Definition for avascular necrosis of bone

Avascular necrosis is a disease resulting from the temporary or permanent loss of the blood supply to the bones. more

Avascular necrosis is a disease resulting from the temporary or permanent loss of the blood supply to the bones. Without blood, the bone tissue dies and causes the bone to collapse. If the process involves the bones near a joint, it often leads to collapse of the joint surface. This disease also is known as osteonecrosis, aseptic (bone) necrosis, and ischemic bone necrosis. While it can, by definition, affect any bone, and half of cases show multiple sites of damage, this disease primarily affects the joints at the shoulder, knee, and hip. There are many causes of avascular necrosis such as alcoholism, excessive steroid use, post trauma, Caisson disease (decompression sickness), vascular compression, hypertension, vasculitis, thrombosis, damage from radiation and (very rarely) sickle cell anaemia. In some cases it is idiopathic (no cause is found). less