1. Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
2. Department of Hygiene and Environmental Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
3. Department of Neurological Surgery, University of California, San Francisco, CA, USA
4. Division of Neurosurgery and Spine Program, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
5. Orthopedic Surgery, UCSF Spine Center, San Francisco, CA, USA
6. Reno Orthopedic Clinic, Reno, NV, USA
7. Departments of Neurosurgery and Orthopaedic Surgery, Duke Medical Center, Durham, NC, USA
8. Department of Neurosurgery, University of Virginia Health System, Charlottesville, VA, USA
9. Department of Orthopaedic Surgery, Oregon Health and Science University, Portland, OR, USA
10. Hospital for Special Surgery, New York, NY, USA
11. USC Spine Center, Los Angeles, CA, USA
12. Department of Neurosurgery, Spine, and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea
13. Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
14. Department of Orthopedics, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
15. Department of Orthopaedics, Churruca Hospital de Buenos Aires, Buenos Aires, Argentina
16. Department of Neurosurgery, University of Caxias do Sul, Caxias do Sul, Brazil
17. Clinica Portoazul, Barranquilla, Colombia
18. Spine Unit, Orthopedic Department, Hospital Español, Mendoza, Argentina
19. Department of Neurological Surgery, Children’s Hospital, La Plata, Argentina
20. Department of Neurosurgery, Technische Universität München, Munich, Germany
21. Centre for Spinal Surgery and Neurotraumatology, BG Unfallklinik, Frankfurt am Main, Germany
22. Department of Neurosurgery, Medical University of Innsbruck, Tyrol, Austria
23. Department of Spine Surgery, Schulthess Klinik Zürich Switzerland and Department of Trauma Surgery, University Medical Center, Regensburg, Germany
24. University Neurosurgical Center Holland, Leiden University Medical Center, Haaglanden Medical Center & Haga Teaching Hospital, Leiden and The Hague, The Netherlands
25. Department of Oncologic and Degenerative Spine Surgery, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
26. Clinique du Dos, Elsan Jean Villar Private Hospital, Bordeaux, France
27. Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
28. Center for Musculoskeletal Surgery (CMSC), Charité - Universitätsmedizin Berlin, Berlin, Germany