1. Center for Musculoskeletal Surgery, Charitè–University Medicine Berlin, Berlin, Germany
2. Department of Orthopaedic Surgery, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Cologne, Germany
3. Center for Musculoskeletal Surgery, Vivantes Klinikum, Berlin-Friedrichshain, Germany
4. Department of Traumatology and General Surgery, Berufsgenossenschaftliche Unfallklinik Murnau, Murnau, Germany
5. Department of Traumatology, Berufsgenossenschaftliche Unfallklinik Ludwigshafen, University of Heidelberg, Ludwigshafen, Germany