个体化导航模板辅助颈椎椎弓根螺钉置入与徒手螺钉置入的准确性比较

摘要

目的 比较个体化导航模板辅助颈椎椎弓根螺钉置入与徒手螺钉置入的准确性.方法 选取颈椎完整的成人尸体8具,随机分为导航辅助组和徒手置钉组各4具.导航辅助组对尸体颈椎(C3~7)进行CT扫描,重建颈椎三维模型,设计与颈椎椎板吻合的反向模板,构建个体化导航模板的数据模型,采用快速成型技术打印个体化导航模板;将导航模板与颈椎椎体后部紧密贴合,辅助置入颈椎椎弓根螺钉.徒手置钉组采用Abumi椎弓根入口直接暴露法进行徒手螺钉置入.术后即刻行颈椎X线和CT断层扫描,观察螺钉置入情况,评价置钉效果,计算置钉准确率.结果 导航辅助组共置入螺钉32枚,置钉效果为Ⅰ级31枚、Ⅱ级1枚,置钉准确率为96.8%(31/32);徒手置钉组共置入螺钉32枚,置钉效果为Ⅰ级29枚、Ⅱ级3枚,置钉准确率为90.6%(29/32);导航辅助组置钉准确率高于徒手置钉组(P<0.05).结论 个体化导航模板辅助颈椎椎弓根螺钉置入的准确性高于徒手螺钉置入.%Objective To compare the accuracy between cervical pedicle screw placement assisted by the individual navigation template and free hand pedicle screw placement.Methods Eight adult cadavers (4 male and 4 famale) were randomly divided into two groups: individual navigation template group and free hand pedicle screw placement group.The cadaver cervical specimens (C3-7) of the individual navigation template group were scanned by CT and the 3D model was reestablished.According to the morphological feature of the posterior cervical spine elements, the reverse template was designed.Then, the best pedicle screw channels were fused into bilateral navigation template.The navigation template was manufactured by rapid prototyping technology.Cervical pedicle screws were inserted with the assistance of navigation templates.Patients in the free hand pedicle screw placement group were treated with Abumi pedicle entrance method.Postoperative X-ray and CT scanning were used to evaluate the accuracy of screw placement.Results A total of 32 pedicle screws were implanted in the individual navigation template group, 31 screws were placed entirely within the pedicle (grade Ⅰ), 1 screw perforated the medial cortex of pedicle (grade Ⅱ), and the accuracy of screw placement was 96.8%.A total of 32 pedicle screws were implanted in the free hand pedicle screw placement group, 29 screws were placed entirely within the pedicle (grade Ⅰ), 3 screws perforated the medial cortex of pedicle (grade Ⅱ) and the accuracy of screw placement was 90.6%.The accuracy of screw placement of the individual navigation template group was higher than that of the free hand pedicle screw placement group (P<0.05).Conclusion The individual navigation template-assist pedicle screw placement has a higher accuracy than the free hand pedicle screw placement.