Safety and Efficacy of Posterior Atlanto-Axial Stabilization Using Intraoperative Navigation System with Preoperative Computed Tomographic Scan

Abstract

Surgical approaches for posterior C1-C2 arthrodesis, such as C1-C2 transarticular and C1-C2 screw stabilization, are known to be demanding because of the anatomic close proximity of cervical vertebrae to neurovascular structures. Currently, navigation by fluoroscopy or intraoperative computed tomography (ICT) is the standard practice. However, fluoroscopy has various limitations, and ICT is time consuming and not available in many centers; furthermore, both diagnostic tools lead to exposure of the operating room staff to radiation exposure. We evaluate the safety, efficacy, and facility of a navigation system using only preoperative cervical computed tomography and computed tomographic angiography (CT/CTA), to prevent the risk of neurovascular damage in atlantoaxial stabilization. The authors report a series of 21 patients who underwent posterior upper cervical spine fixation using a navigation system with intraoperative single-level vertebral registration on preoperative cervical CT/CTA (software BrainLab IPlan Spine 3.0). Intraoperative and postoperative comparative analysis was performed to verify the correspondence between the virtual anatomic position of the surgical instruments and screws represented on the neuronavigator, and the actual positions verified intraoperatively and on postoperative CT. Thirteen patients underwent C1-C2 arthrodesis with a Harms construct, 1 patient with transarticular screw fixation and 4 patients with occipitocervical stabilization. Three patients underwent C1-C2-C3 stabilization with C1 hooks, C2-C3 screws, and rod construct. On postoperative CT, the position of all screws appeared satisfactory. No neurovascular damage occurred in any patients. The use of a neuronavigation system, based on preoperative acquired cervical CT and intraoperative single-vertebra registration, may provide a valuable support for the improvement of the surgical accuracy of posterior C1-C2 screw fixation.