Factors influencing the outcome of operative treatment for lumbar spinal stenosis.

96 patients with lumbar spinal stenosis were operated on after two to sixteen years of disabling symptoms. There were 50 women and 46 men with a mean age of 59 years. 33 of the patients had been previously operated on for spinal complaints. A laminectomy was performed in 61 patients; at one level in 31 patients, at two levels in 23 patients, and at three levels in seven patients. A hemilaminectomy was performed in 35 patients: at one level in 28 patients, at two levels in five patients, and at three levels in two patients. There were neither internal fixation devices used, nor spondylodesis performed in these operations. Special attention was focused on the effect of age, sex, body mass index and smoking, as well as previous surgery and extent of surgical intervention on the outcome of operative treatment. The follow-up time was 3-11 years (5.5 mean). Laminectomy at one level resulted in significantly most acceptable results of operative treatment methods. Younger patients and women were more prone to inferior results of operative treatment. Also the extent of surgical intervention, overweight and smoking seemed to have a tendency to worsen the result of operative treatment.