Osteonecrosis of the Hip
Osteonecrosis of the hip, also called avascular necrosis, is a condition where the blood supply to the femoral head is disrupted. Your femoral head is located at the top of your thigh bone (femur) and forms part of your hip joint.
The lack of normal blood supply to the femoral head causes the bone to die. The bone is then weakened, predisposing it to collapse and osteoarthritis.