1. ETH Zurich, Zurich, Switzerland
2. Klinik St. Anna-Hirslanden, Neuro- and Spine Center, Lucerne, Switzerland
3. Department of Health Sciences, University of Potsdam, Potsdam, Germany
4. Schön Klinik München Harlaching, Spine Center, Munich, Germany
5. Academic Teaching Hospital and Spine Research Institute, Paracelsus Private Medical University Salzburg, Salzburg, Austria