髋关节发育不良髋臼内壁内移截骨全髋置换术的三维有限元分析

目的利用三维有限元力学分析方法,研究髋关节发育不良患者行髋臼内壁内移截骨全髋关节置换术对髋臼假体-骨界面间的应力分布情况的影响。方法选取髋关节发育不良患者的骨盆为实验对象,用螺旋CT做全长连续扫描,然后利用计算机仿真技术对CT图像进行三维重建,建立髋关节发育不良骨盆模型。利用计算机辅助设计(CAD)功能,在计算机环境中对重建模型进行髋臼内壁内移截骨全髋关节置换的模拟手术,利用有限元分析软件SolidWorks对重建模型进行有限元网格化,最后使用SolidWorks软件中的力学分析工具包COSMOS对网格化的模型进行力学分析,得到髋臼假体-骨界面间的应力分布情况的实验结果,对实验结果进行统计和分析,观察术后髋臼假体-骨界面间的应力分布情况。结果术后髋臼压应力分布符合后上象限最大,前下象限最小,前上象限、后下象限居中的趋势。剪切应力分布情况为后上象限剪切应力最大,其他象限无差异。结论髋臼内壁内移截骨术没有改变正常髋臼的应力分布情况。

The three dimensional finite element analysis of the total hip replacement with osteotomy of acetabular medial wall in dysplasia of hip

Objective Using the three dimensional finite element analysis,we studied how the different positions of the osteotomy of acetabular medial wall total hip replacement(THR) in treating the dysplasia of hip affected the stress distribution in acetabular cup-bone interface.Methods We selected the pelvis in the dysplasia of hip,and scanned the pelvis by CT.Using the computer simulation technology to reconstruct the three-dimensional model of the pelvis for observing the dysplasia of hip from CT scan picture.Using the computer aided design(CAD) function of SolidWorks,we simulated the osteotomy of acetabular medial wall and THR in the pelvis model.Then the pelvis and acetabular cup model were meshed.Using the mechanics analysis tool bag-COSMOS in SolidWorks to analyze three-dimensional model,we got the stress data in acetabular cup-bone interface.After the statistical analysis of the experiment result,we observed how the different position of osteotomy affects the stress distribution in acetabular cup-bone interface.Results The condition of compressive stress of the postoperative acetabulum;posterior superior quadrant was maximum,anteroinferior quadrant was minimum,anterior superior quadrant and posterior inferior quadrant was moderate.The condition of shear stress of the postoperative acetabulum;posterior superior quadrant was maximum,there was no difference in other quadrants.Conclusion The osteotomy of acetabular medial wall did not change the stress condition of normal acetabulum.