Differences in chest wall between Dutch adolescents with pectus carinatum and the general pediatric population: A three-dimensional scanning analysis

Introduction: This study compares the External Haller Index (EHI) in pectus carinatum patients to healthy adolescents, using 3D body imaging. Methods: We conducted a cross-sectional study including pectus carinatum patients (aged 12–18) from Amsterdam UMC, and healthy adolescents from Sports Centre: Hoppers and the Jacobus Fruytier Scholengemeenschap, between December 2024 and May 2025. The External Haller Index was calculated using 3D scans (VECTRA®H2). Primary outcome was the difference in External Haller Index between pectus carinatum patients and healthy adolescents. Secondary outcomes included correlations between External Haller Index and influencing variables (gender, age, height, weight, Body Mass Index, Pressure of Initial Correction, complaints, syndromes, symmetry, flaring, scoliosis, previous treatment). Results: Forty-three pectus carinatum patients and 50 healthy adolescents were included. Median age was fifteen years (IQR 14.0–16.0). Median External Haller Index was lower in pectus carinatum patients (1.4, IQR 1.3–1.4) than in healthy controls (1.6, IQR 1.5–1.7, P < 0.001), with a considerable overlap between groups. External Haller Index negatively correlated with Pressure of Initial Correction (ρ = −0.36, P = 0.03) and was lower in patients with syndromes (P = 0.03). A positive correlation was found between External Haller Index and Body Mass Index (ρ = 0.22, P = 0.04). External Haller Index showed no association with reported complaints. Conclusions: Pectus carinatum patients had significantly lower EHI than healthy peers, though overlap limits the use of a strict cut-off. This supports the use of 3D imaging as a non-invasive tool in PC assessment and highlight the need for Body Mass Index-adjusted reference values.