1. BG Trauma Center Ludwigshafen at Heidelberg University Hospital, Ludwigshafen, Germany.
2. Department of Medical Statistics, University Medicine Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Mannheim, Germany.
3. Department of Orthopedic Surgery, Paulinenhilfe, Diakonieklinikum Stuttgart, Stuttgart, Germany.
4. German Joint Center, Atos Clinic, Heidelberg, Germany.