Background Modern imaging techniques such as magnetic resonance imaging and ultrasound demonstrate high prevalence of synovitis in painful hand OA joints. Some studies on knee OA suggest that the presence of synovitis may be a surrogate marker of OA severity and associated with increased risk of disease progression. A similar predictive correlation is less clear for hand OA due to few longitudinal studies.
Objectives To examine whether ultrasound inflammation including grey scale (GS) synovitis and power Doppler (PD) activity can predict radiographic progression after 5 years in patients with hand OA.
Methods We included 78 participants (71 women, mean (SD) age 67.8 (5.2) years) from the Oslo hand OA cohort with US examination at baseline and conventional radiographs taken at baseline and 5-years follow-up. GS and PD were examined in 30 finger joints by US on a semi-quantitative 0-3 scale. Radiographic progression was defined as an increase in global OA according to the Kellgren-Lawrence (KL) scale, or progression of individual OA features according to the OARSI atlas.
For each radiographic definition we examined whether baseline US features predicted radiographic progression using Generalized Estimating Equations, adjusted for age, sex, body mass index, follow-up time and KL grade.
Results Mean (SD) follow-up time was 4.7 (0.4) years. GS and PD were present in 28.7 and 4.6% of OA joints at baseline, respectively. Radiographic progression in joints was found in 20.1% for KL, 12.1% for joint space narrowing (JSN) and 11.7% for osteophytes.
GS and PD were significant and dose-dependent predictors for KL progression (OR=3.1 (95% CI 2.1-4.4) and OR=4.1 (95% CI 2.1-8.0), respectively). GS and PD also predicted progression of all measures of individual radiographic features (table), of which strongest association was seen for osteophyte progression (OR=2.9 (95% CI 2.1-4.0) and OR=5.1 (95% CI 2.8-9.5), respectively).
Conclusions Our study is the first to demonstrate that even small amounts of inflammation seen by ultrasound significantly increase the risk of future radiographic progression in the same finger joint. GS synovitis and PD activity were significantly associated with increased KL grade, JSN, osteophyte score and erosive evolution after 5 years. This study supports the use of US as a tool to detect hand OA patients who are likely to progress.
Disclosure of Interest None declared