1. AO Foundation, Dübendorf, Switzerland
2. St Maartenskliniek, Nijmegen, Netherlands
3. Texas Back Institute, Plano, TX, USA
4. Sparsh Super Speciality Hospital, Bengaluru, Karnataka, India
5. McGill University Health Center, Montreal, Quebec, Canada
6. Institut Mutualiste Montsouris, Paris, France
7. NY Presbyterian Hospital–Weill Cornell Medical College, New York, NY, USA
8. Center for Spine Surgery and Neurotraumatology, Frankfurt, Germany