We analyzed 47 patients with degenerative lumbar canal stenosis treated by posterior decompressive surgery. The average age at the time of surgery was 57.5 years. The average duration of follow-up was ten years and one month. The patients were subdivided into 4 groups. Ten patients were without spondylolisthesis and underwent decompression with fusion (Group I-a). Twenty three were without spondylolisthesis and underwent decompression without fusion (Group I-b). Eleven patients had spondylolisthesis and underwent decompression with fusion (Group II-a). Three patients had spondylolisthesis and underwent decompression without fusion (Group II-b). Surgical outcome was evaluated on the basis of the JOA score. The mean JOA scores after surgery were 21.0 in Group I-a, 19.8 in Group I-b, 22.3 in Group II-a, and 16.0 in Group II-b. There was no significance in the JOA score between with and without fusion. We therefore suggest that simultaneous fusion is not necessary with laminectomy of the lumbar spine in patients who have degenerative lumbar canal stenosis, especially for those without spondylolisthesis.
