Population-specific reference values for calcaneal angular parameters and their limited utility in sex estimation

The calcaneus is the largest tarsal bone located in the lower part of the ankle joint and plays a significant role in walking, running, and maintaining balance. Certain angles of this bone, which is of great clinical and anthropological importance, are used in the diagnosis and treatment of fractures. The aim of this study is to determine the mean values of angular parameters of the calcaneus in a healthy population and to evaluate the accuracy rates of these parameters in predicting sex. In this study, six bilateral angle measurements were performed on radiographs from 540 individuals aged 20-65. Measured angles included Böhler, Gissane, calcaneal inclination, Fowler-Philip, lateral talocalcaneal, and calcaneal compression. The obtained data were compared between sexes, age groups, and right-left sides. Additionally, a receiver operating characteristic analysis was performed for sex prediction. Statistical analyses revealed significant differences between right and left sides in the calcaneal inclination angle and lateral talocalcaneal angle, between sexes in the calcaneal compression angle, and between age groups in the Böhler and Gissane angles. Analyses performed for sex prediction showed that the angles were not suitable for this purpose. The findings and the determination of the mean values of the angles provide useful information for decision-making in clinical diagnosis and treatment processes. It was found that using only calcaneal angles is not appropriate for sex prediction in the Turkish population. The findings may contribute to the establishment of population-specific reference values and provide baseline data for future multivariate or machine learning-based investigations.