Avascular necrosis (AVN) of the Hip is a painful condition where the blood supply to the hip bone (femoral head) causes the death of bone tissue, often leading to breaks and subsequent collapse of the bone. Frequently referred to as osteonecrosis, aseptic necrosis, or ischemic bone necrosis, AVN affects an estimated 10,000 to 20,000 new people each year in the United States. Avascular necrosis is progressive, and the timeline from diagnosis to collapse can range from several months to several years. Diagnosis is usually made by xray and MRI.
Unlike osteoarthritis, Avascular Necrosis of the Hip tends to affect a young population, from 30 to 50 years of age. Until very recently, the most common treatment of AVN of the femoral head has been total hip replacement, often a sub-optimal solution for patients under 50 years of age due to possible activity restrictions and the fact that a synthetic hip joint will wear out with time. Adult stem cell orthopaedic surgery offers young patients a viable, safe alternative to hip replacement surgery.
Causes of Avascular Necrosis of the Hip include:
- Corticosteroids. People who take high doses of corticosteroids, such as prednisone, for short periods of time, or lower doses for long periods of time, are candidates for avascular necrosis.
- Excessive alcohol intake. People who consume large amounts of alcohol on a daily basis may be more likely to experience avascular necrosis. The alcohol can cause fatty deposits to form in one’s blood vessels, restricting the flow of blood to the bones.
- Sickle cell anemia. People suffering from sickle cell anemia are susceptible to AVN, as red blood cell sickle cells become obstructed, preventing blood flow. Deprived of blood's important nutrients, including oxygen, tissues fail to survive and begin to break down (necrosis)
- Lupus. Avascular necrosis can be caused by lupus itself or by high doses of corticosteroids used to treat the disease.
- Cancer treatments, including chemotherapy and radiation.
- Trauma such as fracture or dislocated joint, to the bone. The trauma can damage the blood vessels that deliver blood to the bone, leaving the bone without a source of oxygen and nutrients. As a result, the bone cells die, weakening the bone.