Subchondral bone changes and the impacts on joint pain and articular cartilage degeneration in osteoarthritis.

Subchondral bone has received increasing attention in both basic and clinical research on osteoarthritis (OA). Subchondral bone in OA presents abnormalities in structure, biochemical composition, biomechanics and cellular function. Overall, subchondral bone mainly shows bone resorption in early OA and bone formation in late OA. More and more evidence suggests that abnormalities in subchondral bone of OA promote joint pain generation and articular cartilage degeneration. Inhibition or amelioration of subchondral bone abnormalities can reduce joint pain and can delay cartilage degeneration; thus, subchondral bone-targeted treatment promises to be a new treatment approach for OA. The pathological changes and the role of subchondral bone in OA still require further investigation.