Feasibility of 3D-printed guidance drill template for bilateral anterior cervical pedicle screw placement

English Keywords:Anterior cervical pedicle screw  3D printing molding  Navigation guide plate  Navigation guide template  Trajectory design

English Abstract:

  【Abstract】 Objectives: To study the accuracy of template-assisted anterior cervical pedicle screw placement that based on 3D printing technique and digital orthopedics technique. Methods: Ten normal adult cervical specimens were included, 5 males and 5 females. The anterior soft tissue of vertebra was removed before CT scan evaluation, and the data were imported to Mimics software by DICOM format. Cervical vertebra was 3D modeled and ideal trajectory was designed for anterior cervical pedicle screw, the STL data were imported to 3D printer after the establishment of navigation template model. Finally, drill guidance template was materialized by stereolithography apparatus. Anterior pedicle screws were placed under the guidance of navigation templates and the accuracy was assessed by postoperative CT scan and X-ray. Results: 120 anterior pedicle screws in total were inserted in 10 specimens on both sides from C3 to T1. All the screws were divided into 4 levels according to their placements: grade 0, showing a perfect position without involvement of pedicle cortical bone(115); grade 1, less than 25% of screw diameter violation(1); grade 2, 25% to 50% of screw diameter violation(3); grade 3, more than 50% of screw diameter violation. The accuracy rate of screws placement was 95.8%. Conclusions: Individualized navigation guidance template which based on 3D printing and digital orthopedics technique, can effectively improve the accuracy of anterior cervical pedcile screw placement and reduce the risk of intraoperative injury, and shows a promising prospect for clinical application.