Vulpius and Z-lengthening.

An evaluation of ankle function in gait after 22 Vulpius lengthenings of the gastrocnemius fascia and 27 Z-lengthenings of the Achilles tendon was performed in 33 ambulatory cerebral palsy patients. Simultaneous hip or knee surgeries or both were performed in most instances. Gait analysis including ankle motion, moment, and power data was obtained before surgery and approximately 1 year after. The ankle moments were improved and approached normal in the majority of cases in each group. There were no significant differences between the Vulpius and Z-lengthening groups at follow-up in any of the parameters. There were significant differences between the initial and follow-up measurements of each group. The Vulpius group showed a notable presence of abnormal midstance work initially and had a significant decrease at follow-up. The Z-lengthening group showed a notable presence of equinus and a notable lack of push-off work initially and had a significant decrease in equinus and a significant increase in push-off work at follow-up. Each procedure appears to give satisfactory results because the follow-up results were similar.