Ab0642 Localised Joint Lesions in the Wrist of Patients With Rheumatoid Arthritis Are Difficult to Evaluate on Physical Examination

Background: Joint examination is an essential basic evaluation in treating rheumatoid arthritis (RA). However, physical examination and ultrasound (US) findings are not always consistent. Subclinical synovitis of the wrist is thought to be particularly common in RA patients [1]. Objectives: We aimed to clarify the discrepancy between physical examination and US findings on the wrist of RA patients. Methods: We compared physical examination with US findings in 235 RA patients who underwent US of the bilateral wrist joints. US was performed in three regions (radial, median, and ulnar) on dorsal longitudinal views, and US synovitis was defined as Gray Scale (GS) grade 2 or higher and/or Power Doppler Scale (PD) grade 1 or higher using a 4-point semiquantitative method from 0-3. Subclinical synovitis (SS) was defined as joints with ultrasound synovitis without swelling or tenderness on physical examination, and clinical synovitis (CS) was defined as joints with US synovitis with swelling and/or tenderness on physical examination. We analyzed the factors that lead to SS using a generalized linear mixed model. Results: SS was identified in 100 joints (21%), and CS in 129 joints (27%) of the total 470 joints bilaterally. Comparing the two groups, the total score of the three regions was significantly lower in SS than CS for both GS and PD (median 2 vs. 5 and 1 vs. 4, respectively, p<0.001). In addition, SS showed less counts of involved areas in each wrist joint than CS (median: 1 vs. 3, p<0.001). Furthermore, when radial and median regions were combined for the analyses of wrist synovitis localised in one or two regions, but not in all three regions, the synovitis only on the radial and/or median sides was detected in 55 of 100 SS joints (55%) and 26 of 129 CS joints (20%) (p<0.001), while the synovitis only on the ulnar side was observed in 18 joints (18%) and 13 joints (10%) in SS and CS, respectively (p=0.12). When the following factors (age, gender, disease duration, body mass index, DAS28-CRP and US synovitis findings) were included, SS was significantly associated with DAS28-CRP (OR=0.29, 95% CI [0.14, 0.57], p<0.001), total US score (OR=0.63, 95% CI [0.43, 0.92], p=0.016) and synovitis only on the radial and/or median sides (OR=4.29, 95% CI [1.01, 18.16], p=0.047). Conclusion: It was suggested that arthritis is difficult to detect on examination in the wrist joints of RA patients when the lesions are localised only to the radial and/or median sides. REFERENCES: [1] Nakagomi D et al. Arthritis Rheum. 2013; 65: 890-8. Acknowledgements: NIL. Disclosure of Interests: None declared.