1. Spinal Unit (UVM), Department of Orthopaedics, Centro Hospitalar Universitário do Porto - Hospital de Santo António, Porto, Portugal
2. Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
3. Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, PA, USA
4. Department of Neurosurgery, University of Cambridge, UK
5. Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
6. Department of Orthopaedic Surgery, University of Toyama, Toyama, Japan
7. Department of Orthopaedic Surgery, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan
8. Neurosurgery Department, Ege University, Bornova, Izmir, Turkey
9. Vancouver Spine Surgery Institute, Department of Orthopedics, The University of British Columbia, Vancouver, BC, Canada
10. Division of Neurosurgery, Department of Surgery, University of Toronto, ON, Canada
11. Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
12. Department of Neurosurgery, Medical College of Wisconsin, Wauwatosa, WI, USA
13. Department of Neurosurgery and The Miami Project to Cure Paralysis, The Miller School of Medicine, University of Miami, Miami, FL, USA
14. Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
15. Department of Neurosurgery, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Iran