抄録
To devise appropriate schedules for the treatment of rheumatoid shoulder, a roentgenographical study was made of the natural courses and the prognoses of shoulder joint destructions in RA patients. Eighty-three definite or classic RA patients, for a total of 166 shoulder joints, were the subjects for this study. For the assessment of shoulder joint destruction, we used X-ray patterns and two parameters: 1) Upward migration index (UMI) showing the distance between the undersurface of the acromion and the center of the humeral head.2) Medial displacement index (MDI) showing the distance between the original glenoid surface and the center of the humeral head.
The patterns of joint destruction were classified into five groups: 1) Non-pro g ressive (N) type (n=74) showing only bone atrophy or small erosion even after 15-20 years of RA.2) Hatchet (H)type (n=22) showing marginal erosions but not collapse.3) Collapse (C) type (n=34) showing subchondral cysts followed by collapse.4) Stiff (5) type (n=12) showing osteoarthritic features.5)Mutilating (M) type (n=14) showing mutilating bone destructions. These patterns of joint destruction could be distinguished at 5-10 years of RA.
The various prognoses of destruction of t h e shoulder joint were assessed on the basis of UMI and MDI. The following table shows UMI and MDI at 5-10 years of RA.
From X-ray findings and these two parameters determined at 5-10 years, we could predict the prognosis of shoulder joint destruction after 15-20 years of RA. This study should prove useful for deciding surgical indication, timing, and prosthetic selection for rheumatoid shoulder.
Among patients with rheumatoid arthritis (RA), shoulder joint involvement is not as rare as once thought. However, no therapeutic policy has been established for rheumatoid shoulder. As a first step, knowledge of the natural history of rheumatoid shoulder may help to establish the surgical indication, timing, and prosthetic selection. In this study, the natural history of 166 involved glenohumeral joints in RA patients was studied roentgenographically in order to shed light on the factors involved in the prognosis of this condition.
