Skip to content

Arthritis Health Center

Font Size
A
A
A

Avascular Necrosis (Osteonecrosis)

Avascular necrosis (AVN), also called osteonecrosis, aseptic necrosis, or ischemic bone necrosis, is a condition that occurs when there is loss of blood to the bone. Because bone is living tissue that requires blood, an interruption to the blood supply causes bone to die. If not stopped, this process eventually causes the bone to collapse.

Avascular necrosis most commonly occurs in the upper leg. Other common sites are the upper arm, knees, shoulder, and ankles.

Recommended Related to Arthritis

Understanding Plantar Fasciitis -- Diagnosis and Treatment

Most cases of plantar fasciitis are diagnosed by a health care provider based on your symptoms and a physical exam in which he or she will press on the bottom of your feet -- the area most likely to be painful in plantar fasciitis, inflammation of the thick, fibrous band of tissue (''fascia'') that reaches from the heel to the toes and supports the muscles and arch of the foot. He or she may suggest that you have an X-ray of your foot to verify that there is no stress fracture causing your pain.

Read the Understanding Plantar Fasciitis -- Diagnosis and Treatment article > >

Who Gets Avascular Necrosis and What Causes It?

As many as 20,000 people develop AVN each year. Most are between ages 20 and 50. For healthy people, the risk of AVN is small. Most cases are the result of an underlying health problem or injury. Possible causes include:

Dislocation or fracture of the thigh bone (femur). This type of injury can affect the blood supply to the bone, leading to trauma-related avascular necrosis. AVN may develop in 20% or more of people who dislocate a hip.

Chronic corticosteroid use. Long-term use of these inflammation-fighting drugs, either orally or intravenously, is associated with 35% of all cases of nontraumatic AVN. Although the reason for this is not completely understood, doctors suspect these drugs may interfere with the body's ability to break down fatty substances. These substances collect in the blood vessels -- making them narrower -- and reduce the amount of blood to the bone.

Excessive alcohol use. Much like corticosteroids, excessive alcohol may cause fatty substances to build in the blood vessels and decrease the blood supply to the bones.

Blood clots, inflammation, and damage to the arteries. All of these can block blood flow to the bones.

Other conditions associated with nontraumatic AVN include:

Symptoms of Avascular Necrosis

In its early stages, AVN typically cause no symptoms; however, as the disease progresses it becomes painful. At first, you may experience pain when you put pressure on the affected bone. Then, pain may become more constant. If the disease progresses and the bone and surrounding joint collapse, you may experience severe pain that interferes with your ability to use your joint. The time between the first symptoms and collapse of the bone may range from several months to more than a year.

Today on WebMD

Mature woman exercise at home
Hint: Warming up first is crucial.
feet with gout
Quiz yourself.
 
woman in pain
One idea? Eat fish to curb inflammation.
senior couple walking
Can you keep your RA from progressing?
 
xray of knees with osteoarthritis
Slideshow
close up of man wearing dress shoes
Slideshow
 
feet with gout
Quiz
close up of red shoe in shoebox
Slideshow
 
salad
Video
two male hands
ARTICLE
 
Woman massaging her neck
Quiz
5 Lupus Risk Factors
Article