Surgical treatment of cervical spine fractures in ankylosing spondylitis patients: posterior stabilization using intraoperative CT scanner-based navigation

Introduction: The authors analyzed a series of ankylosing spondylitis patients with cervical spine fracture undergoing posterior stabilization using spinal navigation based on intraoperative CT imaging. The purpose of this study was to evaluate the accuracy and safety of navigated posterior stabilization and to analyze the adequacy of this method for treatment of fractures in ankylosed cervical spine. Methods: Prospectively collected clinical data, together with radiological documentation of a series of 8 consecutive patients with 9 cervical spine fracture were included in the analysis. The evaluation of screw insertion accuracy based on postoperative CT imaging, description of instrumentation- related complications and evaluation of morphological and clinical results were the subjects of interest. Results: Of the 66 implants inserted in all cervical levels and in upper thoracic spine, only 3 screws (4.5%) did not meet the criteria of anatomically correct insertion. Neither screw malposition nor any other intraoperative events were complicated by any neural, vascular or visceral injury. Thus we did not find a reason to change implant position intraoperatively or during the postoperative period. The quality of intraoperative CT imaging in our group of patients was sufficient for reliable trajectory planning and implant insertion in all segments, irrespective of the habitus, positioning method and comorbidities. In addition to stabilization of the fracture, the posterior approach also allows reducing preoperative kyphotic position of the cervical spine. In all patients, we achieved a stable situation with complete bone fusion of the anterior part of the spinal column and lateral masses at one year follow-up. Conclusion: Spinal navigation based on intraoperative CT imaging has proven to be a reliable and safe method of stabilizing cervical spine with ankylosing spondylitis. The strategy of posterior stabilization seems to be a suitable method providing high primary stability and the conditions for a subsequent high fusion rate.