1. Department of Orthopaedic Surgery and Traumatology, Universitätsklinikum Schleswig-Holstein, Kiel, Germany
2. Excellent Center of Medicine and ATOS-Clinic, München, Germany
3. Department of Orthopaedic Surgery, Klinikum rechts der Isar, München, Germany
4. Center of Sportpractice Prof. Knobloch, Hannover, Germany
5. The London independent Hospital, London, Great Britain
6. Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), München, Germany