Ultrasonography has been prevalently used as a valid and objective modality for joint examination in patients with rheumatoid arthritis (RA). This study aimed to examine and compare the concordance between ultrasound, clinical assessment, and patient-reported assessment of joint synovitis in RA.
Fifty patients with RA (84% female, median age 69 years, median disease duration 31 months, and median Disease Activity Score in 28 joints 3.8) completed the self-evaluation of joint symptoms, including pain and considerable stiffness in the (proximal) interphalangeal, metacarpophalangeal, wrist, elbow, shoulder, knee, and ankle joints. These joints were also examined by a physician in order to assess the presence of tenderness or swelling; the presence of imaging synovitis was assessed by ultrasonography.
In a total of 1,492 evaluated joints, symptoms (pain and stiffness), tenderness, and swelling were noted in 288 (19.3%), 182 (12.2%), and 220 (14.7%) joints, respectively, while ultrasound indicated synovitis in 317 (21.2%) joints. Overall concordance with ultrasound findings was lowest for joint tenderness (κ = 0.30), followed by symptoms (κ = 0.39), and by swelling (κ = 0.43), irrespective of the evaluated joint, except for the elbow. Moreover, the percentages of inflamed joints detected only on the basis of symptoms, tenderness, or swelling were 18.6%, 2.2%, and 8.5%, respectively, of all joints with signs of synovitis on ultrasonography.
Joint swelling showed the best concordance with ultrasonography, followed by patient-reported joint symptoms, and joint tenderness. Joint symptoms, rather than tenderness evaluation, may be a better clinical indicator of synovitis in RA patients.