Guide for Navigating 3D-Printed Cortical Bone Trajectory Screws in Situations with Previously Instrumented Pedicle Screws

Purpose Traditional surgical interventions for adjacent segment disease (ASD) repair commonly mandate the exposure of all pre-existing hardware. Cortical bone trajectory (CBT) screws have been innovated to amplify the contact surface between the screw and cortical bone, offering a promising approach to mitigate the challenge sassociated with traditional ASD repair surgeries. Methods In this study, a tangible manifestation of the cortical bone trajectory screw navigation guide was produced by utilizing a 3D printer to facilitate the insertion of cortical bone trajectory screws. A comprehensive set of radiographic images and computed tomography scans was gathered to evaluate the accuracy of K-wire through CBT screw guide inside the vertebrae which was previously implanted with a pedicle screw. Results The variance in the K-pin circle centre distance before and after surgery ranges from 0.2 mm to 3.54 mm. The K-pin angle difference falls within the range of 0.4° to 5.8° in the sagittal plane, ranges from 1.46° to 1.7° in the transverse plane. Conclusion This research process has successfully yielded a navigation guide that holds promise for inserting CBT screw even with previously pedicle screw at the same vertebrae.