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

Robot-assisted transpedicular fusion with the Spine Assist system: Reduction of screw misplacement in complex posterior instrumented fusions?

Meeting Abstract

  • R. Burger - Neurochirurgische Klinik, Krankenhaus Nordstadt, Hannover
  • R. Martinez - Neurochirurgische Klinik, Universitätsklinikum Göttingen
  • S. Kantelhardt - Neurochirurgische Klinik, Universitätsklinikum Göttingen
  • V. Rohde - Neurochirurgische Klinik, Universitätsklinikum Göttingen

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.10-02

doi: 10.3205/09dgnc063, urn:nbn:de:0183-09dgnc0630

Published: May 20, 2009

© 2009 Burger 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: Does miniature robot-assisted transpedicular screw positioning with the „Spine Assist“ system reduce screw misplacement and increase the accuracy of complex posterior instrumented fusions?

Methods: In this preliminary study we included 12 pts. (5 f / 7 m; 90 ±28 kg BW; BMI 31 ± 11; 63 ± 13 yrs.) with the following diseases: spondylodiscitis (n = 5), degenerative spondylolisthesis (n = 4), trauma associated cervical instability (n=1) und secondary postoperative instabilities (n = 2). Instrumented fusion was performed in the cervico-thoracic (n = 1), thoracic (n=3) und lumbar spine (n = 8) with either the “Neon” or the “Tango” System (Ulrich Corp.). The „Spine Assist“ system enables calculation of exact screw trajectories by matching a CT data set with two intraoperative, fluoroscopic images. After robot-assisted drilling of the pedicle over an exactly positioned guiding tube, cannulated screws were inserted. Altogether 36 screws were placed in 12 pts. with the help of the system.

Results: The preoperative robot-assisted planning procedure took up 27 ± 11 min, the acquisition of fluoroscopic images, registration and segmentation 12 ± 9 min. Overall the robot-assisted procedure continued over 63 ±19 minutes. The overall exposure time to radiation was 154 ± 89 sec. 34 of 36 screws were placed according to the preoperative planning. 2 transcutaneously placed pedicle screws in C7 and T1 were malpositioned (5,5 %). A “Hybridspondylodesis“ with mixed fusion systems was possible in one patient since the “Spine Assist” is able to adjust rods and screws with the planning software. Torsions in scoliosis were easily compensated for as well. As a result of obesity and a high BMI the system was not applicable in one patient.

Conclusions: The system enables a reduction of transpedicular screw misplacement and increases the accuracy of intrumentation in complex cases. Particularly, the system runs without failure when flouroscopic data acquisition is easy. Intraoperative exposure time to radiation was significantly reduced.