Topography and Course
The vessel begins as it emerges from the pelvic cavity below the inguinal ligament through the vascular lacuna (lacuna vasorum). Immediately after, it enters the femoral triangle (Scarpa's triangle). Within this region, the main trunk lies lateral to the femoral vein and medial to the femoral nerve (n. femoralis). The artery rests on the pectineus muscle (m. pectineus) and the adductor longus muscle (m. adductor longus), covered by fascia lata and the sartorius muscle (m. sartorius).
Next, the vessel enters the adductor canal (Hunter's canal, canalis adductorius). This canal has three walls:
- Medial: Adductor magnus muscle (m. adductor magnus).
- Lateral: Vastus medialis muscle (m. vastus medialis).
- Anterior: Vastoadductor membrane (lamina vastoadductoria).
After passing through the canal, the vessel exits via its inferior opening—the adductor hiatus (hiatus adductorius)—enters the popliteal fossa, and continues as the popliteal artery (a. poplitea). Notably, within the canal, the femoral nerve runs anterior and lateral to the artery, an anatomical relationship that surgeons must account for during operative approaches.
Superficial Branches
Near its origin, the main trunk gives off three superficial branches that pierce the cribriform fascia (fascia cribrosa):
- Superficial epigastric artery (a. epigastrica superficialis) — courses anteriorly and superiorly along the anterior abdominal wall toward the umbilicus, anastomosing with the superior and inferior epigastric arteries.
- Superficial circumflex iliac artery (a. circumflexa ilium superficialis) — runs laterally along the inguinal ligament toward the anterior superior iliac spine (spina iliaca anterior superior), supplying the skin and regional lymph nodes.
- External pudendal arteries (aa. pudendae externae) — divide into superficial and deep branches, coursing medially toward the scrotum or labia majora, as well as the perineal skin. They form extensive anastomoses with branches of the internal pudendal artery.
Deep Artery of the Thigh
Deep artery of the thigh (a. profunda femoris) is the largest branch and the primary blood supply source for the musculature of the region. Distal to its origin, the main femoral trunk primarily supplies the skin and adductor muscles. It arises 3–5 cm below the inguinal ligament from the posterior (or posterolateral) aspect of the femoral trunk, courses deeply, and descends to the lower third of the thigh.
Its key branches include:
- Medial femoral circumflex artery (a. circumflexa femoris medialis). Passes posteriorly and medially, winding around the femoral neck. Through its acetabular branch (r. acetabularis), it provides critical blood supply to the head of the femur. Injury to this branch during medial femoral neck fractures frequently leads to severe avascular necrosis.
- Lateral femoral circumflex artery (a. circumflexa femoris lateralis). Passes laterally deep to the rectus femoris muscle and divides into ascending, transverse, and descending branches. The descending branch reaches the knee joint and participates in the formation of the genicular articular network (rete articulare genus).
- Perforating arteries (aa. perforantes). Three robust vessels that pierce the muscle attachments close to the bone to reach the posterior aspect of the thigh. They supply the posterior compartment muscles and the femur itself (aa. nutriciae femoris), forming a continuous chain of anastomoses.
Descending Genicular Artery
Descending genicular artery (a. descendens genus) is the final and most distal branch arising within the adductor canal. Unlike the main trunk, it leaves the canal not through the adductor hiatus, but through the anterior opening in the vastoadductor membrane, emerging onto the thigh alongside the saphenous nerve (n. saphenus).
It gives off a saphenous branch (r. saphenus) supplying the skin of the medial leg and articular branches (rr. articulares). The latter travel to the medial side of the knee joint, contributing to the patellar network (rete patellare) and the broader genicular articular network. In cases of gradual occlusion of the popliteal artery (such as in atherosclerosis), this vessel undergoes collateral enlargement to maintain distal perfusion.
Cruciate Anastomosis
On the posterior surface of the thigh, at the level of the lesser trochanter, the cruciate anastomosis (anastomosis cruciata) is formed by the convergence of four arterial sources:
| Direction | Contributing Artery |
|---|---|
| Superior | Inferior gluteal artery (a. glutea inferior) |
| Medial | Ascending branch of the medial femoral circumflex artery |
| Lateral | Ascending branch of the lateral femoral circumflex artery |
| Inferior | First perforating artery (a. perforans prima) |
This arterial junction holds profound clinical significance. If the external iliac or proximal femoral artery becomes occluded by a thrombus or plaque, blood from the internal iliac system flows via the gluteal vessels into the cruciate anastomosis and subsequently into the profunda femoris, effectively rescuing the limb from severe ischemia.