Lumbar disc surgery: results of the Prospective Lumbar Discectomy Study of the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons.

The Prospective Lumbar Discectomy Study enrolled 740 patients in a multiphysician, multicenter, consecutive patient protocol to evaluate the indications and efficacy of lumbar discectomy. Five hundred and thirteen patients could be evaluated at 3 months after surgery. Stepwise logistic regression showed that the factors of fraction of pain referred to the back, work-related injury, absence of back pain on straight leg-raise examination, correspondence of leg pain to typical radicular patterns, leg pain on straight leg-raise examination, and reflex asymmetry were independently predictive of good outcome from surgery. Univariate analysis of the case with different numbers of predictive factors present showed that use of the operating microscope, sensory deficit, central disc bulge, and free disc fragment were correlated with outcome only in subgroups. An analysis of unsatisfactory outcomes showed two patterns: one of failure as a result of mechanical back pain and one of failure as a result of radiculopathy. Factors predictive of outcome did not influence the type of failure. In a stepwise logistic regression analysis, facetectomy and preoperative sensory deficit were associated with increased likelihood of mechanical back pain failure, while preoperative motor deficit was associated with an increased likelihood of radicular failure. The results support several intuitively derived and commonly believed principles of lumbar disc surgery.