Femoral Triangle

trigonum femorale

The femoral triangle is a triangular space at the anterior upper thigh bounded superiorly by the inguinal ligament, laterally by sartorius, and medially by adductor longus. Its floor is formed by iliopsoas (laterally) and pectineus (medially). The femoral triangle contains, from lateral to medial: the femoral nerve (outside the femoral sheath), the femoral artery, and the femoral vein — remembered as VAN from medial to lateral for the sheath contents (Vein, Artery, Nerve), with only vein and artery inside the sheath.

Region: Thigh

Clinical Relevance

Clinical Notes

The femoral triangle is the primary access route for common femoral artery catheterisation in cardiac and vascular interventional procedures, and for femoral arterial and venous access in ECMO and IABP. It is the site of femoral hernia (medial to the femoral vein in the femoral canal) and the site of femoral lymphadenopathy. The femoral nerve at the lateral angle of the triangle is the target for femoral nerve block for hip and thigh analgesia and for femoral arterial access.

Pathology

Common Injuries & Conditions

Femoral Triangle Haematoma After Arterial Access

Femoral artery puncture above or below the inguinal ligament for catheterisation that is inadequately compressed produces a femoral triangle haematoma that may expand rapidly, compress the femoral nerve producing thigh numbness, or develop a pseudoaneurysm requiring ultrasound-guided compression or thrombin injection.