gms | German Medical Science

60. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit den Benelux-Ländern und Bulgarien

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

24. - 27.05.2009, Münster

First clinical application of intraoperative Vertebral Body Tracking (iVEBOT) for spatial correction in spinal navigation and robotics

Meeting Abstract

  • S. Mularski - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin
  • T. Picht - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin
  • P. Vajkoczy - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin
  • T. Kombos - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin
  • O. Suess - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin

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. DocP11-06

doi: 10.3205/09dgnc369, urn:nbn:de:0183-09dgnc3693

Veröffentlicht: 20. Mai 2009

© 2009 Mularski et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: Image guided surgery (IGS) is commonly accepted and used in cranial neurosurgery. In spinal surgery the role of IGS is still under discussion, as most systems do not account for intraoperative movements of the spine. Even after an intraoperative update of the co-registration, forces acting on a single vertebral body cannot be displayed with common navigation techniques. To overcome this problem, we implanted electromagnetic microsensors in models of the cervical spine and performed different surgical procedures in a previous study. The objective of this study was to transmit the results of the laboratory studies into the operating room.

Methods: The Aurora electromagnetic tracking system (NDI Europe GmbH, D) is equipped with two electromagnetic 6D microsensors (1.8 mm dia. x 9 mm length, 6 DOF). The sensors were placed in adjacent vertebral bodies during 10 single level lumbar interbody fusions. Registration was performed with a CT dataset using fluoroscopy co-registration. The vertebral bodies were individually segmented by standard 3D-ISG-software. During surgery spatial data from the sensor-equipped vertebrae were recorded and analyzed online.

Results: The 6D Sensor could be tracked in a cubic measurement volume of 500x500x500mm³ next to the field generator. Sensor inaccuracy gradually increased with growing sensor to transmitter distance (at 200mm: RMS position mean 1.24mm / RMS orientation mean 1.19°; 300mm: 1.46mm / 1.54°; 400mm: 1.89mm / 2.16°). Dynamic positioning errors (e.g. due to breathing excursions; mean 1.94 ± 2.7mm per inspiration) could be separated from static errors due to their oscillating character. Data of vertebral body movement due to mechanical forces during different steps of the surgery (up to 14.8mm during pedicle screw insertion) were collected and displayed.

Conclusions: This first clinical test series proved iVEBOT to be a feasible and reliable method to measure not only intraoperative mechanical vertebral distortion but also spinal motion due to breathing excursions without the need for additional image data acquisition or re-registration. This could improve ISG accuracy in the spinal application and helps to strengthen the acceptance of image guidance as well as robotics in spinal surgery. However, all magnetic spatial measurement systems are affected by the presence of ferromagnetic materials. Therefore, attention has to be focused on a proper field generator placement and incorrect sensor readings due to surgical instruments.