A joint disorder caused by blood deprivation in the subchondral bone causing the subchondral bone to die in a process called avascular necrosis. The bone is then reabsorbed by the body, leaving the articular cartilage it supported prone to damage. The result is fragmentation (dissection) of both cartilage and bone, and the free movement of these osteochondral fragments within the joint space, causing pain and further damage. [https://orcid.org/0009-0006-4530-3154]