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.
The symptoms appear suddenly if it is the 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 affected joint. Your doctor will diagnose the condition using imaging tests such as X-rays, MRI scan and occasionally, a bone scan to help rule out other causes of joint pain.
The treatment for avascular necrosis aims to prevent further loss of bone and cartilage and it depends on the stage of the initial presentation. Conservative treatment would reverse early stages of avascular necrosis, whereas surgical treatment may be required in more advanced stages. Conservative treatment includes rest, anti-inflammatory medical, physical therapy, and electrical stimulation, which may promote new bone growth. Surgical treatment for avascular necrosis depends on the severity of degeneration, and may include:
- Core decompression: During this procedure, the region is drilled through a minimally invasive procedure to relieve the pressure inside the bone. This decreases the pain and allows growth of new blood vessels, thereby stimulating new bone growth.
- Bone transplant: Bone graft obtained from the patient or a bone cartilage transplant can be used to replace damaged tissue.
- 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 performed as a last resort when the bone has collapsed,needing artificial replacement