Causes

Osteonecrosis occurs when part of the bone does not get blood and dies. After a while the bone can collapse. If this condition is not treated, the joint will deteriorate and this will become severe arthritis.

Osteonecrosis can be caused by disease, or a severe trauma, such as a break or dislocation, that affects the blood supply to the bone. Many times, no trauma or disease is present. This is called "idiopathic osteonecrosis" -- meaning it occurs without any known cause.

The following can cause osteonecrosis:

• Long-term treatments with steroids
• Excessive alcohol use
• Sickle cell disease
• Radiation therapy
• Gaucher disease
• Decompression sickness from a lot of deep sea diving
• Dislocation or fractures around a joint

Some diseases that may be associated with the development of this condition include:

• Gout
• Atherosclerosis
• Diabetes

When osteonecrosis occurs in the shoulder joint, it is usually due to long-term treatment with steroids or a history of trauma to the shoulder.

Legg-Calvé-Perthes disease is a similar condition seen in children and adolescents.

Symptoms

There are no symptoms in the early stages. As bone damage worsens, you may have the following symptoms:

• Pain in the joint that may increase over time, and will become very severe if the bone collapses
• Pain that occurs even at rest
• Limited range of motion
• Groin pain, if the hip joint is affected
• Limping, if the condition occurs in or below the hips

Exams and Tests

Your health care provider will do a complete physical exam to find out if you have any diseases or conditions that may affect your bones. You will be asked questions about your symptoms and medical history. The questions might include:

• When did the pain start?
• Does the pain spread (radiate) anywhere?
• Is the pain constant, or does it get better at night or at rest?
• Have you noticed any difference in how much or how far you can move (your mobility)?
• Do pain relievers help?
• Are you taking any steroids now, or have you ever taken them?
• Do you drink alcohol? If so, how much?

Be sure to let your health care provider know about any medications or vitamin supplements you are taking, even over-the-counter medicine.

After the exam, your health care provider will order one or more of the following tests:

• X-ray
• MRI
• Bone scan
• CT scan

Treatment

If your health care provider knows the reason for osteonecrosis, part of the treatment will be aimed at the underlying condition. For example, if a blood clotting disorder is the reason, treatment will consist, in part, of clot-dissolving medicine.

If the condition is caught very early, you will take pain relievers and limit use of the affected area. This may include using crutches if your hip, knee, or ankle is affected. You may need to do range-of-motion exercises. Nonsurgical treatment can often slow the progression of osteonecrosis, but most people will need surgery.

Surgical options include:

• A bone graft
• A bone graft along with its blood supply (vascularized bone graft)
• Cutting the bone and changing its alignment to relieve stress on the bone or joint (osteotomy)
• Total joint replacement
• Removing part of the inside of the bone (core decompression) to relieve pressure and allow new blood vessels to form

Support Groups

You can find more information and support resources at the following organizations:

• National Osteonecrosis Foundation -- www.nonf.org
• ON/AVN Support Group Int’l Association --http://osteonecrosisavnsupport.org
• The Arthritis Foundation -- www.arthritis.org
• Center for Osteonecrosis Research and Education (CORE) -- http://www.osteonecrosis.org

Outlook (Prognosis)

How well you do depends on the following:

• The cause of the osteonecrosis
• Stage of the disease when it was diagnosed
• Amount of bone involved
• Your age and overall health

The outcome can vary from complete healing to permanent damage in the affected bone.

Possible Complications

Advanced osteonecrosis can lead to osteoarthritis and permanent decreased mobility. Severe cases may require joint replacement.

When to Contact a Medical Professional

Prevention

Many cases of osteonecrosis do not have a known cause, so prevention may not be possible. However, in some cases, you can reduce your risk by doing the following:

• Avoid drinking excessive amounts of alcohol.
• When possible, avoid high doses and long-term use of corticosteroids.
• Dive safely to avoid decompression sickness.

Alternative Names

Avascular necrosis; Osteonecrosis; Ischemic bone necrosis; AVN; Aseptic necrosis

References

Chang C, Greenspan A, Gershwin ME. Osteonecrosis. In: Firestein GS, Budd RC, Harris ED Jr, et al, eds. Kelley's Textbook of Rheumatology. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 94.

Shah A, Busconi B. Hip, pelvis, and thigh: Hip and pelvis. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009:chap 21, section A.

Williams MD, Edwards TB, Shoulder: Glenohumeral Arthritis in the Athlete. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009:chap 17, section L.

Update Date: 4/4/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.