Background Musculoskeletal ultrasound (MSUS) use in Rheumatoid arthritis (RA) has been growing over the last decades mainly to monitor response to treatment and for early detection of erosions. Suggestions to involve this technique in RA diagnosis were taking place but not yet implicated (due to absence of specific sonographic criteria confined to RA).
Objectives To verify a proposed combined structural and synovial scoring system's (designed by Kunkel et al., 2012) performance in discriminating RA from osteoarthritis and healthy sonographic findings in small joints of the hand.
Methods Twenty RA patients, 20 hand OA patients and 10 healthy controls were subjected to MSUS to metacarpophalyngeal (MCP) and proximal interphalyngeal (PIP) joints. The novel proposed scoring system was applied characterizing each joint as either RA-supported (according to presence of synovial thickening>2mm, doppler signal and/or erosion) or RA-unsupported. Grading of synovitis as mild, moderate or severe was also applied. In RA group, disease activity was assessed by DAS28 and Anti-CCP serum levels were measured.
Results Upon applying this scoring system, high statistically significant difference was found between study groups (Table 1) as regards presence of synovium>2mm, doppler signal (Figure 1) and erosions. When one or more RA-supported joints were detected, this scoring system had a sensitivity of 100.0% and specificity of 83.0% with diagnostic accuracy of 90.0% for diagnosis of RA. If two or more joints were detected, it had a sensitivity of 95.0% and specificity of 96.7.0% with diagnostic accuracy of 96.0% for diagnosis of RA.
Conclusions The novel suggested combined structural and synovial scoring system showed high performance in differentiating RA from OA and controls.
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Scheel AK, Hermann KG, Kahler E, Pasewaldt D, Fritz J, Hamm B, Brunner E, Müller GA, Burmester GR, Backhaus M: A novel ultrasonographic synovitis scoring system suitable for analyzing finger joint inflammation in rheumatoid arthritis. Arthritis Rheum 2005; 52: 733-43.12.
Disclosure of Interest None declared