Osteotomy of the hind-foot in children and adolescents.

The position of the talus and the os calcaneum has consequences for the architecture of the forefoot. Medial tilting of the talus with vertical position provokes flattening of the medial arch and abduction of the forefoot. Varus position of the calcis and lateral direction of the talus (as in residual clubfoot), however, causes supination and adduction of the forefoot. Repair of deformities in the hindfoot therefore also influences the forefoot. A large number of various osteotomies have been proposed at both bones. The most popular ones are Dwyer's osteotomy at the corpus of the calcis and its modification described by Mitchell at the same location for correction of the cavus foot and the residual clubfoot, and the lengthening osteotomy at the neck of the calcaneum according to Evans. Indication and operative technique of these three procedures are described in detail. The closing wedge osteotomy according to Dwyer is indicated in cases of cavus feet. In clubfeet the os calcis is usually too short and the medial opening wedge osteotomy provokes skin problems. In these cases an osteotomy according to Mitchell with lateral displacement of the tuber calcanei is more suitable. In flat- and skewfeet a lengthening osteotomy at the neck of the calcaneum according to Evans can be indicated, especially when the load of the foot is bigger medially under the talus rather than at the lateral margin of the foot. If these procedures are carried out carefully, they have low complications rates.