Magnetic resonance imaging study of the congenital clubfoot treated with the Ponseti method.

Little information exists about the degree of efficacy of the several nonoperative treatments, such as manipulation and casting, used in correcting the pathology of the virgin clubfoot deformity. The steps in the correction of the displacements and anomalies of the skeletal components have never been visualized. The method reported to have the best long-term results is that of Ponseti. A magnetic resonance imaging protocol was devised to image the described chondroosseous abnormalities of the virgin clubfoot deformity and to illustrate the changes that occur with the Ponseti method of treatment. Scans were performed at the beginning of, in the middle of, and at the end of treatment. Images obtained with this protocol largely agree with postmortem studies of clubfeet. All of the major chondroosseous pathology could be visualized in vivo. With Ponseti treatment, all the abnormalities seen on the initial scans either improved markedly or corrected completely. Treatment resulted in correction not only of the abnormal relationships of the tarsal bones, but also of the abnormal shapes of the individual tarsal osteochondral anlages, probably because of the changes in growth resulting from the changes in mechanical loading of fast-growing tissues.