Avascular necrosis (also called osteonecrosis, aseptic necrosis, or
ischemic bone necrosis) is a disease that results from the temporary
or permanent loss of blood supply to the bone. When blood supply is
cut off, the bone tissue dies and the bone collapses. If avascular
necrosis occurs near a joint, collapse of the joint surface may occur.
Avascular necrosis may occur in any bone, but most commonly occurs
in the ends of a long bone. It may affect one bone, several bones at
one time, or different bones at different times.