The obturator artery is a relatively small vessel in the pelvis that punches well above its weight in clinical importance. It typically branches from the internal iliac artery, dips through the obturator canal alongside the obturator nerve, and supplies the muscles around the inner thigh, the hip joint, and part of the pelvic wall. What makes this artery so interesting to surgeons, radiologists, and anatomists alike is its wild variability: its origin differs from person to person more than almost any other named artery in the body, and one particular variant has earned the ominous nickname “corona mortis,” or crown of death.
Where the Obturator Artery Normally Runs
In most people, the obturator artery arises from the anterior division of the internal iliac artery inside the pelvis. From there it travels forward and downward along the lateral pelvic wall, passes through the obturator foramen (the large opening in the hip bone), and enters the thigh. Once through the foramen, it splits into an anterior and a posterior branch. The anterior branch runs along the front margin of the obturator foramen and supplies the adductor muscles of the thigh, the skin of the medial thigh, and part of the hip joint capsule. The posterior branch curves the other way, sends a small twig through the ligamentum teres into the femoral head, and feeds the deep hip joint structures.
One cadaveric study found the artery originating from the internal iliac artery in about 79% of specimens, which aligns with what most anatomy textbooks teach as the “normal” pattern.1PubMed Central. Reappraisal of the Variations in the Origin of the Obturator Artery With Clinical and Developmental Perspectives: A Cadaveric Analysis Another dissection-based study of 50 pelvic halves confirmed the anterior division of the internal iliac as the most common origin, though exact percentages varied across samples.2PubMed Central. A Study of Variations in the Origin of Obturator Artery and its Clinical Significance The artery is typically only a few millimeters in diameter, which is why it can be easy to overlook on imaging or during open surgery. Despite its modest size, it forms part of a rich network of pelvic anastomoses that become critically important when larger vessels are blocked or injured.
Why the Origin Varies So Much
The obturator artery is one of the most variable vessels in the body when it comes to where it starts. Instead of always coming off the internal iliac, it sometimes arises from the external iliac artery, the inferior epigastric artery, or even from both systems at once. In the cadaveric analysis mentioned above, roughly 19% of specimens had an obturator artery originating from the external iliac system, and about 2% showed a dual origin from both the internal and external iliac territories.3PubMed Central. Reappraisal of the Variations in the Origin of the Obturator Artery With Clinical and Developmental Perspectives: A Cadaveric Analysis
The reason for all this variability lies in how pelvic blood vessels form during embryonic development. In the growing embryo, the pelvic region starts with a web-like network of small arterial channels rather than the clean, branching pattern seen in adults. Some channels enlarge while others shrink, and the final layout of arteries depends on which channels persist. The obturator artery appears to form from an anastomotic connection between what will become the external and internal iliac systems. Depending on which side of that connection becomes dominant, the artery can wind up attached to either system, or occasionally to both.4Journal of Vascular Surgery / J Vasc Bras. Rare origin of the obturator artery from the external iliac artery with two obturator veins This developmental lottery explains why cadaver studies consistently find such a spread of origins, and why two people’s pelvic anatomy can look quite different from each other.
The Corona Mortis
The most clinically feared variant of the obturator artery is the so-called corona mortis, Latin for “crown of death.” This is a vascular connection, either arterial or venous, between the obturator system and the external iliac or inferior epigastric vessels. It runs behind the superior pubic ramus, which is the bony ridge at the front of your pelvis. The name is dramatic but well earned: if this vessel is accidentally cut during surgery or torn in a pelvic fracture, it can bleed heavily and is notoriously hard to control because it retracts behind bone.5PubMed. Corona mortis: an anatomical study with clinical implications in approaches to the pelvis and acetabulum
How common is it? That depends on the study and the detection method. A literature review found that arterial corona mortis vessels are present in roughly 20% of hemipelves, while venous versions show up in about 40%.6PubMed Central. Surgical Anatomy of Corona Mortis: A Literature Review and Its Significance in Minimally Invasive Surgery A South African cadaveric study reported an overall incidence of about 68% when both arterial and venous anastomoses were counted, though the arterial form alone appeared in only about 7% of specimens.7Translational Research in Anatomy. An anatomical study on the variations and clinical significance of the corona mortis within a South African sample A large CT angiography study found arterial corona mortis in nearly a third of patients and recommended routine preoperative screening to help prevent accidental injury during pelvic and acetabular surgery.8PubMed. Frequency and demographic variability of the corona mortis: Insights from computed tomography angiography
The vessels involved typically range from about 2 to 4 mm in diameter and sit 40 to 96 mm from the pubic symphysis.9PubMed. Corona mortis: an anatomical study with clinical implications in approaches to the pelvis and acetabulum That size might not sound impressive, but in the tight retropubic space, a transected vessel of even 2 or 3 mm can cause rapid, difficult-to-stop bleeding. Surgeons approaching the pelvis from the front, whether for fracture fixation, hernia repair, or gynecological procedures, need to be aware that this vessel may be lurking behind the bone.
The Aberrant Obturator Artery in Pelvic Fractures
Pelvic fractures are dangerous injuries, and hemorrhage is one of the leading causes of death in severe cases. When the pelvic ring breaks, any nearby artery can tear. The internal iliac and its branches get most of the attention, but an obturator artery arising from the external iliac system, often called the aberrant obturator artery, can be an overlooked source of life-threatening bleeding.
One study of pelvic fracture patients found that roughly a quarter of those with an aberrant obturator artery had active extravasation (bleeding) from that vessel. The critical problem was that standard flush angiography of the internal iliac artery failed to reveal the bleeding, because the aberrant vessel originates from a different trunk entirely. Only when the inferior epigastric artery was selectively injected did the bleeding become visible.10Journal of Trauma: Injury, Infection & Critical Care. Aberrant Obturator Artery Is a Common Arterial Variant That May Be a Source of Unidentified Hemorrhage in Pelvic Fracture Patients In one case report, embolization teams successfully treated bleeding from the internal iliac branches, but the patient continued to hemorrhage. Only after examining the external iliac system did they find a lacerated aberrant obturator artery arising from the inferior epigastric. Additional coil embolization of that vessel finally stopped the bleeding.11PubMed. Hemorrhage secondary to pelvic fracture: coil embolization of an aberrant obturator artery
The practical takeaway for interventional radiologists and trauma teams is straightforward: when a patient with a pelvic fracture keeps bleeding despite apparently successful embolization of the internal iliac branches, the external iliac system needs to be checked. Fractures involving the superior pubic ramus or the pubic part of the acetabulum are especially high-risk for corona mortis injury. A recent study of embolization for corona mortis bleeding reported technical success in all 14 patients treated, with no procedure-related complications.12PubMed Central. Aberrant obturator artery or corona mortis embolization for the treatment of pelvic trauma hemorrhage: Technique and clinical outcomes
How the Obturator Artery Feeds the Femoral Head
The hip joint depends on a precarious blood supply, and the obturator artery plays a small but historically contentious role in it. The posterior branch of the obturator artery sends a vessel through the ligamentum teres, the small ligament that connects the femoral head to the acetabulum. This foveal artery enters the bone at the fovea, a small pit on the surface of the femoral head. In children and young adults, this vessel can provide meaningful blood supply to the central part of the femoral head. The conventional teaching in some older anatomy textbooks was that this vessel becomes insignificant or absent in most adults.
A clinical study of 266 patients undergoing primary hip replacement challenged that simplistic narrative. Surgeons directly inspected the foveal vessels at the time of surgery and found them intact in about 61% of patients, with a mean age in the mid-60s. The remaining 39% had vessels that were not intact. There was no significant correlation with age, sex, or the underlying reason for the hip replacement.13PubMed Central. Are the anatomy textbooks wrong? A clinical patho-anatomic study of foveal vessels in the round ligament of the hip The finding suggests that the obturator artery’s contribution to the femoral head is not all-or-nothing. In a majority of adults, it persists, though whether it carries enough blood to keep bone alive on its own, say after a femoral neck fracture disrupts the other supply routes, remains a separate and more complicated question. For hip surgeons, the message is to not assume the ligamentum teres is a vestigial structure with no working blood vessels.
Obturator Bypass Surgery
The obturator foramen, the same opening the artery normally passes through, can be exploited as a surgical corridor for vascular bypass grafts. This comes into play in a specific and challenging clinical scenario: infection of a vascular graft in the groin. When a prosthetic graft placed in the femoral region becomes infected, surgeons face the difficult task of removing the contaminated material while still keeping the leg’s blood supply intact. Routing a new bypass through the infected groin is asking for trouble, so an alternative path is needed.
An obturator bypass threads a new graft from the iliac artery through the obturator foramen, bypassing the groin entirely and reaching the femoral artery further down the thigh. The route is anatomically close to the normal path of blood flow, which gives it better long-term patency than some other extra-anatomical alternatives. It requires strong anatomical knowledge and technical skill, because the obturator canal sits deep in the pelvis and is surrounded by the obturator nerve and other structures.14PubMed Central. Obturator bypass in the treatment of prosthetic graft infection: Classic but still effective Despite these demands, case series consistently describe it as a reliable, effective strategy with high patency rates, and some authors advocate for it as a first-line option in groin graft infections.15PubMed Central. Extra-anatomical Obturator Bypass Due to Groin Infection A recent case report confirmed successful revascularization using a ringed PTFE graft routed through the obturator foramen after excision of an infected femoral graft.16Azerbaijan Journal of Cardiovascular Surgery. Obturator Bypass as a Salvage Procedure for Infected Femoral Graft: A Case Report
The Obturator Nerve and Artery Together
The obturator artery travels alongside the obturator nerve through the obturator canal, and this close relationship means that problems affecting one can affect or involve the other. The obturator nerve controls the adductor muscles of the inner thigh and provides sensation to a patch of skin on the medial thigh. When the nerve gets trapped, typically by thick fascia over the short adductor muscle, the result is exercise-induced pain starting in the groin area and radiating down the inner thigh, along with weakness in pulling the leg inward.17PubMed. Obturator nerve entrapment. A cause of groin pain in athletes18PubMed Central. Obturator neuropathy This condition is seen in athletes, especially those in kicking and running sports, and it can mimic other groin injuries.
The shared anatomy also creates surgical hazards. During transurethral resection of bladder tumors, electrical stimulation of the obturator nerve through the bladder wall can cause violent involuntary jerking of the leg. Obturator nerve blocks are performed before these procedures to prevent exactly that. But even with a nerve block, the reflex is not always suppressed. One case report described a patient who developed sudden severe hypotension and a rapidly expanding lower abdominal swelling during bladder surgery, despite a prior obturator nerve block. Emergency surgery revealed that the leg jerk had caused the resectoscope to perforate the bladder and sever the obturator artery, resulting in massive hemorrhage.19PubMed. Life-threatening haemorrhage following obturator artery injury during transurethral bladder surgery: a sequel of an unsuccessful obturator nerve block It is a vivid reminder that the nerve and artery are separated by very little tissue, and that procedures in this area carry compounded risks.
Collateral Flow When Larger Pelvic Vessels Are Blocked
The obturator artery is part of a broader network of pelvic collateral pathways that can step in when the internal iliac artery is intentionally or accidentally interrupted. This situation arises during endovascular aortic aneurysm repair, where one or both internal iliac arteries may need to be sacrificed to allow the stent graft to seal properly. Losing the internal iliac artery threatens the blood supply to the buttock muscles, the pelvic organs, and the hip, potentially causing buttock claudication (cramping pain with walking) or other ischemic complications.
A study of patients who underwent internal iliac artery interruption during aneurysm repair found that the obturator artery on the affected side dilated significantly after surgery, reflecting its recruitment as a collateral channel. The circumflex femoral arteries also enlarged on the same side.20PubMed Central. Pelvic collateral pathway during endovascular aortoiliac aneurysm repair with internal iliac artery interruption: a retrospective observational study This enlargement occurred only on the side where the internal iliac was blocked, confirming that it was a compensatory response rather than a coincidence. The obturator artery’s position, connecting the internal and external iliac territories, makes it a natural bridge for rerouting blood flow. Its ability to dilate and carry more blood helps explain why many patients tolerate internal iliac artery occlusion without severe consequences, though the degree of compensation varies from person to person.
Flap Surgery and Tissue Reconstruction
Beyond trauma and vascular bypass, the obturator artery has found a niche in plastic and reconstructive surgery. The anterior branch of the obturator artery sends a perforating vessel up through the adductor region at a remarkably consistent location near the crease where the thigh meets the groin. Surgeons can harvest a flap of skin and soft tissue based on this perforator and rotate it to reconstruct nearby defects.
This anterior obturator artery perforator flap has proven particularly useful for reconstruction after radical vulvar surgery for cancer and for scrotal defects. The perforator is reliably found at the uppermost territory of the gracilis muscle, and the skin it supplies can measure roughly 7 by 15 centimeters, a generous territory for local reconstruction.21PubMed. The anterior Obturator Artery Perforator (aOAP) flap: surgical anatomy and application of a method for vulvar reconstruction The flap’s proximity to the perineum means it can be swung into position without tension, and because the donor site is in the inner thigh crease, the scar is well hidden. Reports describe it as versatile and reliable for vulvar, vaginal, and scrotal reconstruction.22PubMed Central. Obturator Artery Perforator Propeller Flap for Scrotal and Vulvar Reconstruction For patients undergoing oncologic surgery in these areas, the availability of a well-vascularized local flap can make the difference between a straightforward wound closure and a complicated one.
Preoperative Imaging and Why It Matters
Given all this anatomic variability, a reasonable question is whether surgeons should look for the obturator artery and its variants before operating on the pelvis. The answer is increasingly yes, especially for anterior approaches to the acetabulum, hernia repairs in the preperitoneal space, pelvic fracture fixation, and any procedure that involves working near the superior pubic ramus. CT angiography can identify the corona mortis and map the obturator artery’s origin before the first incision is made. The largest reported CT angiography series to date found arterial corona mortis in nearly a third of patients and showed meaningful variation across demographic groups, reinforcing the argument for routine preoperative screening.23PubMed. Frequency and demographic variability of the corona mortis: Insights from computed tomography angiography
For trauma cases, where there is no time for elective preoperative planning, the practical approach is different. Interventional radiologists treating pelvic hemorrhage should assume the variant exists and check both the internal and external iliac systems during angiography. The lesson from case series is clear: persistent bleeding after what looks like complete embolization of internal iliac branches should prompt a search for an aberrant obturator artery originating from the external iliac side.24Journal of Trauma: Injury, Infection & Critical Care. Aberrant Obturator Artery Is a Common Arterial Variant That May Be a Source of Unidentified Hemorrhage in Pelvic Fracture Patients In minimally invasive pelvic surgery, a review of the literature emphasized that awareness of the corona mortis should be standard knowledge for anyone performing laparoscopic hernia repair, robotic prostatectomy, or similar procedures in the retropubic space.25PubMed Central. Surgical Anatomy of Corona Mortis: A Literature Review and Its Significance in Minimally Invasive Surgery The artery itself may be small, but ignorance of its location and variability has cost patients blood and, in rare cases, their lives.