Triradiate cartilage injury. Report of two cases and review of the literature.

Acetabular fractures in children are not uncommon, but traumatic disruption of the acetabular triradiate cartilage occurs infrequently and may be associated with acetabular dysplasia and subluxation of the hip. The triradiate cartilage is at risk from birth to closure. The earlier the age at the time of injury, the greater the chance of acetabular dysplasia. In two cases of triradiate cartilage injury, one had premature closure of the triradiate cartilage with subsequent acetabular dysplasia requiring acetabular reconstruction. A review of the literature reveals ten other cases of acetabular dysplasia after injury to the triradiate cartilage. A review of all 11 cases reveals age to be the most significant factor in the development of acetabular dysplasia, with the greatest degree of growth disturbance occurring in young patients.