This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
Femoral hernia is always acquired and descends through the femoral canal beneath Poupart' s ligament to make its appearance at the saphenous opening on the thigh. Beneath the inner end of Poupart' s ligament is the iliopectineal line of the horizontal ramus of the pubic bone. The two form an angle with the spine of the pubis as its apex. Gimbernat's ligament is the prolongation of Poupart's ligament from the spine of the pubis for about 2 cm. (3/4 in.) out on the iliopectineal line. From the iliopectineal line the pectineus muscle proceeds downward and outward beneath Poupart's ligament to below and behind the lesser trochanter of the femur. Farther out beneath Poupart's ligament run the femoral vein and artery, the latter being to the outer side of the vein. Between the femoral vein and Gimbernat's ligament is left a space 1 to 2 cm. ( 2/5 to 4/5 in.) wide. This space is called the femoral canal. It is through this canal or opening that femoral hernia descends. The femoral sheath is the continuation downward of the transversalis fascia which is prolonged from the interior of the pelvis over the femoral artery and vein and between the vein and Gimbernat's ligament so as to form three compartments. The outer contains the femoral artery, the middle the femoral vein, and the inner is the femoral canal. The femoral canal is from 1 to 2 cm. ( 2/5 to 4 in) long and runs from the abdominal side of Poupart's ligament to the upper edge of the saphenous opening and lies between the femoral vein and Gimbernat's ligament. Its lower extremity is closed by the meeting of its sides. Above, or superficial to it, is Poupart's ligament, and beneath it is the horizontal ramus of the pubis and pectineal fascia covering the pectineus muscle. It is filled with loose connective tissue, fat, and lymphatics, and sometimes contains a lymphatic node, forming all together what has been called the septum crurale. It will thus be seen that the septum crurale is continuous with the subperitoneal fatty tissue (Fig. 403).
Fig. 403. - The crural arch and the structures which pass beneath it.
When a femoral hernia descends, the intestine pushes in front of it the peritoneum, septum crurale (subperitoneal tissue), and the femoral sheath (transversalis fascia) and makes its appearance at the saphenous opening. The cribriform fascia closing the saphenous opening gives it a covering, and also the subcutaneous tissue and skin above.
This has its centre 4 cm. (1 1/4 in.) below and to the outer side of the spine of the pubis. Its margin blends above with Poupart's ligament to proceed to the spine of the pubis. Its outer and upper edge is marked, forming the falciform process or ligament (of Burns). The upper inner portion of the falciform process is attached to the iliopectineal line and spine of the pubis and, blending with Poupart's ligament above, is called Gimbernat's ligament (ligamentum lacuuare) (Fig. 404).
The part of the fascia lata forming the falciform process thins out over the femoral artery and becomes the cribriform fascia (fascia cribrosa) as it passes from the inner side of the femoral artery on to the femoral vein to blend with the pubic fascia to the inner side. The superficial epigastric, superficial circumflex iliac, and superficial external pudic arteries and veins all pierce this cribriform fascia, as do also the superficial lymphatics and the long or internal saphenous vein.
Fig. 404. - The saphenous opening (fossa ovalis).
Fig. 405. - View of the inguinal and femoral regions from within; the peritoneum has been removed.