Background Foot problems can be a major source of morbidity and disability in patients with SSc. Arthralgia is common in SSc and is poorly understood. It is usually attributed to mechanical factors resulting from fibrosis and tendon friction . Musculoskeletal ultrasonography (MSUS) can identify and characterize subclinical synovial inflammation and joint damage with higher precision than X-rays [2, 3].
Objectives Our study was devoted to identify the presence and to confirm the persistence of subclinical synovial inflammation, utilizing MSUS.
Methods Forty consecutive patients who had a first MSUS between January and December 2009 were included in the study. They underwent a second MSUS between January 2010 and June 2011. The mean interval between the two MSUS was 18±3,5 months (median 20, range 12-24). The study included 40 SSc patients (38 female), age ranged from 17 to 82 years (median 57); 9 (22.5%) with diffuse SSc, 18 (45%) were anticentromere antibodies positive and 13 (32,5%) anti-Scl70 antibodies positive.
Results At first clinical examination 28 patients had arthralgias at metatarsophalangeal level without any symptom or sign of inflammatory arthritis, 4 patients presented calcinosis. At MSUS examination 2 patients presented osteophites, 1 patient joint effusion, no patients presented synovitis or erosions.
After 1 year the patients were evaluated by the same physician. All 40 patients underwent a second MSUS. Metatarsophalangeal explored joints and tendons were evaluated for the presence of synovial fluid and synovial hypertrophy on grey scale and synovitis/tenosynovitis on power Doppler ultrasonography (PDUS) signal according to OMERACT definition criteria. MSUS identified inflammation in a high proportion of patients: tenosynovitis (in 12/40, 30%), and synovitis (in 12/40, 30%) were the most common followed by joint effusion (in 5/40, 10%). 28 (70%) patients had ultrasonography alterations, only 1 of them had not arthralgia at baseline. Arthralgia was found as predictive factor of foot involvement (HR 8; 95% CI 1.08-58.7).
Conclusions This prospective study identifies arthralgia as predictor of foot MSUS alterations in patients with SSc.
Blocka KL, et al. The arthropathy of advanced progressive systemic sclerosis. A radiographic survey. Arthritis Rheum 1981;24:874-84.
Farrant JM, et al. Advanced imaging in rheumatoid arthritis. Part 1: synovitis. Skeletal Radiol 2007;36:269-79.
Terslev L, Torp-Pedersen S, Savnik A et al. Doppler ultrasound and magnetic resonance imaging of synovial inflammation of the hand in rheumatoid arthritis: a comparative study. Arthritis Rheum 2003;48:2434-41.
Disclosure of Interest None Declared