Scale of severity of congenital clubfoot by the degree of rigidity of foot deformity

BACKGROUND: To date, the development of scales and classification systems for congenital clubfoot mainly involves determining the severity of clinical symptoms of foot pathology. However, it does not provide a quantitative assessment of the degree of rigidity of the foot deformity. The use of a scale that determines the foot stiffness index allows individualized long-term treatment plan for each patient. AIM: This study aimed to develop a severity scale for congenital clubfoot based on the determination of the foot rigidity index. MATERIALS AND METHODS: Before treatment, 229 children (350 feet) with typical congenital clubfoot who were treated with the Ponseti method underwent a clinical dynamometric examination. Then, the foot rigidity index was calculated. The number of plaster casts required to eliminate foot deformities in patients with congenital clubfoot of I–II, III, and IV degrees was determined. The Spearman rank method was used to establish correlations between clinical and dynamometric indicators for congenital clubfoot. P 0.05 indicated significant differences. RESULTS: A retrospective analysis of the treatment of children with congenital clubfoot using the Ponseti method revealed that fewer plaster casts are required in correcting a mild deformity than in correcting a severe deformity, and a lower index of foot rigidity is noted in mild than in severe congenital clubfoot. The Spearman correlation analysis was used to identify the criterion “foot stiffness index,” which had the most number of strong correlations between the studied signs with a high statistical significance (p = 0.001). Considering the initial index of foot rigidity, three forms of congenital clubfoot were identified: mobile, rigid, and extremely rigid. The mobile form included a deformity with a rigidity index ≤0.2. The rigid form included a deformity with a foot rigidity index of 0.21–0.3. In an extremely rigid deformity, the foot rigidity index exceeds 0.31. CONCLUSIONS: The foot rigidity index is a criterion that provides a qualitative characteristic of the condition of the foot in patients with congenital clubfoot. Based on the initial foot rigidity index, congenital clubfoot can be classified as mobile, rigid, or extremely rigid.