Robert A. Gatter

Studies on Pathological Calcifications in Human Cartilage: I. Prevalence And Types Of Crystal Deposits In The Menisci Of Two Hundred Fifteen Cadavera

Calcific deposits in the menisci of the knees of 215 cadavera were characterized roentgenographically and crystallographically as part of a study of the pathological basis of calcium pyrophosphate dihydrate crystal deposition disease. Deposits of a primary type were found in multiple cartilages in 5.6 per cent of cadavera: in 3.3 per cent the deposits were composed of calcium pyrophosphate dihydrate (Ca2P2 O7-2H2O) and in 2.3 per cent, of dicalcium phosphate dihydrate (CaHPO4-2H2O). Solitary deposits of the secondary type, composed of hydroxyapatite, were found in 1.4 per cent of cadavera. The implications of these findings are discussed as they affect (1) the possible prevalence of calcium pyrophosphate dihydrate crystal deposition disease, (2) the traditional classification of pathological calcification of cartilage, and (3) the roentgenographic interpretation of meniscal calcification. The crystalline compounds of the three-component system CaO—P2O5—H2O that persist in soil as fertilizer are the same as the compounds identified in the meniseal deposits. Appropriate data from the soil chemistry literature are cited briefly as they provide background for speculation and future work on the mechanisms and significance of pathological calcifications in cartilage.

Tennis-Shoe Traction

To the Editor:— Tennis-shoe traction has been used for years by a small number of physicians. However, this method does not appear in the general texts dealing with musculoskeletal disorders and apparently is not general knowledge among most physicians. Therefore it seems appropriate to point up this traction method which has been most useful in certain patients. The usual form of traction for the lower extremity, Bucks extension, is applied by (1) shaving the leg to the knee, (2) painting with tincture of benzoin, (3) applying moleskin, and (4) wrapping with elastic bandage. However, moleskin cannot be removed for purposes of physical therapy to the extremity once or twice a day as is appropriate for certain arthritic patients with flexion contracture of the knees. Also, blistering under moleskin at times necessitates early removal. Denuding of underlying skin when moleskin is removed in elderly patients or in patients on long-term corticosteroid