical results between different approaches and techniques were compared at mid-term follow-up.Based on the results of this study and a review of previous literature, no significant differences existed between different approaches and techniques for patients with mild ossification of the posterior longitudinal ligament, but anterior corpectomy and fusion had significantly better results in patients with severe ossification of the posterior longitudinal ligament. With respect to the posterior approach, laminectomy and instrumented fusion improved the surgical results of patients with cervical kyphosis, but a high incidence of C5 palsy existed simultaneously.     

颈椎前路手术中后纵韧带切除的探讨

目的：探讨颈椎前路手术后纵韧带切除的指征、方法和注意事项，方法：对2000年4月－2002年4月后纵韧带切除的50例颈椎前路手术患者的临床资料及手术治疗结果进行回顾性分析。结果：42例获得6个月以上随访，根据JOA评分标准，平均改善率为70．5％，优14例，良16例，中9例，差3例，结论：后纵韧带退变肥厚、后纵韧带骨化或硬膜外型颈椎间盘脱出压迫颈髓时，行颈椎前路手术时应切除后纵韧带，彻底减压。     

Progression of ossification of the posterior longitudinal ligament following en bloc cervical laminoplasty.

BACKGROUND: Ossification of the posterior longitudinal ligament often causes compressive myelopathy. Ossification is a progressive disease, and it has been reported that the area of ossification increases after decompressive surgery. However, it is uncertain how the progression of ossification affects the long-term outcome after cervical laminoplasty. This study was performed to clarify the relationship between the progression of ossification of the posterior longitudinal ligament and the clinical results following en bloc cervical laminoplasty. METHODS: Forty-five patients who were followed for more than ten years after laminoplasty participated in this study. Radiographs and tomograms of the cervical spine of each patient were made before and after the operation and at the time of the latest follow-up. The extent of ossification in the longitudinal and sagittal axes was evaluated. Neurological function was graded with use of the Japanese Orthopaedic Association scoring system. The relationship between the progression of ossification and the score-based rate of recovery was analyzed. RESULTS: Thirty-three (73%) of the patients had progression of ossification of the posterior longitudinal ligament after laminoplasty. Progression was frequent in patients with the mixed type of ossification and in those with the continuous type, whereas it was rare in patients with the segmental type. The patients with progression of the ossification were significantly younger than those without progression (p = 0.018). The Japanese Orthopaedic Association score improved rapidly within one year and continued to improve up to five years after surgery. The score tended to decrease thereafter. For thirteen patients, the score had worsened at the time of the latest follow-up. Three patients had neurological deterioration following an increase in the thickness of the ossification. CONCLUSIONS: Progression of ossification of the posterior longitudinal ligament was often observed during the long-term follow-up period after laminoplasty. Young patients with mixed and continuous types of ossification had the greatest risk for progression. Preventive measures, such as the use of a wider laminar opening during the laminoplasty, should be considered for patients who are at risk for progression of ossification.     

Atlantoaxial subluxation associated with ossification of posterior longitudinal ligament of the cervical spine

STUDY DESIGN: Two case reports. OBJECTIVE: To demonstrate two rare cases of atlantoaxial subluxation associated with ossification of the posterior longitudinal ligament of the cervical spine, in which spastic quadriplegia developed. SUMMARY OF BACKGROUND DATA: There are only two reports of an association of diffuse idiopathic skeletal hyperostosis with atlantoaxial subluxation. This condition often accompanies ossification of the posterior longitudinal ligament of the cervical spine, but there is nothing in the literature about the association of ossification of the posterior longitudinal ligament with atlantoaxial subluxation. METHODS: Clinical and radiographic findings of these two cases were demonstrated. In both cases laminoplasty of the cervical spine was performed with occipitoaxial arthrodesis. RESULTS: The spastic quadriplegia of these two patients caused by myelocompression improved after surgical intervention. CONCLUSION: Ossification of the posterior longitudinal ligament of the cervical spine may cause atlantoaxial subluxation.     

Segmental anterior decompression and fusion for multilevel ossification of the posterior longitudinal ligament

The purpose of this study was to evaluate the outcome of segmental anterior decompression and fusion for multilevel ossification of the posterior longitudinal ligament. Data were collected from 23 patients with multilevel ossification of the posterior longitudinal ligament. Average operative time and blood loss were 121 minutes and 201.6 mL, respectively. The Nurick score significantly decreased from 2.7±0.9 preoperatively to 1.8±0.9 at last follow-up (P<.01). The preoperative Japanese Orthopaedic Association score was 8.2, which significantly increased to 13.8 points at last follow-up (P<.01), with an improvement rate of 64.5%. The operation also significantly increased cervical lordosis (P<.01) from 7.7° preoperatively to 13.3° postoperatively. The fusion rate was 95.7% at 6 months postoperatively, and 100% at 12 months postoperatively. The loss of cervical lordosis and height of fusion segments were 1.2° and 0.9 mm at last follow-up, respectively. No hardware complications occurred. Cerebrospinal fluid leakage occurred in 2 patients, and hematoma occurred in 1 patient who needed an emergency operation. Segmental anterior decompression and fusion was generally effective and safe in the treatment of multilevel ossification of the posterior longitudinal ligament if indications were well controlled.     

颈椎后纵韧带骨化症的手术治疗

目的探讨颈椎后纵韧带骨化症手术治疗方法及其疗效。方法回顾性分析2002年1月至2008年1月我院65例颈椎后纵韧带骨化症手术治疗病例。均有程度不等的脊髓压迫症状。41例合并发育性颈椎管狭窄,平均椎管狭窄率42．1％。术前均行X线、CT平扫加矢状位重建和MRI检查。其中23例行前路手术,37例行后路手术,5例行前后路联合手术。结果65例获6～72个月随访,平均随访时间19个月。根据日本矫形外科学会评分标准,颈前路手术平均改善率70％,颈后路手术平均改善率66．3％,颈前后路联合手术平均改善率75．4％。术后并发节段性神经根麻痹5例。结论根据患者病情和影像学表现,尤其是CT矢状位重建,仔细分析后纵韧带骨化部位、范围及椎管狭窄率,选择合适手术方法,方能减少并发症,提高手术疗效。     

Prevalence of ossification of the posterior longitudinal ligament of the cervical spine

ObjectivesTo determine the prevalence of ossification of the posterior longitudinal ligament (OPLL) in cervical spines in Koreans.MethodsWe reviewed the reports of the radiologic examination of cervical spines from January 2002 to September 2005 in Hanyang University Hospital, Seoul, Korea. OPLL was indicated by the presence of heterotopic ossification in the posterior longitudinal ligament on lateral cervical radiograph.ResultsAmong 11,774 adults aged 16 years or more, 71 cases of OPLL were found (0.60%). The male to female ratio was 42:29 (1.45:1). The highest prevalence was in patients aged 50–59 years. In terms of the types of OPLL, the continuous type was noted in 32.0% of the patients, the segmental type in 31.0%, the mixed type in 31.0%, and the localized type in 5.6%. C4, C5, and C3 were most commonly involved, in that order of frequency. Diffuse idiopathic skeletal hyperostosis, which is another common hyperostotic disorder, was also found in eight male patients.ConclusionsThe prevalence of cervical OPLL in Koreans was 0.60%, which was lower than that of Japanese and some previous western reports.     

颈椎后纵韧带骨化症的前路骨化灶悬切减压治疗

目的 探讨颈椎后纵韧带骨化症采取颈前路骨化灶悬切减压治疗效果.方法 颈椎后纵韧带骨化症42例136个骨化节段.颈前路椎体开槽,深至椎体后缘,与硬膜严重粘连不宜切除的骨化灶可用丝线缝穿骨化灶一侧残余的后纵韧带或骨化灶周围的纤维组织,轻轻提起系在植骨块或颈长肌上,使骨化灶完全缩入骨槽内;对体积较小、与硬膜粘连轻的骨化灶予以...     

混合型颈椎后纵韧带骨化症的前路手术治疗

[目的]探讨混合型颈椎后纵韧带骨化症前路椎体次全切除减压的方法及其临床效果。[方法]对37例混合型颈椎后纵韧带骨化症的患者采用一期前路手术治疗,手术依据钙化的后纵韧带和硬脊膜粘连的情况采用彻底切除钙化后纵韧带或使之"漂浮"的方法。其中男24例,女13例;平均54.3岁。患者椎管狭窄率在32%~85%,平均51.4%。神经功能JOA(Japanese orthopaedic association)评分术前4~14分,平均7.9分。[结果]所有患者随访6个月~3年,平均16个月。术后3个月评分10.3分,术后12个月评分11.1分。优良率分别为72.7%和78.8%。[结论]一期行前路椎体次全切术治疗混合型颈椎后纵韧带骨化症,能够获得彻底的椎管减压和良好的临床效果。     

多节段脊髓型颈椎病合并后纵韧带骨化症患者的手术方式探讨

目的探讨多节段脊髓型颈椎病合并局灶型后纵韧带骨化症患者手术入路的选择、不同手术方式及结果。方法本组56例多节段脊髓型颈椎病合并局灶型后纵韧带骨化症患者,18例施行前路椎体及病灶切除减压 髂骨或钛网植骨钢板内固定术。30例行后路全椎板减压 Axis侧块钢板固定 关节突植骨。前后路联合手术8例．3例后路术后一期联合前路手术,5例为后路术后症状改善不明显或症状有加重,二期行前路手术。所有病例随访2年以上,采用JOA评分,观察前路、后路和前后路联合3种手术入路的减压效果。结果随访56例,颈前路患者的手术改善率69．69%;颈后路患者的手术改善率65．04%;前后路联合患者的手术改善率75．25%。3种术式存在显著差别。并发症发生率以颈后路手术者最低。结论多节段脊髓型颈椎病合并局灶型后纵韧带骨化症患者手术效果虽然以前后路联合手术为最好,但并发症发生率也最高,而颈后路手术并发症发生率最低。因此应根据患者体质、病情以及影像学表现仔细分析。选择相应的手术方式。     

Surgical management of cervical cord injury with ossification of the cervical posterior longitudinal ligament

Objective: To identify an appropriate surgical approach for the management of cervical cord injury with ossification of the posterior longitudinal ligament. Methods: A retrospective study of 25 cases of cervical cord injury with ossification of the posterior longitudinal ligament was performed. Two cases were classified as Frankel grade A, three as grade B, fourteen as grade C, and six as grade D. Treatment procedures consisted of anterior decompression with instrumentation (twelve patients), posterior decompression (eight patients), and combined anterior and posterior decompression (five patients). Results: There were no iatrogenic injuries of great vessels, trachea, esophagus or spinal cord. All patients were followed up for 15–86 months (average, 38.3 months). All segment with anterior fixation attained solid fusion, without implants loosening or breakage. No reclosed open‐door was found after posterior laminoplasty. Twenty‐one patients improved by one to two Frankel grades. The patients with complete spinal cord injury achieved no neurologic recovery, but did experience relief of upper limb pain or numbness. Conclusion: The surgical outcomes of cervical cord injury with ossification of the posterior longitudinal ligament were satisfactory. It is important to select a suitable surgical approach according to the findings on radiological imaging and the clinical characteristics and general condition of the patients.     

Systematic review of cohort studies comparing surgical treatment for multilevel ossification of posterior longitudinal ligament: anterior vs posterior approach

There have been no standards or guidelines for the treatment of ossification of posterior longitudinal ligament, especially multilevel ossification of posterior longitudinal ligament. The purpose of this study was to compare results of major surgical treatment for multilevel ossification of posterior longitudinal ligament. Databases including MEDLINE, EMBASE, the Cochrane library, and bibliographies of identified and review articles were searched to find randomized, controlled trials or retrospective cohort studies comparing anterior and posterior approach from 1980 to December 2010. Approximately 1375 articles were found initially, 92 abstracts were screened, 23 articles were retrieved in full; 3 studies were included in the review. No randomized, controlled studies were identified. Because all the studies included in this study are cohort studies with disparity of surgical interventions, heterogeneity of outcome measures and different qualities, we were unable to perform a meta-analysis. All comparison studies are retrospective cohort studies, comparing surgical outcomes of anterior approach (corpectomy and fusion) with that of posterior approach (laminoplasty or laminectomy) for the treatment of multilevel ossification of posterior longitudinal ligament in the cervical spine. A systematic review of retrospective cohort studies was performed to determine which surgical treatment is the most effective in patients with multilevel ossification of posterior longitudinal ligament. Definitive conclusions regarding the surgical treatment of multilevel ossification of posterior longitudinal ligament could not be made in this article. Multilevel corpectomy and fusion are more technical and have a significantly higher rate of cerebrospinal fluid leakage and graft, instrumentation related complications. A well-designed, prospective, randomized controlled, multicenter trial is needed.