Middle-term follow-up results were reported in 144 cases of lumbar canal stenosis that had been treated surgically in our hospital during the past 13 years. They were followed up for a nean of 5 years 2 months (ranging from 3 to 15 years). There were 70 men and 74 women whose ages ranged from 34 to 80 years at the time of surgery (mean: 60.0). 81 cases had degenerative stenosis and 63 cases had degenerative spondylolisthesis. Clinical results were evaluated according to the JOA score system and Hirabayashi's improvement rate. The preoperative score was 11.7 (±4.3) points and postoperatively this increased to 25.2 (±4.4) points giving an improvement rate of 78.8%.
Patients were treated by laminectomy (n=85), fenestration (n=27), Luque's-S. S. I. (n=20), anterior fusion (n=7) and posterior fusion (n=5) . Posterior decompression was done for aged patients and anterior fusion for middle-aged patients. 12 cases treated by posterior decompression (with or without fusion) required reoperation. Causes of recurrence included recurrent stenosis, insufficient decompression, stenosis at other vertebral levels and lumbar disc herniation at the laminectomy site. Of the 8 patients with recurrent stenosis, 5 patients showed bone regrowth at the site of decompression.
