1. Department of Anaesthesiology and Intensive Care Medicine; Witten/Herdecke University; Cologne Merheim Medical Center; Cologne; Germany
2. Institute for Research in Operative Medicine (IFOM); Witten/Herdecke University; Cologne; Germany
3. Department of Trauma and Orthopedic Surgery; Witten/Herdecke University; Cologne Merheim Medical Center; Cologne; Germany
4. Kliniken der Stadt Köln gGmbH; Hospital Cologne-Merheim; University Hospital of the Witten/Herdecke University; Cologne; Germany