Avascular Necrosis (Osteonecrosis)

What is Avascular Necrosis (Osteonecrosis)?

Avascular necrosis is the death of bone tissue due to a shortage of blood supply. Also known as osteonecrosis, it could lead to small cracks in the bone and the bone's eventual collapse.

A broken bone or dislocated joint could interrupt the blood flow to a part of bone. Avascular necrosis or osteonecrosis is also related with prolonged use of high-dose steroid medicines and excessive alcohol consumption.

Anyone could be affected, but the condition is most common in people between the ages of 30 and 50.

Avascular Necrosis Symptoms

Many people have no symptoms in the primitive stages of avascular necrosis. As the disease worsens, your damaged joint may hurt only when you put weight on it. Finally, you may feel the pain even when you are lying down.

Pain could be mild or serious and generally develops slowly. Pain related with avascular necrosis of the hip might center on the groin, thigh or buttock. Besides the hip, the regions likely to be affected are the shoulder, knee, hand and foot.

Some people develop avascular necrosis on both sides or bilaterally for instance in both hips or in both knees.

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When should you see a doctor?

See your doctor or primary care physician if you have continuous pain in any joint. Look for immediate medical attention if you believe you have a broken bone or a dislocated joint.

Avascular Necrosis Causes

Avascular necrosis happens when blood flow to a bone is interrupted or lowered. Lowered blood supply could be caused by:

  • Joint or bone trauma - An injury, like a dislocated joint, may damage nearby blood vessels. Cancer treatments involving radiation also could weaken bone and harm blood vessels.

  • Fatty deposits in blood vessels - The fat (lipids) could block small blood vessels, lowering the blood flow which feeds bones.

  • Specific conditions - Medical diseases, like sickle cell anemia and Gaucher's disease, also could cause decreased blood flow to bone.

For about 25% of people with avascular necrosis, the cause of disrupted blood flow is undisclosed.

Risk factors

Risk factors for developing avascular necrosis involve:

  • Trauma - Injuries, like hip dislocation or fracture, could affect nearby blood vessels and lower blood flow to bones.

  • Steroid use - Use of high-dose corticosteroids, like prednisone, is a common cause of avascular necrosis. The reason is undisclosed, but one hypothesis is that corticosteroids could increase lipid levels in your blood, lowering blood flow.

  • Excessive alcohol use - Consuming numerous alcoholic drinks a day for many years also could cause fatty deposits to form in your blood vessels.

  • Bisphosphonate use - Prolonged use of medications to increase bone density may contribute to developing osteonecrosis of the jaw. This rare problem has happened in some people treated with high doses of these medications for cancers, like multiple myeloma and metastatic breast cancer.

  • Specific medical treatments - Radiation therapy for cancer could weaken bone. Organ transplantation, particularly kidney transplant, also is related with avascular necrosis.

Medical conditions related with avascular necrosis include:

  • Pancreatitis

  • Diabetes

  • Gaucher's disease

  • HIV/AIDS

  • Systemic lupus erythematosus

  • Sickle cell anemia

Avascular Necrosis Complications

Untreated, avascular necrosis is more severe with time. Eventually, the bone could collapse. Avascular necrosis also causes bone to lose its smooth shape, posibbly leading to serious arthritis.

Avascular Necrosis Prevention

To lower your risk of avascular necrosis and improve your general health:

  • Limit alcohol – Excess alcohol consumption is one of the top risk factors for developing avascular necrosis.

  • Keep cholesterol levels low - Small bits of fat are the most common substance preventing blood supply to bones.

  • Monitor steroid use - Make sure your primary care physician knows about your past or present use of high-dose steroids. Steroid associated bone damage appears to worsen with repeated courses of high-dose steroids.

  • Quit Smoking – Quit smoking as it puts you at a higher risk.

Avascular Necrosis Diagnosis

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During a physical examination your primary care physician will likely press around your joints, checking for tenderness. Your primary care physician may also move the joints through a variety of positions to see if your extent of motion has been lowered.

Imaging tests

Many disorders could cause joint pain. Imaging tests could help pinpoint the source of pain. Options include:

  • X-rays - They could reveal bone changes which happen in the later stages of avascular necrosis. In the condition's primitive stages, X-rays generally appear normal.

  • Magnetic resonance imaging (MRI) & Computed tomography (CT) scan - These tests produce detailed pictures which could show early changes in bone which may indicate avascular necrosis.

  • Bone scan - A small amount of radioactive material is administered into your vein. This tracer travels to the portions of your bones which are injured or recovering and shows up as bright spots on the imaging plate.

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Avascular Necrosis Treatment

The goal is to stop further bone loss.

Medications and therapy

In the primitive stages of avascular necrosis, symptoms may be relieved with medication and therapy. Your primary care physician might suggest:

  • Non-steroidal anti-inflammatory drugs - Medicines, for example ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) may help ease the pain related with avascular necrosis.

  • Osteoporosis drugs - Medicines, like alendronate (Fosamax, Binosto), may slow the progression of avascular necrosis, but the evidence is mixed.

  • Cholesterol lowering drugs - Lowering the quantity of cholesterol and fat in your blood may help stop the vessel blockages which could cause avascular necrosis.

  • Blood thinners - If you have a clotting disorder, blood thinners, like warfarin (Coumadin, Jantoven), may be suggested to stop clots in the vessels feeding your bones.

  • Rest - Lowering the weight and stress on your affected bone could slow the damage. You may require to restrict your physical activity or use crutches to keep weight off your joint for many months.

  • Exercises - A physical therapist could teach you exercises to help maintain or improve the extent of motion in your joint.

  • Electrical stimulation - Electrical currents might encourage your body to grow new bone to replace the affected bone. Electrical stimulation could be used during surgery and applied directly to the affected region. Or it could be administered through electrodes attached to your skin.

Surgical and other procedures

Because most people do not develop symptoms until avascular necrosis is fairly advanced, your primary care physician may suggest surgery. The options include:

  • Core decompression - The surgeon removes a portion of the inner layer of your bone. In addition to lowering your pain, the extra space within your bone stimulates the generation of healthy bone tissue and new blood vessels.

  • Bone transplant or graft - This procedure could help strengthen the region of bone affected by avascular necrosis. The graft is a portion of healthy bone taken from another part of your body.

  • Bone reshaping or osteotomy - A portion of bone is removed above or below a weight or load bearing joint, to help shift your weight off the affected bone. Bone reshaping may allow you to delay joint replacement.

  • Joint replacement - If your afflicted bone has collapsed or other treatments are not helping, you may require surgery to replace the affected parts of your joint with plastic or metal parts.

  • Regenerative medicine treatment - Bone marrow aspirate and concentration is a newer procedure which might be appropriate for primitive stage avascular necrosis of the hip. Stem cells are harvested or collected from your bone marrow. During surgery, a core of dead hip bone is removed and stem cells inserted in its place, possibly allowing for growth of new bone. More study is required.

If you or anyone you know is suffering from avascular necrosis or osteonecrosis, our expert providers at now find relief will take care of your health and help you recover.


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