Clinical Predictors of Surgical Outcomes and Imaging Features in Single Segmental Cervical Spondylotic Myelopathy with Lower Cervical Instability

BACKGROUND Cervical degenerative changes are the most common cause of cervical spondylotic myelopathy (CSM) and lower cervical instability (LCI). The purpose of this study was to investigate the associated factors of MRI signal changes and prognosis in single segmental CSM accompanied by LCI. MATERIAL AND METHODS A total of 122 patients met the inclusion criteria and were enrolled in this study with a minimum follow-up period of 2 years. According to the absence/presence of LCI, patients were divided into the unstable group (n=43 [35.2%]) and the stable group (n=79 [64.8%]). Clinical data and radiological parameters were compared between groups. RESULTS The occurrence rate of increased signal intensity (ISI) of the spinal cord was 72.1% in the unstable group and 44.3% in the stable group, and the difference was significant. There were significant differences in preoperative JOA score, duration of symptoms, and number of physical signs between the 2 groups (p<0.001, =0.001 and <0.001, respectively). The recovery rate of the JOA score in the unstable group was significantly lower than in the stable group (p<0.001). Long duration of symptoms, low preoperative JOA score, and more preoperative physical signs were significantly correlated with low JOA recovery rate. CONCLUSIONS Patients suffering from CSM with LCI have higher incidence of ISI of the spinal cord. Longer duration of symptoms, lower preoperative JOA score, and more preoperative physical signs were highly predictive of poor surgical outcomes for patients with single segmental CSM with LCI.