Lumbar spinal stenosis: which predictive factors of favorable functional results after decompressive laminectomy?

Long-term results of decompressive laminectomy in degenerative lumbar stenosis have been studied in only six prospective studies. The objective of our study was to evaluate the functional outcome at long term of patients after decompressive laminectomy in lumbar stenosis and to determine predictive factors of favorable outcome.

A prospective cohort data were collected by an independent observer five years after decompressive laminectomy for degenerative lumbar stenosis. The endpoint was the assessment of the Beaujon score for functional evaluation. The result was considered as favorable if the Beaujon score increased by at last five points between the preoperative stage and at follow-up examination. Logistic regression was then performed with univariate and multivariate analysis to reveal predictive factors of good long-term outcome (P≤0.05).

The preoperative characteristic of our population (n=98) was a mean age of 67.3±8.8 years, a low comorbidity (mean Charlson score=2.8±1.5), overweight status (BMI=29.4±6.3) and the mean Beaujon score was 9.3±3.1. At five years after surgery, the mean Beaujon score became 14.1±4.2. Favorable functional outcome concerned 45.9% of our series. The predictive factor of favorable outcome identified in the univariate analysis the neurological deficit (P=0.05) and in the multivariate analysis the low comorbidity (P=0.01).

The long-term results of surgical treatment of lumbar spinal stenosis were moderate with an improved outcome in 49.5% of cases in our study. The only independent factor to a favorable outcome was the low comorbidity.