Affiliation: | (1) Spine Center, Department of Orthopaedic Surgery, University of Greifswald, Greifswald, Germany;(2) Spine Unit, Department of Orthopaedic Surgery, Asklepios Klinikum Uckermark, Schwedt/Oder, Germany;(3) MEM Research Center for Orthopaedic Surgery, Institute for Evaluative Research in Orthopaedic Surgery, University of Berne, Stauffacherstrasse 78, 3014 Berne, Switzerland;(4) Department of Orthopaedic Surgery, Dunedin Public Hospital, University of Otago, Dunedin, New Zealand |