Background Clinical evaluation has limitations to detect inflammation in JIA. Musculoskeletal ultrasonography (MSKUS) is a useful tool to detect inflammation in various arthropathies, but in children has not been validated for detection of elementary lesions such as synovitis [effusion (SE) and synovial hypertrophy (SH)], erosions, tenosynovitis (TNS) and cartilage damage.

Objectives To evaluate the reliability of MSKUS to detect carpal and metacarpal joint synovitis in patients with JIA.

Methods Seven patients with JIA diagnose according to ILAR criteria were included; they were evaluated by MSKUS for 5 ultrasonographers to evaluate synovitis, erosions, TNS and cartilage in the carpal joint, 2nd and 3rd metacarpophalangeal joints bilaterally; in 2 rounds in one day. Intra- and interobserver variability was established with Cohen's kappa, according to Landis and Koch classification.

Results The mean age of the children was 9 years old; disease duration of 5 years. The inter-observer DS, HS, TNS and erosions agreement was good to excellent (k=.88 0.5889–1.0 95%, p=0.0000) and moderate for cartilage (k=0.43, 95% CI 0.0545 to 0.8964, p=0). The intra-observer variability was good (0.71, IC95% from 0.591 to 0.8498, p=0.0000).

Conclusions The US is reliable for assessing the presence of synovitis, tenosynovitis, erosion and cartilage in hands, in patients with JIA.

Disclosure of Interest None declared