Spinal navigation for posterior instrumentation of C1–2 instability using a mobile intraoperative CT scanner

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Spinal navigation techniques for surgical fixation of unstable C1–2 pathologies are challenged by complex osseous and neurovascular anatomy, instability of the pathology, and unreliable preoperative registration techniques. An intraoperative CT scanner with autoregistration of C-1 and C-2 promises sufficient accuracy of spinal navigation without the need for further registration procedures. The aim of this study was to analyze the accuracy and reliability of posterior C1–2 fixation using intraoperative mobile CT scanner–guided navigation.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>In the period from July 2014 to February 2016, 10 consecutive patients with instability of C1–2 underwent posterior fixation using C-2 pedicle screws and C-1 lateral mass screws, and 2 patients underwent posterior fixation from C-1 to C-3. Spinal navigation was performed using intraoperative mobile CT. Following navigated screw insertion in C-1 and C-2, intraoperative CT was repeated to check for the accuracy of screw placement. In this study, the accuracy of screw positioning was retrospectively analyzed and graded by an independent observer.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The authors retrospectively analyzed the records of 10 females and 2 males, with a mean age of 80.7 ± 4.95 years (range 42–90 years). Unstable pathologies, which were verified by fracture dislocation or by flexion/extension radiographs, included 8 Anderson Type II fractures, 1 unstable Anderson Type III fracture, 1 hangman fracture Levine Effendi Ia, 1 complex hangman-Anderson Type III fracture, and 1 destructive rheumatoid arthritis of C1–2. In 4 patients, critical anatomy was observed: high-riding vertebral artery (3 patients) and arthritis-induced partial osseous destruction of the C-1 lateral mass (1 patient). A total of 48 navigated screws were placed. Correct screw positioning was observed in 47 screws (97.9%). Minor pedicle breach was observed in 1 screw (2.1%). No screw displacement occurred (accuracy rate 97.9%).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSION</jats:title><jats:p>Spinal navigation using intraoperative mobile CT scanning was reliable and safe for posterior fixation in unstable C1–2 pathologies with high accuracy in this patient series.</jats:p></jats:sec>

Clinical Outcome of Dorsal Cervical C1–C2 Fusion Using C1 Lateral Mass Screws, C2 Lamina Screws, and Interarcual Bone Graft Technique

“…Various research described an accuracy rate of up to 98% with the use of intraoperative CT during posterior atlantoaxial fusion. 15 Although we did not use intraoperative CT, we agree with the conclusion that intraoperative neuronavigation allows a high accuracy of screw placement, limits complications by sparing injury to critical structures of the upper cervical spine, and can help surgeons make intraoperative decisions regarding complex pathology. 14 Sugawara et al described a simple and economical method for intraoperative screw navigation using the multistep patient-specific screw template system.…”

Motion-Preserving Navigated Primary Internal Fixation of Unstable C1 Fractures

“…A controlled compression of C1 will further help in fracture reduction, which requires the placement of C1 lateral mass screws. Although navigated surgery in degenerative cervical spine surgeries is a well-documented entity with proven outcomes [21,22], there are significant challenges in the installation of C1 screws in UAF. The accuracy of navigated surgery depends on the maintenance of the immobility of the instrumented spinal column, after completing an ICT scan.…”

Einsatz der spinalen Navigation in der Wirbelsäulenchirurgie – Pro

“…Auf der anderen Seite ist die Fehlertoleranz bei Platzierung der Schrauben aufgrund der Nähe zu kritischen neurovaskulären Strukturen sehr gering. Wir konnten jüngst zeigen, dass gerade in diesem Bereich die spinale Navigation Vorteile mit sich bringt [6]. Hier liegt die Rate an optimalen Schraubenplatzierungen in C1 und C2 bei Einsatz der spinalen Navigation bei über 95 %.…”