1. German Shoulder Center, ATOS Clinic, Munich, Germany.
2. Department of Orthopaedic and Trauma Surgery, Paracelsus Medical University, Salzburg, Austria.
3. Department of Orthopaedics and Traumatology, St Vinzenz Kliniken, Karlsruhe, Germany.
4. Department of Shoulder and Elbow Surgery, Center for Musculoskeletal Surgery, Charitè University Hospital, Berlin, Germany.
5. Department of Orthopaedics, University Clinic, Greifswald, Germany.
6. Department of Shoulder and Elbow Surgery, Schulthess Clinic, Zurich, Switzerland.