Incidence of the boundary condition between bone and soft tissue in a finite element model of a transfemoral amputee
Incidence of the boundary condition between bone and soft tissue in a finite element model of a transfemoral amputee
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DOI：
10.1177/0309364612436409
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发表时间：
2012-02
影响因子：
1.5
通讯作者：
J. Ramírez;J. Vélez
中科院分区：
文献类型：
--
作者：
J. Ramírez;J. Vélez
背景资料：在下肢假肢领域中，已经进行了许多有限元研究，然而，作为边界条件的骨与软组织之间的摩擦尚未被考虑。目的：确定经股截肢者骨与软组织接触边界条件的变化是否影响残肢的应力-应变状态。研究设计：有限元分析比较。方法：建立4例股骨截肢患者的有限元模型。在这些模型中，包括了骨槽、软组织和股骨，并且对每个模型进行了两次模拟，其中一次模拟将骨和软组织之间的相互作用定义为束缚（表面之间没有相对位移），另一次模拟将其定义为摩擦边界条件。结果：当使用摩擦定义时，von Mises应力和应变峰值比使用束缚接触定义时高。当接触定义从束缚到摩擦时，应力和应变的分布模式也发生变化。结论：得出的结论是，骨和软组织之间的摩擦对下肢假肢系统的有限元模型的结果有显着的影响，因此在其预测能力。临床相关性了解骨-软组织相互作用可以产生更真实和准确的有限元模型，用于预测假肢使用者残肢的应力-应变状态，从而预测深部组织损伤的发生。
Background: Many finite element investigations have been made in the field of lower limb prosthetics; however, friction between bone and soft tissues as a boundary condition has not been considered. Objectives: To establish whether the change in the contact boundary condition between bone and soft tissues in a transfemoral amputee affects the stress-strain state on the residual limb. Study Design: Finite element analysis comparison. Methods: Finite element models of four transfemoral amputees were developed. In these models the socket, soft tissues and femur were included and two simulations were made for each model, in one of them the interaction between bone and soft tissues was defined as tied (there is no relative displacement between surfaces) and in the other it was defined as a friction boundary condition. Results: The von Mises stress and strain peaks are higher when the friction definition is used than for tied contact definition. The distribution pattern of stresses and strains also change when the contact definition varies from tied to friction. Conclusions: It was concluded that the friction between bone and soft tissues have a significant impact on the results of finite element models of lower limb prosthetic systems, and therefore in its predictive capabilities. Clinical relevance Understanding the bone-soft tissue interaction can lead to more realistic and accurate finite element models used to predict the stress-strain state in the residual limb of prosthetic users and therefore predict the occurrence of deep tissue injuries.