1. Department of Orthopedic Surgery and Sports Traumatology, Sana Medical Centre Witten/Herdecke University Aachener Str. 445‐449 50933 Cologne Germany
2. Department of Trauma Surgery, Orthopaedic Surgery and Sports Traumatology, Cologne Merheim Medical Centre Witten/Herdecke University Cologne Germany
3. Center for Musculoskeletal Surgery Charité ‐ University Medicine Berlin Berlin Germany
4. Faculty of Medicine University of Cologne Cologne Germany
5. Wisplinghoff Laboratories Cologne Germany
6. Institute for Virology and Microbiology Witten/Herdecke University Witten Germany
7. Institute for Medical Microbiology, Immunology and Hygiene University of Cologne Cologne Germany