1. Department of Orthopaedics and Trauma Surgery, University of Cologne, Faculty of Medicine and University Hospital Cologne, Germany
2. Clinic for Trauma and Reconstructive Surgery, University Hospital Aachen, Germany
3. Trauma and Hand Surgery, Schön Clinic Hamburg-Eilbek, Germany
4. Spinal Surgery, Professional Accidents Clinic Murnau, Germany
5. Clinic and Polyclinic for Orthopaedics, Trauma Surgery and Plastic Surgery, University of Leipzig Medical Faculty, Germany