1. Department of Orthopedic Surgery, University Medical Centre, Johannes Gutenberg University Mainz, 55131 Mainz, Germany
2. Medical Park Kliniken Bad Wiessee, 83707 Bad Wiessee, Germany
3. BG Unfallklinik Frankfurt am Main gGmbH, 60389 Frankfurt am Main, Germany
4. Interdisciplinary Centre for Clinical Trials Mainz, University Medical Center, Johannes Gutenberg University Mainz, 55131 Mainz, Germany