1. Clinic of Orthopaedic and Traumatology, Regional Hospital and Kochanowski Medical University , Grunwaldzka 45, Kielce 25-736, Poland
2. Department of Orthopaedics and Traumatology, Bürgerspital Solothurn , Schöngrünstrasse 42, Solothurn 4500, Switzerland
3. Hip Arthroscopy of Mexico, Hospital Angeles Valle Oriente , Av. Cto. Frida Kahlo 180, Valle Oriente, San Pedro Garza García, N.L. 66260, Mexico
4. Hip Arthroscopy Australia , 21 Erin St, Richmond, Melbourne, VIC, Australia
5. Department of Orthopedics, University Hospital Balgrist, University of Zurich , Forchstrasse 340, Zürich 8008, Switzerland