598 A MANUAL OF ANATOMY 



branch of the superficial or anterior division of the obturator nerve. When 

 present it will usually be found piercing the fascia lata at about the 

 centre of the inner side of the thigh, between the posterior border of the 

 sartorius and the anterior border of the gracilis. The two divisions of the 

 internal cutaneous nerve, anterior and posterior, should next be dissected. 

 The anterior division will be found piercing the fascia lata at the junction 

 of the middle and lower thirds of the thigh. It should then be followed to 

 the inner side of the knee and patellar plexus. The posterior division will 

 be found piercing the fascia lata at the level of the inner condyle, after which 

 it descends to the inner side of the leg, where it will be afterwards dissected. 

 The patellar branch of the internal or long saphenous nerve is to be shown. 

 It pierces the sartorius and the fascia lata at the level of the inner condyle, 

 and should be followed to the integument over the patella and patellar plexus. 

 The patellar plexus itself is to be carefully dissected. 



The fascia lata is now to be cleaned and examined. Its deep processes 

 will only come into view as it is being removed to expose the muscles. The 

 muscles of the front and inner side of the thigh are to be cleaned by removing 

 the fascia lata. A strip of this fascia, the so-called ilio- tibial band, about 

 2 inches broad, and extending from the fore part of the iliac crest to the front 

 of the external tuberosity of the tibia, should be preserved. In removing the 

 fascia lata from the pectineus and adductor longus the inferior external pudic 

 artery is to be dissected. 



The boundaries of Scarpa's triangle should be defined. In the triangle 

 the following muscles should be cleaned from without inwards, namely, the 

 iUacus, psoas magnus, pectineus, and adductor longus. The contents of the 

 triangle are now to be cleaned and studied, namely, (i) the anterior femoral 

 nerve; (2) the common femoral and superficial femoral arteries; (3) the origins 

 of the superficial epigastric, superficial circumflex iliac, superior external pudic, 

 and inferior external pudic arteries; (4) the origin of the arteria profunda 

 femoris, and its external circumflex and internal circumflex branches, and 

 (5) the femoral vein and its tributaries. In cleaning the anterior femoral nerve 

 its branch to the pectineus should be noted as it passes inwards behind the 

 femoral sheath. 



Having completed the superficial dissection of Scarpa's triangle, the 

 remainder of the sartorius should be cleaned. The following muscles should 

 also be cleaned in the order named : tensor fasciae femoris, rectus femoris, 

 and gracilis. In cleaning the tensor fasciae femoris the branch of the superior 

 gluteal nerve entering its deep surface should be shown by dissecting between 

 the muscle and the gluteus medius, the ilio-tibial band should be studied, 

 and a strong lamina of the fascia lata should be shown passing upwards on 

 the deep surface of the muscle to the dorsum of the ilium. The two heads 

 of the rectus femoris should be exposed. 



The sartorius should now be held aside in the middle two-fourths of the thigh, 

 in order to study Hunter's canal and its contents. The aponeurotic covering 

 or roof of the canal should be shown as an upward expansion from the tendinous 

 anterior margin of the femoral opening in connection with the adductor magnus. 

 It should be observed that this tendinous roof is strong over the lower part of 

 the canal, where it is pierced by a branch of the long. saphenous nerve to the 

 subsartorial plexus, and by the arteria anastomotica magna. An endeavour 

 should be made at this stage to expose the subsartorial plexus as it lies upon 

 the aponeurotic covering of Hunter's canal. This covering should now be 

 removed, and the contents and boundaries of the canal exposed. It should 

 be observed that the nerve to the vastus internus is only contained in the 

 upper half of the canal, and that the arteria anastomotica magna arises from 

 the superficial femoral at the extreme lower end of the canal. 



The deep dissection of Scarpa's triangle should now be undertaken. A 

 slight interval may be noted between the lower part of the pectineus and 

 adductor longus, in which a partial view may be obtained of the adductor 

 brevis and the superficial or anterior division of the obturator nerve. The 

 superficial femoral artery should be divided just below the origin of the arteria 

 profunda femoris, as well as the femoral vein. The arteria profunda femoris 



