1. Department of Orthopedics and Trauma Surgery, Helios University Hospital, University Witten/Herdecke, 42283 Wuppertal, Germany
2. Department of Orthopedics, Trauma and Reconstructive Surgery, RWTH Aachen University, 52062 Aachen, Germany
3. Department of Trauma and Reconstructive Surgery, BG Bergmannstrost, 06120 Halle (Saale), Germany
4. Department of Trauma and Reconstructive Surgery, University Hospital Halle, 06120 Halle (Saale), Germany