数字化导航模板辅助胸椎椎弓根螺钉置钉实验研究

目的探讨数字化导航模板辅助胸椎椎弓根螺钉置入的准确性和可行性。方法将20具尸体胸椎标本随机分为两组,每组10具标本,由同一位具有一定腰椎椎弓根螺钉置钉经验但无胸椎椎弓根螺钉置钉经验的骨外科医师分别采用导航模板法和徒手法进行胸椎椎弓根螺钉的置入手术。术后CT扫描比较两种方法的置钉准确性。结果导航模板法和徒手法各置入240枚螺钉。对两种方法的置钉准确率及风险螺钉发生率进行比较,导航模板法的置钉准确率高于徒手法,风险螺钉发生率低于徒手法,差异有统计学意义（P〈0.05）。徒手法学习曲线明显,导航模板法学习曲线不明显。结论数字化导航模板辅助胸椎椎弓根螺钉置入安全可行,手术操作简单,置钉准确率高,为胸椎椎弓根螺钉置入提供了一种新的方法。

Empirical study of transpedicular screw placement assisted by digital navigation templates in the thoracic spines

Objective To investigate the accuracy and feasibility of transpedicular screw placement assisted by the navigation templates in cadaveric thoracic spines. Methods Twenty thoracic cadavers specimens were randomly divided into two groups （n = 10）, group 1 for navigation template and 2 for bare-handed. All screws were implanted by the same orthopedic surgeon with transpedicular screw placement experiences in lumbar spines but lacked experiences in thoracic spine placement. Two hundred and forty thoracic screws were inserted respectively by navigation template or bare-handed method. CT scans were performed to evaluate screw exit rates and orientation relative to the pedicle axis. The relative position of the screw to the pedicle was graded. Results In the group 1 accuracy rate of screw placement is higher compared with group 2, while the incidence of the risk of the screw misplace is lower than that of bare-handed method with statistical significance （P〈 0.05）. The learning curve of bare-handed method was significant longer but not for navigation template method. Conclusion Transpedicular screw placement assisted by digital navigation templates in thoracic spines may be used as a novel method for its advantage of safety, feasibility, simple operative procedure and screw placement accuracy.