1535. Customized 3D-printed guiding template for pedicle screw fixation in upper cervical spine

Authors: Chih-hui Chang; Chih-Lung Lin; Yu-Feng Su (Kaohsiung, Taiwan)

Introduction: Upper cervical spine instability or deformity were caused by many diseases. Surgical intervention for upper cervical spine instability or deformity often requires a fixation system but precise and safe of insertion upper cervical spine posterior pedicle screws remains challenging. Aims of this study is to evaluated screws accuracy and clinic results of upper cervical spine pedicle screw insertion assist with modified customized 3D-printed guiding template. Methods: We use CT-base cervical spine bone image reconstruction model to develop customized 3D-printed guiding template. Drilling path is planned by self-developed computer software, followed by sleeve and holder designed along the trajectory, and then, a guiding block is produced by 3D printer. Screw accuracy were evaluated by grading system: grade 0: no deviation, grade 1: deviation of ≦2 mm, grade 2: deviation of >2 mm and ≦4 mm, grade 3: deviation of >4 mm. Results: A total of 33 pedicle screws in 9 cases were placed. There were no significant differences in transverse or sagittal angles between pre-operation designed trajectories and post-operative pedicle screws (p > 0.05). Of the 33 screws, 29 (87.8%) were rated as grade 0, 2(6.0%) as grade 1a, 2(6.0%) as grade 1b and none as grade 2 or 3. Malposition of these screw did not cause any neurological or vascular deficit. Conclusion: The customized 3D-printed guiding template for upper cervical spine pedicle screw insertion is clinically feasible because of advantages of screw accuracy and safety.