THE THIGH 243 



into the opening so as to produce the appearance of a 

 dimple. 



Femoral Hernia. Femoral hernia is the name applied to a patho- 

 logical condition which consists of the protrusion of some of the contents 

 of the abdominal cavity into the thigh. As they descend they pass 

 behind the inguinal ligament into the femoral canal or most medial 

 compartment of the femoral sheath. The arrangement of the parts which 

 occupy the interval between the hip bone and the inguinal ligament 

 has been carefully considered, and the dissector should therefore be in 

 a position to understand how the occurrence of such a protrusion is 

 possible. To the medial side of the femoral sheath the interval is closed 

 by the lacunar ligament, which, by its strength and firm connections, 

 constitutes an impassable barrier in that locality. To the lateral side of the 

 femoral sheath a hernial protrusion is equally impossible. There the fascia 

 transversalis on the anterior wall of the abdomen becomes continuous with 

 the fascia iliaca on the posterior wall of the abdomen, and along the line 

 of union both are firmly attached to the inguinal ligament (Fig. 105). 



It is in the region of the femoral sheath, then, that femoral hernia takes 

 place. The three compartments of th,e sheath open above into the abdominal 

 cavity, but there is an essential difference between the three openings. The 

 lateral two, which hold the artery and the vein, are completely filled up by 

 their contents. The femoral canal, or most medial compartment, is not 

 completely filled, for it is wider than is necessary for the passage of the 

 fine lymph vessels which traverse it. Further, its widest part is the upper 

 opening or femoral ring. It has been noted that that is wide enough to 

 admit the point of the little finger, and it forms a weak point in the 

 parietes of the abdomen ; a source of weakness which is greater in the 

 female than in the male, seeing that in the former the distance between 

 the iliac spine and the pubic tubercle is proportionally greater, and that, 

 in consequence, the femoral ring is wider. Femoral hernia, therefore, is 

 more common in the female (Fig. 105). 



When attempts are made to reduce a femoral hernia, it is necessary 

 that the course which the protrusion has taken should be kept constantly 

 before the mind of the operator. In the first instance it passes distally 

 for a short distance in a perpendicular direction. It then turns forwards 

 and bulges through the fossa ovalis. Should it still continue to enlarge, it 

 bends upwards over the inguinal ligament, and pushes its way laterally 

 towards the anterior superior spine of the ilium. The protrusion is thus 

 bent upon itself, and if it is to be reduced successfully it must be made 

 to retrace its steps. In other words, it must be drawn down, and 

 then pushed gently backwards and upwards. The position of the limb 

 during this procedure must be attended to. When the thigh is fully 

 extended and rotated laterally all the fascial structures in the neighbour- 

 hood of the femoral canal are rendered tense. When, on the other hand, 

 the limb is flexed at the hip-joint and rotated medially, the upper horn 

 of the margin of the fossa ovalis, and even the lacunar ligament, are 

 relaxed. That, then, is the position in which the limb should be placed 

 during the reduction of the hernia. 



As the hernia descends it carries before it, in the form of coverings, 

 the various layers which it meets. First it pushes before it the peritoneum, 

 and that forms the hernial sac. The other coverings from within outwards 

 are (i) the septum femorale ; (2) the wall of the femoral sheath ; (3) the 

 fascia cribrosa ; and lastly, (4) the superficial fascia and skin. 



The femoral canal, as already noted, is surrounded by very unyielding 

 structures. Strangulation due to pressure is, therefore, of very common 

 I 16 a 



