脊柱椎弓根定位数字化导航模板的试验研究

目的 利用逆向工程原理和快速成型技术为脊柱椎弓根定位提供一种新的方法,并通过尸体标本试验验证其可行性.方法 选取老年男性正常人体脊柱标本一具,范围:L1-3 CT连续扫描数据集,三维重建软件Amira3.1建立L4-3,椎体模型,以.stl格式导出模型.在UG lmageware 12.0平台打开三维重建模型,定位三维参考平面.利用椎弓根内切圆原理设计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快速成型技术生产出实物模板.将制作的实物模板与标本的椎板相吻合,利用导航模板的导航孔进行椎弓根的定位,置入椎弓根钉,术后利用X线片、CT扫描验证椎弓根钉位置的准确性.结果 建立了椎体个体化钉道模型,通过快速成型技术生产出的带椎弓根准确信息的导航模板具有较好的准确性.结论 利用逆向工程原理和快速成型技术为椎弓根的定位提供了一种新的方法,该方法为脊柱椎弓根螺钉的置入提供了一种新的方法,值得进一步在临床推广应用.

A new digital template as navigation to spinal pedicle instrumentation

Objective To determine the accuracy of a novel method of spinal pedicel stereotaxy which is developed by Reverse Engineering and rapid prototyping.Methods A 3-D CT scan of L1-L3 vertebrae of an old man cadaver was performed.The CT data were transferred via a DICOM network to a computer workstation.Three dimensional software amira3.1 was used to establish the L1-L3 3-D model.The 3-D model was preserved by STL code.The 3-D model was processed in UG imagewarel2.0 and the 3D coordinate system was located.The best pedicle channel was designed according to the Reverse Engineering.A template was established which accorded with the laminar anatomic traits.The best pedicle channel and the template were integrated into a navigational template.An exact vertebral and navigational template was manufactured by rapid prototyping(SLA technique).The accuracy of pedicel instrumentation was confirmed by X-ray and CT scan.Results A new method of spinal pedicel stereotaxy was established by Reverse Engineering and rapid prototyping.The navigational template was found to be highly accurate.Conclusion The spinal stereotaxy developed by Reverse Engineering and rapid prototyping provides a new method for pedicle screw insertion.