The natural history of the rheumatoid shoulder: a prospective long-term follow-up study.

The purpose of this study was to evaluate the natural history of rheumatoid disease of the shoulder over an eight-year period. Our hypothesis was that progression of the disease is associated with a decrease in function with time. A total of 22 patients (44 shoulders; 17 women, 5 men, (mean age 63)) with rheumatoid arthritis were followed for eight years. All shoulders were assessed using the Constant score, anteroposterior radiographs (Larsen score, Upward-Migration-Index (UMI)) and ultrasound (US). At final follow-up, the Short Form-36, disabilities of the arm, shoulder and hand (DASH) Score, erythrocyte sedimentation rate and use of anti-rheumatic medication were determined. The mean Constant score was 72 points (50 to 88) at baseline and 69 points (25 to 100) at final follow-up. Radiological evaluation showed progressive destruction of the peri-articular structures with time. This progression of joint and rotator cuff destruction was significantly associated with the Constant score. However, at baseline only the extent of rotator cuff disease and the UMI could predict the Constant score at final follow-up. A plain anteroposterior radiograph of the shoulder is sufficient to assess any progression of rheumatoid disease and to predict functional outcome in the long term by using the UMI as an indicator of rotator cuff degeneration.