Ultrasound anatomy in the neonatal clubfoot.

Our objective was to assess clubfoot anatomy by US in newborn babies before and in the early phase of treatment. Reproducible US projections and measurements were carried out on 30 untreated clubfeet in 22 children, consecutively included in the study. The position of the navicular in relation to the head of the talus was visualised in all feet. The mean distance between the medial malleolus and the navicular was significantly shorter in the clubfeet than in normal feet. There was a tendency to medial displacement of the cuboid. Soft tissue thickness at the medial side of the foot was increased in all deformed feet. The measurements showed an acceptable intra- and inter-observer reliability for the different variables assessed ( r=0.71-0.96, Pearson's correlation coefficient). With US it is possible to obtain well-defined planes of investigation that give important information about the clubfoot deformity concerning the talo-crural, the talo-navicular and the calcaneo-cuboid joints. The method is simple enough to be used in everyday clinical practice and we recommend it as a guide during the non-operative treatment and for preoperative planning.