非均匀材料股骨在不同负荷情况下的生物力学分析

Biomechanical analysis of non-uniform material femur under different loads

背景:目前股骨有限元模型仅分析单一负荷下的生物力学特性,不同负荷条件下的骨应力应变分布有助于评估和预测疾病恢复情况并改善手术效果。目的:通过建立股骨三维模型,探索人体在不同姿势下股骨近端力学分布特点,明确股骨易骨折危险区域。方法:基于人体股骨CT影像资料,利用Mimics,Geomagic Studio,Hypermesh以及Abaqus等三维重建软件建立股骨有限元模型,沿重力方向,在股骨冠状面与矢状面,分别成角-20°,-10°,0°,+10°,+20°,共5组工况,股骨头施加力300 N,股骨下段添加固定约束,观察股骨不同位置在不同角度生理负荷作用下的应力与应变的分布特征。结果与结论:在冠状面+10°与矢状面-20°股骨的应力值与应变值出现峰值,股骨应力值整体分布:股骨干>股骨转子下>股骨颈,股骨应变值整体分布:股骨干>股骨颈>股骨转子下。患者髋内收10°站立位下与髋外展20°站立位下会使得股骨应力值与应变值增大,股骨整体力学所受负荷会增大。

BACKGROUND:The current femoral finite element model analyzes only the biomechanical studies at a single load,and the stress strain distribution of the bones under different load conditions helps to evaluate and predict the disease recovery and improve the surgical results.OBJECTIVE:Through the establishment of a three-dimensional model of the femur,to explore the mechanical behavior of the proximal femur in different postures of the human body,and clarify the risk area of femur fracture.METHODS:Based on the CT image data of the human femur,Mimics,Geomagic Studio,Hypermesh and Abaqus and other three-dimensional reconstruction softwares were used to establish a finite element model of the femur.Along the direction of gravity,on the coronal and sagittal planes of the femur,the shape surfaces were angled at-20°,-10°,0°,+10°,+20°,a total of five groups of working conditions,and the femoral head exerted a force of 300 N.The lower part of the femur added a fixed constraint.At different positions of the femur,the distribution characteristics of stress and strain were observed under angular physiological load.RESULTS AND CONCLUSION:The stress and strain of the femur peaked at+10°in the coronal plane and-20°in the sagittal plane.The overall distribution of femoral stress values was femoral shaft>subtrochanteric>femoral neck;the overall distribution of femoral strain values was femoral shaft>femoral neck>subtrochanteric.The stress value and strain value of the femur could increase under the standing position of 10°hip adduction and 20°of hip abduction,and the load on the overall mechanics of the femur could increase.