Ultrasound evaluation of foot deformities in infants

Foot deformity in infants is the most common congenital musculoskeletal condition. A precise diagnosis can sometimes be impossible to establish clinically. Radiologic imaging plays a major role in the evaluation of musculoskeletal abnormalities. However conventional imaging techniques, such as plain radiographs of the foot, are of very little help in this age group because of the lack of ossification of the tarsal bones. US presents a significant advantage because it permits the visualization of cartilaginous structures. This leads to the detailed assessment of foot deformities in infants. Furthermore, US can also be used as a dynamic imaging modality. Different scanning views are beneficial to evaluate the complete anatomy of the foot; depending on the suspected clinical diagnosis, some planes are more informative to display the pathological features of a specific deformity. We describe the US findings of five of the most common foot deformities referred to our pediatric orthopedic clinic (clubfoot, simple metatarsus adductus, skewfoot, and oblique and vertical talus). For each deformity we propose a specific imaging protocol based on US to provide an accurate diagnosis. US is a complementary tool to the clinical examination for determining the diagnosis and the severity of the deformity and also for monitoring the efficacy of treatment. Radiologists investigating foot deformities in infants should consider using US for the detailed assessment of the foot in this age group.