The femoral canal is an anatomical compartment located in the anterior thigh. It is the smallest and most medial part of the femoral sheath, and is approximately 1.3cm long.
In this article we shall look at the anatomy of the femoral canal – its borders, contents, and clinical relevance.
The femoral canal is located in the anterior thigh within the femoral triangle. It can be thought of as a rectangular shaped compartment with four borders and an opening.
The opening to the femoral canal is located at its superior border, known as the femoral ring. The femoral ring is closed by a connective tissue layer – the femoral septum. This septum is pierced by the lymphatic vessels exiting the canal.
The femoral canal contains:
The empty space allows distension of the adjacent femoral vein, so it can cope with increased venous return, or increased intra-abdominal pressure.
The femoral canal is of particular clinical importance, as it is a common site of bowel herniation. A hernia is defined as ‘where an internal part of the body pushes through a weakness in the muscle or surrounding tissue wall.’ In a femoral hernia, part of the small intestine protrudes through the femoral ring.
It presents as a lump situated inferolateral to the pubic tubercle. This type of herniation is more common in women, due to their wider bony pelvis. The borders of the femoral canal are tough, and not particularly extensible. This can compress the hernia, interfering with its blood supply. A hernia with a compromised blood supply is known as a strangulated hernia.
The femoral canal is a fibro-osseous tube that extends from the iliopubic tract to the femoral triangle. It forms the lower part of the femoral sheath and is located beneath the inguinal ligament. The canal's borders are the inguinal ligament anteriorly, the lacunar ligament medially and the pectineal ligament posteriorly. The femoral canal has a round or oval opening, which is narrowed by an internal fibrous ring called the femoral ring. The femoral ring is a fibrous structure that separates the femoral sheath from the femoral vein and is made up of transversalis fascia and the inferior epigastric vessels.
The contents of the femoral canal include the femoral vein, lymphatic vessels, deep lymph nodes, a small amount of empty space, and loose connective tissue. Femoral hernias occur when the contents of the abdomen bulge into the femoral canal through the femoral ring. Symptoms of a femoral hernia include pain, swelling, and a bulge in the inner thigh. Risk factors for a femoral hernia include obesity and previous pelvic surgery.
Treatment for a femoral hernia is often surgical. Surgery can be open or laparoscopic, and includes hernia repair, where the hernia is pushed back into the abdominal cavity, and herniorrhaphy, which is a procedure to repair the hernia defect. Following hernia repair, the patient will usually be instructed to wear a compression garment for a number of weeks to aid in healing.
