Human Tibial Cartilage Reveals Non-Linear and Non-Uniform Regional Topography Under Physiological Loading Rates

Abstract

Nearly 3% of individuals worldwide experience pain, immobility, and compromised quality of life due to knee osteoarthritis (OA)1. It has been widely accepted that joint mechanics play a critical role in the initiation and progression of knee OA2. A shift away from the normal joint motion, for example due to injury or malalignment, is believed to produce an abnormal pattern of cartilage loading that creates unusual and damaging stresses within the tissue. Accurate knowledge of cartilage’s normal mechanical response to physiological loading—and particularly the regional dependence of this response—is critical to successfully testing this theory. To our knowledge, little is known about the regionally-dependent mechanical response of healthy human tibial cartilage under physiological loading conditions. There is also a compelling need for more accurate cartilage data to be integrated into computational simulations of the knee joint. Hence, the purpose of this study was two-fold: 1) to characterize the typical stress-strain response of tibial cartilage at 21 locations across the tibial plateau when subjected to loading representative of human walking, and 2) to demonstrate that these 21 sites can be reduced to a small number of regions displaying significantly different average moduli.