3D打印导航模板引导双侧下颈椎前路椎弓根螺钉置钉的可行性

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

中文关键词:  颈椎前路椎弓根螺钉  3D打印成型  数字化骨科  导航模板  钉道设计

英文关键词:Anterior cervical pedicle screw  3D printing molding  Navigation guide plate  Navigation guide template  Trajectory design

中文摘要:

  【摘要】 目的：通过3D打印技术及骨科数字化技术制作下颈椎前路椎弓根螺钉置钉导航模板，观察模板辅助下置钉的准确性。方法：选取正常成人颈椎湿性标本10具（男、女各5具），将椎前软组织剔除，采用64排薄层CT扫描后获取其DICOM格式数据，导入Mimics软件后三维建模并为颈前路椎弓根螺钉选取理想钉道，设计建立螺钉导航模板后导出其STL数据，通过3D打印机快速打印成型。在导航导板引导下进行下颈椎前路椎弓根螺钉置钉，通过X线及CT评价螺钉的准确性。结果：10具尸体分别于C3~T1每节段置入2枚螺钉，共计120枚，根据螺钉的位置将其分为4级：0级，螺钉完全在椎弓根内，共115枚；1级，螺钉穿破椎弓根皮质，穿出部分小于螺钉直径的25%，1枚；2级，螺钉穿破椎弓根皮质，穿出部分为螺钉直径的25%~50%，3枚；3级，螺钉穿出椎弓根部分大于螺钉直径的50%，1枚。5枚穿破椎弓根皮质者2枚穿破椎弓根内侧皮质，3枚穿破外侧皮质，总体准确性为95.8%。结论：在湿性尸体颈椎标本上应用3D打印及骨科数字化技术制作的导航模板辅助行下颈椎前路椎弓根螺钉置钉的准确性高，为临床应用提供了依据。

英文摘要:

  【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.