Relationship of foot anthropometry with Modified Pirani score during Ponseti correction of idiopathic congenital talipes equinovarus: a prospective observational study

BACKGROUND: The Ponseti method is the gold standard treatment for idiopathic congenital talipes equinovarus (CTEV). Clinical monitoring during correction primarily relies on the Modified Pirani score, which evaluates deformity severity based on clinical findings. However, objective quantitative assessment of morphological foot changes during treatment remains limited. This study aimed to evaluate the relationship between serial foot anthropometric measurements and Modified Pirani scores during Ponseti correction of idiopathic clubfoot. METHODS: A prospective observational cohort study was conducted in 30 children with idiopathic unilateral CTEV undergoing Ponseti correction at a tertiary care center between June 2024 and February 2026. Five anthropometric parameters were measured weekly for eight weeks: great toe to midheel distance (GT-MH), little toe to midheel distance (LT-MH), second toe to midheel distance (ST-MH), medial malleolus to midheel distance (MM-MH), and lateral malleolus to midheel distance (LM-MH). Modified Pirani scores were assessed simultaneously by two independent observers. Pearson correlation analysis and inter-observer reliability testing were performed. RESULTS: Significant improvement was observed in all anthropometric parameters and Pirani scores over the study period (p < 0.001). Mean GT-MH increased from 80.73 ± 3.36 mm to 87.56 ± 3.41 mm, LT-MH from 65.36 ± 2.04 mm to 70.22 ± 2.05 mm, and MM-MH from 26.19 ± 0.79 mm to 30.85 ± 0.78 mm. LM-MH decreased from 28.40 ± 0.56 mm to 25.25 ± 0.51 mm, reflecting correction of hindfoot varus. Pirani score improved from 5.33 ± 0.24 to 0.03 ± 0.18. Strong inverse correlations were observed between Pirani score and GT-MH (r = -0.56), LT-MH (r = -0.61), ST-MH (r = -0.71), and MM-MH (r = -0.88), while LM-MH demonstrated a positive correlation (r = 0.71). Inter-observer reliability was excellent, with ICC values ranging from 0.9956 to 1.000. Percutaneous Achilles tenotomy was required in 80% of patients. CONCLUSIONS: Serial anthropometric assessment demonstrates significant correlation with Modified Pirani scoring during Ponseti correction of idiopathic clubfoot. Anthropometric measurements provide objective and reproducible quantitative data that complement clinical scoring and may improve monitoring of deformity correction during treatment. TRIAL REGISTRATION: Institutional Ethics Committee approval was obtained prior to commencement of the study.