[Clinical manifestations of joint chondrocalcinosis].

Articular chondrocalcinosis is identified by radiological opacity of articular cartilage and fibrocartilage with calcium intensity. This disease is often asymptomatic. The most significant clinical pattern is an acute arthritis, caused by microcrystals of calcium pyrophosphate dihydrate, the so-called pseudo-gout syndrome. Chronic pyrophosphate arthropathy can blend mechanical illness and inflammatory flares. When the X-rays are normal or display ordinary osteoarthritis, arthrocentesis makes the diagnosis thanks to the identification of calcium pyrophosphate crystals by polarizing microscope. Large joints are usually involved but the disease can impair the spine, small joints, tendon sheaths or synovial bursae. Though unpredictable the evolution can be worse than that of common osteoarthritis and strike joints that are usually spared by primary arthrosis. One can even see articular destruction. Thus certain patients may resemble rheumatoid arthritis, others a Charcot joint. The disease does not exist in children. Its outcome before the age of fifty implies the search for familial occurrence or a secondary form (hyperparathyroidism, hypophosphatasia, hemochromatosis, hypomagnesemia). The sporadic, primary chondrocalcinosis is very frequent in old age.