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Posterior lumbar vertebral rim fracture and associated disc protrusion in adolescence.

Two cases of posterior lumbar vertebral rim fracture and associated disc protrusion in adolescents are presented. Disc compliance and developing vertebral structure were thought to be primarily responsible for this unusual injury. Occurring primarily in adolescent males, this entity most commonly affects the L-4 vertebra. One of the cases involved disc rupture at three levels. This injury is thought to be due in part to union of the anuli by the posterior longitudinal ligament, and in part to rim fracture and limited prolapse rather than frank single-level herniation in an adolescent. A review of the embryology, literature, and theoretical mechanism for occurrence at multiple levels is included.