1 Spinecenter and Sektion of Neurosurgery, Department of Orthopaedic Surgery, Trauma Surgery and Spine Surgery, Donau-Ries-Klinik Donauwoerth, Neudegger Allee 6, 86609 Donauwoerth, Germany.
2 Spinecenter and Sektion of Neurosurgery, Department of Orthopaedic Surgery, Trauma Surgery and Spine Surgery, Donau-Ries-Klinik Donauwoerth, Neudegger Allee 6, 86609 Donauwoerth, Germany. Electronic address: anreinke@gmx.de.