Microscopic laminotomies for degenerative lumbar spinal stenosis.

In this retrospective study, we investigated 50 patients who had undergone primary lumbar microsurgical multiple laminotomy without spinal fusion for degenerative spinal stenosis. There were 31 men and 19 women with a median age of 66 years (35-85 years). Thirteen patients had grade I spondylolisthesis, most at L4-L5 levels (11 of 13). Single-level laminotomy was done in 13 patients, two levels in 30, and three levels in 7. The median follow-up period was 27 months (range, 15-48 months). A standardized self-reported questionnaire was used for clinical outcome study. The demographic data and clinical features of these patients were analyzed for the prognostic factors. The analysis showed excellent results in 18 patients, good in 16, fair in 8, and poor in 8, whereas 30 patients reported that they were very satisfied with the surgery results, 10 were somewhat satisfied, 2 were somewhat dissatisfied, and 8 were very dissatisfied. Therefore, the satisfactory rate of the surgery was higher if judged by patient satisfaction. Among the parameters analyzed, the presence of neurogenic claudication (p = 0.008), coexisting disease (p = 0.04), and the absence of motor deficit (p = 0.03) were associated with lower total scores. In addition, longer duration of symptoms (p = 0.04) was associated with less improvement of back pain score, whereas the absence of motor deficit (p = 0.004) was associated with less improvement of leg pain score. The presence of spondylolisthesis did not affect outcomes.