The evaluation of safe zones for the corona mortis using a cadaver simulation of the Modified Stoppa approach

The Modified Stoppa approach is a minimally invasive method of accessing the pelvis when treating pelvic ring and acetabular fractures. Although this approach is reported to be effective in exposing pelvic fractures, there are iatrogenic risks associated with the procedure. These risks arise from the inadvertent severing of vessels along the pelvic brim, resulting in bleeding, prolonged recovery, or even death. The specific vessels of concern include the corona mortis (CM) anastomosis and aberrant vasculature, which course over the superior pubic ramus. The current study aimed to create and validate clinically significant safe zones to avoid injury to these anomalous vessels during the Modified Stoppa approach. Measurements were taken between the CM and crossing vessels (CV), as well as various bony landmarks encountered during the anterior approach, using 63 cadavers. Measurements were statistically analyzed for any significant differences between sides and sex using t-tests, and safe zones were formulated. The safe zones were then assessed for precision using a stepwise cadaver simulation of the Modified Stoppa approach. Safe zones from the pubic tubercle were calculated as 57.96 mm (SD ± 21.40) for the CM, while safe zones for the CV were reported as 48.07 mm (SD ± 25.52). These safe zones proved to be accurate when implemented during the cadaver simulation of the Modified Stoppa approach, as all cases of CM and aberrant vessels were positioned outside the prescribed zones. The results reiterate the clinical significance of the CM and its impact on orthopedic surgery and patient care. • The corona mortis (CM) is a clinically significant anomaly intercepting the Modified Stoppa approach to the pelvis. • Up to 4 vessels can be found crossing a singular superior pubic ramus in an individual. • Safe zones of the CM and crossing vessels can prevent injury and hemorrhage. • Safe zones can be validated using clinical simulations of the medical procedure. • Validated safe zones in relation to the pubic tubercle resulted in 57.96mm for the CM and 48.07mm for crossing vessels.