1. Division of Sports Medicine, Department of Orthopaedic Surgery, Vanderbilt University, Nashville, Tennessee, USA
2. Department of Orthopaedic Surgery, Captain James A. Lovell Federal Health Care Center, North Chicago, Illinois, USA
3. Department of Surgery, Walter Reed National Military Medical Center and Uniformed Services University, Bethesda, Maryland, USA
4. Department of Orthopaedics, Duke University, Durham, North Carolina, USA