Predictable Localization of Arterial Corona Mortis on the Superior Pubic Ramus: A Computed Tomography-based Proportional Mapping Study

Abstract Purpose: Corona mortis (CM) is a vascular variation crossing the superior pubic ramus and represents a well-recognized source of hemorrhagic risk during pelvic and retropubic procedures. This study aimed to determine the crossing location of the arterial CM using a proportional mapping approach to provide a body size-normalized anatomical reference. Methods: This retrospective cross-sectional study evaluated contrast-enhanced pelvic computed tomography scans from 500 consecutive adult patients (1000 hemipelvises). Arterial CM was defined as any vessel originating from the external iliac or inferior epigastric artery crossing the superior pubic ramus. The proportional ratio was calculated as: CM-pubic symphysis (PS) distance/PS-anterior superior iliac spine distance. Sex-based and age-stratified analyses were performed. Results: Arterial CM was identified in 83 hemipelvises (8.3%), with prevalence numerically lower than that reported in many studies. The mean proportional ratio was 0.327 ± 0.033, corresponding to 3.27 ± 0.33 units on a 10-unit scale. A high-frequency zone (ratio: 0.29–0.36) captured 71.1% of all CM vessels. Male hemipelves demonstrated significantly larger arterial diameter and a more medial CM position compared with female hemipelves. No significant age-related variation was observed. Interobserver and intraobserver reliability were excellent (intraclass correlation coefficient range: 0.85–0.96). Conclusion: Proportional mapping provides a reproducible, body size-normalized reference system for CM localization. The consistent clustering around the junction of the medial and middle thirds of the PS-anterior superior iliac spine axis defines a predictable anatomical high-frequency zone, supporting standardized interpretation of arterial CM topography in anatomical studies.