快速成型导向模板技术在枢椎椎板交叉螺钉置钉中的应用

A novel computer-assisted drill guide template for C2 crossing laminar screws placement： a cadaveric experimental study

目的验证在快速成型导向模板辅助下枢椎椎板交叉螺钉置钉的安全性、准确性及偏差因素分析。方法选取正常颈椎标本18具，行螺旋CT扫描。扫描数据经Mimics软件三维重建后行枢椎椎板交叉螺钉最佳钉道的计算机辅助设计，建立与枢椎椎板及棘突后表面解剖结构互补的基板，组合形成导向模板。在激光快速成型机上进行导向模板实体化，利用导向模板辅助置钉。扫描置钉后的标本，分割重建螺钉钉道路径。将置钉前后的标本配对拟合，测量理想钉道与实际螺钉的进钉点及进钉角度。结果上、下位椎板螺钉理想钉道长度分别为（29．12±1．39）、（29．62±1．40）mm；

Objective To validate the security and accuracy of C2 crossing laminar screws place- ment under the assistance of rapid prototyping oriented template. Methods CT scan was performed in the 18 normal cervical specimens. The data were reconstructed by software Mimics 10.01. The ideal trajectory for C2 crossing laminar screws were designed with a baseplate which is a complementary template for posteri- or lamina and spinous process, then materialize drill guide template in rapid prototyping machine. The screws were segmented in Mimics after CT scanning. The entry point and nail way direction of the ideal and actual trajectory were measured after matching the position of the pre- and post-operative specimen, whose coordinate axis has been fitted.