数字化导航模板在上颈椎椎弓根定位中的初步临床应用

Primary clinical result of digital template as navigation to supper cervical pedicle instrumentation

目的观察数字化导航模板在上颈椎椎弓根定位中的初步临床应用。方法对患者进行CT连续扫描，三维重建软件Amira 3．1建立上颈椎三维模型，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，建立与椎体后部解剖学形态一致的模板。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，通过导航孔进行上颈椎椎弓根的定位，置入椎弓根螺钉。术后根据X线片和CT扫描评价椎弓根螺钉的位置。结果通过3例患者建立了制作个体化导航模板的方法，术后CT扫描显示椎弓根螺钉的位置准确，未出现相关椎弓根钉置入并发症。结论利用RE原理和RP技术生产出的导航模板具有较好的准确性，为上颈椎椎弓根置钉提供了一种新的方法，具有较大的应用前景。

Objective To observe the primary clinical result of digital template as navigation to the upper cervical pedicle instrumentation. Methods CT scan of upper cervical vertebrae was performed. 3-D model of upper cervical vertebrae was recon structured by software Amira 3. 1 and was preserved in STL format. Then 3-D model was run in software UG Imageware 12. 0, the best pedicle channel was extracted according to the reverse engineering principle. A virtual navigational template was established according to he lamina anatomic trait, and the best pedicle channel. The virtual vertebrae and navigational template were manufactured using rapid prototyping. The navigational template was sterilized and used intra operative to assist with the placement of pedicle screw. The Accuracy of screw placement was confirmed with postoperative X-ray and CT scanning. Results The digital navigational template had been established and used in the 3 cases, the good trajectory of cervical pedicle had been showed by the CT scan of post operation. There were not complications of related pedicle screw insertion. Conclusions A novel method of upper cervical pedicle location using Reverse Engineering and rapid prototyping has been developed; the navigational template is found to be highly accuracy and has great expectation.