Is the absence of the ossific nucleus prognostic for avascular necrosis after closed reduction of developmental dysplasia of the hip?

The presence of the ossific nucleus before reduction of developmental dysplasia of the hip may reduce the rate of avascular necrosis. Forty-eight hips in 45 children who underwent successful closed reduction had at least a 2-year follow-up. Medical records were reviewed for sex, side, Pavlik harness, traction, age at reduction, adductor tenotomy, cast duration, length of follow-up, and subsequent surgery. Prereduction radiographs were reviewed for presence or absence of the ossific nucleus. Avascular necrosis was noted as present if there was evidence of Bucholz and Ogden type II, III, or IV on the postreduction radiographs. Avascular necrosis was noted postreduction in 17 hips. Adductor tenotomy may reduce the rate of avascular necrosis following closed reduction. Delaying closed reduction until the presence of the ossific nucleus can be detected radiographically may reduce the rate of avascular necrosis. The presence of avascular necrosis increases the need for subsequent surgery.