What is avascular necrosis?
Avascular necrosis is bone death that occurs
when the blood supply to the bones is decreased or
stopped. Without an adequate blood supply, the bone breaks down and dies
and collapses. If the bone affected is near a joint, the joint may
also collapse. Although any bone can be affected, avascular necrosis most often
affects ends of the long bones, such as the upper leg bone at the
hip.
Avascular necrosis is also called osteonecrosis, aseptic
necrosis, or ischemic bone necrosis.
What causes avascular necrosis?
An injury, such as a forceful impact
in an auto accident, or a complication of a hip fracture or dislocation can lead to avascular necrosis.
Diseases such as sickle cell anemia, gout, and lupus also may
lead to avascular necrosis.
Long-term use of alcohol or oral or intravenous
corticosteroids increases the risk of
avascular necrosis.
What are the symptoms?
Symptoms include mild to moderate hip or groin pain, decreased hip
movement, and a limp. Pain may be sudden and become worse with standing or
walking. Rest usually relieves the pain. Avascular necrosis occurs most often
in men between 40 and 50 years old.
Children with avascular necrosis may have spasms in the hip muscle, have a limp, or refuse to bear weight.
Legg-Calve-Perthes disease is a type of avascular
necrosis in children that causes hip symptoms.
How is it treated?
Doctors usually start with treatments to limit further
damage to the bone and joint and to help the bone to grow. These may include
medicines, exercises, limiting weight bearing on the joint, and electrical
stimulation. Anti-inflammatory drugs (NSAIDs) may be
prescribed to reduce pain. Eventually, most people with avascular necrosis need
surgery.