Predictors for the outcome in cervical myelopathy. A postoperative follow-up study in 219 cases

Introduction: Degenerative disorders of the cervical spine such as prolaps of the nucleus pulposus or spondylosis, are very common. This study should analyzes the results of surgical treatment in 219 patients in an effort to establish what factors are relevant for outcome. Methods: Between 1976 and 1995 219 patients underwent surgery for a degenerative disease of the cervical spine. Of these, 143 patients (65.3%) were male and 76 (34.7%) were female. Patients were divided in two groups: the first group (n = 80) with those disorders caused by “hard disc” (spondylosis) and the second group (n = 87) constituted by patients with a “soft disc” (nucleus pulposus). Surgery was performed in 299 segments. One hundred and seventy patients were submitted to a long term follow-up analysis (mean 30 months after surgery) by means of a questionnaire. Of these, 102 underwent a clinical follow-up examination. Neurological symptoms were evaluated according to a modified score of the Japanese Orthopedic Association (JOA-Score). The recovery rate (percentage of improvement) was also analyzed. Results: Statistical evaluation was performed by Mann-Whitney Rang Sum test. There were significant differences in outcome between patients with high (JOA 14-17) and low (JOA 0-9) initial JOA-Scores (p < 0.05). Unfavorable results were frequent in patients older than 60 (p < 0.05). Hospitalization lasted longer (p < 0.05) and complications tended to be more frequent in this group of patients. Significant differences in outcome was also seen between the groups (recovery rate 60% in group 1 vs. 41% in group 2, p < 0.05) and between patients with or without cervical myelopathy (recovery rate 47% vs. 63%, p < 0.05). Complications occurred in 17% (29 patients). We found in 5 cases permanent paresis of the recurrent nerve, in one case occurred a Brown-Séquard-Syndrome postoperatively. Fifty percent (14 patients) of the complications was seen at the iliac crest, casting doubt on the advantage of autologous bone grafts. Discussion and Conclusions: Surgery should be performed as early as possible in cases of beginning cervical myelopathy to achieve a satisfactory outcome. The initial JOA-Score and the presence of cervical myelopathy are excellent predictors for outcome in degenerative disorders of the cervical spine