Effect of Degenerative Changes of Articular Cartilage on Knee Joint Stresses – Functional Imaging by Combining Clinical MRI and Finite Element Modeling

INTRODUCTION: Degenerative changes in the structure and composition of articular cartilage in osteoarthritis, such as collagen fibrillation, proteoglycan depletion and increased water fraction, alter the mechanical behavior of cartilage [1, 2]. It has been shown that the collagen fibrils primarily modulate cartilage mechanical response under dynamic and impact loading [3]. This emphasizes the role of the depthwise collagen fibril network in modulating cartilage function in a knee joint. However, effects of osteoarthritic changes in cartilage on stresses in a knee joint have not been shown. The aim of this study was to combine clinical magnetic resonance imaging (MRI) and finite element (FE) modeling, and to apply a fibril reinforced poroelastic model [4, 5] to examine especially the influence of the collagen network fibrillation of osteoarthritic articular cartilage on the stress distribution in a knee joint.