POPLITEAL. 445 



The popliteal vein, which is intimately attached to the artery, lies superficial and 

 external to it, until near its termination, when it crosses it and lies to its inner 

 side. The popliteal nerve is still more superficial and external, crossing, however, 

 the artery below the joint, and lying on its inner side. Laterally, it is bounded 

 by the muscles which form the boundaries of the popliteal space. 



in point of division. Occasionally the popliteal artery divides prematurely into 

 its terminal branches ; this division occurs most frequently opposite the knee-joint. 



Unusual branches. This artery sometimes divides into the anterior tibia? and peroneal, the 

 posterior tibial being wanting, or very small. In a single case, this artery divided into three 

 branches, the anterior and posterior tibial, and peroneal. 



Surgical Anatomy. Ligation of the popliteal artery is required in cases of wound of that 

 vessel, but for aneurism of the posterior tibial it is preferable to tie the superficial femoral. The 

 popliteal may be tied in the upper or lower part of its course ; but in the middle of the space 

 the operation is attended with considerable difficulty, from the great depth of the artery, and 

 from the extreme degree of tension of its lateral boundaries. 



In order to expose the vessel in the upper part of its course, the patient should be placed in 

 the prone position, with the limb extended. An incision about three inches in length should then 

 be made through the integument, along the posterior. margin of the Semi-membranosus, and, the 

 fascia lata having been divided, this muscle must be drawn inwards, when the pulsation of the 

 vessel will be detected with the finger; the nerve lies on the outer or fibular side of the artery, 

 the vein, superficial and also to its outer side ; having cautiously separated it from the artery, 

 the aneurism needle should be passed around the latter vessel from without inwards. 



To expose the vessel in the lower part of its course, where the artery lies between the two 

 heads of the Gastrocnemius, the patient should be placed in the same position as in the preceding 

 operation. An incision should then be made through the integument in the middle line, com- 

 mencing opposite the bend of the knee-joint, care being taken to avoid the external saphenous vein 

 and nerve. After dividing the deep fascia and separating some dense cellular membrane, the 

 artery, vein, and nerve will be exposed, descending between the two heads of the Gastrocnemius. 

 Some muscular branches of the popliteal should, if possible, be avoided, or, if divided, tied immedi- 

 ately. The leg being now flexed, in order the more effectually to separate the two heads of the 

 Gastrocnemius, the nerve should be drawn inwards and the vein outwards, aud the aneurism 

 needle passed between the artery and vein from without inwards. 



The branches of the popliteal artery are the 

 Aluscular I Su P erior - 



o>J-U.oL; Lllul \ x _ ri T 



( Interior or Sural. 

 Cutaneous. 



Superior external articular. 

 Superior internal articular. 

 Azygos articular. 

 Inferior external articular. 

 Inferior internal articular. 



The superior muscular branches, two or three in number, arise from the upper 

 part of the popliteal artery, and are distributed to the Vastus externus and Flexor 

 muscles of the thigh ; anastomosing with the inferior perforating, and terminal 

 branches of the profunda. 



The inferior muscular or sural are two large branches, which are distributed 

 to the two heads of the Gastrocuemius and Plantaris muscles. They arise from 

 the popliteal artery opposite the knee-joint. 



Cutaneous branches descend on each side and in the middle of the limb, between 

 the Gastrocnemius and integument ; they arise separately from the popliteal 

 artery, or from some of its branches, and supply the integument of the calf. 



The superior articular arteries, two in number, arise one on either side of the 

 popliteal, and wind round the femur immediately above its condyles to the front 

 of the knee-joint. 



The internal branch passes beneath the tendon of the Adductor magnus, and 

 divides into two, one of which supplies the Yastus internus, inosculating with the 

 aua.stomotica magna and inferior internal articular ; the other ramifies close to the 



