PRACTICAL CONSIDERATIONS : ABDOMINAL HERNIA 1777 



Lumbar hernia undoubtedly occurs most frequently in the space known as 

 Petit' s triangle (Fig. 1499, page 530), although its protrusion through that space 

 has not been demonstrated by exact dissection. 



Above Petit' s triangle is another triangular space, — Grynfelt and Lesshaft's 



Fig. 1499. 



Latissimus dorsi, cut edgi 



-XII rib— 



Fascial triaiigle 



Quadratus lumborum— ; 



Internal oblique '(L 



(Petit's triangle) '^ 



Vertebral aponeurosis 



Cut digitation of latissimus dorsi 



External oblique 



Iliac crest 



Entrance of hernia 



Dissection of postero-lateral abdominal wall, showing fascial (Grynfelt and Lesshaft's) triangle; posterior boundary 



of Petit's triangle has been cut away. 



triangle, — bounded posteriorly by the quadratus lumborum, anteriorly by the internal 

 oblique, and above by the twelfth rib. When the latissimus dorsi is turned aside 

 here it covers only the aponeurotic origin of the transversalis (Fig. 1499). 



Braun has found, at a place just posterior to Petit's triangle, the fibres of the 

 aponeurosis of the latissimus dorsi lacking on both sides in a case in which a lumbar 

 hernia existed on one side. 



Obturator hernia escapes through the obturator canal, which runs downward, 

 forward, and inward below the horizontal ramus of the pubes. The internal hernial 



orifice is at the fissure in the obturator 

 Fig. 1500. ' internus muscle which permits of the pas- 



sage of the vessels and nerve. A hernia 

 starting there passes through the opening 

 between the upper edge of the obturator 

 membrane and the lower surface of the 

 pubic ramus (Fig. 1500), and usually 

 descends between the obturator externus 

 and pectineus muscles to lie beneath the 

 latter muscle and the adductor longus. 

 It is therefore to be looked or felt for 

 below the pubes and the inner end of 

 Poupart's ligament, but at a point both 

 lower and more internal than the site of 

 femoral hernia. The thigh should be 

 flexed, adducted, and rotated outward to 

 relax the pectineus, adductor longus, and 

 obturator externus. As this hernia occurs most frequently in elderly females, it is 

 well to note that the inner orifice of the canal may be felt through the vagina. The 

 narrowness of the canal and the rigidity of the thin pectineus and obturator externus 

 muscles make the nerve-pressure symptoms of this hernia of exceptional diagnostic 



^--Obturator 

 nerve 



\rtery 

 \ ein 



Hernia seen through obturator membrane 



Right obturator hernia, seen from within. 



112 



