Rheumatoid arthritis is a systemic disease of connective tissue affecting many organs and structures in addition to the bones and joints. Its outstanding clinical manifestation is a chronic deforming arthritis, particularly of the hands and wrists. The chief lesion is a proliferative synovitis, of both joints and tendon sheaths, with synovial inflammation and hyperplasia often developing into large nodular masses. Although much has been written about the general radiographic features of this disease (1–4), apparently little is known concerning the pathogenesis of the bone erosions. Vague references to “malignant synovitis” and “invasion by synovium” contribute little toward recognizing the factors involved in this process.

The bone lesions in rheumatoid arthritis do not develop in a haphazard manner. Their pattern is in fact characteristic and predictable (5). In this study x-ray films of the hands and wrists of patients with rheumatoid arthritis were analyzed to define this pattern more precisely in terms of anatomic and functional factors.

One hundred consecutive clinic patients with rheumatoid arthritis were selected, and routine films of the hands and wrists, with non-screen technic, were obtained. A number were recalled for special projections. The medical records were reviewed in all cases and the diagnoses confirmed. The majority of patients had been followed for years, and prior films were often available for comparison. The radiographic characteristics and sites of predilection of the bone erosions were studied. The hands and wrists of two cadavers and one necropsied patient with rheumatoid arthritis were examined in an effort to correlate the radiographic findings with the anatomy.

At times the earliest films showed such advanced disease as to preclude the evaluation of certain features which may have been present earlier. In some patients the hands and wrists were little or not at all affected. Therefore, the quantitative features of this study are not to be taken as absolute measures. Obviously such values depend on the severity of the disease in the selected patients, the follow-up period, and the frequency of radiologic examination.

Certain pitfalls in a study of this type deserve emphasis. Routine views of the hands and wrists present many blind spots. Not only are there irregular bone surfaces which are difficult to project advantageously, but there is much super-imposition in oblique and lateral projections. Furthermore, in patients with advanced arthritic deformities various bones show rotational changes which make evaluation difficult. Needless to say, recognition of these drawbacks prompted great caution in interpretation.

Of the 100 patients studied, 69 were females.