1. Department for Orthopaedics, University of Heidelberg, Schlierbacher Landstraße 200a, 69118 Heidelberg, Germany
2. Department of Pathology, University of Heidelberg, 69120 Heidelberg, Germany
3. Gerhard Domagk Institute of Pathology, University Hospital Muenster, Albert-Schweitzer-Campus 1, Building D17, 48149 Muenster, Germany
4. Study Center of the German Society of Surgery (SDGC), University of Heidelberg, Im Neuenheimer Feld 130.3, 69120 Heidelberg, Germany
5. Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, 69118 Heidelberg, Germany