Corona mortis: an anatomical study with clinical implications in approaches to the pelvis and acetabulum.

The "corona mortis" is an anatomical variant, an anastomosis between the obturator and the external iliac or inferior epigastric arteries or veins. It is located behind the superior pubic ramus at a variable distance from the symphysis pubis (range 40-96 mm). The name "corona mortis" or crown of death testifies to the importance of this feature, as significant hemorrhage may occur if accidentally cut and it is difficult to achieve subsequent hemostasis. It constitutes a hazard for orthopedic surgeons especially in the anterior approach to the acetabulum. We carried out forty cadaver dissections (80 hemi-pelvises) through the ilioinguinal approach. A vascular anastomosis was found in 83% of specimens. Of these, 60% had a large diameter (>3 mm) channel along the posterior aspect of the superior pubic ramus. In clinical practice, however, 492 anterior approaches (to the best of our knowledge the largest series described) have been carried out over the last 15 years by the senior author (MB) and only five of these problematic vessels were discovered, and in only two cases was there troublesome bleeding. This study confirms a paradox: in anatomical dissections a large vessel was identified behind the superior pubic ramus, whereas in clinical practice this vessel does not seem to be as great a threat as initially perceived. Orthopedic surgeons planning an anterior approach to the acetabulum, such as the ilioinguinal or the intrapelvic approach (modified Stoppa), have to be cautious when dissecting near the superior pubic ramus. Despite the high prevalence of these large retropubic vessels in the dissecting room, surgeons should exercise caution but not alter their surgical approach for fear of excessive hemorrhage.