抄録
Radiographic changes of the thumb and wrist were examined in 150 patients with rheumatoid arthritis. The relations of radiographic changes of IP, MP and CM of the thumb to the duration of the disease, deformity of the thumb, and radiographic changes of the wrist were investigated. Each Steinbrocker's stage (I-IV) was subdivided into two (a and b) and the radiographic findings were classified into 8 stages.
Stages IIIa and up (≥IIIa) were found in 70% for wrist joint (W), 40% for CM, 25% for MP, and 20% for IP. By duration of disease, the corresponding figures in cases of less than 5 years were 34% for W, 14% for CM, 5% for MP, 2% for IP, and those in cases of 20 years or longer were 89% for W, 75% for CM, 60% for MP, and 40% for IP. The wrist joint showed bone destruction comparatively early, while the bone destruction of thumb's joints, particularly of IP joints, was less remarkable. More than 90% of the patients with IIIb bone destructions of the IP and MP joints showed severe bone destruction of the wrist joint. In contrast, about one-half of the patients with ≥IIIb bone destruction of the wrist joint showed only ≥ IIb bone destructions of the IP and MP joints.
Deformity of the thumb was found in 102 thumbs (34%), with Type 1 deformity accounting for a large majority (76 thumbs) . In Type 1 deformity, the frequency of ≥IIIb bone destructions of the MP joint was slightly high as compared with the CM joint. About a half of the cases of Type 1 deformity showed very little alterations (≥IIa) of the MP joint. It was thought that early synovitis without associated bone destruction could be a causative factor in deformity of the thumb.
