Does initial Pirani score and age influence number of Ponseti casts in children?

Abstract

Purpose: The prediction of number of casts in the Ponseti method has always remained a subject of interest. We investigated the correlation of the number of casts before tenotomy with the age and initial Pirani score in Ponseti treatment of club foot.

Methods: Inclusion criteria were idiopathic clubfeet corrected by Ponseti method requiring tenotomy for equinus correction in children up to ten years of age. Defaulters (noncompliance with serial casting schedule), children with postural, non idiopathic, previously surgically treated, recurrent clubfoot and clubfoot not requiring tenotomy were not included in this study. Further, children who did not require tenotomy were also excluded. ANOVA regression analysis was used for finding correlation between initial Pirani score, age in months and number of corrective casts prior to tenotomy.

Results: There were a total of 297 children (442 feet) in the study. The average age of the child at presentation was 10.3 months and the average initial Pirani score was 4.8. The average number of corrective casts was seven per child (range, two to18). The regression analysis showed both Pirani and age had positive correlation with number of casts, although weak (r2 = 0.05-0.20). The initial Pirani scoring correlated ten times more than age (in months) to the number of casts.

Conclusion: The number of casts for correction in idiopathic clubfoot, although variable, is influenced by both initial Pirani score and age.

Fig. 1

The X variable 1 line-fit plot depicting the regression analysis between initial Pirani score and the number of corrective casts. The pink dots show the predicted number of casts on the basis of initial Pirani score and the blue dots show the actual number of casts. The point from where the pink dots start is the intercept which is the average minimum number of casts

Fig. 2

The X variable 1 line-fit plot depicting the regression analysis between age and the number of corrective casts. The pink dots show the predicted number of casts on the basis of age and the blue dots show the actual number of casts. The point from where the pink dots start is the intercept which is the average minimum number of casts