My Orthopaedic Surgeon

Certain joints of the body have only a few blood vessels that bring in blood. One of these joints is the hip. This document will describe what happens when this blood supply is damaged and results in what is called avascular necrosis (AVN) of the hip.
This guide will help you understand
* how AVN develops
* how doctors diagnose the condition
* what treatments are available

Avascular Necrosis (Aseptic Necrosis) of the hip represents a condition where the hip has at least temporarily lost the critical blood supply to the ball part (femoral head) of the hip. This can cause a condition where the bone begins to collapse at this weakened site and then arthritis can begin.

Avascular necrosis (AVN), better known as osteonecrosis, of the femoral head, is "a disease that causes death of bone."

Avascular necrosis is death of bone tissue due to a lack of blood supply. This can lead to tiny breaks in the bone and the bone's eventual collapse. Avascular necrosis most often affects the head of the thighbone (femur), causing hip pain. But it may affect other bones as well.
Blood supply to the bone can be impaired for a number of reasons, including injuries. Avascular necrosis is also associated with long-term use of steroid medications and excessive alcohol intake. Your doctor might use other terms to describe avascular necrosis, such as osteonecrosis, aseptic necrosis or ischemic bone necrosis.

Avascular necrosis most commonly occurs in people between the ages of 30 and 60. It most commonly affects the thigh bone (femur) at the hip (the head of the femur). Often, both hips are affected. In people older than 50, avascular necrosis is usually caused by a hip fracture but may be caused by a disease that blocks the small blood vessels that supply to the ends of the long bones. For instance, emboli consisting of fatty material may block these blood vessels in people with alcohol-induced liver damage. The thigh bone at the knee is also commonly affected; the arm bone at the shoulder is sometimes affected.

The National Osteonecrosis Foundation is made up of a group of patients, physicians and others who want to see the end of this disease.