Dominik Baschera1, Adam Lawless2, René Zellweger3. 1. Department of Neurosurgery, Lucerne Cantonal Hospital, Spitalstrasse, 6004, Lucerne, Switzerland. Dominik.baschera@luks.ch. 2. Department of Orthopaedics, Fiona Stanley Hospital, Murdoch, Western Australia, Australia. 3. Department of Orthopaedics and Trauma Surgery, Royal Perth Hospital, Perth, Western Australia, Australia.