Radiographic Indicators of Surgery and Functional Outcome in Ponseti-Treated Clubfeet

Background: Evaluation of the results of treatment for clubfoot by the Ponseti technique is based on clinical and functional parameters. There is a need to establish universally recognized quantitative measurements to compare, better understand, and more precisely evaluate therapeutic outcome. Methods: Nine angles were measured on standard radiographs of 145 children with idiopathic clubfeet treated between 2000 and 2010 with the Ponseti method. The average follow-up was 6.3 years. The need for additional surgery and the functional outcome was correlated to the radiologic measurements. Results: Three radiologic parameters were identified as having significant (P ≤ .001) predictive value. The lateral tibiocalcaneal angle with the ankle at maximal dorsiflexion measuring fixed equinus was larger in the preoperated group (77 ± 12 degrees) compared to the nonoperated group (67 ± 14 degrees). Functional outcome was better with smaller angles. The lateral talocalcaneal angle with the ankle at maximal dorsiflexion measuring hindfoot rigidity was smaller (29 ± 8 degrees) in the preoperated group compared to the nonoperated group (35 ± 9 degrees). Functional outcome was better with larger angles. The lateral talo-first metatarsal angle with the ankle at maximal plantarflexion measuring foot cavus was larger in the preoperated group (31 ± 10 degrees) compared to the nonoperated group (22 ± 11 degrees), whereas functional outcome did not correlate with this angle. Conclusions: The lateral view with the foot in maximal dorsiflexion was found to be the most significant and useful view to detect abnormality in Ponseti-treated clubfeet. In our practice now, we are using only this view in order to reduce the radiation exposure to the child. Level of Evidence: Level III, retrospective case series.