Chul Ki Goorens1, Jan Wouter Huizing1, Jean F Goubau2. 1. Department of Orthopaedics and Traumatology, Regional Hospital of Tienen, Tienen, Belgium; Department of Orthopaedics and Traumatology, University Hospital of Brussels, Vrije Universiteit Brussel, Brussels, Belgium. 2. Department of Orthopaedics and Traumatology, University Hospital of Brussels, Vrije Universiteit Brussel, Brussels, Belgium.