MR imaging of bone infarction and epiphyseal osteonecrosis

No single musculoskeletal disorder has generated more passionate discussion than bone osteonecrosis. Surprisingly, its physiopathogenesis remains largely unknown despite in-depth studies. Its treatment is still debated, and its wide range of clinical manifestations which vary from totally asymptomatic to the catastrophic event of irreversible epiphyseal collapse remains a fascinating question for the clinicians (1-4). Magnetic Resonance (MR) imaging has given a large tribute to the discussion during the last decade by allowing detection of marrow infarcts at a presymptomatic period of the disease, thus providing data on its natural history. Unfortunately, MR imaging has also contributed to increase the confusion among various epiphyseal disorders. The aim of the current paper is to provide an overview of the current knowledge of imaging features by stressing accepted data and delineating blind areas.