OSTEONECROSIS OF THE HIP
Osteonecrosis, also referred to as avascular necrosis, atraumatic necrosis, ischemic necrosis, or aseptic necrosis, is a musculoskeletal condition in which death of bone occurs. It most often affects weight-bearing joints with poor access to blood flow. Consequently, the most common areas of occurrence are the hip followed by the knee, shoulder, and ankle. In 1925, Haenisch first described a case of osteonecrosis in an adult patient who suffered ischemic necrosis of the femoral head. 1 Since then, the knowledge regarding hip osteonecrosis has substantially improved. The disease prevalence is 10,000 to 20,000 new cases per year. Hip osteonecrosis can affect patients of any age. However, patients living in their third decade are especially prone to the disease. 2 If untreated, approximately 80% of affected hips will progress and eventually develop painful osteoarthritis and require surgical intervention. 2 This includes 59% to 66% of asymptomatic hips. 3, 4 There is a wide spectrum of treatment options ranging from nonoperative pharmacotherapies to surgeries, which remove the necrotic bones, to replacing the joints. The optimal treatment, of course, depends on the stage of the disease and the age of the patient. However, most of the patients are eventually referred to orthopedic surgeons. In the United States, up to 10% of hip replacements performed involve osteonecrosis.
