1. From the Department of Radiology, Division of Musculoskeletal Radiology (S.L.V., E.M.H., M.B., T.T.W.), and Department of Orthopedic Surgery, The Center for Shoulder, Elbow, and Sports Medicine (C.A.P., C.S.A., W.N.L.), New York-Presbyterian Hospital, Columbia University Medical Center, 622 W 168th St, MC-28, New York, NY 10032.