Bone requires a constant blood supply to remain healthy; without it, bone begins to die and collapse. This is called avascular necrosis, literally bone death due to lack of blood vessels. In the hip, the head of the femur (the acetabulum, or “ball”) is primarily affected. If not treated, the joint surface breaks down, leading to arthritis, pain and disability.
The most common reason why the femoral blood supply is compromised is a hip fracture that tears the vessels supplying blood to the head of the femur. Another cause is taking steroid medications, such as prednisone and other immunosuppressant drugs. AVN is often seen in patients with chronic asthma, rheumatoid arthritis, lupus and organ transplants.
Avascular necrosis can be diagnosed with x-rays, bone scans and other imaging methods. To prevent further bone destruction and ensure the survival of the affected hip joint, there are a variety of treatment options. Less invasive ones include reduced weight-bearing, medications and electrical stimulation to increase the growth of new bone and blood vessels.Several surgical procedures are also available.Core decompression, best used in patients with early-stage disease, removes the inner layer of bone, reducing pressure and increasing blood flow.An osteotomy can be done to reshape the bone, alleviating stress on the affected area. (This comes with a very long recovery period, however.)Bone grafts can help support the bone after core decompression by transplanting some of the patient’s healthy bone into the diseased area.When the architecture of the hip joint is completely destroyed due to avascular necrosis, total joint replacement is the treatment of choice.