To evaluate the relation of glenohumeral (GH) and acromioclavicular (AC) joint involvement in a cohort of 74 patients with seropositive and erosive rheumatoid arthritis (RA) followed up prospectively.
At the 15 year follow up radiographs of 148 shoulders were evaluated, and the grade of destruction of GH and AC joints were assessed by the Larsen method. One GH joint arthroplasty had been performed after 13 years of the disease onset and the preoperative radiograph was evaluated.
Erosive involvement (Larsen grade >/= 2) was observed in 96 of 148 (65%) of the shoulders. Both GH and AC joints were affected in 62 of 148 (42%) shoulders. GH joint alone was involved in nine (6%) shoulders and only AC joint was affected in 25 (17%) shoulders. AC joint destruction correlated with the GH joint destruction, r=0.74 (95% confidence intervals (CI) 0.65 to 0.80 ).
In RA AC joint is affected more often than the GH joint, but in half of the patients both joints are involved. This should be remembered when treating painful rheumatoid shoulder.