Why subchondral bone in osteoarthritis? The importance of the cartilage bone interface in osteoarthritis.

Osteoarthritis is a whole joint disease characterised by the disappearance of the cartilage associated with subchondral bone sclerosis, formation of osteophytes and a mild inflammation of the synovial membrane. Although all these events have been independently studied, functional interactions between these different joint tissues should exist, especially between subchondral bone and cartilage. Moreover, recent studies show that cartilage and subchondral bone act as a single functional unit. This review highlights this novel concept.