Computed tomography of posterior lumbar apophyseal ring fractures.

Lumbar apophyseal fracture is an uncommon injury that occurs during adolescence. We described two cases in young adults with back pain. The radiographic findings were distinctive. In both cases CT demonstrated characteristic bony fragments displaced posteriorly into the spinal canal and a corresponding defect in the posteroinferior aspect of the vertebral body rim. Recognition of this entity is important in evaluating back pain in both adolescents and adults.