Avascular Necrosis

What is avascular necrosis?

Avascular necrosis is a disease that results from the short-term (temporary) or lifelong (permanent) loss of blood supply to the bone. When blood supply is cut off, the bone tissue dies and the bone collapses. If avascular necrosis happens near a joint, the joint surface may collapse.

This condition may happen in any bone. It most commonly happens in the ends of a long bone. It may affect one bone, several bones at one time, or different bones at different times.

What causes avascular necrosis?

Avascular necrosis may be the result of:

• Injury

• Broken bone (fracture)

• Harm to blood vessels

• Long-term use of medicines, such as corticosteroids

• Heavy, long-term use of alcohol

• Certain long-term (chronic) health conditions

Who is at risk for avascular necrosis?

You are more at risk if any of these apply to you:

• Injury

• Bone surgery

• Steroid use

• Alcohol use

• Blood disorders, such as sickle cell anemia

• Radiation treatments

• Chemotherapy

• Pancreatitis

• Diver's disease or "the bends" (decompression sickness)

• Blood clots easily

• High cholesterol

• Autoimmune disease

• HIV

What are the symptoms of avascular necrosis?

The following are the most common symptoms of avascular necrosis. But symptoms occur a bit differently in each person. Symptoms may include:

• Minor early joint pain

• Joint pain gets worse as bone and joint start to collapse

• Limited range of motion because of pain

The symptoms of avascular necrosis may look like other health conditions or bone problems. Always talk with your healthcare provider for a diagnosis.

How is avascular necrosis diagnosed?

Along with a complete medical history and physical exam, you may have one or more of the following tests:

• X-ray. This test uses energy beams to make images of internal tissues, bones, and organs onto film.

• CT scan. This is an imaging test that uses X-rays and a computer to make detailed images of the body. A CT scan shows details of the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

• MRI. This test uses large magnets, radio waves, and a computer to make detailed images of organs and structures in the body.

• Radionuclide bone scan.  This imaging test uses a very small amount of radioactive material. It is injected into the blood to be seen by a scanner. This test shows blood flow to the bone and cell activity in the bone.

• Biopsy. The healthcare provider removes tissue samples with a needle or during surgery. The samples are looked at under a microscope. It’s done to find cancer or other abnormal cells or to remove tissue from the affected bone.

• Functional assessment of bone. These tests often are done during surgery to measure the pressure inside the bone.

How is avascular necrosis treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

The goal of treatment is to improve your ability to use the joint and stop more damage to the bone or joint. Treatments are needed to keep joints from breaking down. They may include:

• Medicines. These are used to control pain.

• Assistive devices. These are used to reduce weight on the bone or joint.

• Core decompression. For this surgery, the inner layer of bone is removed to reduce pressure, increase blood flow, and slow or stop bone and joint destruction.

• Osteotomy. This procedure reshapes the bone and reduces stress on the affected area.

• Bone graft. In this procedure, healthy bone is transplanted from another part of the body into the affected area.

• Joint replacement. This surgery removes and replaces an arthritic or damaged joint with an artificial joint. This may be considered only after other treatments have failed to ease pain or disability.

Other treatments may include certain medicines and combination therapies to promote bone growth.

Key points about avascular necrosis

• Avascular necrosis is a disease that results from the temporary or permanent loss of blood supply to the bone. It happens most commonly in the ends of a long bone.

• Avascular necrosis may be the result of injury, use of medicines, or alcohol. Or it may occur after bone injury or bone surgery.  

• Symptoms may include joint pain and limited range of motion.

• Medicines, assistive devices, or surgery may be used to improve functionality or to stop more damage to the affected bone or joint.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.