From Landmark Uncertainty to Clinical Confidence: Screening for Developmental Dysplasia of the Hip

Front. Med. Technol. Sec. Medtech Data Analytics 1. University of Oxford, Oxford, United Kingdom 2. Alder Hey Children's Hospital, Liverpool, United Kingdom Article metrics View details Clinical image annotation-based assessment methods often rely on anatomical landmarks to derive landmark-based measurements (angle or distance) that underpin screening, diagnosis and treatment decisions. In screening pathways, landmark-based measurements typically use predefined thresholds to classify patients as healthy or unhealthy. There is natural variability among clinicians in landmark placement and, consequently, in the derived measurement and screening decisions, reflecting genuine uncertainty in these assessments. We propose a method to estimate uncertainty associated with landmark-based measurements. We define measurement uncertainty, on the basis of which to derive a confidence estimate for the clinical screening task, providing context for the measured uncertainty. While the approach is applicable to screening in general, we demonstrate its utility in detecting Developmental Dysplasia of the Hip (DDH) in neonates, using two standard clinical landmark-based measurements: the Graf α angle and the Femoral Head Coverage percentage. We show a strong correlation between multiple clinicians' confidence and the model's confidence. This indicates that the model and the clinicians identify the same cases which are difficult or borderline. To our knowledge, this work presents the first method to evaluate a model's confidence when predicting clinically relevant landmark-based measurements. This confidence estimate can establish trust in automated models, facilitating wider clinical adoption which, in turn, can widen access to screening. Keywords confidence, Landmark detection, Landmark-based measurements, screening, uncertainty Copyright © 2026 Clement, Willoughby, Perry and Voiculescu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. *Correspondence: Allison Clement Disclaimer All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.