Development and validation of a delayed presenting clubfoot score to predict the response to Ponseti casting for children aged 2–10

The aim of the study was to develop a simple and reliable clinical scoring system for delayed presenting clubfeet and assess how this score predicts the response to Ponseti casting. We measured all elements of the Diméglio and the Pirani scoring systems. To determine which aspects were useful in assessing children with delayed presenting clubfeet, 4 assessors examined 42 feet (28 patients) between the ages of 2-10 years. Selected variables demonstrating good agreement were combined to make a novel score and were assessed prospectively on a separate consecutive cohort of children with clubfeet aged 2-10, comprising 100 clubfeet (64 patients). Inter-observer and intra-observer agreement was found to be greatest using the following clinically measured angles of the deformities. These were plantaris, adductus, varus, equinus of the ankle and rotation around the talar head in the frontal plane (PAVER). Measured angles of 1-20, 21-45 and > 45 degrees scored 1, 2 and 3 points, respectively. The PAVER score was derived from both the sum of points derived from measured angles and a multiplier according to age. The sum of the points was multiplied with 1, 1.5 or 2 for ages 2-4, 5-7 and 8-10, respectively. This demonstrated a good association with the total number of casts to achieve a full correction (tau = 0.71). A score greater than 18 out of 30 indicated a cast-resistant clubfoot. The score could be used clinically for prognosis and treatment, and for research purposes to compare the severity of clubfoot deformities.