Phalangeal bone ultrasound is of limited value in patients with juvenile idiopathic arthritis.

Objective. In children with juvenile idiopathic arthritis (JIA), alterations of the skeletal system have been described. The aim of this cross-sectional study was to evaluate a phalangeal bone ultrasound device in the assessment of the skeletal status in children with active JIA. Methods. In 49 children with oligoarticular, polyarticular or systemic JIA, the speed of an ultrasound signal (Ad-SOS) through the phalanges of the dominant hand was measured using the Igea 1200. Results. Children in all subgroups were significantly smaller than those in the reference population, but there were no significant deficits in Ad-SOS. The finger width was reduced only in patients with polyarticular JIA. The Ad-SOS correlated highly with height, but no correlation between the finger width and Ad-SOS, and no correlation between the standard deviation scores of body height and Ad-SOS were seen. Conclusions. Phalangeal ultrasound is strongly dependent on body and therefore bone size, but other parameters of bone and soft tissues influence the measurements as well. It is not possible to differentiate as to which extent the various components of bone and soft tissue influence the measurement results. Ultrasound might therefore be of limited value in the assessment or screening of the skeletal system in children with JIA.