1. Department of Trauma and Orthopaedic Surgery, Berufsgenossenschaftliche Unfallklinik Frankfurt am Main, Frankfurt am Main, Germany.
2. Department of Sporttraumatology, Knee- and Shoulder-Surgery, Berufsgenossenschaftliche Unfallklinik Frankfurt am Main, Frankfurt am Main, Germany.
3. Department of Orthopaedics and Trauma Surgery, University Hospital Bonn, Bonn, Germany.
4. Department of Orthopaedics and Rheumatology, University Hospital Marburg, Marburg, Germany.
5. Department of Sports Science, University of Bielefeld, Bielefeld, Germany.