This is a weakening and collapse of the bone in the head of your femur. That's the ball that fits in the socket of your hip. As this bone gradually dies and breaks apart, you can develop painful arthritis in your hip.
Avascular necrosis is caused by a problem with blood circulation. It happens when your bone doesn't get the blood supply it needs. Bone is a living tissue that contains its own blood vessels. Blood allows the cells of your bones to grow and make repairs. If blood circulation is cut off, the bone cells die. Blood flow can be cut off to the head of your femur if you dislocate or break your hip. Blood flow is also affected by alcoholism, medications, and by certain medical conditions that involve your circulatory system.
At first, you may not have any symptoms. But eventually you may begin to feel pain in your hip or buttocks. You may notice it during physical activity. This pain gradually gets worse. Eventually it may hurt to stand or to put weight on your hip, or even when you lie down.
In its early stages, medications, rest and physical therapy may help your symptoms and slow the progression. But as it gets worse, you may need a surgical procedure. Your healthcare provider can create a plan that's right for you.