see avascular necrosis.

The process of bone cells dying in mass. Dysbaric — Changes in structure of bone in which the relative density of the affected bone is increased by sclerosis (hardening). Observed changes are the result of a healing process following insult (trauma). Found in caisson workers and more recently in divers, and probably due to inadequate decompression. Synonymous with aseptic bone necrosis and avascular bone necrosis. Juxta-articular — Osteonecrosis occurring near the joint articulation, usually hip or shoulder. May lead to collapse of the joint, together with pain and dysfunction. Medullary — Osteonecrosis occurring in the shaft of the bone, usually symptomless and detected by x-ray.

necrosis of bone tissue due to impaired or disrupted blood supply (as that caused by traumatic injury or disease) and marked by severe pain in the affected region and by weakened bone that may flatten and collapse. Also called avascular necrosis.

Dead bone substance, i.e. no longer containing living osteoblasts or other cells