Chondrocalcinosis.
Journal: BMJ (1968)

ChondrocalcinosisIn 1963 D. Zitn'an and S. Sitai I and their colleagues in Czechoslovakia published a comprehensive account of a disorder they termed chondrocalcinosis articularis, and gave references to 32 cases previously reported.They described in detail 27 cases "of a condition characterized by multiple calcification of hyaline and fibrous cartilage both of the joints and of the vertebral discs."Of the 27 patients aged 26 to 77 years 11 were men and 16 women.The disorder was manifested by episodes of acute or subacute inflammation of one or more joints, the knees being most often affected.Swelling developed rapidly, reaching its peak in three or four days, but the inflammatory changes lasted from 7 to 50 days (average 15).Systemic upset with fever, anorexia, and loss of weight occurred with the attacks, and prodromal indefinite articular pains often preceded the acute attack.Superficial calcification appeared in radiographs of the affected articular cartilages, and after several years inflammatory features and radiological calcification lessened and gave way to generalized osteoarthrosis.Zitfian and SitAj considered the condition hereditary rather than familial, "carbonate apatite " being deposited primarily in the cartilage and secondarily in the joint fluid, where it acted as an irritant.The same authors2 at the recent European Congress of Rheumatology in Lisbon described the spinal changes found in this disorder in 39 patients.Changes are most marked in the cervical spine but are also present in the lumbar spine.The condition leads gradually to loss of spinal mobility.In 1961 D. J. McCarty and J. L. Hollander3 used com- pensated polarized light microscopy to analyse synovial fluid as a diagnostic test for gout and accidentally discovered crystals of calcium pyrophosphate dihydrate (C.P.P.D.) crystals.They reported seven such patients with this " pseudo- gout syndrome ": in retrospect they seem to have been de- scribing the same disorder as the Czechoslovakian workers.McCarty4 found C.P.P.D. crystal deposition disease in asso- ciation with diabetes mellitus, hypertension, atherosclerosis, azotaemia, hyperuricaemia, gynaecomastia, hyperparathyroid- ism, renal stones, and a few cases of classical gout, where urate crystals were also found.He compares the features of the two disorders, gout and pseudo-(calcium pyrophosphate) gout, considering the acute manifestations in both disorders to be due to actual crystal deposition.While there are many points of similarity, gout is predominantly a male disease, while pseudo-gout attacks either sex, with a slightly increased incidence in women.Gout affects more commonly peripheral small joints, such as the big toe ; pseudo-gout affects larger ones, such as the knees.Colchicine usually improves true gout, rarely pseudo-gout, but this may not always be true, and is probably an unreliable point of distinction.Radiological and pathological findings are distinctive.Superficial calcifi- cation in cartilage is not seen in true gout, but it is of interest that McCarty reported an elevated plasma uric acid in 34% of cases of pseudo-gout.McCarty5 reports that in chondro- calcinosis calcification is especially frequent in fibrocartila- ginous structures, including the menisci of the knee, the articular disc of the distal radio-ulnar joint, the annulus fibro- sus of the intervertebral discs, and the symphysis pubis.He notes that such deposits are usually symmetrical, whereas calcification in articular cartilage is often asymmetrical, appearing as fine superficial radio-opaque lines.The most useful x-ray films in diagnosis of the condition are of the knees, the pelvis, and the wrists.More recently R.