Recurrence of equinus foot deformity after tendo-Achilles lengthening in patients with cerebral palsy

Abstract

Background: Recurrence of equinus deformity after surgery is common in patients with cerebral palsy. This retrospective study was undertaken to estimate the recurrence rate of the equinus deformity after tendo-Achilles lengthening (TAL) in patients with cerebral palsy and to investigate the risk factors associated with the recurrence. Methods: Two-hundred forty three ambulatory patients with cerebral palsy, who underwent TAL for equinus foot deformity since 1995, and had undergone a preoperative and postoperative 3-dimensional gait analysis, were included. Cox proportional hazards model was used to determine the significant contributing factor for the recurrence of equinus foot deformity. Results: The mean patient age at surgery was 7.8 +/- 2.7 years and the mean follow-up duration was 8.1 +/- 3.4 years. Equinus deformity recurred in 22 of the 243 patients (9.1%) and the Kaplan-Meier survival estimate was shown to be 89.4% at 10 years not needing repeat surgery. According to the multivariate analysis using the Cox proportional hazard model, preoperative ankle dorsiflexion at initial contact (P = 0.016) was the only significant factor for recurrence of equinus deformity after surgery. Age at surgery and the type of limb involvement were not associated with the recurrence (P = 0.433 and 0.269). The cutoff values of preoperative gait kinematics between the non-recurrence and recurrence groups were -19 degrees of ankle dorsiflexion at initial contact (P = 0.018). Conclusions: This study showed that the severity of preoperative equinus deformity was a risk factor associated with recurrence after TAL in patients with cerebral palsy. Therefore, surgeons should consider the recurrence and later revision surgery for the patients with severe equinus foot deformity.