Compressive strain, articular

Articular joints are exposed to compressive forces that are applied very quickly, as well as to very large shear forces. Stammen et al. [53] recognized PVA-C as a viable option for total joint replacement but only if the load-bearing properties could be matched with those of natural tissue. Studies of the compressive tangent modulus and shear tangent modulus were undertaken for the PVA-C product, and a limited strain-rate dependence under unconfined compression was displayed. 

In this study, a 5% confined compression test was carried out numerically. 5 % compression was chosen as the purpose of this study was to understand why articular cartilage chondrocytes may die when exposed to impact loading but survive when exposed to muscular loading of similar magnitude. Therefore, the strain magnitude was chosen very small so that it should not be injurious by itself. Previous experimental studies showed that 5% compression applied to cartilage tissue in 0.3s resulted in cell death in the superficial zone [7]. This made the 5% compression a reasonable choice for the current study. 

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