Avascular necrosis of the femoral head may lead to surgery to replace this joint
The femoral head (the ball part of the hip) is the most frequent bone 
involved... [DOC] [TLE] Core Decompression for Avascular Necrosis - Aetna [PAR] With secondary collapse of the femoral head, disabling hip pain may result in the 
need for .... total hip replacement after decompression and cancellous bone 
grafting.