[Arthropathies due to calcium pyrophosphates].

Articular chondrocalcinosis results from the deposits of calcium pyrophosphate microcrystals in the articular hyalin and fibrocartilages, the synovium and at times the tendons. In our area it is seen most frequently as isolated cases in the elderly and may be asymptomatic. When the affected joints present clinical manifestations, they vary from acute to subacute or chronic recurrent arthritis. A marked articular destruction can be observed in some cases. There is a classical radiological picture: linear opacities are most frequently seen localized in the mid-zone layer of the hyalin cartilage running parallel to but at a certain distance from the bone cortex. A part of our research has shown that in contrast to urate gout, articular chondrocalcinosis results from a metabolic disturbance of the calcium pyrophosphate localized almost exclusively in the same articular structures. Precise information is lacking at the present time to explain why calcium pyrophosphate mycrocrystals accumulate in the cartilage, the synovium and at times at the tendons; nor do we understand the precise role played by the pyrophosphate in bone and cartilage destruction.