Institution: | (1) Spine Unit, Department of Orthopaedics, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands;(2) Department of Surgery, Neurosurgery, University of South Dakota, 100 MacLane, Pierre, SD, USA;(3) University of Arizona Egyptian Expedition, Tucson, AZ, USA;(4) University of Toronto, Ontario, Canada |