1. Department of Epidemiology, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
2. Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd., Jordan Medical Education Center, Philadelphia, PA 19104, USA
3. School of Engineering and Applied Science, University of Pennsylvania, 220 South 33rd Street, 107 Towne Building, Philadelphia, PA 19104, USA
4. Division of Sports Medicine, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, 235 S 33rd St, Philadelphia, PA 19104, USA
5. Department of Surgery, Stanford University, School of Medicine, 300 Pasteur Dr, Stanford, CA 94305, USA
6. Department of Orthopaedic Surgery, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA
7. Department of Orthopaedic Surgery, University of Malawi, College of Medicine, P/B 360, Chichiri, Blantyre 3, Malawi
8. Flinders University School of Medicine, Sturt Rd, Bedford Park, South Australia 5042, Australia
9. Institute of Global Orthopaedics and Traumatology, Department of Orthopaedic Surgery, University of California San Francisco, 2550 23rd Street, Building 9, 2nd Floor, San Francisco, CA 94110, USA
10. Department of Surgery, Columbia University College of Physicians and Surgeons, 177 Fort Washington Ave., New York, NY 10032, USA
11. Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA
12. Surgeons OverSeas, 99 Avenue B, Suite 5E, New York, NY 10009, USA