Osteoarthritis (OA) is a painful, debilitating disease affecting approximately three million Canadians, most commonly at the knee. In addition to joint cartilage damage, the disease is also marked by changes in the underlying bone. It has been suggested that changes in bone stiffness, thickness and density influence and accelerate the breakdown of cartilage and the development of OA. In order to verify this (i.e. understand when during the disease process these changes occur and assess their impact on the timing and extent of damage to the bone or cartilage) there is an urgent need to develop a tool that can reliably assess bone and cartilage simultaneously. The aim of James Johnston’s research is to understand early onset and progression of osteoarthritis and to develop diagnostic tools for its early detection. Johnston has already developed a novel method of matching bone to cartilage that can be used to assess cartilage and underlying bone simultaneously in any joint. He is now working on a method to investigate relationships between bone (thickness, density) and cartilage (thickness, biochemistry) using magnetic resonance imaging (MRI), computed tomography (CT) and three-dimensional assessments. He will then link information gained through these imaging methods with physical stiffness measures to determine how these properties are affected at early and late stages of OA, compared to healthy subjects. This research will improve understanding of how OA develops, and contribute to the development of methods for the early detection and treatment of the disease.