Many people have no symptoms in the early stages of avascular necrosis of bone. As the disease worsens, your affected joint may hurt only when you put weight on it. Eventually, the joint may hurt even when you're lying down.
Pain can be mild or severe and usually develops gradually. Joints most likely to be affected are the hip, shoulder, knee, hand and foot. Pain associated with avascular necrosis of the hip may be focused in the groin, thigh or buttock. Some people experience avascular necrosis bilaterally — for example, in both hips or in both knees.
When to see a doctor
See your doctor if you experience persistent pain in any joint. Seek immediate medical attention if you believe you have a broken bone or a dislocated joint.
Avascular necrosis occurs when blood flow to a bone is interrupted or reduced, which may be caused by:
- Joint or bone injury. A traumatic injury, such as a dislocated joint, may reduce the blood supply to a section of bone, leading to bone death. Cancer treatments involving radiation also can weaken bone and harm blood vessels.
- Pressure inside the bone. Some medical conditions, such as sickle cell anemia or Gaucher's disease, can increase the pressure inside the bone — making it more difficult for fresh blood to enter.
Your risk of developing avascular necrosis can be increased by certain diseases, medical treatments or excessive drinking.
Several alcoholic drinks a day for several years can cause fatty deposits to form in your blood vessels. This can restrict the flow of blood to your bones. The more alcohol you habitually drink every day, the higher your risk of avascular necrosis.
Certain types of medications can increase your risk of avascular necrosis. Examples include:
- Steroids. Taken at high doses and for long periods of time, corticosteroids, such as prednisone, increase your risk of avascular necrosis. Like alcohol, these drugs may increase the amount of fat in your blood, leading to blockage of the small vessels feeding your bones. Doctors often prescribe high doses of corticosteroids for diseases such as vasculitis or lupus.
- Osteoporosis drugs. People who take bisphosphonates — a type of medicine used to help strengthen bones weakened by osteoporosis — sometimes develop osteonecrosis of the jaw. This risk is higher for people who have received large doses of bisphosphonates intravenously to counteract the damage caused by cancer in the bones.
Some underlying medical conditions increase your risk of developing avascular necrosis. They include:
- Sickle cell anemia
Several types of medical procedures increase your risk of avascular necrosis. Examples include:
- Cancer treatments such as radiation
- Dialysis, a process to clean the blood after kidney failure
- Kidney and other organ transplants
Avascular necrosis that goes untreated will worsen with time. Eventually the bone may become weakened enough that it collapses. When the bone loses its smooth shape, severe arthritis can result.
It's hard to tell if reducing your risk factors will help prevent avascular necrosis, but the following tips can also help improve your general health:
- Limit alcohol. Heavy drinking is one of the top risk factors for developing avascular necrosis.
- Keep cholesterol levels low. Tiny bits of fat (lipids) are the most common substance blocking blood supply to bones.
- Monitor steroid use. Make sure your doctor knows about any past or present use of high-dose steroids. Steroid-related bone damage appears to worsen with repeated courses of high-dose steroids.