Ultrasound-detected synovitis in symptomatic hand osteoarthritis is associated with functional impairment: data from the LIHOA cohort

To determine the association of ultrasound (US) parameters with clinical features of patients with symptomatic hand osteoarthritis (HOA). 72 patients (61.9 ± 10.3 years-old), 94 (92%) women with a diagnosis of painful HOA fulfilling ACR criteria seen between August 2019 and May 2023 were evaluated. Evaluations included pain (0–10 cm; VAS, visual analogue scale), grip (GrS) and pinch (PiS) strength (KgF), Cochin hand functional scale (CHFS), functional index for hand osteoarthritis (FIHOA), number of interphalangeal joints (IP) with pain/nodes, and serum C reactive protein (CRP). US was semi-quantitatively scored (0–3) in the most painful IP, assessing grey scale synovitis (GSS), synovial thickening (ST), effusion, and power Doppler signal (PD). Comparisons were made assuming the variables as independent and continuous, using Student’s “t” test and multivariate analysis. GSS ≥ 2 synovitis was associated with lower GrS (p = 0.022) with a non-significant trend to be associated with higher FIHOA (p = 0.074) and Cochin (p = 0.093) scores. ST was also associated with lower GrS (0.003) and higher FIHOA (p = 0.045) with also a trend for higher Cochin score (p = 0.068). All but 4 joints had a negative PD, which precluded further evaluation. US parameters were neither associated with pain at rest/movement nor with number of IP nodes. Also, US features were similar regardless of serum CRP level and presence of OA in joints other than the hands. GSS and ST are associated with worse physical function, meaning lower GrS, but not with pain level in symptomatic HOA patients.