1. Radboud University Nijmegen Medical Center; Department of General and Trauma Surgery; PO Box 9101 Nijmegen Netherlands 6500 HB
2. Princess Alexandra Hospital; Department of Trauma & Orthopaedics; Hamstel Road Harlow UK CM20 1QX
3. Saint Elisabeth Hospital; Department of General and Trauma Surgery; Hilvarenbeekseweg 60 Tilburg Noord Brabant Netherlands 5022 GC
4. Radboud University Nijmegen Medical Center; Department of Surgery; PO Box 9101 Nijmegen Netherlands 6500 HB