Department of Orthopedic Surgery, MGH/BWH Orthopedic Spine Surgery Fellowship Program, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA; Department of Orthopedic Surgery, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA; The Spine Journal, North American Spine Society, 7075 Veterans Boulevard, Burr Ridge, IL 60527, USA.