Long-term follow-up evaluation of a few patients with spondylolisthesis treated by excision of the loose lamina with decompression of the nerve roots without spinal fusion.

Long-term follow-up observations were recorded in 52 patients with spondylolisthesis who were treated by excision of the loose lamina with decompression of the nerve roots without spinal fusion. The longest follow-up period was 146 months (average, 71 months). Measured by the method of Taillard, the average postoperative increase in displacement in all of the patients, including children, was 5%. In patients with increasing slippage, results were satisfactory in 90% and failures in 10%, whereas 82.7% of the results were satisfactory and 17.3% were failures in the group that showed no progression. Five patients underwent long-term follow-up examinations with roentgenographic studies. Follow-up periods ranged from 17 to 32 years. The largest total displacement was 14%, while only 9% occurred in the other patients. It is obvious, even in this small series, that as the disc degenerates, forward displacement occurs; however, once the disc collapses, further displacement does not occur. The study also revealed that forward displacement does not necessarily cause symptoms. Despite the unusual appearance of recent roentgenograms, the five patients were asymptomatic and satisfied with the end results at last follow-up evaluation.