What is avascular necrosis?
Avascular necrosis, or AVN, is a bone disorder that results from vascular injury. Issues arise when a bone that is nourished by microscopic blood vessels lacks cross circulation. When the area of bone supplied by the clogged vessel dies, the body responds by removing the dead bone and replacing it with new living bone. At this point, the perfect fit between the ball and socket of the hip is lost, leading to arthritis. The collapse itself can also be painful and often leads to the need for hip replacement.
Avascular necrosis of the femoral head (AVN) is associated with the use of certain drugs and with certain diseases. Alcoholism and prolonged use of steroid medications can lead to AVN. Sickle cell anemia also causes avascular necrosis and hip disease is a common morbidity associated with this blood disease.
What are some of the causes of avascular necrosis?
Rheumatologic diseases, most notably systemic lupus erythematous and the immune vascular diseases, are frequently associated with the development of AVN. HIV infection and AIDS is currently one of the most commonly associated diseases with this disorder.
Patients who have received organ transplants frequently develop AVN, which may be associated with the transplant itself as well as the required anti-rejection medications.
Dr. Charles N. Cornell is a Hip and Knee Surgeon and Clinical Director of Orthopedic Surgery at Hospital for Special Surgery. He practices at both the HSS Outpatient Center in Stamford and the hospital’s main campus in New York.