Calcaneal Lengthening for Planovalgus Foot Deformity in Patients With Cerebral Palsy

Abstract

Calcaneal lengthening has been used to correct planovalgus foot deformities in patients with cerebral palsy (CP). This study was performed to investigate the amount of correction that can be achieved after calcaneal lengthening for the treatment of a planovalgus deformity in patients with CP and to provide cutoff values based on the preoperative radiographic measurements that suggest additional procedures to achieve satisfactory correction. Seventy-five consecutive patients with CP who underwent calcaneal lengthening for planovalgus deformity were included. Radiographic indices were measured on preoperative and latest followup weightbearing foot radiographs. The cutoff values of the preoperative radiographic measurements between the corrected and undercorrected groups were analyzed. The cutoff values are the reference values that can judge the possibilities of sufficient correction of a planovalgus deformity by calcaneal lengthening. The mean age of the patients at the time of surgery was 11.0 ± 5.2 years and the minimum followup was 1.0 years (mean, 3.1 ± 2.2 years; range, 1.0-8.4 years). AP talus-first metatarsal angle, calcaneal pitch angle, talocalcaneal angle, lateral talus-first metatarsal angle, and naviculocuboid overlap showed major improvements after calcaneal lengthening. The cutoff values of preoperative measurements between the corrected and undercorrected groups were 23° AP talus-first metatarsal angle, 36° lateral talus-first metatarsal angle, and 72% naviculocuboid overlap. Calcaneal lengthening with concomitant peroneus brevis lengthening is an effective procedure for correcting a planovalgus foot deformity in patients with CP. However, for patients with greater than 23° AP talus-first metatarsal angle, 36° lateral talus-first metatarsal angle, and 72% naviculocuboid overlap, additional procedures for medial stabilization, such as tibialis posterior tendon reefing and talonavicular arthrodesis, should be considered as a result of the possibility of undercorrection with calcaneal lengthening alone.