Non-zero Pirani score in corrected clubfoot due to empty heel: A prognostic dilemma

Purpose: The aim of this study was to track the correction of individual components of Pirani scoring system (PSS) over the manipulation and tenotomy phase of Ponseti casting method in idiopathic clubfoot. Additionally, non-zero PSS scores were analysed to find out the residual deformities.

Methods: The included feet were assessed initially according to the six component PSS. The individual scores of each component of midfoot and hindfoot were scored at each visit till the final follow up. The final scoring was done before the start of the bracing phase of the feet (with or without tenotomy).

Results: Evaluation was performed for 42 feet in 28 infants (14 bilateral) with mean age of 42.5 ± 39.2 days (range, 15-150 days). All the six components of PSS showed a significant change from the first cast till the pre tenotomy cast. Post tenotomy, there was a significant change in the scores of posterior crease (0.4 ± 0.2 to 0.1 ± 0.1, p < 0.001) and rigid equinus (0.8 ± 0.3 to 0.1 ± 0.2, p < 0.001). 66.7 % (28/42) of the feet had an abnormal empty heel sign of either 0.5 [22/42 (52.3 %)] or 1 [6/42 (14.4 %)] at initiation of bracing.

Conclusions: The individual components of Pirani scoring system changed to a variable extent as the treatment progressed. Curvature lateral border and talar head reached normalcy prior to tenotomy. Posterior crease and rigid equinus showed a significant reduction after tenotomy. The non-zero empty heel component may require careful interpretation both post treatment and during follow ups.