1. Lower Extremity Orthopaedics, Musculoskeletal Center, Schulthess Clinic, Zurich, Switzerland.
2. Gelenkzentrum Rhein-Main, Wiesbaden, Germany.
3. OCM Clinic Munich, Munich, Germany.
4. Musculoskeletal Regeneration Program, AO Research Institute Davos, AO Foundation, Davos, Switzerland.
5. Department of Trauma Surgery, University Medical Center Regensburg, Regensburg, Germany.
6. Sporthopaedicum Regensburg, Regensburg, Germany.