1. Massachusetts General Hospital Department of Orthopaedic Surgery, Sports Medicine Center, Boston, Massachusetts, USA
2. Department of Orthopaedic Surgery, University of Kentucky, Lexington, Kentucky, USA
3. Department of Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
4. Department of Orthopaedic Surgery, University of Utah, Salt Lake City, Utah, USA
5. Department of Orthopaedic Surgery, University of Massachusetts, Worcester, Massachusetts, USA