Sites of inflammation in painful rheumatoid shoulder assessed by musculoskeletal ultrasound and power Doppler sonography

Ultrasonography (US) and power Doppler sonography (PDS) was used to investigate causes of new onset of shoulder pain and sites of shoulder inflammation in 157 shoulders of 99 patients with rheumatoid arthritis (RA). US detected effusion and/or synovitis in 92/157 glenohumeral joints, subdeltoid bursitis in 56/157 shoulders and tenosynovitis of biceps tendon in 55/157 shoulders. Bursitis and/or tenosynovitis were accompanied by glenohumeral synovitis in 68/90 shoulders. 68% of serologically active and 12% of serologically inactive patients had glenohumeral synovitis. PDS showed increased microvascular blood flow in 33 of the 44 investigated shoulders. Glenohumeral synovitis was correlated to elevated C-reactive protein levels (p = 0.0001) and microvascular blood flow assessed by PDS (p = 0.02). This study shows that rheumatoid shoulder pain is not caused by glenohumeral synovitis in 32% of patients, despite serologically active RA. US and PDS are mandatory to elucidate the origin of inflammatory and noninflammatory shoulder pain.