Spondyloarthritis
ORIGINAL RESEARCH Development and validation of a new ultrasound score (SONAR-7) for synovitis in psoriatic arthritis and axial spondyloarthritis Gehad G Elsehrawy , 1,2 Delphine S Courvoisier, 1 Erik Deman, 3 Diana Dan, 4 Raphael Micheroli , 5 Hans Ziswiler, 6 Pascal Zufferey, 7 Laure Brulhart, 8 Michael J Nissen 1
To cite: Elsehrawy GG, Courvoisier DS, Deman E, et al . Development and validation of a new ultrasound score (SONAR-7) for synovitis in psoriatic arthritis and axial spondyloarthritis. RMD Open 2026; 12 :e006802. doi:10.1136/ rmdopen-2026-006802 ► Additional supplemental material is published online only. To view, please visit the journal online (https://doi.org/10.1136/ rmdopen-2026-006802).
ABSTRACT Objectives Development of a new ultrasound (US) synovitis score (SONography in Arthritis and Rheumatism (SONAR)-7) with evaluation of its diagnostic performance in a cohort of patients with psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), in comparison with healthy controls (HC). Methods We included 121 participants: 41 patients with PsA and 39 patients with axSpA, from six Swiss hospitals and 41 HC. All participants underwent a clinical examination of joints (68/66 tender joint count/swollen joint count (SJC)), followed by a detailed musculoskeletal US examination of 22 joints to assess for greyscale (GS) and power Doppler (PD) synovitis in adherence with the definitions established by the Outcome Measures in Rheumatology US working group.
is characterised by joint, tendon and enthe- seal lesions (mechanical and inflammatory) in both peripheral joints and the axial skel- eton. This manifests as synovitis, tenosyno- vitis and enthesitis, leading to progressive damage, functional impairment, disability and reduced quality of life over time. 1 Among the articular changes observed in PsA, synovitis stands out as a hallmark feature, with prevalence rates ranging from 10% to 100% in previous ultrasound (US) studies. 2 It has also been reported as an early finding in asymptomatic patients with psori- asis, suggesting a preclinical stage of PsA. 3 4 Even though spinal inflammation is the main feature of axSpA, many patients have concom- itant peripheral arthritis. Previous studies WHAT IS ALREADY KNOWN ON THIS TOPIC ⇒ Musculoskeletal joint ultrasound (US) is becoming increasingly used in patients with spondyloarthritis (SpA) for diagnostic, disease activity assessment and prognostic purposes; however, there is no con- sensus on the number and sites of the joints to be examined by US for the evaluation of both inflamma- tory and structural changes. WHAT THIS STUDY ADDS ⇒ Our study identified the key sonographic synovial lesions and the joint regions most specific for SpA (axial SpA and psoriatic arthritis) compared with healthy controls. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY ⇒ This study is an important step towards identifying the simplest and least time-consuming set of le- sions and joints that should be examined by US in patients with SpA to determine the most useful and feasible synovitis score for routine clinical practice.
Received 31 January 2026 Accepted 27 March 2026
Results The ‘SONAR-7’ score incorporated GS and PD lesions across 14 joints, including four
metacarpophalangeal joints, four distal interphalangeal joints of the hands, two metatarsophalangeal joints, knees and wrists. It demonstrated an area under the receiver operating characteristic curve of 0.831 (95% CI 0.76 to 0.90), with an excellent specificity (95.1%) and moderate sensitivity (44%), comparable to existing US scores. The inflammatory components of the SONAR-7 correlated significantly with clinical measures of inflammation and disease activity (correlation: 0.37 for SJC-28, 0.33 for Disease Activity in Psoriatic Arthritis and 0.48 for US enthesitis). New bone formation in the same joints was associated with the Health Assessment Questionnaire (p=0.035) and Bath Ankylosing Spondylitis Metrology Index (p=0.016). Conclusion The SONAR-7 score represents a fast and effective US-based tool for the evaluation of inflammatory and structural joint involvement in patients with PsA and axSpA, with high specificity and meaningful associations with clinical and quality-of-life outcomes.
For numbered affiliations see end of article. permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group. Correspondence to Dr Gehad G Elsehrawy; gehadgamal@med.suez.edu.eg © Author(s) (or their employer(s)) 2026. Re-use
INTRODUCTION Psoriatic arthritis (PsA) and axial spondy- loarthritis (axSpA) are categorised under the umbrella of spondyloarthritis (SpA), which
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Elsehrawy GG, et al . RMD Open 2026; 12 :e006802. doi:10.1136/rmdopen-2026-006802
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