OBJECTIVE The goal of this study was to investigate the prevalence and risk factors of clinical adjacent-segment pathology (CASP) following central corpectomy for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL). METHODS The authors reviewed 353 cases involving patients operated on by a single surgeon with a minimum 12-month follow-up after central corpectomy for CSM or OPLL between 1995 and 2007. Patients with symptoms consistent with CASP at follow-up were selected for the study. The authors analyzed the prevalence and risk factors for CASP after central corpectomy for CSM/OPLL. RESULTS Fourteen patients (13 male, 1 female; mean age 46.9 ± 7.7 years) were diagnosed with symptoms of CASP (3.9% of 353 patients) at follow-up. The mean interval between the initial surgery and presentation with symptoms of CASP was 95.6 ± 54.1 months (range 40-213 months). Preoperative Nurick grades ranged from 2 to 5 (mean 3.5 ± 1.2), and the Nurick grades at follow-up ranged from 1 to 5 (mean 3.0 ± 1.3, p = 0.27). Twelve patients had myelopathic symptoms and 2 had radiculopathy at follow-up. Patients with poorer preoperative Nurick grades had a higher risk for development of CASP (HR 2.6 [95% CI 1.2-5.3], p = 0.01). CONCLUSIONS In the present study, CASP was seen in 3.9% of patients following central corpectomy for CSM/OPLL. The risk of CASP after central corpectomy for CSM/OPLL was higher in patients with poorer preoperative Nurick grades.
Keywords: CASP = clinical adjacent-segment pathology; CSM = cervical spondylotic myelopathy; OPLL = ossification of the posterior longitudinal ligament; adjacent-segment disease; cervical corpectomy; cervical spondylotic myelopathy; subaxial cervical spine.