Congenital flat foot: different clinical forms.

Using standard lateral x rays of 32 congenital flat feet (CFF) treated in our institutions, we studied the alignment in the sagittal plane of the tarsal and metatarsal bones. All feet presented with a complete dislocation of the talonavicular joint and a vertical talus. In some cases, however, the alignment of the calcaneocuboid joint was abnormal. In these, both the talus and the calcaneus appeared verticalized with no apparent subtalar joint subluxation (type I). Other cases, by contrast, had a normally aligned calcaneus thus implying subluxation of the subtalar joint (type II). Between the two types, a spectrum of clinical forms combining features from both categories exists. Recognition of the different varieties of CFF is of importance when planning surgery. Type I CFF requires reduction and stabilization of the whole midtarsal joint, while in type II CFF attention must be given to both the subtalar and calcaneocuboid joints.