Introduction: C1-C2 surgical stabilization can be challenging due to the proximity of neurovascular structures, high frequency of anomalous vertebral arteries, and degree to which upper cervical pathology can distort normal anatomical structures. Precise instrumentation placement is important to avoid complications. We provide additional evidence that intraoperative neuronavigation improves the safety and efficacy of surgical fixation of instability at the complex C1-C2 region.
Methods: Retrospective study of 10 patients who underwent posterior C1-C2 fusion from February 2005 to January 2014 with intraoperative frameless stereotactic O-arm® Surgical Imaging and StealthStation® Neuronavigation (Medtronic, Inc., Minneapolis MN) to aid in screw placement at the atlantoaxial (C1-C2) junction. Outcome measures included screw placement accuracy, neurologic status, radiation dosing, and surgical complications.
Results: Seven of 10 patients had fusion at C1-C2 only, while three had fixation extending down to C3 due to anatomical considerations for screw placement recognized on intraoperative imaging. Out of 31 screws placed, all demonstrated minimal divergence from desired placement in the C1 lateral mass, C2 pedicle, or C3 lateral mass (if required). Solid fusion was achieved in all 10 patients. No neurovascular compromise was seen following the use of intraoperative guided screw placement. The average radiation dosing resulting from intraoperative imaging was 39.0 mGy. All patients were followed for at least 12 months.
Conclusions: C1-C2 fusion using O-arm® CT-guided navigation is a safe and effective way to treat atlantoaxial instability. While the patient’s exposure to radiation is more significant than with conventional techniques, intraoperative neuronavigation allows for improved accuracy of screw placement and reduced complications due to injury-sparing of critical structures in the upper cervical spine, and allows surgeons to make intraoperative decisions regarding complex pathology.
Patient Care: Intraoperative neuronavigation during C1-C2 fixation allows for improved screw placement accuracy and reduced complications, and allows surgeons to make intraoperative decisions regarding complex pathology.
Learning Objectives: Describe how intraoperative neuronavigation improves the safety and efficacy of C1-C2 surgical stabilization.