RADIOGRAPHIC CHANGES OF DISTAL INTERPHALANGEAL JOINTS IN RHEUMATOID-ARTHRITIS

In patients affected with rheumatoid arthritis (RA) the radiographic e valuation of distal interphalangeal joints (DIP) may be difficult due to the possible coexistence of other rheumatic disorders. Ninety-six R A patients - 49 seropositive and 47 seronegative, well matched for age , sex, and disease duration - and 80 controls also age and sex matched , without any evidence of degenerative or inflammatory joint disorders were studied. The following parameters were checked by soft-tissue ra diography: marginal erosions, soft-tissue swelling, symmetrical and as ymmetrical joint space narrowing, degenerative changes. Fifty-three pe rcent of RA patients vs 37.5% of controls showed one or more radiograp hic abnormality of DIP joints (p < 0.05). Inflammatory lesions (i.e, m arginal erosions plus symmetrical joint space narrowing) were signific antly more frequent in RA patients (23%) than in controls (9%) (p < 0. 05). We did not find differences between seropositive and seronegative cases, nor a significant association with age, sex, disease duration or with inflammatory changes of other hand joints. Degenerative change s plus symmetrical joint space narrowing were equally common in RA pat ients and in controls (37.9% vs 33.8%) and significantly associated wi th patients' age. Inflammatory and degenerative lesions were rarely fo und to be present together in the same DIP joint (17.6% of the cases). Asymmetry of DIP inflammatory changes was common (68.2% of the cases) with unilateral marginal erosions in 84.6%. In RA, inflammatory lesio ns of DIP joints are not rare, although much less frequent than those in the other joints of the hand. They are frequently unilateral and do not appear to be associated either with other clinical manifestations of PA or with degenerative lesions.