Does tendon lengthening surgery affect muscle tone in children with Cerebral Palsy ?

The objective of this study was to determine if surgical lengthening of the hamstrings and gastrocnemius/Achilles complex affects muscle tone in patients with cerebral palsy. The question was if the dynamic component of muscle length changes after orthopedic surgery. A retrospective study was performed on ambulatory children with cerebral palsy who underwent either hamstring lengthening or gastrocnemius/Achilles tendon lengthening. A total of 135 consecutive patients with an average age of 13 years were included in the study. A single random side was selected for children with bilateral surgery and the affected limb was analyzed for those undergoing unilateral surgery. The popliteal angle measurement was performed with a quick and slow stretch, as well as the ankle dorsiflexion, and measurements were made using a goniometer. The difference (Delta ml) between initial grab with fast stretch and end of range (EOR) with slow stretch was used as a measure of spasticity. The Bohannon modification of the Ashworth score was also assessed. Postoperatively, 18 degrees popliteal angle improvement in end-of-range and 32 degrees improvement in quick stretch in the hamstrings group were noted, with change in slow stretch, quick stretch and Delta ml (comparison between quick and slow stretch) being significant at p < .0001. In the triceps surae group, 14 degrees ankle dorsiflexion improvement in end-of-range, and 18 degrees improvement in quick stretch were noted postoperatively, with change in slow stretch, quick stretch and Delta ml at p < .0001, p < .0001, and p < .0180 respectively. Ashworth scale was reduced by at least one grade in 89% of subjects in the hamstring group and 78% of subjects in the triceps surae group of the children with preoperative Ashworth 3 and above.