gms | German Medical Science

60th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Benelux countries and Bulgaria

German Society of Neurosurgery (DGNC)

24 - 27 May 2009, Münster

Intra-operative 3D imaging and navigation with a new mobile device (O-Arm®) – results of the first 600 thoracic and lumbar pedicle screws

Meeting Abstract

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  • J. Schröder - ZW-O Zentrum für Wirbelsäulenchirurgie am Klinikum Osnabrück
  • M. Winking - ZW-O Zentrum für Wirbelsäulenchirurgie am Klinikum Osnabrück
  • G. H. Arndt - ZW-O Zentrum für Wirbelsäulenchirurgie am Klinikum Osnabrück

Deutsche Gesellschaft für Neurochirurgie. 60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit den Benelux-Ländern und Bulgarien. Münster, 24.-27.05.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. DocMO.10-06

doi: 10.3205/09dgnc067, urn:nbn:de:0183-09dgnc0676

Published: May 20, 2009

© 2009 Schröder et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Computer assisted image guided surgery is advancing into the operating theatres to improve surgical accuracy and minimise implant related morbidity. Nevertheless image acquisition and registration of the navigational device proved to be time consuming and not always accurate. In fluoroscopic navigation the important axial information is missing. The O-Arm® (Breakaway-Imaging, Medtronic) is a mobile fluoroscopic device for 3D image acquisition. The gantry can be opened for positioning around the patient. In the operating room the O-Arm completes in a the 3D Multiplanar Reconstruction (MPR) Imaging mode a 3D spin taking 355 images within 13 seconds, reconstructs them and performs in connection with an navigation device (Treon®, Medtronic) an automatic registration to the patient.

Methods: We report about our results of total number of 614 navigated pedicle screw placed in the lumbar and thoracic spine in 119 Patients (42 male, 77 female, 62 ± 12-year-old range 83–27, BMI 27 ± 4 range 38–18, number of segments treated: 79x one, 24x two, 16 more) The screw placement was assessed using a 4 grade scale (grade 1: completely in, grade 2: threads in the pedicle wall, grade 3: screw core in the pedicle wall, grade 4: completely out).

Results: The majority of 594 screws (96.8%) were found accurately placed, the CT artefact of 15 screws (2.4%) was in projection of the pedicle wall, but intraoperatively not perforated (Grad 1), 2 screws (0.3%) were half out (Grade 2) but left in place and 3 screws (0.5%) were found to be malplaced in the final intra-operative scan. These 3 screws could be repositioned during the same operation. Our re-operation rate for implant repositioning dropped to zero, as did our implant related complication rate. Compared to a historical group of 100 patients treated conventionally with either intra-operative sequential imaging or fluoroscopic navigation no prolongation of the procedures could be observed. (Cutting time fluoroscopic navigation 185 min ± 49 (n=81) versus 3D Navigation 195 ± 53 (n=119) p>0.05.

Conclusions: The described device proved to be a reliable tool for intra-operative image acquisition and navigation in image guided spinal surgery. The technology opens new opportunities for minimally invasive spine procedures.