Avascular necrosis (AVN), also called osteonecrosis, is a condition in which bone death occurs because of inadequate blood supply. 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 lead to collapse. The hip joint is most commonly affected; however, the knee and shoulder may also be involved.
AVN symptoms often appear suddenly similar to those of an injury. In other situations, the pain and stiffness may gradually appear over a period of time. 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.
Treatment for avascular necrosis aims at preventing further loss of bone and depends on the bone damage that has occurred already. Conservative treatment aims to treat the symptoms of AVN and possible slow progression of the disease whereas surgical treatment may be required in more advanced stages.
- Medications: Non-steroidal anti-inflammatory drugs (NSAID’S) may be prescribed that help control your pain and swelling
- Rest: Restriction of physical activities and use of crutches to decrease weight bearing on your joints may be beneficial
- Exercises: Regular exercises that improve your range of motion may be done
- Electrical stimulation: Electric currents promote new bone growth. They can be applied directly to the area of damage or through electrodes fixed on skin. The effectiveness of electrical stimulation remains unproven
- Core decompression: During this procedure, a portion of the inner layer of the bone is removed to relieve the pressure inside the bone. This decreases the pain and allows growth of new blood vessels thereby stimulates new bone growth
- Bone transplant: A healthy bone from harvested from other part of your body is grafted into the affected area.
- Bone reshaping (osteotomy): This procedure is done in advanced stages and involves reshaping of the bone which is done to decrease the stress placed over the affected bone.
- Joint replacement: Joint replacement surgery is done as a last resort when the bone has collapsedneeding artificial replacement