Background We previously reported that shoulder synovitis in polymyalgia rheumatica (PMR) is milder than that in elderly-onset rheumatoid arthritis (EORA) patients with PMR-like onset (polymyalgic-EORA) by using semi-quantitative ultrasound (US) scoring of the synovial components in the shoulder in spite of the higher serum CRP (1).
Objectives We aimed to evaluate the contribution of the extra-synovial inflammation in PMR patients by power Doppler (PD) US.
Methods We analyzed US records of 14 untreated PMR patients and 14 untreated polymyalgic-EORA patients using a semi-quantitative four-point scale (0 = absent, 1 = mild, 2 = moderate or 3 = severe). For the comprehensive evaluation of shoulder synovitis, the severity of the biceps tenosynovitis, subacromial/subdeltoid bursitis and glenohumeral joint synovitis were subjectively scored on a gray scale and by PD on a 4-point scale (0–3). The sum of six scores (0–18) for one shoulder was defined as shoulder synovitis score (SSS). For the evaluation of extra-synovial inflammation in the shoulder, the hyperemia adjacent to the anterior aspect of the subscapularis tendon (SubST) was analyzed in the horizontal long axis view. The severity of PD-signals on SubST was subjectively scored on a 4-point scale (0–3) as exemplified in the figure, and the score was defined as the extra-synovial hyperemia score (ESHS).
Results The ESHS/SSS ratio was significantly higher in PMR shoulders than in polymyalgic-EORA shoulders (0.447 ±0.251 vs 0.303 ±0.277, p=0.0138). The bilateral ESHS/bilateral SSS ratio was significantly higher in PMR patients than in polymyalgic-EORA patients (0.475 ±0.269 vs 0.236 ±0.182, p=0.00776).
Conclusions Semi-quantitative US scoring of the synovial and the extra-synovial components in the shoulder revealed the larger involvement of the extra-synovial soft tissue inflammation in PMR patients than in EORA patients with PMR-like onset.
Arthritis Rheumatol. 2015; 67 (suppl 10)
Disclosure of Interest None declared