1. From the Department of Radiology (J.C.M., R.A.M., A.D.S., B.K.), Division of Musculoskeletal Imaging and Intervention (J.C.M.), Division of Emergency Radiology (A.D.S., B.K.), and Department of Orthopedic Surgery (M.J.W., M.B.H.), Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115.