- Particularly common in the upper end of the femur.
- Usually occurs in elderly women
- Loss of blood supply to an epiphyses or other parts of a bone results in death of bone tissue (avascular necrosis)
- After every fracture, small areas of adjacent bone undergo necrosis.  In some fractures, avascular necrosis of a large fragment of bone may occur.
- In fractures of the hand, avascular necrosis of the proximal fragment of the scaphoid bone (pathological death of bone resulting from poor blood supply) may occur and produce degenerative joint disease of the wrist.
- In wrist fractures, like Colles Fracture, b/c of poor blood supply, avascular necrosis of the lunate bone may occur.
- In the case of avascular necrosis, usually the bone has to be taken out and replaced by metal.
- Avascular necrosis is increasing b/c of cigarette smoking.  Smokers are at increased risk of avascular necrosis.  The patient ends up having to have a hip replacement.