Accuracy and Safety of Using Customized Guiding Templates for Cervical Pedicle Screw Insertion in Severe Cervical Deformity, Fracture, and Subluxation: A Retrospective Study of 9 Cases

Objective: To assess accuracy and safety of self-developed customized guiding templates for cervical pedicle screw (CPS) insertion surgery. Methods: From July 2016 to December 2017, 57 screws were implanted in 9 patients with the assistance of customized guiding templates. Customized guiding templates were manufactured from acrylonitrile-butadiene-styrene plastic material using a three-dimensional printer after establishing pedicle screw trajectories for each vertebra with the assistance of a virtual surgical planning software program, developed by our team, for the insertion of CPSs. Results: CPSs were evaluated using the following grading system: grade 0 (contained), grade 1 (exposure), grade 2 (perforation), and grade 3 (penetration). Each patient underwent postoperative computed tomography to evaluate accuracy of screw position. Of 57 screws, 54 were graded 0, and 3 were graded 1; no screws were graded 2 or 3. No vascular or nerve injuries were noted after the operations. Conclusions: CPSs, which provide strong biologic strength, are especially suitable for treating osteoporosis and severe deformity. However, CPS insertion remains a challenging procedure with high incidences of vascular and nerve injuries reported. The results of this study indicate that use of customized guiding templates can improve safety of CPS insertion surgery.