Avascular Necrosis, Osteoarthritis and Synovitis

Avascular osteonecrosis mostly concerns young adults in full activity. Besides traumas, most of the aetiologies are corticosteroid therapy, drepanocytose and alcoholism. After avascular necrosis, the cancellous bone rebuilt itself rather promptly unlike the subchondral bone. The subchondral bone disappears faster than it is reformed. It becomes a sensitive junction between the subchondral bone and the cancellous bone, with less resistance and a weak point that can promote subchondral fractures. If MRI allows establishing a complete statement of the necrosis, CT scan can be more precise in detecting subchondral fracture and minimal femoral head deformities [26].