髋关节置换术中2种不同髋关节假体的有限元分析:应力集中和位移变化比较

Finite element analysis of two different hip prostheses in hip arthroplasty:Comparison of stress concentration and displacement

目的:应用有限元方法模拟不同假体下全髋关节置换术中应力集中和位移变化情况,通过分析这2种指标术后可能产生的假体晃动和松动等临床结果,为临床实际情况分析提供参考。方法:选取1例正常男性志愿者的髋关节CT数据进行三维重建,取2种假体(Corail和Synergy porous)进行建模处理,通过Mimics和ABAQUS等软件进行股骨非均质属性赋值,分析人体以站立姿态下2种股骨模型的应力集中与位移变化。结果:Corail模型股骨与Synergy porous模型股骨最大应力多集中于假体远端1/3处与近端拐角处,最大应力分别为31.82和55.05MPa,均小于股骨屈服强度(138MPa)。Corail与Synergy porous型假体模型最大相对位移分别为0.604和0.747mm,均小于极限位移(1.500mm)。以上指标均满足置换要求。结论:Corail型假体在模拟后应力集中与位移变化结果方面均优于Synergy porous型假体,不同类型假体的有限元分析可为髋关节置换术的预后效果评价提供重要参考。

Objective:To apply the finite element method to simulate the stress concentration and displacement of different hip prostheses in total hip arthroplasty,to analyze the clinical outcomes of prosthesis subsidence and loosening after surgery with these two indicators,and to provide reference for clinical surgeons.Methods:The three-dimensional hip from the hip CT data of a normal male volunteer was reconstructed.Two types of prosthesis models were built(Corail and Synergy porous).The femoral heterogeneous properties were assigned by Mimics,ABAQUS and other softwares.The stress concentration and displacement changes of two hip prostheses in the posture of standing were analyzed.Results:The maximum stress of Corail and Synergy porous hip prostheses was mostly concentrated in the one third of distal end and the proximal corner,and the maximum stresses were 31.82 and 55.05 MPa,respectively,which were less than the femoral yield strength(138 MPa).The maximum relative displacements of Corail and Synergy porous prosthesis models were 0.604 and 0.747 mm,respectively,which were less than the ultimate displacement(1.500 mm).The results above met the hip replacement standards.Conclusion:Corail stem prosthesis has a better behavior in stress concentration and displacement than Synergy porous prosthesis by finite element analysis.The finite element analysis of different hip prosthesis may provide the important references for the prognosis of total hip arthroplasty.