To evaluate the incidence of involvement and nature of destruction of glenohumeral (GH) joints in a prospectively followed cohort of 74 patients with seropositive and erosive rheumatoid arthritis (RA).
At the 15 year followup radiographs of 148 GH joints were evaluated, and the grade of destruction was assessed by the Larsen method.
Erosive involvement (Larsen grade 2) was observed in 71/148 (48%) GH joints in 41/74 (55%) patients; 30 patients had bilateral and 11 unilateral involvement. The incidence of mild erosions (Larsen grade 2) was 401148 (27%), and of severe (Larsen 3-5) 31/148 (21%). The 11 most severely involved (Larsen grade 5) joints were seen in 6 (8%) patients. Erosions were most often (61/71 joints) observed on the superolateral articular surface of the humerus. Glenoidal involvement was less common (28/71 joints). The Larsen score (0-100) for peripheral joints correlated significantly with the GH joint Larsen grade on both sides (p < 0.001).
After 15 years more than half the patients with RA showed definite involvement and 1 in 4 had severe destruction of the GH joint. The greatest destruction was almost always bilateral.