1. University of Virginia Medical Center, Charlottesville, Virginia
2. Department of Orthopedic Surgery, University of California - San Francisco, San Francisco, California
3. Spine Surgery Associates, PC, Chattanooga, Tennessee
4. University of Missouri Orthopedic Surgery, Columbia, Missouri
5. Health Sciences Centre, Winnipeg, Manitoba, Canada
6. The Royal National Orthopedic Hospital, London, United Kingdom
7. Arnold Palmer Children's Hospital, Orlando, Florida
8. Orthopaedics Department, Oregon Health & Science University, Portland, Oregon
9. Division of Orthopedic Surgery, Hospital for Sick Children, Toronto, Ontario, Canada
10. Orthopedic Surgery, University of Pittsburgh Physicians, Pittsburgh, Pennsylvania
11. Department of Orthopedic Surgery and Neurosurgery, University of Minnesota, Minneapolis, Minnesota
12. Twin Cities Spine Center, Minneapolis, Minnesota