Retraction notice

Abstract

Background: Collagen fiber volume fraction of articular cartilage alters by race and age of samples and has a key role in the mechanical behavior of articular cartilage. Methods: This study presented innovative micromechanics models to predict the mechanical properties of superficial and deep zones of any kind of articular cartilage for different races and ages as a function of cartilage component mechanical properties and collagen fiber volume fraction. Results: Collagen fiber volume fraction as a function of normalized depth of an articular cartilage sample was calculated in this study by micromechanics models from variation measurements of its axial elastic modulus. Poisson’s ratio and aggregate modulus was also computed from this function and compared to the experimental data for verification. Since collagen fiber volume fraction was reported in a huge range for different articular cartilages with different races and ages, the effect of this variation is discussed in detail in this paper. The results showed that, as the collagen volume fraction increases, the mechanical properties of articular cartilage in all planes and directions increase as well. Conclusion: Aging reduces all the elasticity mechanical properties of articular cartilage in all directions and planes.