395 riceps at or separated from the superior margin of the patella (Figure 2). These densities are not common in the general population but are observed in approximately 4% of patients with calcium pyrophosphate deposition disease (2). In this condition, tendon calcification is not limited to the quadriceps mechanism but also occurs elsewhere, including the rotator cuff region of the shoulder, triceps, and achilles tendons in association with calcification of cartilage (chondrocolcinosis), synovium, ligaments, and soft tissue. A report has appeared that biopsy of a calcified achilles tendon in one such patient demonstrated calcium pyrophosphate dihydrate crystals (3). Patellar Osteophytes. If we reserve the term osteophyte in the current discussion to b.one formation occurring at the articular margins of the patella, these excrescences are seen at the posterior superior and posterior inferior margins of the patella (Figure 3). They are distinct from anterior hyperostosis and quadriceps calcification. Osteophytes may be seen in patellofemoral osteoarthritis and as part of the structural joint change which is characteristic of calcium pyrophosphate deposition disease (2). Each of these recognizable radiodensities-patellar hyperostosis, quadriceps tendon calcification, and patellar osteophytes-is associated with different clinical manifestations and may be the radiographic clue to an underlying disease process such as diffuse idiopathic skeletal hyperostosis, calcium pyrophosphate deposition disease, and osteoarthritis. DONALD RESNICK,M . D . Chief. Department of Radiology Veterans Administration Hospital 3350 La Jolla Village Drive San Diego, California 92161 REFERENCES I . Resnick D, Shaul SR, Robins JM: Diffuse idiopathic skeletal hyperostosis (DISH): Forestier’s disease with extraspinal manifestations. Radiology I I5:5 13-524, 1975 2. Resnick D, Niwayama G, Goergen TG, Utsinger PD, Shapiro RF, Haselwood DM. Wiesner K B Clinical, radiographic and pathologic abnormalities in calcium pyrophosphate dihydrate deposition disease (CPPD): pseudogout. Radiology 122:1-15, 1977 3. Gerster JC, Baud CA, Lagier R, Boussina I, Fallet GH: Tendon calcifications in chondrocalcinosis: a clinical, radiologic, histologic and crystallographic study. Arthritis Rheum 20:717-722, 1977 Radiographic Survey of the Knees Figure 3. Parellar osteophytes. To the Editor: The letter to the editor by Mink et al. ( I ) has much merit in the areas that they mention: abundant information, reducing cost, and reducing radiation. However, for approximately 254, the standing views of both knees are much more useful if done on a 14 X 17 cassette (standard chest size in a vertical position). This will allow the physician to determine more adequately the amount of varus or valgus deformity, and more bone is seen with very little additional radiation. The amount of technician time and developing time is identical and the cost of the film is neglible for the added information. These will allow the orthopedic surgeons to see what type of total knees might be more appropriate, the adequacy of bone stock, and whether an osteotomy (though rarely indicated in rheumatoid arthritis) may be considered. 396 Obviously additional views can be ordered if specific complaints exist, but I certainly agree that this is an adequate and mandatory workup in the initial survey of all patients with a suspected diagnosis of rheumatoid arthritis and I congratulate the authors. ED BERG, M.D. Associate Professor of Surgery (Orthopedics) Associate Professor of Medicine (Rheumatology) ChieJ Section of Orthopedics Veterans Administration Hospital Medical College of Georgia In three cases of classical RA treated with Dpenicillamine (600 mg for 15 days, 900 mg for 30 days), we observed an increase in urinary excretion of zinc and copper (Figure 1 ) and an increase in serum zinc. These changes occurred at the same time as a fall in serum copper (Figure 2). We agree with Lyle (2) that cupruresis is an index of absorption and chelating activity of D-penicillamine. Our preliminary studies favor the hypothesis that the favorable effect of D-penicillamine in RA is due to the effects of the drug in zinc absorption. PROF.U. AMBANELLI DR. G. F. FERRACCIOLI I Clinica Medica Department of Rheumatology University of Parma Parma, Italy REFERENCE I . Mink JH, Gold RH, Bluestone R: Radiographic arthritis survey. Arthritis Rheum 2 0 1564, 1977 D-Penicillamine and Zinc To the Editor: Based on McCall’s observations ( I ) , we raise the possibility that D-penicillamine acts in rheumatoid arthritis (RA) by aiding the absorption of zinc. REFERENCES I . McCall JT, Goldstein NP, Randall RV, Gross JB: Am J Med Sci 254:13, 1967 2. Lyle WH: Lancet 4207982, 1976 u MgJ24 HOI Zn Y! 700 900 190 150 600 800 180 140 500 700 170 130 400 600 160 120 300 500 150 110 600 mg D-Penicillamine 200 600 rng D-Penicillamine 900 rng D-Penicillamine 140 400 1 15 --- Zn 22 29 35 42 DAYS Figure 1. Medium values of zinc and copper (daily urinary excretion) aJier D-penicillamine treatment. 100 I 1 I 15 900 mg D-Penicillamine I 22 I I 29 35 I 42 DAYS Figure 2. Medium values of zinc and copper (in serum) after D-penicillaniine treatment.