Calcium-containing crystals and osteoarthritis: implications for the clinician.

The clinical implication of articular deposits of calcium-containing crystals (specifically of calcium pyrophosphate dihydrate and hydroxyapatite) in osteoarthritis is unknown. Recent longitudinal studies have suggested that in some instances calcium crystals are direct participants in cartilage damage, while in other situations they are merely markers of joint damage. Better understanding of the mechanisms of crystal formation, especially in relation to inorganic pyrophosphate regulation, has lead to potential avenues for therapeutic intervention. The current treatment of osteoarthritis associated with calcium-containing crystals should involve nonsteroidal anti-inflammatory drugs, intra-articular steroids, and in resistant cases, joint irrigation can be considered. While preliminary studies suggest the possibility of favorable benefits from colchicine and hydroxycholorquine in this osteoarthritis disease subset, more rigorous studies need to be conducted to establish their roles.