Osteoarthritis is the most common musculoskeletal disabling disease worldwide. Preclinical studies on mice are commonly performed to test new interventions. Finite element (FE) models can be used to study joint mechanics, but usually simplified geometries are used. The aim of this project was to create a realistic subject specific FE model of the mouse knee joint for the assessment of joint mechanical properties. Four different FE models of a C57Bl/6 female mouse knee joint were created based on micro-computed tomography images of specimens stained with phosphotungstic acid in order to include different features: individual cartilage layers with meniscus, individual cartilage layers without meniscus, homogeneous cartilage layers with two different thickness values, and homogeneous cartilage with same thickness for both condyles. They were all analyzed under compressive displacement and the cartilage contact pressure was compared at 0.3 N reaction force. Peak contact pressure in the femur cartilage was 25% lower in the model with subject specific cartilage compared to the simpler model with homogeneous cartilage. A much more homogeneous pressure distribution across the joint was observed in the model with meniscus, with cartilage peak pressure 5–34% lower in the two condyles compared to that with individual cartilage layers. In conclusion, modeling the meniscus and individual cartilage was found to affect the pressure distribution in the mouse knee joint under compressive load and should be included in realistic models for assessing the effect of interventions preclinically.

中文翻译：

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用于临床前应用的小鼠膝关节主题特定有限元模型的开发

骨关节炎是全世界最常见的肌肉骨骼残疾疾病。通常对小鼠进行临床前研究以测试新的干预措施。有限元 (FE) 模型可用于研究关节力学，但通常使用简化的几何形状。该项目的目的是创建一个现实的特定主题的小鼠膝关节有限元模型，用于评估关节机械性能。基于用磷钨酸染色的标本的微计算机断层扫描图像创建了 C57Bl/6 雌性小鼠膝关节的四种不同 FE 模型，以包括不同的特征：具有半月板的单个软骨层、没有半月板的单个软骨层、均质软骨层具有两个不同的厚度值，并且两个髁具有相同厚度的均匀软骨。它们都在压缩位移下进行了分析，并在 0.3 N 反作用力下比较了软骨接触压力。与具有均质软骨的简单模型相比，具有受试者特定软骨的模型中的股骨软骨中的峰值接触压力低 25%。在半月板模型中观察到整个关节的压力分布更加均匀，与单个软骨层相比，两个髁中的软骨峰值压力低 5-34%。总之，发现半月板和单个软骨建模会影响压缩载荷下小鼠膝关节的压力分布，应将其包含在临床前评估干预效果的现实模型中。3 N 反作用力。与具有均质软骨的简单模型相比，具有受试者特定软骨的模型中的股骨软骨中的峰值接触压力低 25%。在半月板模型中观察到整个关节的压力分布更加均匀，与单个软骨层相比，两个髁中的软骨峰值压力低 5-34%。总之，发现半月板和单个软骨建模会影响压缩载荷下小鼠膝关节的压力分布，应将其包含在临床前评估干预效果的现实模型中。3 N 反作用力。与具有均质软骨的简单模型相比，具有受试者特定软骨的模型中的股骨软骨中的峰值接触压力低 25%。在半月板模型中观察到整个关节的压力分布更加均匀，与单个软骨层相比，两个髁中的软骨峰值压力低 5-34%。总之，发现半月板和单个软骨建模会影响压缩载荷下小鼠膝关节的压力分布，应将其包含在临床前评估干预效果的现实模型中。在半月板模型中观察到整个关节的压力分布更加均匀，与单个软骨层相比，两个髁中的软骨峰值压力低 5-34%。总之，发现半月板和单个软骨建模会影响压缩载荷下小鼠膝关节的压力分布，应将其包含在临床前评估干预效果的现实模型中。在半月板模型中观察到整个关节的压力分布更加均匀，与单个软骨层相比，两个髁中的软骨峰值压力低 5-34%。总之，发现半月板和单个软骨建模会影响压缩载荷下小鼠膝关节的压力分布，应将其包含在临床前评估干预效果的现实模型中。