Roles of Subchondral Bone Lesion in the Pathogenesis of Osteoarthritis

Osteochondral junction is a functional unit composed of articular cartilage, calcified cartilage, and subchondral bone. Alteration in any individual component of this composite unit can disrupt joint integrity and function directly or indirectly. Biomechanical and biochemical signals mediate the crosstalk between the tissues and play an essential role in the initiation and progression of OA (osteoarthritis). During the pathogenesis of OA, the damage or defect in articular cartilage results in significantly more mechanical loading onto subchondral bone, leading to abnormal bone remodeling and microcracks, which further impair the normal mechanical properties of cartilage-bone unit. As the OA progresses, articular cartilage is exposed to excessive mechanical loading, which exacerbates the damage and degeneration of cartilage. Conversely, abnormal bone remodeling leads to increased angiogenesis and porosity in subchondral plate, which further triggers biochemical signals to mediate the crosstalk between cartilage and bone, and contributes to the progression of OA.

CSTR: 32200.14.cjcb.2020.07.0015