Avascular necrosis
（重定向自Osteonecrosis）
Avascular necrosis (AVN), also called osteonecrosis, bone infarction, aseptic necrosis, and ischemic bone necrosis, is cellular death (necrosis) of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses. If avascular necrosis involves the bones of a joint, it often leads to destruction of the joint articular surfaces. (see Osteochondritis dissecans).