【摘要】 目的 研究分别植入径向和轴向功能梯度材料(functionally graded materials, FGM)踝关节假体后，胫骨假体与胫骨远端松质骨的力学响应。方法 使用3种FGM,分别为钛合金-生物活性玻璃复合FGM(FGM-Ⅰ)、钛合金-理想骨弹性材料复合FGM(FGM-Ⅱ)、钛合金-羟基磷灰石复合FGM(FGM-Ⅲ)。建立全踝关节置换三维有限元模型，利用仿真软件ABAQUS基于Fortran进行二次开发，通过改变体积分数，在轴向和径向上调整所建功能梯度胫骨假体的力学特性。分析FGM轴向和径向胫骨假体植入后，在站立位工况下胫骨假体与胫骨松质骨上的应力分布。结果 与钛合金胫骨假体相比，3种FGM均可有效减小胫骨假体上的应力集中，其中FGM-Ⅲ胫骨假体总体效果优于FGM-Ⅰ和FGM-Ⅱ胫骨假体，且相对于轴向分布而言，FGM沿径向分布可以有效降低假体的最大von Mises应力。对于胫骨松质骨，3种FGM径向胫骨假体和FGM-Ⅲ轴向胫骨假体均能有效增加其远端应力，从而减轻松质骨上的应力遮挡，其中FGM-Ⅲ径向胫骨假体最为有效地改善了松质骨上的应力水平。结论 FGM-Ⅲ径向踝关节假体可以有效降低假体上的应力集中现象并减小应力遮挡效应，以此达到延长假体寿命的目的，具有潜在的应用前景。更多还原

【Abstract】 Objective To study the mechanical response of tibial prostheses and the distal tibial cancellous bone after implantation of radial and axial functionally graded materials(FGM) into the ankle joint. Methods Three FGM were used: titanium alloy-bioactive glass composite FGM(FGM-Ⅰ), titanium(Ti) alloy-ideal bone elastic composite FGM(FGM-Ⅱ), and Ti alloy-hydroxylapatite composite FGM(FGM-Ⅲ). A three-dimensional finite element model of total ankle arthroplasty(TAA) was established, and the simulation software ABAQUS was used for secondary development based on Fortra. By changing the volume fraction, the mechanical properties of the FGM tibial prosthesis can be adjusted both axially and radially. The stress distributions of the tibial prosthesis and cancellous bone after FGM axial and radial tibial component implantation in the standing position were analyzed. Results Compared with Ti alloy tibial prosthesis, three kinds of FGM could effectively reduce the stress concentration on the tibial prosthesis, and the overall effect of FGM-Ⅲ tibial prosthesis was better than that of FGM-Ⅰ and FGM-Ⅱ tibial prosthesis; the radial distribution of FGM could effectively reduce the maximum von Mises stress of the prosthesis. For the tibial cancellous bone, the three types of FGM radial tibial prostheses and FGM-Ⅲ axial tibial prostheses could effectively increase the distal stress, thus, relieving the stress shielding on the cancellous bone; the FGM-Ⅲ radial tibial prosthesis was the most effective in improving the stress level of the cancellous bone. Conclusions FGM-Ⅲ radial ankle prosthesis can effectively reduce the stress concentration phenomenon and the stress shielding effect on the prosthesis to prolong its life, with potential application prospects.更多还原