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Avascular necrosis typically causes pain and reduced range of motion in the affected joint. The most common joints affected by avascular necrosis include:

• Hip. In addition to pain in the hip joint itself, pain also may radiate into your groin or go down your thigh to your knee.
• Knee. In avascular necrosis of the knee, the pain occurs most often on the inside of the knee and worsens with activity.
• Shoulder. Several bones come together at the shoulder, but the one most commonly affected by avascular necrosis is the upper arm bone.

Some people experience avascular necrosis bilaterally — for example, in both hips or in both knees. Signs and symptoms may appear suddenly if caused by an injury. In other cases, the pain and stiffness may build up slowly over several months. Some people with avascular necrosis experience no symptoms at all.

Other joints that are affected by avascular necrosis include:

• Ankles
• Feet
• Hands
• Jaw
• Spine
• Wrists

When to see a doctor
See your doctor if you experience persistent pain in any joint. Seek immediate medical attention if you believe you have a broken bone or a dislocated joint.

©1998-2012 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
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Avascular necrosis occurs when blood flow to a bone is interrupted or reduced, which may be caused by:

• Joint injury. Impacts that result in a broken bone or a dislocated joint may also damage or destroy nearby blood vessels. Without a steady supply of oxygen and nutrients, bone cells die.
• Narrowed blood vessels. The blood flow to a bone can be decreased if the passage through a vessel becomes narrowed or clogged, most commonly by a tiny bit of fat or — in the case of sickle cell anemia — by clumps of deformed blood cells.
• Pressure inside the bone. Some medical treatments or conditions, such as Legg-Calve-Perthes disease or Gaucher's disease, can increase the pressure inside the bone — making it more difficult for fresh blood to enter.

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The two most common risk factors of avascular necrosis are:

• Corticosteroids. People who take high doses of corticosteroids, such as prednisone, for long periods of time — for instance, people with chronic illnesses such as rheumatoid arthritis and lupus — are more likely to experience avascular necrosis.
• Heavy drinking. Several alcoholic drinks a day for several years can cause fatty deposits to form in your blood vessels. This can restrict the flow of blood to your bones. The more alcoholic drinks you consume on a daily basis, the higher your risk of avascular necrosis.

Osteoporosis drugs may harm jaw
People who take bisphosphonates — a type of medicine used to help strengthen bones weakened by osteoporosis — sometimes develop osteonecrosis of the jaw. This risk is higher for people who have received high doses of bisphosphonates intravenously to counteract the damage caused by cancer in the bones.

Procedures can increase risk
Several types of medical procedures can weaken bones, making it easier for you to develop avascular necrosis. Examples include:

• Cancer treatments such as chemotherapy or radiation
• Dialysis, a process to clean the blood after kidney failure
• Kidney and other organ transplants

Conditions linked to bone death
Many underlying medical conditions increase your risk of developing avascular necrosis. They include:

• Diabetes
• Gaucher's disease
• HIV
• Kienbock's disease
• Legg-Calve-Perthes disease
• Lupus
• Sickle cell anemia

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Avascular necrosis that goes untreated will continue causing deterioration of the bone. Eventually the bone may become weakened enough that it collapses, causing pain and disability. Letting your avascular necrosis go untreated could lead to severe pain and loss of movement within two to five years.

©1998-2012 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Read this article on Mayoclinic.com.

Although you may initially bring your signs and symptoms to the attention of your family doctor, he or she may refer you to a rheumatologist — a doctor who specializes in disorders of the joints — or to an orthopedic surgeon.

What you can do
Before your appointment, you may want to prepare a list that answers the following questions:

• Where exactly does it hurt?
• Does any particular joint position make the pain better or worse?
• How long have you had this pain?
• Have you ever injured this joint in the past?
• What other medical conditions, if any, do you have?
• Are there health problems that tend to run in your family?
• What types of medications and supplements do you take?

What to expect from your doctor
During the exam, your doctor will press around your joint, checking for tenderness. He or she may also move your joints through a variety of positions to see if your range of motion has been reduced.

©1998-2012 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
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Many disorders can cause joint pain. Imaging tests can help pinpoint the proper diagnosis.

• X-rays. In the early stages of avascular necrosis, X-rays usually appear normal. But X-rays can often reveal bone changes that occur in later stages of the disease.
• Magnetic resonance imaging (MRI). MRI scans can show early changes in the bone that may indicate avascular necrosis. MRI uses radio waves and a strong magnetic field to produce detailed images of internal structures.
• Bone scan. For a bone scan, a small amount of radioactive material is injected into your vein. This material then travels to the parts of your bones that are injured or healing, and shows up as bright spots on the imaging plate.

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The treatment goal for avascular necrosis is to prevent further bone loss. What treatment you receive depends on the amount of bone damage you already have. Early stages of avascular necrosis may benefit from more conservative treatment, while later stages may require surgery.

Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs, such as aspirin or ibuprofen (Advil, Motrin, others), may help relieve the pain and inflammation associated with avascular necrosis.
• Bisphosphonates. Some studies indicate that osteoporosis medications, such as alendronate (Fosamax), may slow the progression of avascular necrosis.

Therapy

• Rest. Reducing the amount of weight and stress on your affected bone may slow the damage of avascular necrosis. You may need to restrict the amount of physical activity you engage in. In the case of hip or knee avascular necrosis, you may need to use crutches to keep weight off your joint for several months.
• Exercises. Certain exercises may help you maintain or improve the range of motion in your joint. A physical therapist can choose exercises specifically for your condition and teach you how to do them.
• Electrical stimulation. Electrical currents may encourage your body to grow new bone to replace the area damaged by avascular necrosis. Electrical stimulation can be used during surgery and applied directly to the damaged area. Or it can be administered through electrodes attached to your skin.

Surgical and other procedures

• Core decompression. In this operation, your surgeon removes part of the inner layer of your bone. This can relieve pressure within your bone, reducing your pain. The extra space allows your bone to form new blood vessels and stimulates the production of new bone.
• Bone transplant (graft). During this procedure, your surgeon takes healthy bone from another part of your body and implants it into the area affected by avascular necrosis. Sometimes this is done in conjunction with core decompression.
• Bone reshaping (osteotomy). This procedure reshapes the bone to reduce the amount of stress placed on the area affected by avascular necrosis. Osteotomy is usually used in people with advanced avascular necrosis. Recovery may take up to a year.
• Joint replacement. If your diseased bone has already collapsed or other treatment options aren't helping, you may need joint replacement surgery. Joint replacement surgery replaces your joint with an artificial one. It requires months of recovery, including time spent learning to use your new joint.

©1998-2012 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Read this article on Mayoclinic.com.