Anterior sonography of glenohumeral joint in patients with inflammatory joint disease

Ultrasonography (US) was shown as an effective imaging modality in evaluating the shoulder. The shoulder joint is probably the most accessible joint for sonography in adults. However, inflammatory changes of the shoulder have received too little attention in US studies. Anterior access for US assessment of glenohumeral joint (GHJ) has not been investigated. Another problem of patients with acute synovitis of glenohumeral joint is the difficulty to perform a 90 degrees abduction for the axillary US because of severe pain and active and passive limitation. We offer the anterior access for assessment of glenohumeral joint synovitis (GHS). Sonographic evaluation (Sonosite-Titan) was carried out in 25 patients with acute GHS and 15 healthy controls. The diagnosis of GHS was made after the patients underwent physical examination and the laboratory evidence was obtained. We used the anterior position of transducer applied laterally to coracoid processus along the anterior joint cavity. The problem of anterior joint cavity investigation in neutral position is a poor presentation of the joint and the application of the biceps tendon. The problem is simply resolved after supination of the hand and external rotation of the shoulder. We measured and compared upper, middle, and lower width of the anterior GHJ cavity. Echogenicity of joint cavity was assessed by comparison with adjacent tissues. Homogeneity and regularity of GHJ cavity was designated in both groups as well. We measured labrum-infraspinatus distance on posterior view for assessment of GHJ synovitis. All cases of GHJ synovitis were confirmed by a US Doppler study. US investigation of healthy controls enabled to find normal values of the width of the anterior GHJ cavity that was less than 7.4 mm. The synovitis group showed GHJ cavity expansion: 8.3+/-2.4 (p=0.001) and 10.5+/-3.1 (p<0.001) for the middle and the lower anterior part of the GHJ respectively. The upper part width was not different in synovitis and control groups. Anterior joint cavity extension to 7.4 mm and upper in its lower part was high sensitive (96%) and specific (86%) US sign of synovitis with the test power above 0.9. The posterior labrum-infraspinatus extension had high specificity for synovitis (100%), but only seven of 25 patients (28%) had increased (>2 mm) the value of the labrum-infraspinatus dimension, which was previously proposed as the US sign of synovitis. Echogenicity of the anterior joint cavity in healthy controls was moderately high (far more echogenic than deltoid muscle). Echogenicity of synovitis declined, and mild effusions were found to be common. Those were not to be seen on US of GHJ in neutral position and were revealed only in supination and external rotation of the shoulder. Intra-articular tissue of healthy controls was relatively echo-homogenic compared with nonhomogenic one of the synovitis group. Bone irregularity was found in patients with long-standing GHJ synovitis reflecting erosive process. A certain position of the shoulder and good knowledge of the normal anterior joint cavity parameters enabled us to diagnose synovitis by anterior shoulder sonography, with the patients experiencing minimal pain during movements.