Rate and predictors of relapse and surgery in idiopathic clubfeet after successful Ponseti treatment in infancy : a single centre, retrospective, comparative study.

Aims: To assess the rates of relapse and risk factors for release and surgical intervention in patients with idiopathic clubfoot. Methods: A retrospective review of all patients with idiopathic clubfoot and initiation of Ponseti treatment between February 2005 and December 2015 was conducted. All patients with successful initial Ponseti casting treatment at the study institution and one year of follow-up were included. Rates of relapse, surgery, and types of surgical procedures performed were collected. Results: The final cohort included 268 children with 397 idiopathic clubfeet, consisting of 98 females (36.6%) and 170 males (63.4%). The successfully Ponseti-treated group without relapse was composed of 171 children with 252 feet (63.5% of total cohort). A total of 97 patients (36.2%) had a relapse and required further intervention (relapse group). There was a greater proportion of patients with complex-type clubfoot in the relapse group (18.6% vs 4.7%, p = 0.001). Patients who never relapsed presented at a median age of 33.7 days (IQR 40.8), while those who relapsed presented at a significantly younger age, at a median of 25.1 days (IQR 17.2) (p < 0.001). Children in the no-relapse group required significantly fewer casts to achieve correction, with a mean of 4.3 compared with 5.2 in patients with relapse (p < 0.001). Children in the no-relapse group showed a significantly higher rate of good adherence compared with those in the relapse-group (94.9% vs 62.3%, p < 0.001). In total, 24 children (23 feet, 5.8% of total cohort) underwent surgery, whereas 74 had a relapse but did not require surgery. The most common surgical procedures performed were tibialis anterior tendon transfer (n = 25) and open tendoachilles lengthening (n = 21). Conclusion: We confirm that a higher number of casts to achieve correction in the initial Ponseti series, younger age at presentation, complex clubfoot features, and poor brace adherence may be correlated with risk of relapse and surgery. The need for joint invasive surgery is rarely indicated.