Prospective analysis of surgical outcomes in patients undergoing decompressive laminectomy and posterior instrumentation for degenerative lumbar spinal stenosis.

OBJECTIVES: The aim of this study was to evaluate the outcome of wide surgical decompression and concomitant posterior instrumentation in patients with degenerative lumbar spinal stenosis.

METHODS: Thirty-seven consecutive patients (14 men, 23 women; mean age 64 years; range 36 to 82 years) with degenerative lumbar spinal stenosis were prospectively evaluated following surgical treatment with spinal decompression and concomitant instrumented posterior fusion. The mean duration of symptoms before surgery was 24 months (range 12 to 60 months). Preoperatively, six patients had degenerative spondylolisthesis (grade 1) and two patients had degenerative lumbar scoliosis. Decompression was performed at one level in four patients, at two levels in 16 patients, at three levels in 11 patients, and at four levels in six patients. Discectomy was also performed in seven patients. Preoperatively and postoperatively, the patients were assessed by the Oswestry Disability Index and a visual analog scale for overall pain (leg and low back pain). The satisfaction level of the patients for surgical outcome was also questioned. The mean follow-up period was 4.6 years (range 1 to 7 years).

RESULTS: Preoperatively, the mean Oswestry Disability Index score was 60.5% and the mean overall pain score was 7.5. Postoperatively, the Oswestry Disability Index score significantly decreased to 36.8% and the overall pain score significantly decreased to 3.5 (p<0.001). Preoperative and postoperative walking distances of the patients were as follows, respectively: more than 1,000 meters (6 and 14 patients), 500 to 1,000 meters (5 and 7 patients), less than 500 meters (26 and 16 patients). Twenty patients did not use any analgesics and eight patients used analgesics on a weekly basis. Twenty-six patients were satisfied with the surgical outcome, nine patients were somewhat satisfied, and two patients were dissatisfied. Overall, the outcomes were excellent to good in 22 patients (59.5%). None of the patients required revision surgery.

CONCLUSION: Most patients with degenerative lumbar spinal stenosis benefit from decompressive surgery. Patients with long-standing preoperative symptoms and concomitant diseases often have poor results and are less satisfied with the postoperative outcome.