The purpose of this study was to clarify whether residual subtalar varus in treated clubfoot affects the configuration of the ankle joint in the coronal plane. Radiographic characteristics of the ankle and subtalar joint in congenital clubfoot, after a minimum of 10 years of treatment, were analyzed and presented. Weight-bearing radiographs of the ankles and feet, as well as computerized tomographic images of the hindfoot, were obtained for 30 patients (41 feet), at a mean of 15.2 +/- 6.1 years after initial treatment. Subtalar varus was measured in terms of the tilting angle of the posterior facet of the talocalcaneal joint, as viewed using computerized tomographic scans, and a larger angle was indicative of greater subtalar varus. Ankle valgus was measured with anteroposterior mortise views; a larger angle was indicative of greater ankle valgus. The analyses showed that feet with greater subtalar varus also showed statistically significantly greater valgus of the ankle mortise angles (P = .003). These results suggest that the ankle compensates for residual deformity of the subtalar joint in the coronal plane in patients treated for clubfoot. It also suggests that the configuration of the ankle during the course of treatment may warrant closer attention.
Level of clinical evidence: 2.