1. Department of Orthopaedics, Duke University School of Medicine, Durham, North Carolina, USA
2. Department of Orthopaedic Surgery, University of Iowa School of Medicine, Iowa City, Iowa, USA
3. Department of Orthopaedics, University of Wisconsin Medical Center, Madison, Wisconsin, USA
4. Division of Sports Medicine, Rush University Medical Center, Chicago, Illinois, USA
5. Vanderbilt Orthopaedic Institute, Vanderbilt University Medical Center, Nashville, Tennessee, USA