1. Department of Sports Orthopedics, Technical University of Munich, Munich, Germany.
2. Department of Orthopaedic Surgery, UConn Musculoskeletal Institute, University of Connecticut, Farmington, Connecticut, USA.
3. Beaumont Orthopedic Institute Royal Oak, Royal Oak, Michigan, USA.
4. Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
5. Harvard Medical School, Boston, Massachusetts, USA.