动态测量非生理状态下髋臼外展角及临床意义

The dynamic measurement of acetabulum abduction angle under non-physiological state and its clinical significance

目的通过MSCT三维重建骨盆,测得骨盆在不同倾斜程度下髋臼外展角数值,探讨非生理状态下全髋关节置换术(THA)个体化置入髋臼假体的放置角度。方法选择100位患者(即200个髋臼)为研究对象行螺旋CT扫描,利用容积再现(VRT)技术把骨盆重建为立体图像,为模拟病理状态进而对骨盆进行不同程度的前倾(以10°为间隔,从10°前倾到90°),利用多平面重组(MPR)重建出冠状位图像,进而分别测得两侧髋臼外展角。计算平均值和标准差,绘制出非生理状态下髋臼外展角随骨盆倾度改变而发生变化的相关性变化曲线,找到规律。结果 MSCT法检测髋臼外展角结果如下:当骨盆倾度从10°逐渐增至90°时,外展角的变化曲线呈抛物线。当骨盆倾度为70°时,外展角最大为48°,说明此状态下的髋臼对股骨头覆盖最好,关节的稳定性也最佳。性别对髋臼外展角的影响结果表明在相同条件下,不同性别间的外展角差异无统计学意义(P>0.05)。结论髋臼的外展角随着骨盆倾度的变化而发生改变,外展角的变化曲线呈抛物线,不同性别之间的髋臼外展角没有显著性差异;说明性别因素对髋臼外展角的影响不大,髋臼外展角随骨盆倾度动态变化的规律,可以为临床THA髋臼假体放置角度提供理论依据。

Objective To detect acetabulum abduction angle of pelvis at different sloping degrees through multi-slice spiral CT（ MSCT） three-dimensional reconstruction pelvis,and to explore the reasonable placing angle during total hip arthroplasty（ THA） under non-physiological state. Methods One hundred patients（ 50 males and 50 females） including 200 acetabulums were scanned by MSCT to reconstruct pelvis into stereoscopic picture by means of valume rendering technique（ VRT）,then to make pelvis at different inclination（ 10° ~ 90°） in simulated pathological conditions,to reconstruct coronal view image by multiplanar reconstruction（ MPR） so us to measure abduction angle of acetabulum in both sides. The statistical software was used to calculate mean value and standard deviation,to draw the related changing curve of abduction angle of acetabulum changing with pelvis sloping degree in non- pathological conditions in order to find out related regulation. Results The results by MSCT showed that acetabular abduction angles were as follows： when pelvis inclination was changed from 10° to 90°,abduction angle change showed a parabola curve,when pelvis inclination was 70°,the abduction angle was 48°,which suggested that not only the acetabular coverage to femoral head was the best,but also the articular stability was the best.Besides there was no significant difference in acetabulum abduction angle under the same condition between males and females（ P 〈0. 05）. Conclusion There is no significant difference in the acetabular abduction angle between males and females,which suggests that the influence of gender factors on acetabular abduction angle is not obvious. The acetabular abduction angle is changed with the changing of pelvic inclination,showing a parabola,thus,which can provide theoretical basis for selecting reasonable placing angle in THA.