Musculoskeletal ultrasound for treating rheumatoid arthritis to target-a systematic literature review

Abstract

Objective: We aimed to systematically review the literature to retrieve evidence on the diagnostic and prognostic value of musculoskeletal ultrasound for a treat to target (T2T) approach in RA.

Methods: Eight research questions were developed addressing the role of ultrasound (including different ultrasound scores and elementary lesions) for diagnosis, monitoring and prognosis of RA. PubMed and EMBASE were searched (2005-2020). Articles on RA and reporting data on musculoskeletal ultrasound were included and extracted according to the underlying questions, and risk of bias assessed according to the study design.

Results: Out of 4632 records, 60 articles were included. Due to clinical heterogeneity, meta-analysis was not possible. Ultrasound better predicted disease relapses with respect to clinical examination in patients in remission, while both methods performed similarly in predicting response to therapy, achievement of remission and radiographic progression. Ultrasound was superior to clinical examination in diagnosing joint involvement using another imaging modality, such as magnetic resonance imaging, as reference. Limited ultrasound scores performed like more extensive evaluations for the detection of joint inflammation and for outcome prediction. Higher ultrasound scores of synovitis were linked to poor outcomes at all disease stages, but a specific cut-off distinguishing between low- and high-risk groups did not emerge.

Conclusions: These data confirm the pivotal role of ultrasound when evaluating synovial inflammation and when identifying RA patients at higher risk of relapse. Further research is needed to better define the role of ultrasound in a T2T management strategy in moderately-to-highly active RA.

Keywords: RA; diagnosis; imaging; prediction; prognosis; systematic literature review; ultrasound.

Fig. 1

Flowchart showing the selection process

Fig. 2

Risk of bias assessment The risk of bias was defined through different tools, depending on study design. For the Newcastle–Ottawa scale: for selection red corresponds to ≤1 star, yellow to 2–3 stars, green to 4 stars; for comparability, red corresponds to 0 stars, yellow to 1, green to 2; for exposure/outcome red corresponds to ≤1 star, yellow to 2 stars, green to 3 stars. For the QUADAS 2: for selection, red corresponds to 3 no, yellow to 1 yes or at least 1 unclear, green to 3 yes; for test: red corresponds to 2 no, yellow to 1 yes or at least 1 unclear, green to 2 yes; for standard, red corresponds to 2 no, yellow to 1 yes or at least 1 unclear, green to 2 yes; for flow/timing: red corresponds to 3 no, yellow to 1–2 yes or at least 1 unclear, green to 3 yes. For RCTs: red corresponds to low risk of bias, yellow to some concerns on the risk of bias, red to high risk of bias. *Risk of bias assessed through the Newcastle-Ottawa scale; **Risk of bias assessed through the Cochrane tool for RCTs; ***Risk of bias assessed through the QUADAS. RCT: randomized controlled trial. Colour version available online.

Fig. 3

Summary of studies evaluating ultrasound vs clinical examination to predict outcomes The main finding of the studies (ultrasound being inferior, equal or superior to clinical examination for predicting outcomes) is represented by the grey box. Studies on remission and response were performed in patients with active disease, while those on relapse in patients in clinical remission. Radiographic progression was assessed both in studies on clinical remission and active disease. US: ultrasound.

Fig. 4

Summary of studies evaluating the value of lesion A vs lesion B to predict outcome The main finding of the studies (power Doppler being inferior, equal or superior to grey scale for predicting outcomes) is represented by the grey box. Studies on disease activity included patients with active disease, while those on relapse were performed in clinical remission. Radiographic progression was assessed both in studies on clinical remission and in studies on active disease. GS: grey scale; PD: power Doppler.