1. Department of Sports Medicine, Palo Alto Medical Center, Palo Alto, USA
2. Department of Orthopedic and Traumatology, Technical University Munich, Munich Germany
3. Städtisches Krankenhaus Kiel, Kiel
4. Department of Orthopaedic Surgery and Traumatology, University Schleswig Holstein, Kiel, Germany
5. Orthopedic Department, Physical Medicine and Rehabilitation, University Hospital of Munich, Germany
6. Department of Orthopedic Surgery and Traumatology, Orthopaedic Medical Center Dr. Ringeisen, Augsburg, Germany
7. Orthopedic Department, SportPraxis Prof. Dr. med. Karsten Knobloch, Hannover