股骨头置换重建股骨矩的三维有限元分析

摘要

目的 利用三维有限元技术对高龄患者股骨矩缺损型粗隆间骨折进行建模,分析在髋关节置换中利用骨水泥重建及骨折碎片复位重建股骨矩后的生物力学特性, 并分析2种重建方法的稳定性.方法 建立股骨矩缺损型粗隆间骨折模型(Evans-jeasonⅣ型理想模型),在骨水泥型髋关节置换中分别利用骨水泥重建及股骨矩骨折碎片重建股骨矩,利用三维有限元方法模拟及分析患者双足站立位时,在正常载荷下2种股骨矩重建方法的生物力学稳定性.结果力学加载后,骨水泥重建股骨矩模型最大应力值及最大位移值均较股骨矩骨折复位型小,二者应力值分别为0.635、0.641 MPa,位移值分别为0.028 74、0.028 91 m.分别在2种模型上选取5个相同位点的应力值和位移值作t检验分析,2种模型关节假体的应力值及位移值比较,差异均有统计学意义(P<0.05).结论 2种股骨矩重建方式在假体应力大小、应力分布及假体位移方面有差异,在应力分布均匀性、应力大小及初始微动方面,骨水泥重建型均优于股骨矩骨折复位型.对于股骨矩缺损型粗隆间骨折行骨水泥型髋关节置换时,采用骨水泥直接重建股骨矩生物力学稳定性更好.%Objective To conduct the modelling of femoral calcar defected intertrochanteric facture by using the three-dimensional finite element technology,to analyze the biomechanical characteristics of rebuilding femoral calcar by using the bone cement reconstruction and restoration of fracture fragments in hip replacement ,and to analyze the stability of two kinds of recon struction method. Methods The fracture model of femoral calcar defected intertrochanteric facture (Evans-Jeason typeⅣideal model) was established. The femoral calcar was reconstructed by using the bone cement reconstruction and restoration reconstruc-tion of fracture fragments in hip replacement. The three-dimensional finite element method was used to simulate and analyze the biomechanical stability of the two kinds of femoral calcar reconstruction at the feet standing position and under normal load. Re-sults After mechanical loading,compared with the femoral calcar fracture restoration,the maximum stress value and maximum displacement value in the femoral calcar reconstruction model by bone cement were smaller than those in the femoral calcar re-construction model by femoral calcar fracture reduction,the stress values were 0.635,0.641 MPa,the displacement values were 0.028 74,0.028 91 m,respectively. The stress values and displacement values at 5 same points were selected from each model for conducting t test analysis. The stress values and displacement values had statistical differences between these two models of athroplasty(P<0.05). Conclusion Two kinds of femoral calcar reconstruction mode have differences in the aspects of stress intensity , stress distribution and athroplasty displacement,the bone cement reconstruction mode is superior to the femoral calcar fracture reduction mode in the aspects of uniformity of stress distribution ,stress intensity and initial micromotion. Adopting bone cement for directly reconstructing humeral calcar in the bone cement hip replacement of femoral calcar defected intertrochanteric facture has better biomechanical stability.