824 SURGICAL ANATOMY OF INGUINAL HERNIA, 



are directed obliquely downwards and inwards. It is attached to the anterior 

 superior spinous process of the ilium, the spine of the pubes, the pectineal line, 

 front of the pubes, and linea alba. That portion of the aponeurosis which 

 extends from the anterior superior spine of the ilium, to the spine of the pubes 

 is termed Poupart's ligament, or the crural arch ; and that portion which is 

 inserted into the pectineal line, is termed Gimbernat's ligament. 



Just above and to the outer edge of the crest of the pubes, a triangular 

 interval is seen in the aponeurosis of the External Oblique, called the external 

 abdominal ring, which transmits the spermatic cord in the male, and the round 

 ligament in the female. This aperture is oblique in direction, somewhat trian- 

 gular in form, and corresponds with the course of the fibres of the aponeurosis. 

 It usually measures from base to apex about an inch, and transversely about 

 half an inch. It is bounded below by the crest of the os pubis ; above, by a 

 series of curved fibres, the inter columnar, which pass across the upper angle of 

 the ring so as to increase its strength ; and on either side, by the free borders 

 of the aponeurosis, which are called the columns or pillars of the ring. 



The external pillar, which, at the same time, is inferior from the obliquity of 

 its direction, is the stronger; it is formed by that portion of Poupart's ligament 

 which is inserted into the spine of the pubes ; it is curved round the spermatic 

 cord, so as to form a kind of groove, upon which the cord rests. 



The internal or superior pillar is a broad, thin, flat band, which interlaces with 

 its fellow of the opposite side, in front of the symphysis pubis, that of the right 

 side being superficial. 



The external abdominal ring gives passage to the spermatic cord in the male, 

 and round ligament in the female ; it is much larger in men than women, on 

 account of the large size of the spermatic cord, and hence the greater fre- 

 quency of inguinal hernia in men. 



The intercolumnar fibres are a series of curved tendinous fibres, which arch 

 across the lower part of the aponeurosis of the External Oblique. They have 

 received their name from stretching across between the two pillars of the ex- 

 ternal ring; they increase the strength of the membrane which bounds the 

 upper part of this aperture, and prevent the divergence of the pillars from one 

 another. They are thickest below, where they are connected to the outer third 

 of Poupart's ligament, and are inserted into the linea alba; describing a curve, 

 with the convexity -downwards. They are much thicker and stronger at the 

 outer angle of the external ring than internally, and are more strongly developed 

 in the male than in the female. These fibres are continuous with a thin fascia, 

 which is closely connected to the margins of the external ring, and has received 

 the name of the intercolumnar or external spermatic fascia ; it forms a tubular 

 prolongation around the outer surface of the cord and testis, and incloses them 

 in a distinct sheath. The sac of an inguinal hernia, in passing through the 

 external abdominal ring, receives an investment from the intercolumnar fascia. 



The finger should be introduced a short distance into the external ring, and 

 then, if the limb is extended and rotated outwards, the aponeurosis of the Ex- 

 ternal Oblique, together with the iliac portion of the fascia lata, will be felt to 

 become tense, and the -external ring much contracted ; if the limb is, on the 

 contrary, flexed upon the pelvis and rotated inwards, this aponeurosis will 

 become lax, and the external ring sufficiently enlarged to admit the finger with 

 comparative ease ; hence the patient should always be put in the latter position 

 when the taxis is applied for the reduction of an inguinal hernia, in order that 

 the abdominal walls may be as much relaxed as possible. 



The aponeurosis of the External Oblique should be removed by dividing it across in the same 

 direction as the external incisions, and reflecting it outwards ; great care is requisite in separat- 

 ing it from the aponeurosis of the muscle beneath. The lower part of the Internal Oblique and 

 C remaster are then exposed, together with the inguinal canal, which contains the spermatic 

 cord (Fig. 447). The mode of insertion of Poupart's and Gimbernat's ligaments into the pubea 

 should also be examined. 



