1. Department of Orthopedic and Trauma Surgery, Medical Faculty, University of Cologne, Cologne, Germany
2. Department of Orthopaedics, Trauma Surgery and Plastic Surgery, University Hospital Leipzig, Sachsen Germany
3. Department of Orthopaedics and Trauma Surgery, University Hospital, Paracelsus University, Hospital Nürnberg, Nuernberg, Germany
4. Department of Orthopaedics and Trauma Surgery, Ev.Stift St. Martin, Hospital Mittelrhein, Koblenz, Germany
5. Center for Spine surgery, Sana Hospital Leipziger Land, Borna, Germany
6. Department of Orthopaedics, Trauma Surgery and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
7. Department of Trauma Surgery, University Hospital Erlangen, Erlangen, Germany
8. Spine Department, Center for Musculoskeletal Surgery, Charité University Medicine Berlin, Berlin, Germany
9. Center for Spine Therapy, Schön Klinik Hamburg Eilbeck, Hamburg, Germany
10. Department of Trauma and Plastic Surgery, University Hospital Jena, Jena, Germany
11. Center for Spine and Scoliosis Therapy, Malteser Waldkrankenhaus St. Marien, Erlangen, Bayern, Germany
12. Department of Orthopedics and Traumatology, Paracelsus Private Medical University Nuremberg, Nuremberg, Germany