Incidence of glenohumeral joint involvement in seropositive rheumatoid arthritis. A 15 year endpoint study

Objective. To evaluate the incidence of involvement and nature of destructi on of glenohumeral (GH) joints in a prospectively followed cohort of 74 pat ients with seropositive and erosive rheumatoid arthritis (RA). Methods. At the 15 year followup radiographs of 148 GH joints were evaluate d, and the grade of destruction was assessed by the Larsen method. Results. Erosive involvement (Larsen grade 2) was observed in 71/148 (48%) GH joints in 41/74 (55%) patients; 30 patients had bilateral and 11 unilate ral involvement. The incidence of mild erosions (Larsen grade 2) was 40/148 (27%), and of severe (Larsen 3-5) 31/148 (21%). The 11 most severely invol ved (Larsen grade 5) joints were seen in 6 (8%) patients, Erosions were mos t often (61/71 joints) observed on the superolateral articular surface of t he humerus. Glenoidal involvement was less common (28/71 joints). The Larse n score (0-100) for peripheral joints correlated significantly with the GH joint Larsen grade on both sides (p < 0.001). Conclusion. After 15 years more than half the patients with RA showed defin ite involvement and 1 in 4 had severe destruction of the GH joint. The grea test destruction was almost always bilateral.