Bone Marrow Lesions in Osteoarthritis and Their Relation to Cartilage Contact and Stresses

One in eight Canadians suffers from osteoarthritis (OA), a debilitating joint disease that frequently includes bone bruises, known as BMLs. The question we want to answer is, do BMLs result from changes in muscle strength and coordination, or poor condition of ligaments (connecting tissues) or cartilage (smooth joint lining) that cause the cartilage loading to increase? This study investigates whether BMLs might be a result of the loading environment of the knee. Though the exact cause of these bruises is not known, they have been linked to increased pain and worsening of OA. This study will measure the size and location of BMLs in people with OA and relate them to cartilage contact and stress (loading over an area). A unique standing Magnetic Resonance Imaging Scanner (MRI; i.e., looking inside the body with powerful magnets in an upright position) will be used to image OA patients during a knee bend. The BMLs will be mapped over the contact areas and stresses. Findings will provide insights into what positions (e.g. depth of a knee bend) yield contact and stress closest to the BMLs. If BMLs are linked to loading, clinical changes can be made to loading (e.g., bracing) or drugs may be taken to intervene.