1. Steadman Philippon Research Institute, Vail, Colorado, USA.
2. The Steadman Clinic, Vail, Colorado, USA.
3. Oregon Health and Science University, Portland, Oregon, USA.
4. Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
5. Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.