Inter- and intra-rater reliability of video-documented Pirani Böhm Sinclair score: A potential method to screen for signs of recurrence in children with idiopathic clubfoot?

Purpose: The recurrence rate in children with idiopathic clubfoot is high. The Pirani Böhm Sinclair score is a clinical tool screening for signs of recurrence. This study examined the inter- and intra-rater reliability of video-documented Pirani Böhm Sinclair score.

Methods: In two pediatric orthopedic centers, children with idiopathic clubfoot aged 4-15 years were consecutively included and filmed using a standardized protocol to complete the Pirani Böhm Sinclair score. Four pediatric orthopedic surgeons with extensive experience treating clubfoot patients viewed the videos and scored the feet according to the Pirani Böhm Sinclair score. Intra-class correlation coefficient and Kappa statistics were used to determine reliability.

Results: Fifty-five children with 85 clubfeet were included (54% bilateral). A subset of 30 videos was reassessed at a separate occasion by two of the four raters. Fleiss unweighted Kappa showed substantial agreement between all raters for the item "early heel rise," and moderate agreement for all remaining items except "swing phase supination" which was fair. Intra-class correlation coefficient for the total Pirani Böhm Sinclair score was almost perfect for both agreement and consistency on a group level and for each rater pair, respectively. Examination of intra-rater reliability showed substantial to almost perfect agreement for five items for both raters, but not the same five items.

Conclusions: This study highlights the potential use of video-documented Pirani Böhm Sinclair score. A high level of agreement was found for the item "early heel rise" where reduced playback speed and repeated viewing may aid assessment, while a low level of agreement was observed for the clinically important item "walking supination." Further development of the scoring instructions is required.