Combined upper cervical canal stenosis and cervical ossification of the posterior longitudinal ligament resulting in myelopathy: A case series and literature review

Combined upper cervical canal stenosis and cervical ossification of the posterior longitudinal ligament (OPLL) is an under-recognized disorder. The objective of the present study was to investigate the radiological manifestations and surgical outcomes of this disease combination. Between May 2011 and July 2014, we studied the radiological manifestations of 18 cases of combined upper cervical canal stenosis and cervical OPLL. Appropriate decompression procedures were performed and the clinical outcomes were evaluated using a visual analog scale (VAS) and the Japanese Orthopedic Association (JOA) scoring system. Radiological outcomes, including the space available for the spinal cord (SAC) at the cephalad-adjacent level, occupying ratio of OPLL, and cervical sagittal alignment, were measured. We found that the etiologies of upper cervical canal stenosis included craniovertebral junction deformity, atlantoaxial subluxation, and OPLL extending to the C2 level. The radiological features of OPLL varied. Postoperatively, all patients showed evidence of improvement in their VAS and JOA scores. The radiological results were satisfactory in terms of the SAC at the cephalad-adjacent level, occupying ratio of OPLL, and cervical alignment. We found that the radiological manifestations of combined upper cervical canal stenosis and cervical OPLL varied among patients. Satisfactory results can be achieved by applying appropriate decompression techniques.