Congenital lumbar ridge causing spinal claudication in adolescents. Report of two cases.

Two adolescent boys had classic histories and findings of spinal claudication. Their plain x-ray films were read as normal and myelograms demonstrated a ventral defect at L4-5. Surgical exploration revealed ventral bony ridges in both cases. Laminectomy initially provided substantial relief, but spinal fusion was necessary for complete abolition of symptoms.