The main risk factors are bone fractures, joint dislocations, alcoholism, and the use of high-dose steroids. Other risk factors include radiation therapy, chemotherapy, and organ transplantation. Osteonecrosis is also associated with cancer, lupus, sickle cell disease, HIV infection, Gaucher's disease, and Caisson disease (dysbaric osteonecrosis). The condition may also occur without any clear reason. Bisphosphonates are associated with osteonecrosis of the mandible. Prolonged, repeated exposure to high pressures (as experienced by commercial and military divers) has been linked to<unk> , though the relationship is not well understood. In children,<unk>  osteonecrosis can have several causes. It can occur in the hip as part of Legg–Calvé–Perthes syndrome, and it can also occur as a result after malignancy treatment such as acute lymphoblastic leukemia and allotransplantation.
Avascular necrosis
Legg–Calvé–Perthes disease
Acral necrosis
Osteopetrosis
Dysbaric osteonecrosis
Rheumatoid arthritis
Osteoradionecrosis
Sickle cell disease