THE POPLITEAL FOSSA. 



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extending from a point midway between the sciatic tuberosity and the greater 

 trochanter to the centre of the popliteal fossa. The nerve enters the thigh under 

 cover of the lateral border of the biceps, whereas the posterior cutaneous nerve of 

 the thigh which takes the same line, descends superficial to the biceps, between 

 it and the fascia lata. In the operation of stretching the sciatic nerve it is cut 

 down upon immediately distal to the lower border of the glutseus maximus. 

 The surgeon, standing on the side of the patient opposite to the leg to be operated 

 upon (Chiene), makes an incision in the line of the nerve through the integuments 

 and fascia lata, and, sweeping the index-finger round the lateral border of the 



Quadriceps extensor tendon 



Extra-synovial fat 



Vastus raedialis 



Adductor tubercle 



Musculo-articular 

 branch of arteria 

 genu suprema 

 Tendon of adductor 

 magnus 



Sartorius 



Stratum synoviale of knee 



Vastus lateralis 

 Ilio-tibial tract 



Proximal lateral 

 genicular artery 



Fat 



Popliteal artery 

 Biceps 



Popliteal vein 

 Common peroneal nerve 



Tibial nerve 

 Lymph gland 



Gracilis 

 Semimembranosus Semitendinosus 



FIG. 1119. SECTION THROUGH THE THIGH IMMEDIATELY PROXIMAL TO THE PATELLA. 



biceps, hooks up the nerve as it lies between that muscle and the adductor 

 magnus. 



The common peroneal nerve may be rolled under the finger as it passes distally 

 immediately behind the tendon of the biceps and the head of the fibula ; so close is 

 the nerve to the tendon that the tendon should be divided, in cases where this is 

 necessary, by the open method rather than subcutaneously. 



Abscesses may reach the flexor compartment of the thigh from various sources, viz. : (1) from 

 the posterior aspect of the hip-joint; (2) from the pelvis, through the greater sciatic foramen; 

 (3) from one or other of the bursse under the glutseus maximus ; (4) from the front of the hip- 

 joint, by passing backwards under the tensor fasciae latae ; or by winding backwards beneath the 

 neck of the femur, and through the interval between the quadratus femoris and the adductor 

 magnus ; (5) from the iliac fossa under the inguinal ligament into the fascial trigone, and thence 

 to the back of the thigh by one or other of the routes already mentioned ; (6) the pus may spread 

 proximally from the popliteal surface of the femur, the knee, a popliteal gland, or from a bursa. 



THE POPLITEAL FOSSA. 



When the knee is extended the popliteal fascia is put upon the stretch, and 

 obliterates the hollow of the popliteal fossa ; by flexing the knee the fascia is 

 relaxed, and the fingers may be pressed deeply into the proximal or femoral 



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