Equinus deformity during tibial lengthening with ankle orthoses for equalization of leg-length discrepancies

Although it is known that equinus deformity develops at a high rate during tibial lengthening, the efficacy of ankle orthoses for preventing equinus deformity and the etiology of equinus deformity remain unknown. The purpose of this study was to clarify the incidence and causes of equinus deformity in tibial lengthening with ankle orthoses worn for 16 h a day.

102 patients who had tibial lengthening were included in this study. There were 80 males and 22 females with ages at surgery from 6 to 70 years. Tibial lengthening was performed at the proximal tibia using an Ilizarov fixator. During limb lengthening, an ankle orthosis was used for more than 16 h a day to prevent equinus deformity. The rates and the causes of equinus deformity were investigated.

Equinus deformity was observed for eight cases (7.8%). Among these, the final gain in length was less than 5 cm in 6 patients. There were no significant differences between final gain in length, average lengthening rate, and final percentage gain of tibial length in the group with occurrence of equinus deformity and that without.

The incidence of equinus deformity was 7.8% during tibial lengthening wearing ankle orthoses.