[Analysis of the long-term outcome of anterior approach surgery on cervical spondylotic myelopathy].

OBJECTIVE: To investigate the long-term efficacy of anterior approach surgery on cervical spondylotic myelopathy and factors affecting prognosis. METHODS: The data in 116 patients suffered from cervical spondylosis from January 1992 to December 2000 were reviewed, including 80 male cases and 36 female cases, whose age ranged from 36 to 76 years (mean, 51 years). The preoperative course of disease was 2 months to 20 years (mean, 19 months). There were 65 cases (56.0%) with single segments involved, 44 cases (37.9%) with two segments, 7 cases (6.0%) with three segments. Ninety-eight cases were onset slowly, 18 cases with no remote cause and aggravating quickly. Three kinds of surgeries were performed: anterior cervical decompression and autoiliac bone interbody fusion, anterior cervical decompression and fusion with threaded fusion cage, anterior cervical decompression and autoiliac bone interbody fusion with anterior screw-plate system. Improvement in spinal cord function was assessed using the Japanese Orthopaedic Association (JOA) scoring system, the long-term efficacy and influential factors were also analyzed. RESULTS: The mean follow-up time was 7 years and three months (5 - 12 years). The mean preoperative JOA score was 9.34 +/- 1.81. The mean postoperative JOA score was 10.35 +/- 1.85. At the final follow-up, the JOA score was 14.09 +/- 1.90 and the recovery rate was 63.2%. Among the total patients, 27 cases were excellent, 47 cases were fine, 23 cases were good, 19 cases were poor, the fineness rate was 63.8%. The long-term efficacy of anterior approach surgery has close correlations with time of course, age of onset, preoperative spinal cord function and the number of affected segments, but has no correlations with modes of fusion and internal fixation. CONCLUSIONS: The patients will be attentively observed while having a definite diagnosis of cervical spondylotic myelopathy. The good long-term results will be obtained after early anterior cervical decompression and fusion.