Traditional pedicle screw versus cortical bone trajectory in the upper thoracic spine: A technical description and retrospective comparative review

Background: The cortical bone trajectory (CBT) screw is a relatively new vertebral fixation technique described for use in the lumbar spine by Santoni and Hynes et al. It has been shown to have advantageous biomechanical properties with respect to torsional and pullout strength. The evaluation of CBT in cervical-thoracic fixation has been quite limited. The primary objective of the current study was to determine the mid to long term results of CBT over traditional pedicle screw fixation in the upper thoracic spine. Methods: The current study completed a retrospective chart review of consecutive patients undergoing posterior cervical thoracic fixation in the setting of degenerative, trauma, infection and oncologic etiologies at a single academic centre. Patients with a greater than 1 year radiological follow up were included in the research study. Data was collected by an independent observer, which included patient demographics, complications. Preserved immediate postoperative sagittal alignment at 1 year was considered the primary outcome of this study. Results: Of the 47 patients who met the inclusion criteria, 18 had undergone upper thoracic spine instrumentation with CBT and 28 had TPS trajectories. The operative time was found to be significantly lower in the CBT group (p