1. Spinal Unit (UVM), Department of Orthopaedics, Centro Hospitalar Universitário Do Porto, Portugal
2. Instituto de Ciências Biomédicas Abel Salazar, Universidade Do Porto, Portugal
3. Hospital CUF Trindade, Porto, Portugal
4. Department of Orthopaedics, Government Medical College, Dindigul, India
5. Orthopaedic Research Group, Coimbatore, India
6. Department of Neurosurgery, Hospital Clínico Regional de Concepción, Concepción, Chile
7. Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN, USA
8. Department of Neurosurgery, BG Klinikum Bergmannstrost Halle, Germany
9. Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
10. Department of Neurosurgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
11. Gerling Institute, Brooklyn, NY, USA
12. Department of Orthopedic Surgery, NYU Grossman School of Medicine, NY, USA