Femoral triangle
Trigonum femoris
- Eponym: Scarpa
Definition
The femoral triangle (of Scarpa) is an anatomical region of the upper inner human thigh. It is a subfascial space which in living people appears as a triangular depression inferior to the inguinal ligament when the thigh is flexed, abducted and laterally rotated.
The femoral triangle is bounded:
- (superiorly) by the inguinal ligament.
- (medially) by the medial border of the adductor longus muscle.
- (laterally) by the medial border of the sartorius muscle.
Its floor is formed by the pectineus and adductor longus muscles medially and iliopsoas muscle laterally. Its roof is formed by the fascia lata, except at the saphenous opening where it is formed by the cribriform fascia.
The femoral triangle is shaped like the sail of a sailing ship and hence its boundaries can be remembered using the mnemonic, "SAIL" for Sartorius, Adductor longus and Inguinal Ligament.
The femoral triangle is important as a number of vital structures pass through it, right under the skin. The following structures are contained within the femoral triangle (from lateral to medial):
- Femoral nerve and its (terminal) branches.
- Femoral sheath and its contents:
- Femoral artery and several of its branches.
- Femoral vein and its proximal tributaries (e.g., the great saphenous and deep femoral veins).
- Deep inguinal lymph nodes and associated lymphatic vessels.
