1. Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
2. Department for Orthopaedic and Trauma Surgery, BG Klinik Ludwigshafen, 67071 Ludwigshafen am Rhein, Germany
3. Department for Orthopaedic and Trauma Surgery, Helios Clinic, 75175 Pforzheim, Germany
4. Department for Orthopaedics, Trauma and Spinal Surgery, Neckar-Odenwald Clinics, 74821 Mosbach, Germany
5. German Joint Center, ATOS Clinic Heidelberg, 69115 Heidelberg, Germany