1. Cedars-Sinai Medical Center, Los Angeles, CA, USA
2. Mercy Medical Center, Baltimore, MD, USA
3. New York University Grossman School of Medicine, New York, NY, USA
4. Johns Hopkins School of Medicine, Baltimore, MD, USA
5. Georgetown School of Medicine, Washington, DC, USA
6. Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USA
7. Hospital for Special Surgery, New York, NY, USA
8. Washington University School of Medicine, St. Louis, MO, USA
9. Department of Orthopedic Surgery, University of Colorado School of Medicine, Aurora, CO, USA
10. University of Washington, Seattle, WA, USA
11. Kantonspital Baselland, Liestal, Switzerland