Topographic Variation in Biomechanical Properties of Articular Cartilage Induced by Loss of Meniscal Load Sharing and Early Osteoarthritis in Sheep

Osteoarthritis is one of the most prevalent degenerative joint diseases facing human and veterinary medicine. Existing diagnostic and investigative methods lack the ability to identify subtle degenerative changes in articular cartilage’s (AC) structural properties indicative of early-stage OA, causing delayed introduction of pharmacological interventions. This thesis presents a sensitive ex vivo technique for characterizing early stage degeneration in AC’s mechanical properties on a topographic basis. AC thickness and instantaneous modulus (IM) were calculated from data obtained via indentation and needle penetration testing of sheep (n=29) AC and presented as surface maps. Mapping data were subtracted from aggregate maps of healthy cartilage to calculate the magnitude of change in each property. This diagnostic index rendered differential diagnostic maps characterizing degenerative changes across each articular surface. This thesis provides quantitative insight into the topographic degenerative patterns of early-stage OA and presents a novel method for evaluating the efficacy of pharmacological interventions.