Wilson W, Huyghe J M, van Donkelaar C C
Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Osteoarthritis Cartilage. 2006 Jun;14(6):554-60. doi: 10.1016/j.joca.2005.12.006. Epub 2006 Feb 13.
The composition of articular cartilage changes with progression of osteoarthritis. Since compositional changes are associated with changes in the mechanical properties of the tissue, they are relevant for understanding how mechanical loading induces progression. The objective of this study is to present a computational model of articular cartilage which enables to study the interaction between composition and mechanics.
Our previously developed fibril-reinforced poroviscoelastic swelling model for articular cartilage was combined with our tissue composition-based model. In the combined model both the depth- and strain-dependencies of the permeability are governed by tissue composition. All local mechanical properties in the combined model are directly related to the local composition of the tissue, i.e., to the local amounts of proteoglycans and collagens and to tissue anisotropy.
Solely based on the composition of the cartilage, we were able to predict the equilibrium and transient response of articular cartilage during confined compression, unconfined compression, indentation and two different 1D-swelling tests, simultaneously.
Since both the static and the time-dependent mechanical properties have now become fully dependent on tissue composition, the model allows assessing the mechanical consequences of compositional changes seen during osteoarthritis without further assumptions. This is a major step forward in quantitative evaluations of osteoarthritis progression.
关节软骨的成分会随着骨关节炎的进展而发生变化。由于成分变化与组织力学性能的变化相关，因此它们对于理解机械负荷如何导致病情进展具有重要意义。本研究的目的是提出一个关节软骨的计算模型，该模型能够研究成分与力学之间的相互作用。
我们先前开发的用于关节软骨的纤维增强多孔粘弹性肿胀模型与基于组织成分的模型相结合。在组合模型中，渗透率的深度依赖性和应变依赖性均由组织成分决定。组合模型中的所有局部力学性能都直接与组织的局部成分相关，即与蛋白聚糖和胶原蛋白的局部含量以及组织各向异性相关。
仅基于软骨的成分，我们就能同时预测关节软骨在受限压缩、无限制压缩、压痕以及两种不同的一维肿胀试验中的平衡响应和瞬态响应。
由于静态和随时间变化的力学性能现在都完全取决于组织成分，该模型无需进一步假设就能评估骨关节炎过程中成分变化的力学后果。这是骨关节炎进展定量评估方面向前迈出的重要一步。
