An anatomical study on the variations and clinical significance of the corona mortis within a South African sample

Introduction

Anterior orthopaedic approaches, much like the Modified Stoppa approach, target fractures of the anterior column of the pelvis and acetabulum. The approach is described as a minimally invasive technique that may lead to iatrogenic haemorrhage and fatality in patients. Such mortality is due to the inadvertent severing of the corona mortis vessels, a clinical term referring to the anastomosis between the obturator vessels and the external iliac vessels typically via an accessory obturator vessel that courses over the pelvic brim. Knowledge regarding the prevalence and clinical significance of the corona mortis, especially within the South African population is lacking, and therefore further investigation of this anomaly is necessary.

Materials and methods

This study investigated the incidence and variations of the corona mortis vessels in a South African sample using 63 adult cadavers obtained from the Department of Anatomy, University of Pretoria. After careful dissection of the blood supply to the pelvis, the prevalence of corona mortis was investigated. Variations regarding the composition of the corona mortis and the incidence of aberrant obturator vessels were documented.

Results

The incidence of corona mortis was observed in 67.5% of the study sample, with 91.6% being venous and 8.4% being arterial in composition. An incidence of 26.0% of aberrant obturator arteries and 8.1% of aberrant obturator veins were observed originating or draining directly into the external iliac system, respectively. A single rare instance of corona mortis was observed and involved an anastomosis with the superior vesical vein rather than the typical obturator vein. While variations amongst anomalous accessory vessels were observed which resulted in as many as 3 aberrant vessels coursing over the pelvic brim. No significant difference was concluded for the incidence of corona mortis between the left and right sides or between males and females.

Conclusion

Mapping out the parameters of the corona mortis and examining the variation linked with the anomaly will aid orthopaedic surgeons in implementing anterior approaches with reduced vascular damage and iatrogenic deficit. Further understanding of its incidence in the South African population will in turn assist in interpreting its clinical significance.