股骨近端骨干组配式假体在下蹲步态下的三维有限元分析

摘要

对骨干组配式假体重建股骨近端在下蹲步态下的生物力学特性进行分析,探究骨干组配式假体在下蹲步态下的稳定性及应力分布变化规律.根据已获得的CT数据利用计算机辅助技术建立完整的股骨-骨干组配式假体的三维有限元模型,将下蹲步态周期拆分为前期、中期与末期.通过对三维有限元模型施加下蹲步态下的关节力与肌肉力载荷,获得股骨-骨干组配式假体的应力分布.研究结果表明:在下蹲步态下股骨-骨干组配式假体中下段为主要承重部位,为应力主要集中处.其中在下蹲步态整个周期中,假体为股骨相应地分担了一部分应力,避免了应力集中,在下蹲步态三个时期中的末期应力最大为34.374 MPa.该研究能够为后续组配式假体的设计与改进与医学临床工作提供生物力学依据.%The biomechanical characteristics of the proximal femoral shaft with the prosthesis were analyzed and the stability and stress distribution of the prosthesis under the squatting gait were investigated.Three-dimensional finite element model of the femoral diaphyseal compound prosthesis was established by computer aided technique and CT data and the squatting gait cycle was divided into the prophase,the middle stage and the last stage.The stress distribution of the femoral shaft fitted prosthesis was obtained by applying the joint force and muscle force load under the squatting gait of the three dimensional finite element model.The results showed that under the squatting gait,the middle and lower segments of the femoral shaft prosthesis were the main weight-bearing parts and the stress concentration was the main place.The prosthesis shares a portion of the stress for the femur avoiding stress concentration and the stress value reached the maximum at the end of the three stages of squat gait to 34.374 MPa in the whole cycle of the squat gait.This study can provide a biomechanical basis for the design and improvement of follow-up group prosthesis and medical clinical work.