Nguyen Vu-Hieu, Rosi Giuseppe, Naili Salah, Michel Adrien, Raffa Maria-Letizia, Bosc Romain, Meningaud Jean-Paul, Chappard Christine, Takano Naoki, Haiat Guillaume
a Laboratoire de Modélisation et de Simulation MultiEchelle, UMR CNRS 8208 , Université Paris-Est , Créteil , France.
b INSERM U955 , Université Paris-Est , Créteil , France.
Comput Methods Biomech Biomed Engin. 2017 Sep;20(12):1312-1325. doi: 10.1080/10255842.2017.1357703. Epub 2017 Aug 3.
Although the biomechanical behavior of the acetabular cup (AC) implant is determinant for the surgical success, it remains difficult to be assessed due to the multiscale and anisotropic nature of bone tissue. The aim of the present study was to investigate the influence of the anisotropic properties of peri-implant trabecular bone tissue on the biomechanical behavior of the AC implant at the macroscopic scale. Thirteen bovine trabecular bone samples were imaged using micro-computed tomography (μCT) with a resolution of 18 μm. The anisotropic biomechanical properties of each sample were determined at the scale of the centimeter based on a dedicated method using asymptotic homogenization. The material properties obtained with this multiscale approach were used as input data in a 3D finite element model to simulate the macroscopic mechanical behavior of the AC implant under different loading conditions. The largest stress and strain magnitudes were found around the equatorial rim and in the polar area of the AC implant. All macroscopic stiffness quantities were significantly correlated (R > 0.85, p < 6.5 e-6) with BV/TV (bone volume/total volume). Moreover, the maximum value of the von Mises stress field was significantly correlated with BV/TV (R > 0.61, p < 1.6 e-3) and was always found at the bone-implant interface. However, the mean value of the microscopic stress (at the scale of the trabeculae) decrease as a function of BV/TV for vertical and torsional loading and do not depend on BV/TV for horizontal loading. These results highlight the importance of the anisotropic properties of bone tissue.
尽管髋臼杯（AC）植入物的生物力学行为对手术成功起着决定性作用，但由于骨组织的多尺度和各向异性特性，其评估仍然困难。本研究的目的是在宏观尺度上研究种植体周围小梁骨组织的各向异性特性对AC植入物生物力学行为的影响。使用分辨率为18μm的微型计算机断层扫描（μCT）对13个牛小梁骨样本进行成像。基于一种使用渐近均匀化的专用方法，在厘米尺度上确定每个样本的各向异性生物力学特性。用这种多尺度方法获得的材料特性被用作三维有限元模型的输入数据，以模拟AC植入物在不同加载条件下的宏观力学行为。在AC植入物的赤道边缘和极区周围发现了最大应力和应变幅值。所有宏观刚度量均与骨体积分数（BV/TV）显著相关（R>0.85，p<6.5×10^-6）。此外，冯·米塞斯应力场的最大值与BV/TV显著相关（R>0.61，p<1.6×10^-3），并且总是出现在骨-植入物界面处。然而，微观应力的平均值（在小梁尺度上）在垂直和扭转加载时随BV/TV降低，而在水平加载时不依赖于BV/TV。这些结果突出了骨组织各向异性特性的重要性。
