559 Predicting the severity of clubfoot using novel antenatal sonographic markers

Abstract

To assess the accuracy of a novel sonographic angle and cavus in the fetus to predict the severity of neonatal clubfoot, quantified by grade-stratified Dimeglio scores. We identified 563 infants seen at a pediatric orthopedics clinic with a diagnosis of clubfoot between September 2010 and September 2019. A prenatal orthopedic consultation occurred in 223 of those cases based upon abnormal ultrasound findings. Corresponding maternal-fetal dyad records were identified for 179 infants. Of those, 84 were excluded due to inadequate pediatric or antenatal data, leaving 95 subjects to be analyzed. Maternal and neonatal demographics and medical history were gathered by chart review. Dimeglio scores were calculated for each extremity by a pediatric orthopedic specialist and stratified by grade (Figure A). A sonographic medial tibial-pedal (MTP) angle was calculated and cavus was assessed by an MFM specialist for each extremity (Figure B). ANOVA and Chi Squared tests were performed to assess the relationship between the sonographic measures and postnatal assessment. 141 club feet were diagnosed sonographically among 95 fetuses (190 feet). Of those, 135 were confirmed postnatally (true positive rate 95.7%); 10 did not meet criteria for clubbing on postnatal evaluation (false positive rate 4.3%). An additional 8 were diagnosed postnatally despite a normal-appearing ultrasound (false negative rate 5.7%). The MTP angle was not calculable for 12 patients due to image quality. 48% of postnatal cases were bilateral and 92% were idiopathic, consistent with prior studies. There was no significant interaction between MTP angle and postnatal Dimeglio grade (ANOVA, p=0.33). Secondary analysis of MTP restricted to idiopathic cases remained nonsignificant (ANOVA, p=0.67). Presence of sonographic cavus did not reliably predict postnatal cavus (Χ2, p=0.35). Use of a novel sonographic angle was not reliably predictive of postnatal clubfoot severity by Dimeglio grade. This points to limitations in counseling prenatal patients on the anticipated severity of and course of treatment for clubfoot.View Large Image Figure ViewerDownload Hi-res image Download (PPT)