[Pathology of Cartilage-to-Bone Crosstalk: A New Angle for Animal Experimental Studies on Osteoarthritis]

Osteoarthritis (OA), a common age-related chronic disease, is characterized by degenerative changes in the joints and surrounding tissues. Traditionally, research on OA has primarily focused on the pathological changes in articular cartilage and its repair. However, with the advancements in animal disease modeling in recent years, especially the widespread use of spatiotemporally specific transgenic mouse models, scholars have gradually come to realize that the subchondral bone also plays an important role in the occurrence and development of OA. That is, the pathological changes in articular cartilage and bone mutually affect and promote each other, jointly driving the progression of OA, involving such pathological processes as vascular invasion, ectopic calcification, nerve growth, and the occurrence of pain. Given the complexity of cartilage-bone pathological relationship, it is difficult to conduct in-depth research on subchondral bone pathology using clinical human samples, or to simulate the pathological processes of OA through in vitro cell experiments. Therefore, animal models play an irreplaceable role in investigating the pathological mechanisms of OA and developing clinical drugs. This review, in addition to providing an overview of OA animal models, synthesizes the latest progress in animal experimental research on OA, highlighting the active role of the cartilage-bone pathological relationship in OA progression. These new findings provide references for future in-depth investigations and also provide a theoretical basis for developing fundamental strategies for OA prevention and treatment.