Avascular Necrosis (AVN or Osteonecrosis)

Avascular necrosis, also known as AVN or osteonecrosis, is a disease that may happen if something blocks the flow of blood to bone tissue near your joints. Your bone tissue dies when it doesn’t receive enough blood. Without treatment, this condition can get worse so that dead bone eventually breaks down or crumbles. Osteonecrosis near or in your joints may cause them to collapse. The disease may affect any bone in your body. But it most often affects:

• The upper and lower parts or ends of your thighbone (the upper part includes your hip, and the lower part includes your knee)
• The ends of your upper arm bone and your shoulder

Avascular necrosis can worsen over time. Early diagnosis and treatment may keep the disease from causing more damage to your bones.

Symptoms of avascular necrosis

AVN symptoms develop over weeks or months. Symptoms that may appear over time include:

• Pain when you put weight or pressure on your bone
• Pain when you try to bend or straighten your arms or legs
• Stiff joints and joint pain
• Limping if AVN affects your knees or hip
• Difficulty climbing stairs, standing or walking

Osteonecrosis causes

Bone fractures, certain diseases and lifestyle activities that affect your blood flow may cause AVN. Your skeletal system needs a steady flow of blood to make healthy bone tissue to replace dying bone tissue. Without blood flow, your skeletal system can’t produce new bone tissue fast enough. The dying bone starts to crumble and collapse.

Healthcare providers may classify AVN as traumatic or nontraumatic avascular necrosis. Traumatic AVN happens when you break a bone or dislocate a joint. Hip fractures or dislocations are a common cause.

Nontraumatic AVN may happen if you have a medical condition or treatment that keeps blood from flowing to your bone tissue. Nontraumatic avascular necrosis often affects the same bones on both sides of your body. That means osteonecrosis in your right shoulder may affect your left shoulder. Medical conditions or treatment that may lead to AVN include:

• Blood disorders like sickle cell anemia
• Decompression sickness
• HIV
• Lupus
• Cancer treatments like radiation therapy
• Organ transplantation medication, like corticosteroids that keep your body from rejecting a transplanted organ

You may develop this condition if you smoke, drink a lot of alcohol, or use prednisone or other corticosteroids for a long time.

How doctors diagnose avascular necrosis

A healthcare provider will ask about your symptoms and your medical history, including specific medical treatments that may lead to AVN. They may do an MRI to look for osteonecrosis signs.

How is this condition treated?

A healthcare provider will recommend treatment based on your bone damage, including:

• Cold packs
• Heat treatment
• Rest
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Physical therapy
• Walking aids like canes and crutches

Surgery for osteonecrosis may be:

• Bone grafting: This is surgery to remove dead bone tissue and replace it with healthy bone tissue. The bone tissue may come from another bone in your body or from a donor.
• Core decompression: Your surgeon drills small holes (cores) in your affected bone to improve blood flow to the affected bone. This procedure might be combined with injections or bone grafts to promote healing.
• Joint replacement: This is surgery to replace your damaged joint with an artificial one.

What can I expect if I have AVN?

Avascular necrosis can affect your quality of life. But it isn’t life-threatening and won’t affect how long you’ll live. People who have avascular necrosis can also develop severe osteoarthritis. If that’s your situation, you may need surgery, including joint replacement.

When should I seek care?

You should contact a healthcare provider if you:

• Have pain when you walk or move around that doesn’t go away or get better when you rest or take pain relievers
• Limp for no known reason