Reasons for failure of L5-S1 intervertebral disc excisions.

This study reviews 247 patients who still had preoperative complaints six months to two years after disc excision. In over half, spondylosis of the L5-S1 facets was present, concurrently associated with a pelvic obliquity. A number of other organic causative factors were identified in 18% of the patients. Nonorganic reasons accounted for failure in only 13%. Over 70% of patients with associated spondylosis were improved by treatment directed at this condition.