Degenerative spondylolisthesis: lumbar stenosis and instability.

Degenerative spondylolisthesis may manifest itself with different clinical pictures depending on the phase of the spondylotic disease. Based on pathophysiological criteria 24 patients affected with degenerative spondylolisthesis were divided into three groups: group I: those with spondylotic instability; group II: those with lumbar stenosis and current or potential segmental instability; group III: those with lumbar stenosis and naturally stabilized spondylolisthesis. Group I was treated by posterolateral fusion; group II by laminectomy, removal of the medial portion of the facets and posterolateral fusion; group III by laminectomy and removal of the medial portion of the facets. Long-term results were positive in 100% of the cases in group I, 90% in group II and 83% in group III, with no statistically significant differences between groups, because of the limited series of cases. The authors conclude that surgery for the treatment of degenerative spondylolisthesis must be based on age, symptoms, and the phase of the disease, and that when these indications suited to the clinical-radiographic picture are taken into account, good results may be obtained with different operations.