Validation of the ankle-specific pediatric arthritis ultrasound scoring system in children with juvenile idiopathic arthritis.

Objective: To validate the ankle-specific Pediatric Arthritis Ultrasound Scoring System (PAUSS-ankle) in children with juvenile idiopathic arthritis (JIA).
Methods: Patients with a diagnosis of JIA prospectively underwent a standard clinical assessment and musculoskeletal ultrasound (MSUS) of one or both ankles. B-mode and Power-Doppler mode MSUS images were acquired and scored according to the PAUSS-ankle protocol. A subset of patients received a contrast-enhanced MRI (ceMRI) of the affected ankle. ceMRI scoring for synovitis was performed according to the Rheumatoid Arthritis MRI System (RAMRIS). Test characteristics of the PAUSS-ankle scores were evaluated with ceMRI as reference. Associations between the findings on physical examination, PAUSS-ankle, and RAMRIS were investigated.
Results: Thirty-two patients with JIA contributed 63 MSUS and 15 ceMRIs of the ankles. The PAUSS-ankle total B-mode score had a moderate correlation with physical examination findings (correlation (r)=0.43, p < 0.001). The PAUSS-ankle B-mode score ≥1 exhibited a sensitivity of 79 % and specificity of 100 %, demonstrating excellent diagnostic accuracy with an area under the curve (AUC)= 0.89 (confidence intervals, CI, 0.78-1.00) while clinical assessment had a sensitivity of 57 % and AUC= 0.71 (CI: 0.58-0.85). The PAUSS-ankle B-mode score had significant strong correlations (r = 0.68-0.90, p < 0.005) with the RAMRIS for the assessment of disease severity for each joint area and the ankle joint as a whole.
Conclusion: Our findings demonstrate excellent diagnostic accuracy of the PAUSS-ankle in detecting the presence and severity of ankle synovitis when compared to ceMRI. The PAUSS-ankle holds significant promise as an accurate measurement that may complement current clinical standards.
Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare related to this publication. All co-authors have seen and agree with the contents of the manuscript and there is no financial interest to report.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)