Avascular necrosis occurs when blood flow to a bone is interrupted or reduced, which may be caused by:

  • Joint or bone injury. A traumatic injury, such as a dislocated joint, may reduce the blood supply to a section of bone, leading to bone death. Cancer treatments involving radiation also can weaken bone and harm blood vessels.
  • Pressure inside the bone. Some medical conditions, such as sickle cell anemia or Gaucher's disease, can increase the pressure inside the bone — making it more difficult for fresh blood to enter.
May. 04, 2012