[The course and treatment of avascular necrosis of the femoral head in developmental dysplasia of the hip].

Proximal femoral growth disturbance, commonly referred to as avascular necrosis (AVN) of the femoral head in the literature, is a potentially devastating complication in the treatment of developmental dysplasia of the hip (DDH). The early onset of debilitating degenerative changes in the hip joint when treatment options are limited remains the biggest fear. Controversy exists regarding the pathophysiology of this disorder, as well as exactly defining and diagnosing this problem. The natural history of AVN in the setting of DDH is very variable. Current practice concentrates primarily on prevention of this disorder, as there are no reliable ways to intervene at an early stage when changes are potentially reversible. Newer techniques using magnetic resonance imaging may have a role in early diagnosis of this condition before irreversible damage has occurred, and allow for interventions that will favorably affect the natural history of AVN. Treatment options for established AVN in DDH concentrate on improving the biomechanics of the proximal femur but unfortunately do not obviate the need for arthrodesis or arthroplasty at a later date.