Clinic of Masticatory Disorders, Removable Prosthodontics, Geriatric and Special Care Dentistry, Center of Dental Medicine, University of Zurich, Switzerland.
J Biomech. 2013 Sep 3;46(13):2137-44. doi: 10.1016/j.jbiomech.2013.07.001. Epub 2013 Jul 31.
Abnormal mechanical loading may trigger cartilage degeneration associated with osteoarthritis. Tissue response to load has been the subject of several in vitro studies. However, simple stimuli were often applied, not fully mimicking the complex in vivo conditions. Therefore, a rolling/plowing explant test system (RPETS) was developed to replicate the combined in vivo loading patterns. In this work we investigated the mechanical behavior of bovine nasal septum (BNS) cartilage, selected as tissue approximation for experiments with RPETS, under static and dynamic loading. Biphasic material properties were determined and compared with those of other cartilaginous tissues. Furthermore, dynamic loading in plowing modality was performed to determine dynamic response and experimental results were compared with analytical models and Finite Elements (FE) computations. Results showed that BNS cartilage can be modeled as a biphasic material with Young's modulus E=2.03 ± 0.7 MPa, aggregate modulus HA=2.35 ± 0.7 MPa, Poisson's ratio ν=0.24 ± 0.07, and constant hydraulic permeability k0=3.0 ± 1.3 × 10(-15)m(4)(Ns)(-1). Furthermore, dynamic analysis showed that plowing induces macroscopic reactions in the tissue, proportionally to the applied loading force. The comparison among analytical, FE analysis and experimental results showed that predicted tangential forces and sample deformation lay in the range of variation of experimental results for one specific experimental condition. In conclusion, mechanical properties of BNS cartilage under both static and dynamic compression were assessed, showing that this tissue behave as a biphasic material and has a viscoelastic response to dynamic forces.
异常的机械负荷可能会引发与骨关节炎相关的软骨退变。组织对负荷的反应一直是许多体外研究的主题。然而，通常应用的是简单的刺激，而不能完全模拟复杂的体内条件。因此，开发了一种滚动/犁耕实验测试系统（RPETS），以复制体内的复合加载模式。在这项工作中，我们研究了牛鼻中隔软骨（BNS）在静态和动态加载下的机械行为，该软骨被选为 RPETS 实验的组织近似物。确定了双相材料特性，并与其他软骨组织的特性进行了比较。此外，还进行了犁耕模式下的动态加载，以确定动态响应，并将实验结果与分析模型和有限元（FE）计算进行了比较。结果表明，BNS 软骨可以建模为双相材料，杨氏模量 E=2.03 ± 0.7 MPa，综合模量 HA=2.35 ± 0.7 MPa，泊松比 ν=0.24 ± 0.07，以及常数水力渗透率 k0=3.0 ± 1.3×10(-15)m(4)(Ns)(-1)。此外，动态分析表明，犁耕会引起组织的宏观反应，与施加的载荷力成正比。分析、FE 分析和实验结果的比较表明，预测的切向力和样本变形在一个特定实验条件下的实验结果变化范围内。总之，评估了 BNS 软骨在静态和动态压缩下的机械性能，表明该组织表现为双相材料，并对动态力具有粘弹性响应。
