1 Center of Orthopaedics and Traumatology, University Hospital Brandenburg/Havel, Brandenburg Medical School Theodor Fontane, Brandenburg a.d.H., Germany.
2 Faculty of Health Sciences Brandenburg, Brandenburg Medical School Theodor Fontane, Brandenburg a.d.H., Germany.
3 Department of Physical Therapy, Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
4 Department of Orthopaedics, Sahlgrenska University Hospital, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
5 Basel University, Switzerland.
6 Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland, Bruderholz, Switzerland.
7 Norton Orthopedic Institute, Louisville, Kentucky, USA.
8 Department of Orthopaedic Surgery, University of Louisville, Kentucky, USA.