60 ANATOMY OF THE GROIN : HERNIA. 



The femoral or crural sheath (figs. 22 and 23), is a somewhat funnel-shaped 

 structure surrounding the upper parts of the femoral artery and vein. It is wide 

 above, but embraces the vessels closely below. It is continuous superiorly with 

 the lining fasciae of the abdomen, namely, with the transversalis fascia in front, 

 and the iliac fascia behind. On removing its anterior wall, the sheath is found 

 to be divided into three compartments by fibrous septa ; the outer compartment 

 containing the femoral artery, the middle, the femoral vein, and the inner being 

 occupied merely by lymphatic vessels, a gland, and some fat. The inner compart- 

 ment is about half an inch long, and from its being the passage through which 

 the hernia descends, has been called the femoral or crural canal. The upper 

 extremity of the canal presents an oval aperture towards the cavity of the abdomen, 

 usually of sufficient size to admit the point of the forefinger : its size, however, 

 varies in different persons, and it is larger in the female than in the male, its 

 transverse diameter, which is the longest, being on an average 25mm. in the 

 former, and 15mm. in the latter. This aperture is called the femoral or crural 

 ring (annulus femoralis'), and is covered when viewed from the inside by perito- 

 neum, which at this spot frequently shows a slight depression -fovea femoralis 

 (p. 54), and beneath that by the subperitoneal connective tissue, which here forms 

 the femoral septum (Cloquet). On the outer side lies the external iliac vein covered 

 by its sheath, but on the other three sides the ring is bounded by very unyielding 

 structures. In front are the femoral arches, the superficial being formed by Poupart's 

 ligament, and the deep by a variably developed bundle of fibres, which, springing 

 from the under surface of Poupart's ligament outside the femoral vessels, extends 

 across the fore part of the femoral sheath and, widening at its inner end, is fixed to 

 the ilio-pectineal line behind Gimbernat's ligament. Behind the ring is the hip- 

 bone covered by the pectineus muscle and the thickened upper part of the pectineal 

 fascia ; and on the inner side are several layers of fibrous structure connected with 

 the ilio-pectineal line namely, Gimbernat's ligament, the conjoined tendon of the 

 two deeper abdominal muscles, and the transversalis fascia, with the deep femoral 

 arch. The last-mentioned structures those bounding the ring at the inner side- 

 present more or less sharp margins towards the opening. 



Relations to blood-vessels. Besides the external iliac vein, the position of 

 which has been already stated, the epigastric vessels are closely related to the ring, 

 lying above its outer side. It not infrequently happens that an aberrant obturator 

 artery descends into the pelvis at the outer side of the ring, or immediately across it; 

 and in rarer cases this vessel passes in front of the ring to its inner side (Vol. II, 

 p. 477). A pubic vein, also, has occasionally the same course ; and the 'small pubic 

 branch of the epigastric artery will be generally found ramifying on the superior 

 aspect of Gimbernat's ligament. In the male, the spermatic vessels are separated 

 from the canal only by the femoral arches. 



The saphenous opening (fossa ovalis) of the fascia lata is placed at the upper 

 and inner part of the thigh, immediately below Poupart's ligament. Its upper 

 extremity is about one inch (2 - 5 cm.) external to the pubic spine, and its vertical 

 extent measures from one and a half to two inches (4 5 cm.). On the inner side the 

 opening is not sharply defined, the pectineal fascia being here prolonged over its 

 muscle, and passing behind the femoral vessels. On the outer side of the opening, 

 when the loose tissue in its area constituting the cribriform fascia (fascia cribrosa) has 

 been removed, the iliac portion of the fascia lata forms a distinct crescentic edge 

 known as thefakiform border, which ends above and below in curved portions termed 

 the superior and inferior cornua. Through the lower part of the opening the 

 internal saphenous vein passes backwards to enter the femoral vein, and the inferior 

 cornu curves sharply round in the angle between the two vessels to join the pectineal 

 fascia internally. _The superior cornu is thicker and less curved than the inferior : 



