Avascular necrosis is the death of bone tissue due to a lack of blood supply. Also called osteonecrosis, avascular necrosis can lead to tiny breaks in the bone and the bone's eventual collapse.
The blood flow to a section of bone can be interrupted if the bone is fractured or the joint becomes dislocated. Avascular necrosis of bone is also associated with long-term use of high-dose steroid medications and excessive alcohol intake.
The hip is the joint most commonly affected by avascular necrosis. While avascular necrosis of bone can happen to anyone, it usually occurs in men between the ages of 30 and 60.