Fig. 1.

Representative sample from human proximal tibia with mild OA vs. sample from healthy control. Although the density in the OA sample is clearly higher, the mechanical stiffness is almost the same. Analyses from Day et al. [2] showed that at the tissue level the elastic modulus in mild OA subchondral bone is about 50% less than in healthy tissue. As a consequence, the overall stiffness in the higher density OA bone is about the same as the healthy tissue