Osteonecrosis in patients with SLE.

Osteonecrosis is a clinical entity characterized by death of bone marrow and trabecular bone as a result of disruption of blood supply to the bone (1,2). Other aspects of this condition include avascular necrosis, aseptic necrosis, and osseous ischemic necrosis of bones. Osteonecrosis is classified into two main forms; post-traumatic and nontraumatic. The post-traumatic form of osteonecrosis usually develops as a result of traumatic displacement of bone fragments, which leads to impaired blood supply and ischemia to the affected bone. Osteonecrosis of the femoral head is common following fracture of the femoral neck. A variety of systemic diseases and clinical conditions are associated with nontraumatic osteonecrosis. These include autoimmune rheumatic diseases, alcoholism, pregnancy, Gaucher's disease, thrombophilia, corticosteroid therapy, Sickle-cell anemia, pancreatitis, inflammatory bowel diseases, and use of cytotoxic drugs and others. Idiopathic forms of osteonecrosis have also been reported (2-4). Among the rheumatic diseases, osteonecrosis is strongly associated with systemic lupus erythematosus (SLE) (5). However, osteonecrosis has been diagnosed in patients with primary antiphospholipid syndrome (APS) (6), rheumatoid arthritis (7), and systemic vasculitis (8). This article reviews the causes, clinical and epidemiological features, diagnosis, and treatment options for osteonecrosis among patients with SLE.