UC San Diego

In the United States, the estimated lifetime risk of developing knee osteoarthritis is approximately 44%. Therefore, animal models are necessary to study the etiology of the disease as well as the efficacy of therapeutic treatments. In this study, a combination of anterior cruciate ligament transection (ACLT) and partial medial meniscal transection (pMMT) was performed on rat knees to investigate changes in behavior, cartilage, and bone morphology due to post-traumatic osteoarthritis (PTOA). Hyaluronic acid (HA) intra- articular injection was administered to the knee one week after the surgeries. ACLT + pMMT surgery resulted in a temporary contralateral preference in static weight bearing, minor degeneration of the articular cartilage, and generally decreased bone quality. However, among the parameters analyzed, the most sensitive parameter for characterizing PTOA changes in the ACLT + pMMT model was trabecular thickness from μCT analyses. Treatment with HA was also found to attenuate the progression of PTOA changes in articular cartilage and bone morphology.