ABSTRACT
Results from lumbar disc operation in general are favorable in 70% to 90% of patients. The rate of necessary reintervention of the primary discectomy, however, may be as high as one fifth of cases even though diagnostic and technical standards have been improved. The purpose of this study was to analyse the reasons for failure of primary discectomy and which factors might have influenced the outcome of revisions in 53 patients with failed back surgery syndrome from the years 1989 to 1993. Mean follow up duration was 11.4 months with range of 1 to 69 months. Before revisions, all patients had one or more lumbar disc operations in whom disabling pain, neurologic deficits, and/or lumbar instabilities have been persisted or newly developed. The most common intraoperative findings of patients with revision were recurrent or persistent disc material(35.9%) followed by incomplete decompression from previous operations(24.5%), and disc lesions at new level(11.3%). In overall, 77.3% of total patients showed satisfactor y results(fair, good, and excellent) but this figure drops to 39.6% when those with at least good or excellent outcomes are only considered as definitively improved. Moreover only 22.9% good results were obtained among 35 patients with those less than 6 months of symptom duration. As for the total number of operations undertaken, it can not be conclusively stated due to small numbers in each categories, but less favorable results have been observed in those with more than one revisions. The factors predicting good outcome from revisions in our series were:1) greater than 6 months of pain relief after primary operation, 2) sciatica more prominent than lower back pain, 3) fewer operations.