Occult subluxation of the subtalar joint in clubfoot (using computerized tomography).

Routine radiographic analysis does not visualize the posterior aspect of the hindfoot (posterior facet of the talocalcaneal joint). To help evaluate patients with persistent hindfoot abnormalities, computerized tomographic coronal sections in 22 clubfeet were studied. Seventeen feet (77.3%) had a lateral subluxation of the calcaneus. Of 14 feet with acceptable radiographic analysis, 12 (85.7%) had a lateral subluxation of the calcaneus. This study is evidence that a lateral subluxation of the calcaneus can exist, through a horizontal rotation, in the presence of acceptable radiographic analysis, reinforces the necessity for a posteromedial lateral release, and emphasizes that routine radiographic analysis should be supplemented with computerized tomography in evaluation of the resistant hindfoot deformity.