The paediatric foot: prevalence and differentiation of sonographic and podiatric findings in juvenile arthritis and healthy children.

Objectives: We aimed to, first, determine the prevalence of ultrasound (US) findings and podiatric anomalies in the paediatric foot, and to compare these findings between healthy and asymptomatic juvenile idiopathic arthritis (JIA) subjects, and then to analyse the associations between US and podiatric findings.

Methods: Healthy children and asymptomatic JIA patients underwent US and podiatric assessments. Grey-scale (GS) findings and Doppler signal in the joint recess, the tendon sheath and the enthesis of paediatric feet were assessed as present or absent. The podiatry assessment included: Foot Posture Index (FPI), footprint, standing heel-rise test, mobility of first toe and the Jack test.

Results: Forty-six children had at least one US finding (25 of 54 healthy children and 20 of 28 asymptomatic JIA patients). GSUS findings at the first metatarsophalangeal joint recess and physiological vascularisation at several locations were the most frequently detected findings in both groups. GSUS findings at the tibiotalar and subtalar joints were only detected in the JIA group. In comparison to the healthy group, the JIA group showed a trend towards pronated foot with abnormal footprint. However, the tibiotalar synovitis was significantly associated with supinated FPI.

Conclusions: Improving the knowledge of US findings in the paediatric foot is crucial to evaluate properly children with suspected inflammatory diseases. US, in addition to podiatric assessment, would enable paediatric rheumatologists to discriminate between normal physiological findings and pathological abnormalities in asymptomatic children having JIA. Further studies are needed to confirm it.