THE THIGH 233 



The infrapatellar branch pierces the sartorius muscle and 

 the fascia lata on the medial side of the knee, and turns 

 laterally towards the anterior aspect of the joint, distal to the 

 level of the patella (Fig. 107). 



Patellar Plexus. Twigs of four of the cutaneous nerves 

 of the thigh have been traced to the skin of the knee, viz., 

 the anterior division of the lateral cutaneous nerve of the thigh, 

 the intermediate cutaneous, the anterior division of the medial 

 cutaneous, and the saphenous nerve. These nerves communi- 

 cate with each other and form an interlacement which is situated 

 over the patella, the ligamentum patellae, and proximal part of 

 the tibia. The interlacement is termed the patellar plexus. 



On the medial side of the thigh two minute cutaneous nerve twigs some- 

 times make their appearance which do not belong to any of the above 

 main cutaneous trunks. One appears distal to the ilio-inguinal nerve, and 

 is a twig from the perineal branch of the posterior cutaneous nerve of the 

 thigh ; the other pierces the deep fascia at the middle of the medial area of 

 the thigh, and comes from the obturator nerve. 



Dissection. After the cutaneous nerves have been cleaned 

 the remains of the superficial fascia must be removed in order 

 that the fascia lata may be studied. 



Fascia Lata. This is the name which is given to that 

 portion of the general fascial investment of the inferior 

 extremity which clothes the thigh and preserves its figure. 

 Only a portion of it is displayed at present, but the dissector 

 should obtain a general idea of its attachments and parts 

 before proceeding further with the dissection of the anterior 

 femoral region. One of its striking features is the marked 

 difference in strength which it shows in the lateral and 

 medial aspects of the thigh. In the lateral side of the limb 

 it is generally so dense and strong that it appears to be more 

 aponeurotic than fascial in its character, whilst, in addition, a 

 special band called the tractus ilio-tibialis is formed in it. The 

 tractus ilio-tibialis extends from the crest of the ilium to the 

 lateral condyle of the tibia and the head of the fibula, and 

 into it are inserted the tensor fasciae latae and the greater part 

 of the glutssus maximus muscle ; its distal part, therefore, 

 serves as an aponeurotic tendon by means of which the two 

 muscles gain insertion into the lateral condyle of the tibia 

 and the head of the fibula. The ilio-tibial tract serves as a 

 powerful brace, on the lateral aspect of the limb, which, in 

 the erect posture, helps to steady the pelvis and at the same 

 time keep the knee joint firmly extended. On the medial 



