Interobserver reliability of Pirani scoring for idiopathic clubfoot in walking-age children.

Abstract

Pirani scoring system is one of the most commonly used tools to assess the initial deformity, monitor the treatment progression, and identify relapse in clubfoot. The method has been demonstrated to correlate well with the sequential correction of deformity for children under age 1 year. We conducted a study to examine the interobserver reliability of Pirani scores in children of walking-age. The retrospective study focused on children >1 year age with idiopathic clubfoot presenting for primary treatment. The Pirani scores at presentation charted by pediatric orthopedic consultant and orthopedic registrars were compared and the intergroup reliability calculated using Cohen's kappa. Thirty-five feet in 22 clubfoot children (13 bilateral) were analyzed. The mean child's age was 3.9 years. The mean Pirani score for the consultant was 3.2 and for the registrars was 3.6. The overall reliability of Pirani score was 0.3 ('fair'). The highest reliability was calculated for the head of talus (0.55), rigid equinus (0.48), and lateral border (0.44) (moderate). A lower kappa was recorded for medial crease (0.28), posterior crease (0.34), and empty heel (0.4). The registrars graded the clubfoot deformity in the walking-age child as more severe compared to the consultant. The mean Pirani scores for medial and posterior crease subcomponents were low. Contrary to the common perception, empty heel manifested even in this age group. Looking to the statistics of 'fair' reliability of Pirani score for older child, further research is warranted to develop more reliable scores for assessment and treatment of clubfoot.