1. Division of Orthopaedic Surgery, Arthritis Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
2. Department of Surgery, University of Toronto, Toronto, ON, Canada
3. Department of Orthopaedics, University of Zurich, Balgrist University Hospital, Zurich, Switzerland
4. Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, ON, Canada, Canada
5. Department of Orthopedic and Trauma Surgery, Medical University Vienna, Vienna, Austria
6. Department of Neurological Surgery, University of California - Davis, Sacramento, CA, USA
7. Department of Orthopaedic, Hebrew University, Hadassah Medical Center, Jerusalem, Israel
8. Department of Orthopedics, Medical Center, Radboud University, Nijmegen, Gelderland, The Netherlands
9. Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
10. Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
11. Department of Orthopedic Surgery, The Spine Hospital, Medical Center, Columbia University, New York, NY, USA
12. Department of Orthopedics and Traumatology, Acibadem Mehmet ali Aydinlar University, Istanbul, Turkey
13. Hospital Universitari de la Vall d’Hebron, Barcelona, Spain
14. Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong
15. Sint Maartenskliniek Nijmegen, Gelderland, the Netherlands
16. Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, USA
17. Department of Orthopaedic Surgery, Duke University, Durham, NC, USA
18. Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
19. Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO, USA
20. Division of Orthopedic Surgery, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, USA
21. Spine Unit, Rigshospitalet, University of Copenhagen, Denmark
22. Department of Neurosurgery and Orthopaedic Surgery, University of California, San Francisco, CA, USA