Age is not a contraindication to surgery, but the patient's general medical condition must be considered.12 Decompression alone is usually done for stable, central forms of degenerative spinal stenosis, while stabilization through fusion is added for unstable spinal stenosis. Extreme lateral recess decompression or facetectomy may create instability or potential instability, necessitating fusion. Symptoms include both back pain and radicular symptoms, usually in an L-5 distribution. Plain films show the olisthy and facet sclerosis without a pars interarticularis defect. Myelography-CT reveals an hourglass constriction, with obliteration of the lateral recesses.
Surgical treatment consists of both decompression and fusion.
Decompression alone may transiently relieve symptoms of neural compression. However, further posterior destabilization may lead to continued mechanical back pain, as well as progression of the slippage. Herkowitz and Kurz,17 in a randomized prospective study, found a statistically significant improvement in patients treated by decompression and fusion, as opposed to decompression alone, for degenerative lumbar spondylolisthesis. They believe the resultant discrepancies might be due to either increased postoperative olisthy or increased motion in the unfused group. The risk-benefit issues and ultimate effects of internal fixation are still under investigation.