Posterior limbus vertebrae: a cause of radiating back pain in adolescents and young adults.

Four cases of posterior limbus vertebrae are presented, three in the lumbar spine and one in the lower thoracic spine. All four patients have myelographic documentation of herniated disc material affecting the spinal canal. One patient underwent an additional discogram that confirms the pathophysiology of the limbus vertebra by demonstrating that contrast material injected into the nucleus pulposus tracks between the body and the detached fragment.