Arif KESKİN, Tayfun AYGÜN, Gökhan TONKAZ
Medical Science and Discovery - 2026;13(6):117-126
Objective: Pes planus is a prevalent foot deformity characterized by the collapse of the medial longitudinal arch. Although various radiomorphometric parameters are employed in its assessment, comprehensive studies comparing their collective predictive power remain limited. This study aimed to evaluate four radiomorphometric parameters and model their independent predictive utility for pes planus. Materials and Methods: This retrospective study analyzed 200 lateral weight-bearing foot radiographs (100 pes planus, 100 control) from an open-access dataset. Four parameters-Böhler angle, Gissane angle, Meary angle, and calcaneal pitch angle-were measured digitally using ImageJ. Intergroup comparisons were performed using independent samples t-tests and Mann-Whitney U tests. A binomial logistic regression model was constructed to identify independent predictors of pes planus; the calcaneal pitch angle was excluded from this model to prevent circularity, due to its geometric equivalence to the grouping criterion (Calcaneal Inclination Angle). Reliability was assessed using the intraclass correlation coefficient (ICC). Results: All four parameters showed statistically significant differences between the groups. The calcaneal pitch angle demonstrated the most pronounced between-group divergence (pes planus: 12.42 +/- 3.21 derece vs. control: 21.06 +/- 2.50 derece; p < 0.001), validating the grouping criterion. In the multivariate logistic regression model (Pseudo R² = 0.172; AUC = 0.763; p < 0.001), both the Böhler (OR = 0.885, 95% CI: 0.837-0.937) and Meary (OR = 1.229, 95% CI: 1.127-1.340) angles emerged as independent predictors of pes planus, whereas the Gissane angle did not contribute significantly. ICC values for all parameters indicated good-to-excellent reliability. Conclusions: The Böhler and Meary angles serve as robust, independent radiomorphometric indicators for the presence of pes planus. While the calcaneal pitch angle exhibits the highest discriminatory potential, its clinical application as an independent diagnostic tool is limited by its geometric overlap with standard grouping criteria. Consequently, we propose a multiparametric radiomorphometric approach, integrating Böhler and Meary angles, to enhance the diagnostic precision of pes planus beyond single-parameter evaluations.
