Evertor muscle activity as a predictor for recurrence in idiopathic clubfoot

Clubfoot is a complex three-dimensional deformity. Although brace compliance after initial correction was previously found to be significantly associated with recurrence in clubfoot, few previous studies have specifically examined evertor muscle function as a factor that contributes to recurrence in children with idiopathic and non-idiopathic clubfoot. The aim of this study was to investigate the relationship among brace compliance, evertor muscle grading, and recurrence rate in pediatric clubfoot patients.

Children with idiopathic clubfoot who were treated and followed for a minimum of 2 years were included. Patients who used their brace <20–23 h a day for the first 3 months and then <8–10 h per day during sleep and nap times thereafter were classified as group I. Patients who complied fully by using the brace 23 h a day for the first 3 months and then 8–10 h per day during sleep and nap times thereafter were classified as group II. Demographic and clinical data including age, gender, follow-up time, recurrence, evertor muscle grading, types of surgery, brace compliance, severity of initial deformity, age at onset, number of casts required for initial correction, and the need for Achilles tenotomy were collected and analyzed.

Seventy-nine children with clubfoot were included. There were 47 males and 32 females, mean age was 3.2 years (range 2.1–6.3), and the mean follow-up time was 31.4 months. All patients had follow-up of at least 2 years. Primary correction was obtained in all children. There was no significant difference in mean age, mean follow-up time, or recurrence rate between groups. There was, however, a statistically significant difference in mean brace time between groups (p = 0.002). The recurrence rate was 26.2% in group I and 22.2% in group II. The recurrence rate in group a (Pirani score 0) was 3.9%, group b (Pirani score 0.5) 43.8%, and group c (Pirani score 1) 75% (p < 0.001). No significant association was found between severity of the initial deformity, age at the onset of treatment, number of casts required for correction, or reported brace compliance and recurrence or rates of surgery. Only poor or absent evertor muscle activity was found to be statistically significantly associated with risk of recurrence.

Good evertor muscle grading was found to be a significant protective factor against recurrence of idiopathic clubfoot. Thus, improvement in muscle balance around the ankle, especially the evertor muscle, should be emphasized to parents after the casting regimen is completed and correction is achieved.