Clinical Study of Postoperative Lumbar Canal Stenosis.

We analyzed 39 cases of postoperative lumbar canal stenosis. Subjects included 25 men and 14 women with a mean age at the time of operation of 53.7 years. The period before recurrence of symptoms following the first operation ranged from 11 months to 34 years (mean: 9 years and 8 months). Duration of follow-up ranged from 1 year to 6 years and 2 months (mean: 2 years and 1 month).In regard to the first operation in this series, Love's operation was done in 24 cases, fenestration in 5 cases, laminectomies in 6 cases and fusion operations in 4 cases.Laminectomies were performed in most of the second operations. From operative findings CT and MRI the main cause of postoperative stenosis was shown to be new bone formation at the site of operation. In some cases the main cause was spinal fibrosis.The preoperative average JOA score was 10.0±2.5 points, postoperative JOA score was 22.6±1.8 points.