What is the Femoral Triangle?

The femoral triangle, also referred to as Scarpa’s triangle or, more commonly, the groin, is a triangular-shaped space located at the upper part of the thigh. When the thigh is flexed at the hip joint, the femoral triangle is created as a depression below the inguinal ligament. It is also bounded by the sartorius muscle and the adductor longus muscle on either side. This muscle is clinically important due to the fact it contains important nerves, arteries and veins.

Three muscles primarily define the borders of the triangle. The superior aspect of the femoral triangle is defined by the inguinal ligament. Closest to the mid-line of the body is the medial aspect, defined by the adductor longus muscle. Laterally, the part of the triangle furthest from the mid-line, the femoral triangle is defined by the sartorius muscle, also commonly referred to as the tailor’s muscle.

The bottom of the triangle, the part closer to the interior aspect of the body, is shaped like a gutter. It is made up of three muscles: the iliopsoas, the pectineus, and the adductor longus. The ilopsoas and pectineus overlap to create the gutter shape.

Forming the top, or roof, of the triangle is the fascia lata. Fascia is a layer of fibrous tissue and in the case of the thigh area it is referred to as a deep fascia, or fascia lata in Latin. Deep fascia surrounds an individual muscle and creates compartments by dividing groups of muscles.

The femoral triangle is the easy access for physicians to the nerves, arteries, and ligaments. Both the femoral vein and nerve, as well as the femoral artery, are located within the triangle. It is easily accessible and because the vein and artery are quite large, they can be punctured easily. This is helpful in the case of damage to the area, or if it needs to punctured in a medical procedure. Applying pressure to points in the triangle can help stop bleeding of the leg, and is also a good spot to take the femoral pulse.

It is easy to remember the anatomy of the triangle by using some mnemonic devices. The muscles that border the triangle can be put together to from the word “SAIL", which stands for Sartorius, Adductor longus, and Inguinal Ligament. This can be put with the mnemonic for the nerve, artery, vein and ligament. When put in order, laterally to medially, it spells out NAVEL. The “E” stands for “empty” and the “L” stands for ligament or lymph, referring to the deep inguinal lymph nodes, which are also part of the femoral triangle.