Ann Rheum Dis (1983), 42, Supplement p 19 Pathology of articular deposition of calcium salts and their relationship to osteoarthrosis

Since the reports of Zitnan and Sitaj in 1963, ' articular chondrocalcinosis, also known as calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, ' is now a well recognised clinical entity. It is characterised by intra-articular deposition of CPPD crystals, which encrust hyaline and fibrocartilages, synovium and sometimes intra-articular ligaments. The common finding of crystals in synovial fluid provides a simple clinical test for assessing the microcrystalline nature of an acute pseudogout attack,3 4the latter being a characteris-tic, though not most common, clinical feature associated with chondro-calcinosis.2 Numerous radiological and clinical reports have established three major circumstances that may influence the appearance of intra-articular calcification or a pseudogout attack. Occasionally, it is a familial disorder '-1 " with an autosomal dominant mode of transmission established in a few kindreds."9 More often, it is a sporadic disease of adults usually found in association with hyperparathyroidism,'- 'S haemo-chromatosis,'6 " ' Wilson's disease,' ochronosis " " and other hormonal and metabolic disorders.23 24 Of interest, though of minor importance, are those cases associated with hypo-phosphatasia3 ' and hypo-magnesaemia. " 2 Trauma has been given as the explanation for meniscal calcifications and more recently chondrocalcinosis of the knee has been linked to meniscectomy.28 An unusually high incidence of chondrocalcinosis is found in the elderly,29 34 in whom calcifications often remain clinically silent,35 bein