The natural history of spondylolysis and spondylolisthesis: 45-year follow-up evaluation.

Study Design.A prospective study of spondylolysis and spondylolisthesis was initiated in 1955 with a radiographic and clinical study of 500 first-grade children.Objective.To determine the natural history of spondylolysis and spondylolisthesis.Summary of Background Data.Most studies on the natural hi