Avascular necrosis, also called osteonecrosis is a condition in which bone death occurs because of inadequate blood supply to it. Lack of blood flow may occur when there is a fracture in the bone or a joint dislocation that may damage nearby blood vessels. Chronic use of high doses of steroid medications and heavy alcohol consumption are the two main risk factors of avascular necrosis. Initially, small breaks appear in the bone that may eventually collapse. Hip joint is most commonly affected; however, the knee and shoulder may also be involved.
The symptoms appear suddenly if it's a result of an injury. In other situations, the pain and stiffness may gradually appear over a period. Typically, avascular necrosis causes pain and restricted range of motion in the joint affected. Your doctor will diagnose the condition using imaging tests such as X-rays, MRI scan and bone scan that help rule out other causes of joint pain.
The treatment for avascular necrosis aims at preventing further loss of bone and it depends on the bone damage that has occurred already. Conservative treatment would reverse early stages of avascular necrosis whereas surgical treatment may be required in more advanced stages.