The authors report a further 3-year follow-up review of a series of 59 patients suffering with intractable pain due to lumbar spondylosis and treated by multiple-level bilateral laminectomies and facetectomies. Routine postoperative x-ray examination revealed that six of 59 patients had developed spondylolisthesis. Two of the six were symptomatic and required a secondary fusion procedure. Analysis of the patients who had developed vertebral slippage revealed that 6% of the patients with only two levels (L-4 and L-5) removal developed spondylolisthesis, but in those with three or more levels removed 15% showed slipped vertebrae. After an average follow-up period of 6 years, 87% of patients still had a worthwhile result as contrasted with 91% of the same series who had had a good result after a follow-up period averaging 3 years.
