计算机导航中髋臼杯角度设定的可行方法及其精确性验证

Feasibility and accuracy of image based surgical navigation system in setting the orientation of acetabular component

目的:分析计算机导航对人工髋关节臼杯置入角度设定的可行性方法并评估其精确性。方法:将CT扫描资料进行计算机三维影像重建,并进行虚拟像与真实骨盆间匹配对应,在虚拟空间中,确立骨盆冠状、矢状、水平及前倾平面,并以此为基准进行计算机导航辅助下多角度设定的臼杯置入,由角度测量仪对臼杯置入角度的精确性进行测量验证。结果:导航辅助臼杯外展角置入,设定值与真实值间差异(0.46±1.53)°;对于臼杯前倾角,差异(0.79±1.37)°。两次独立操作所得结果作配对t检验,臼杯外展及前倾角均无显著性差异(t外展=1.15,t前倾=1.14,P>0.05)。结论:研制的基于CT影像资料的计算机导航可有效的设定臼杯假体置入角度,精确地引导臼杯置入。

Objective： To evaluate the feasibility of image based surgical navigation system in setting the orientation of acetabular component and improving the accuracy of it in total hip arthroplasty. Methods： CT scan data of one cadaver without deformity were used to reconstruct 3-D image, the coronal, sagital and horizonal planes of pelvis were established to confirm the abduction and anteversion of acetabular cup. Matching between cadaver and its 3-D images was performed, and the acetabular cup was implanted in various angle using image based navigation, then the angles were measured with matched goniometers in order to evaluate the accuracy. Resulta： Difference of abduction angle between the setting one and real one was （0.46±1.53）°, and that for anteversion angle was （0.79±1.37）°. There was no significant difference between the first and second time of placement of acetabular component with the help of navigation （P〉0.05）. Conclusion： Reconstruction of reference plane basing on the CT scan data was feasible to confirm the desired orientation of acetabular component. Precise placement of acetabular component in the desired orientation can be achieved by the image based hip navigation system in the total hip arthroplasty.