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68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

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Transpedicular C1 screw placement with help of intraoperative O-arm® imaging and navigation guidance

Meeting Abstract

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  • Gabriela Maria Escobar Magana - Gießen, Deutschland
  • Marco Stein - Gießen, Deutschland
  • M. Reza Boroumand - Gießen, Deutschland
  • Jörg Focke - Gießen, Deutschland
  • Eberhard Uhl - Gießen, Deutschland
  • Karsten Schöller - Gießen, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocDI.21.02

doi: 10.3205/17dgnc293, urn:nbn:de:0183-17dgnc2931

Published: June 9, 2017

© 2017 Escobar Magana et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

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Objective: Screw placement in the lateral mass of C1 via the lateral arch, i.e. transpedicular (TP) screw placement, has biomechanical advantages over the traditional lateral mass screw technique, and potentially reduces the risk of injuries to the paravertebral venous plexus and the C2 nerve root. Technical limitations due to the small dimensions of the C1 pedicle might be overcome by intraoperative 3D imaging and navigation guidance, which hypothetically allow for an accurate procedure and for a reduced need for revision surgery.

Methods: Retrospective single center analysis of patients receiving a TP C1 screw placement as part of a posterior cervical stabilization procedure using the O-arm® and StealthStation® navigation system. Operation time, intraoperative details, and revision surgeries were documented. The C1 intramedullary pedicle height (IMH) was measured on coronal CT scans at the midpoint of the vertebral artery groove. On postoperative CT scans the screw position was graded using the Neo classification (Neo et al., Spine 2005).

Results: The median age of our 22 patients (f: n=12) was 75 years. Indications for surgery were traumatic odontoid or complex C2 fractures in the majority of cases (n=19), that were combined with C1 arch fractures in 7 patients. Operation time improved from 202 min. in the first 11 patients to 150 min. in the last 11 patients. 40 screws were successfully placed via the C1 pedicle; in 4 patients TP screws could only be placed unilaterally. Measurements on CT scans showed that the IMH of the C1 pedicle was 1.63±0.93 mm on the left, and 1.41±0.79 mm on the right. Intraoperative C1 screw revisions had to be conducted in 5 instances. The IMH of pedicles with screw revisions was 1.19±0.73 mm (range: 0-1.88mm), while the IMH of the pedicles without a screw revision was 1.56±0.88 mm (range: 0-3.15mm). No postoperative pedicle perforation was documented in 24 screws, pedicle violations <2mm were found in 12 screws, and pedicle violations between 2 and 4 mm in 4 screws. There was no pedicle violation >4mm. 1 revision surgery was necessary due to screw loosening after 13 months.

Conclusion: The TP C1 screw placement using O-arm® imaging and navigation guidance is feasible in the majority of cases, also in patients with C1 arch fractures. The accuracy of screw placement is good, and revision surgery due to screw malposition can be eliminated. However, the IMH might be a technical limitation, which has to be evaluated in further studies.