Treatment of valgus hindfoot in cerebral palsy by peroneus brevis lengthening.

Twenty cerebral-palsied patients (30 feet) with hindfoot valgus due to muscle imbalance were reviewed and it was shown that the deformity can be reduced by peroneus brevis lengthening. The method of choice is intramuscular lengthening, which reduces the power of peroneus brevis by one point on the MRC grading and corrects the hindfoot valgus by one grade of severity. For full correction by tendon lengthening, the deformity must be treated while it is still mild. Repeat lengthening may be necessary if there is a severe muscle imbalance.