Bilateral femoral head collapse in an adolescent with brachydactyly (multiple epiphyseal dysplasia tarda type 1c).

Children with femoral head radiographic changes suggestive of bilateral avascular necrosis require a careful differential diagnosis. Although the child may be found to have an epiphyseal dysplasia, the course may not be benign. At adolescence, in certain of the multiple epiphyseal dysplasia tarda forms, rapid destruction of the femoral head occurs with clinical and radiographic features indistinguishable from avascular necrosis. A possible interrelationship between epiphyseal dysplasia and avascular necrosis is considered.