1. Department of Orthopedics University Medical Center Utrecht Utrecht the Netherlands
2. Department of Radiation Oncology Sunnybrook Odette Cancer Centre and University of Toronto Toronto Ontario Canada
3. Department of Orthopedic Surgery Kanazawa Medical University Hospital Kanazawa Japan
4. Department of Neurosurgery, Division of Surgery The University of Texas MD Anderson Cancer Center Houston Texas
5. Department of Neurosurgery Johns Hopkins University School of Medicine Baltimore Maryland
6. Division of Surgery McGill University and Montreal General Hospital Montreal Quebec Canada
7. National Center for Spinal Disorders Buda Health Center Budapest Hungary
8. Division of Neurosurgery and Spine Program University of Toronto and Toronto Western Hospital Toronto Ontario Canada
9. Department of Neurosurgery Hospital of the University of Pennsylvania Philadelphia Pennsylvania
10. Department of Neurosurgery Mayo Clinic Rochester Minnesota
11. Department of Neurosurgery University of Kansas Hospital Kansas City Kansas
12. Institutes for Care and Scientific Research (IRCCS) Galeazzi Orthopedic Hospital Milan Italy
13. Department of Neurosurgery Warren Alpert Medical School of Brown University, Rhode Island Hospital, and Miriam Hospital Providence Rhode Island
14. Division of Spine Surgery, Department of Orthopaedics University of British Columbia and Vancouver General Hospital Vancouver British Columbia Canada