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Avascular Necrosis

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To request an appointment or for additional information, please call 1-855-828-9795 or submit a form online.

What Is Avascular Necrosis (AVN)?

AVN happens when a bone loses its blood supply. Without blood bringing essential nutrients, the tissue in the bone dies. And in time, the bone collapses.

Although AVN (also called osteonecrosis of the hip) can occur in the knees and shoulders, it's most common in the hip. It affects the femoral head (thigh bone) in one or both hips.

As the disease worsens, pain increases and range of motion decreases.

Doctors in the U.S. treat more than 20,000 people for AVN every year.

The disease is most common between the ages of 40 and 65.

More men than women get AVN. 

AVN causes

Sometimes the cause of AVN is unknown. But doctors can often pinpoint the reason blood supply to a bone declines.

Reasons for reduced blood supply to a bone include:

  • Injury, such as a bone fracture or joint dislocation.
  • Blood clots, fatty deposits in blood vessels, or damage to arteries.
  • Radiation from cancer treatments, which can weaken bones and blood vessels.
  • Prolonged use of steroids, such as prednisone.
  • Excessive alcohol use.
  • Health problems (Crohn's disease, lupus, sickle cell disease, thrombosis) that diminish blood flow to bone. 

How to prevent AVN

The best way to prevent AVN is to lead a healthy, active lifestyle.

These changes can help keep your bones strong:

  • Cut back on alcohol.
  • Quit smoking.
  • Keep your weight in a healthy range.
  • Keep your cholesterol at a normal level.
  • Let your doctor know about long-term steroid use.
  • Maintain strength and flexibility with exercise.

Why choose UPMC Orthopaedic Care for AVN?

U.S. News and World Report ranks us as one of the best orthopaedic programs in the nation.

Here are just a few of the reasons why:

  • Experts in sports medicine. As experts in preventing and treating sports-related injuries, we know the problems athletes face. We know you want to stay active and keep playing the sport you love. We use the most advanced treatments and therapies to make that happen.
  • Interconnected services. We offer one place for all your orthopaedic needs. Our doctors, nurses, and physical therapists provide complete care — from diagnosis through recovery and rehab. We coordinate all of your care, so all you have to focus on is getting better.
  • Many ways to rehab. We have more than 70 locations throughout the region where you can go for outpatient rehab.
  • Unmatched in research. We are leaders in the western Pa. region for NIH-funded orthopaedic research and clinical trials. We're always seeking better ways to diagnose and treat conditions such as AVN.
  • Specialty programs. With specialists in each type of orthopaedic injury and condition, we have the experts to cater to your specific needs. The Hip Preservation Program at UPMC Orthopaedic care specializes in hip problems from the mild to the severe, including AVN.

Avascular Necrosis Symptoms and Diagnosis

In the early stages, you may not notice any symptoms of AVN.

As the disease gets worse, you may notice:

  • Groin pain that can wrap around to the back of the hip.
  • Stiffness in the hip joint.
  • Pain when walking or moving the hip.
  • A limp.
  • Inability to put weight on one leg.

If your hip pain is persistent or getting worse, you should see a doctor and find out if it's AVN.

Diagnosing AVN

There are 4 stages of AVN.

In Stage 1 of AVN, the hip is still healthy. By stage 4, the femoral head collapses and causes severe osteoarthritis.

The earlier doctors diagnose and treat AVN, the better the chances of a good recovery.

Your doctor will:

  • Ask about your medical history.
  • Perform an exam.
  • Have you move your hip in different ways to pinpoint your pain and range of motion.

To confirm the diagnosis, the doctor will order imaging tests.

Those may include:

  • X-rays
  • MRI scan
  • Bone scan
  • CT scan
  • Bone biopsy

Avascular Necrosis Treatment

The doctors at UPMC are experts at treating AVN. Their goal is to restore function to the affected joint so you can continue to lead an active life.

Treatment for AVN will depend on:

  • The stage of the disease.
  • Your age.
  • Overall health.

Lifestyle changes and medicine will not cure AVN. But they can relieve pain and delay the need for surgery. In the later stages of the disease, surgery is almost always necessary.

Non-medical treatments for AVN

In the early stages of AVN, lifestyle changes and physical treatments may slow the progression of the disease and allow some healing.

Some treatments that may help include:

  • Crutches, to limit the amount of weight you put on the joint.
  • Rest.
  • Physical therapy.
  • Electrical stimulation, which can help your body produce new bone.

Medical treatments for AVN

Certain medications can relieve pain and help manage the disease. Doctors may prescribe them along with lifestyle changes.

  • Anti-inflammatory drugs.
  • Blood thinners to prevent clots.
  • Cholesterol-lowering drugs, to keep fat from blocking the blood supply to the bones.

Surgery to treat AVN

Many people will eventually need surgery for AVN. The type of operation depends on the progression of the disease.

Your doctor will decide the method that's best for you.

Core decompression

Core decompression is a form of surgery that relieves pressure in the bone. It may be a good option if your AVN is in the early stages. It won't work if the bone has already collapsed.

During core decompression surgery, doctors drill a hole in the core of the affected bone. This reduces pressure and creates channels for new blood vessels. Blood circulation in the hip improves and the bones become healthier.

It takes about 3 months to fully heal.


This surgery reshapes the bone to reduce stress on the joint. Doctors use it when you have a small area of affected bone.

Recovery takes anywhere from 3 to 12 months.

Bone grafting

A bone graft is when your doctor takes healthy bone from you or a donor and inserts it into the diseased bone. This procedure, known as osteochondral (bone and cartilage) grafting, helps regenerate healthy bone and support cartilage at the hip joint.

Another type of bone grafting is the vascularized fibular graft.

Doctors take a piece of healthy bone from the small leg bone (fibula) along with the artery and vein. They transplant and attach it to the hip so that healthy bone can grow.

Recovery from bone grafting takes a few months.

Total hip replacement

If you have Stage 3 or 4 AVN (collapsed), your doctor will likely perform a hip replacement. This procedure replaces the damaged bone with artificial parts.

It takes about 8 weeks to heal after hip replacement surgery.