Background: The Ponseti method is the preferred technique to manage idiopathic clubfoot deformity; however, there is no consensus on the expected relapse rate or the percentage of patients who will ultimately require a corrective surgical procedure. The objective of the present systematic review was to determine how reported rates of relapsed deformity and rates of a secondary surgical procedure are influenced by each study's length of follow-up.
Methods: A comprehensive literature search using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed to identify relevant articles. The definition of relapse, the percentage of patients who relapsed, the percentage of feet that required a surgical procedure, and the mean duration of follow-up of each study were extracted. Pearson correlations were performed to determine associations among the following variables: mean follow-up duration, percentage of patients who relapsed, percentage of feet that required a joint-sparing surgical procedure, and percentage of feet that required a joint-invasive surgical procedure. Logarithmic curve fit regressions were used to model the relapse rate, the rate of joint-sparing surgical procedures, and the rate of joint-invasive surgical procedures as a function of follow-up time.
Results: Forty-six studies met the inclusion criteria. Four distinct definitions of relapse were identified. The reported relapse rates varied from 3.7% to 67.3% of patients. The mean duration of follow-up was strongly correlated with the relapse rate (Pearson correlation coefficient = 0.44; p < 0.01) and the percentage of feet that required a joint-sparing surgical procedure (Pearson correlation coefficient = 0.59; p < 0.01). Studies with longer follow-up showed significantly larger percentages of relapse and joint-sparing surgical procedures than studies with shorter follow-up (p < 0.05).
Conclusions: Relapses have been reported to occur at as late as 10 years of age; however, very few studies follow patients for at least 8 years. Notwithstanding that, the results indicated that the rate of relapse and percentage of feet requiring a joint-sparing surgical procedure increased as the duration of follow-up increased. Longer-term follow-up studies are required to accurately predict the ultimate risk of relapsed deformity. Patients and their parents should be aware of the possibility of relapse during middle and late childhood, and, thus, follow-up of these patients until skeletal maturity may be warranted.
Level of evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.