Alterations of the Subchondral Bone in Osteoarthritis: Complying with Wolff’s Law

Abstract

Abstract: Osteoarthritis (OA) is a whole joint disease that is significantly related to abnormal me-chanical loads. Subchondral bone alterations, during the evolution course of OA, are considered a reflection of the adaptation of the bone tissue to mechanical loads. However, some of these altera-tions are taken as a detriment and paradoxical. What are these structure, composition, and mechani-cal property alterations or mechanical functions for are not quite clear. In this review, we discuss the possibility that these alterations are used for maintaining the joint function. With taking exces-sive load as a risk factor and under conditions of articular cartilage gradually lose its thickness and its function of evenly distributing the load on the subchondral bone plate, and applying Poroelastici-ty to bone mechanics; moreover, Boussinesq’s pressure bulb theory and bone optimal design princi-ples are utilized. We found that each subchondral bone alteration has its unique mechanical function in resisting loads and maintaining the joint function, and these alterations comply with both bone optimal design principles and Wolff’s law within a proper range.