计算机辅助导航模板在下颈椎椎弓根定位中的临床应用

目的 利用逆向工程(reverse engineering,RE)原理和快速成型(rapid prototyping,RP)技术设计一种新的下颈椎椎弓根定位的方法,并探讨其临床应用.方法 采用患者CT连续扫描数据集,三维重建软件Amira 3.1建立颈椎三维模型,以STL格式导出模型.在UG Imageware 12.0平台打开三维重建模型,定位三维参考平面.利用RE原理寻找椎弓根的最佳进钉钉道.提取椎板的表面解剖学形态,建立与椎体后部解削学形态一致的模板.拟合模板和椎弓根孔道成定位模板,将椎体和定位模板通过激光Rp技术生产出实物模板,手术时利用建立的定位模板与椎体的后部结构相吻合,通过导航孔进行下颈椎椎弓根的定位,植入椎弓根螺钉.术后根据X线片和CT扫描评价椎弓根螺钉的位置.结果 建立了制作个体化导航模板的方法,通过RP技术生产出的导航模板具有较好的准确性,适用于颈椎椎弓根螺钉的导航定位.结论 利用RE原理和RP技术为颈椎椎弓根的定位提供了一种新的方法,该方法为下颈椎椎弓根螺钉植入提供了一种新的方法,具有较大的应用前景.

Clinical application of Computer-assisted navigation template in lower cervical pedicle stereotaxy

Objective To develop and validate a new method of lower cervical pedicle stereotaxy by reverse engineering and rapid prototyping, and explore its clinical application. Methods CT scan of cervi- cal vertebrae was performed, and three dimensional software amira 3.1 was used to establish the cervical 3- D model. 3D model was preserved by STL code. To open 3D model in UG imageware12.0, and locate 3D coordinate system. To extract the best pedicle channel according to the Reverse Engineering. Establish a template according with the laminec anatomic trait, and fuse the best pedicle channel and template as the navigational template. Manufacture exact vertebrae and navigational template by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist with surgical navigation anti the placement of pedi- cle screw. Accurate screw placement was confirmed with postoperative X-ray and CT scanning. Results A new method of spinal pedicai stereotaxy was established by reverse engineering and rapid prototyping. The navigational template were founded to get highly accurate for stereotaxy. Conclusion The authors have developed a novel method of cervical pedicle location using Reverse Engineering and rapid prototyping. Pro- vide a new method for pedicle .screw insertion and have great expectation.