Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Department of Biomedical Engineering, Lund University, Lund, Sweden.
PLoS Comput Biol. 2022 Jun 3;18(6):e1009398. doi: 10.1371/journal.pcbi.1009398. eCollection 2022 Jun.
Abnormal loading of the knee due to injuries or obesity is thought to contribute to the development of osteoarthritis (OA). Small animal models have been used for studying OA progression mechanisms. However, numerical models to study cartilage responses under dynamic loading in preclinical animal models have not been developed. Here we present a musculoskeletal finite element model of a rat knee joint to evaluate cartilage biomechanical responses during a gait cycle. The rat knee joint geometries were obtained from a 3-D MRI dataset and the boundary conditions regarding loading in the joint were extracted from a musculoskeletal model of the rat hindlimb. The fibril-reinforced poroelastic (FRPE) properties of the rat cartilage were derived from data of mechanical indentation tests. Our numerical results showed the relevance of simulating anatomical and locomotion characteristics in the rat knee joint for estimating tissue responses such as contact pressures, stresses, strains, and fluid pressures. We found that the contact pressure and maximum principal strain were virtually constant in the medial compartment whereas they showed the highest values at the beginning of the gait cycle in the lateral compartment. Furthermore, we found that the maximum principal stress increased during the stance phase of gait, with the greatest values at midstance. We anticipate that our approach serves as a first step towards investigating the effects of gait abnormalities on the adaptation and degeneration of rat knee joint tissues and could be used to evaluate biomechanically-driven mechanisms of the progression of OA as a consequence of joint injury or obesity.
由于损伤或肥胖导致的膝关节异常负荷被认为是骨关节炎（OA）发展的原因。小动物模型已被用于研究 OA 进展机制。然而，尚未开发出用于研究临床前动物模型中动态载荷下软骨响应的数值模型。在这里，我们提出了一个大鼠膝关节的肌肉骨骼有限元模型，以评估步态周期中软骨的生物力学响应。大鼠膝关节的几何形状是从 3D MRI 数据集获得的，关节中的加载边界条件是从大鼠后肢的肌肉骨骼模型中提取的。大鼠软骨的纤维增强多孔弹性（FRPE）特性是从机械压痕试验的数据中得出的。我们的数值结果表明，模拟大鼠膝关节的解剖和运动特征对于估计组织响应（如接触压力、应力、应变和流体压力）是相关的。我们发现，在中侧室，接触压力和最大主应变几乎保持不变，而在外侧室，它们在步态周期的开始时显示出最高值。此外，我们发现最大主应力在步态的支撑阶段增加，在中间支撑时达到最大值。我们预计，我们的方法将作为研究步态异常对大鼠膝关节组织适应和退化影响的第一步，并可用于评估关节损伤或肥胖导致 OA 进展的生物力学驱动机制。
Zotero 插件
