Does damage cause inflammation? Revisiting the link between joint damage and inflammation.

Rheumatoid arthritis (RA) is characterised by both inflammation, as manifested by pain and swelling, and destruction of the joints. Unequivocal evidence indicates that disease activity, and thus the inflammatory response, is linked to joint damage. From this viewpoint we suggest that, vice versa, joint damage might be a cause of the active disease process, thus leading to a vicious cycle of events. The background to this notion stems from the known autoimmune response in RA, the potential of cartilage and bone breakdown products to elicit inflammation and notions that in joints that have undergone surgery with cartilage removal RA does not flare. However, the clinical evidence for this relationship is still to be provided as proof of the concept.