Objective: To explore the anterior extraperitoneal anatomical targeted surgical approach for acetabular
fractures and to meet the requirements for precise minimally invasive robotic-assisted orthopedic surgery. Methods:
Fresh adult Chinese cadavers were used with arterial perfusion. Based on the clinical needs of internal fixation of
acetabular fractures, five most common fracture sites of acetabulum were selected, including anterior column, anterior
wall, acetabular roof, medial quadrilateral surface and greater ischial notch. The distribution and density of blood
vessels with diameter ≧ 2.0 mm were measured in the above areas. The shortest linear distance between blood vessels
and bone was categorized as follows: Grade Ⅰ (extremely hazardous, 0–5.0 mm), Grade Ⅱ (highly hazardous, 5.0–10.0
mm), or Grade Ⅲ (moderately hazardous, 10.0–20.0
mm). Venous and arterial distribution density ≥ 10, 8, 6
vessels within a 30.0 mm radius was classified as Grade
A (extremely hazardous), Grade B (highly hazardous),
or Grade C (moderately hazardous). According to the
above measurements, the vascular protection levels for5 regions were drawn up. The extraperitoneal targeted minimally invasive surgical pathways were summarized to
avoid important blood vessels. Results: Grade I vessels included the corona mortis, obturator artery and vein, femoral
artery and vein, superior gluteal artery and vein, which required level Ⅰ protection. Grade Ⅱ vessels comprised
iliolumbar artery and vein, internal iliac artery and vein and their branches, external iliac artery and vein, inferior
gluteal artery and vein, which needed level Ⅱ protection. Grade Ⅲ vessels consisted of deep inferior epigastric artery
and vein, umbilical artery and vein, testicular artery and vein, which called for level Ⅲ protection. Grade A area
was located at the greater sciatic notch. Grade B area was located at the obturator area of the superior pubic ramus,
the acetabular roof and the medial quadrangle. Grade C area was located on the anterior wall. Blood vessels with a
diameter ≧ 5.0mm could cause rapid fatal hemorrhage after injury, including common iliac artery and vein, external
iliac artery and vein, and internal iliac artery and vein. The vascular protection levels for the five regions were as
follows: level ⅠA (superior gluteal artery and vein, obturator artery and vein, and coronary artery of death), level IB
(Femoral artery and vein), level ⅡA (internal iliac artery and vein, external iliac artery and vein), level ⅡB (inferior
gluteal artery and vein), level ⅢB (testicular artery and vein, uterine round ligament artery and vein, umbilical artery
and vein). Five extraperitoneal targeted minimally invasive pathways for acetabular fractures were identified in
superior pubic ramus, anterior wall (2 sites), acetabulum roof, and the greater sciatic notch area of arcuate line. Three
newly discovered arteries, with 1.0–1.5 mm in diameter, which were not described in previous anatomical works and
literature, were named as the pubic posterior trophic branch of the coronary artery of death, the psoas major branch
and peritoneal branch of the superior gluteal artery, and the acetabular parietal trophic branch of the iliacus vessel.
Conclusion: This study provides five targeted pathways for robotic-assisted orthopedic surgery to achieve precise
and minimally invasive treatment of acetabular fractures, which can allow rapid access to the five targeted fracture
sites of the acetabulum and reduce the iatrogenic damage to normal tissues in non-fracture areas. The three newly
discovered vessels enrich anatomical understanding of acetabular vasculature and are of significant significance to
avoid intraoperative vascular injury and bleeding.
