Functional changes in the antagonists after lengthening the agonists in cerebral palsy. I. Triceps surae lengthening.

In a recent study, children with spastic cerebral palsy (median age, five years) were examined before and up to a median of 14 months after 52 operations involving elongation of the tendo Achillis or aponeurotomy of the gastrocnemius. On removal of the cast four weeks postoperatively, strength in the dorsiflexors had increased by more than 50%, as evaluated by the ability to raise a weight from a scale. Postoperative function was correlated with preoperative function. Strength had increased more than 200% by 14 months postoperatively, with no instance of excessive lengthening of the triceps. In 13 cases, the dorsiflexors had been without function preoperatively. Two of those cases again lost the dorsiflexor function achieved postoperatively, when dynamic shortening recurred after one year. The study thus confirms the view that antagonist function improves when spasticity in the agonist is reduced by tendon lengthening.