快速成形个体化导航模板辅助枢椎椎板螺钉的植入

目的 观察快速成形(rapid prototyping,RP)个体化导航模板在C2椎板螺钉植入中的初步临床应用.方法 对患者行上颈椎CT连续扫描,三维重建软件Amira 3.1建立C2三维模型,以STL格式导出模型.在UG Imageware 12.0平台打开三维重建模型.利用逆向工程(reverse engineering,RE)原理寻找C2椎板螺钉的最佳进钉钉道.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.拟合模板和椎板孔道成定位模板,将椎体和定位模板通过激光RP技术生产出实物模板,手术时利用实物导航模板与椎体的后部结构相吻合,通过导航孔进行C2椎板螺钉的定位,植入椎板螺钉.术后根据X线片和CT扫描评价椎板螺钉的位置.结果 采用RP导航模板为5例患者植入C2椎板螺钉,术后CT扫描显示椎板螺钉的位置准确,未出现相关C2椎板螺钉植入的并发症.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C:椎板螺钉的置钉提供了一种新的方法 ,具有较大的应用前景.

Placement of C2 laminar screws using rapid prototyping navigational temple

Objective To observe the placement of C2 laminar screws using rapid protyping naviga-tional template. Methods CT scan of C2 vertebrae was performed. 3-D model of C2 vertebrae was reeon-structured by software amira 3.1 and was preserved in STL format. Then 3-D model was runed in sofeware UG imageware 12.0, the best trajectory of laminar screw was extracted according to the reverse engineering principle. A virtual navigational template was established according to he lamina anatomic trait. 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 laminar screw. The accuracy of screw placement was confirmed with postoperative X-ray and CT scanning. Results The digital navigational tem-plate had been established and used in the five patients undergoing posterior cervical fusion. Overall, eleven C2 laminar screws were placed. There were no complications in any of the patients. Postoperative computed tomographic (CT) scanning was available allowing evaluation of placement of C2 laminar screws, all of which were in good position with no spinal canal violation. There were not complications of related screw insertion. Conclusion A novel method of C2 laminar screw placement using Reverse Engineering and rapid prototyp-ing has been developed, the navigational template is found to be highly accuracy and has great expectation.