Robert Gunzburg1, Marek Szpalski2, Claudio Lamartina3. 1. Cavell Spine Centre, Edith Cavell Clinic, Edith Cavell Street 32, 1180, Brussels, Belgium. robert@gunzburg.be. 2. Department of Orthopedics, Iris South Hospital, 21 Avenue Coghen, 1180, Brussels, Belgium. 3. II Spine Surgery Division, IRCSS Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi, 4, 20161, Milan, Italy.