Radiographic changes in the ossific nucleus in congenital dislocation of the hip.

Twenty one patients with a delayed diagnosis of congenital dislocation of the hip were studied to assess the relevance of radiographic changes in the ossific nucleus of the proximal femur during the first year following treatment. All abnormal hips demonstrated sclerosis of the margins of the ossific nucleus with irregularity of its surface at three months following surgery. In nineteen patients a head within a head was identified. These common changes are interpreted as the radiographic appearance of a spherical growth disturbance line formed by the ossific nucleus. It is concluded that these radiographic changes which are often accepted as indicators of avascularity are of no detrimental significance in the absence of physeal injury.