1. Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal
2. Rothman Institute, Thomas Jefferson University, Philadelphia, PA, USA
3. Institute for Clinical & Experimental Surgery, University of Saarland, Homburg/Saar, Germany
4. Harborview Medical Center, University of Washington School of Medicine, Seattle, WA, USA
5. University Medical Center, Utrecht, Netherlands
6. Berufsgenossenschaftliche Unfallklinik Frankfurt, Center for Spinal Surgery and Neurotraumatology, Frankfurt am Main, Germany
7. University of British Columbia, Vancouver, British Columbia, Canada
8. R. Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD, USA
9. Cajuru University Hospital, Catholic University of Parana, Curitiba, Brazil
10. Ganga Hospital, Coimbatore, Tamil Nadu, India
11. Schön Klinik Nürnberg Fürth, Center for Spinal Surgery, Fürth, Germany