1. Department of Orthopedic Surgery, St-Trudo Hospital, St Truiden, Belgium
2. Department of Orthopedic Surgery, AZ Herentals, Herentals, Belgium
3. Department of Orthopedic Surgery, University Hospitals, Leuven, Belgium
4. Department of Orthopedic Surgery, St-Maarten Hospital, Mechelen, Belgium
5. Department of Orthopedic Surgery, St Jan, Genk, Belgium