1. University Hospital Marburg, Center for Orthopedics and Traumatology, Baldingerstrasse, 35043 Marburg, Germany
2. Department of Orthopaedic Surgery, University Hospital of Saint Etienne, France
3. Clinic Jung-Stilling, Department for Trauma, Siegen, Germany
4. Orthomedicum Mittelhessen, Stadtallendorf, Germany
5. Orthopaedicum Lich, Germany
6. Joint Center Hilden, Ruhr-University Bochum, Germany
7. ORTHOmedic Frankfurt Offenbach, Germany