THE POPLITEAL ARTERY 



695 



another is situated between it and the bone, and the rest are placed on either 

 .side of it. 



The popliteal artery, in its course downward from the aperture in the Adductor 

 magnus to the lower border of the Popliteus muscle, rests first on the inner surface 

 of the femur, and is then separated by a little fat from the hollowed popliteal 

 surface of the bone; in the middle of its course it rests on the posterior ligament 

 of the knee-joint, and below on the fascia covering the Popliteus muscle. Super- 

 ficially, it is covered above by the Semimembranosus; in the middle of its course, 

 by a quantity of fat, which separates it from the deep fascia and integument; and 

 below it is overlapped by the Gastrocnemius, Plantaris, and Soleus muscles, the 

 popliteal vein, and the internal popliteal nerve. The popliteal vein, which is 

 intimately attached to the artery, lies superficial and external to it above; it then 

 crosses it and lies to its inner side. The internal popliteal nerve is still more super- 

 ficial and external above, but below the joint it crosses the artery and lies on its 

 inner side. Laterally, the artery is bounded by the muscles which are situated on 

 either side of the popliteal space. 



PLAN OF THE RELATIONS OF THE POPLITEAL ARTERY. 



//( front. 

 Femur. 



Ligamentum po, 

 Popliteus.^ 



Inner side. 



Semimembranosus. 

 Internal condyle. 

 Gastrocnemius (inner head). 



Behind. 



Semimembranosus. 



Fascia. 



Popliteal vein. 



Internal popliteal nerve. 



Gastrocnemius. 



Plantaris. 



Soleus. 



Peculiarities in Point of Division. Occasionally the popliteal artery divides prematurelv 

 into its terminal branches; this unusual division occurs most frequentlv opposite the knee-joint. 

 The anterior tibial under these circumstances may pass in front of the Popliteus muscle. 



Unusual Branches. The artery sometimes divides into the anterior tibial and peroneal, the 

 posterior tibial being wanting or very small. Occasionally the popliteal is found to divide into 

 three branches, the anterior and posterior tibial and peroneal. 



Surface Marking. The course of the upper part of the popliteal artery is indicated 1>\ 

 a line drawn from the outer border of the Semimembranosus muscle at the junction of the middle 

 and lower third of the thigh obliquely downward to the middle of the popliteal space, exactly 

 behind the knee-joint. From this point it passes vertically downward to the level of a line 

 drawn through the lower part of the tubercle of the tibia. 



Applied Anatomy. The popliteal artery is not infrequently the seat of injury. It may be 

 torn by direct violence, as by the passage of a cart-wheel over the knee or by hyperextension of 

 the knee; and in the dead body, at all events, the middle and internal coats may be ruptured by 

 extreme flexion. It may also be lacerated by fracture of the lower part of the shaft of the femur 

 or by antero-posterior dislocation of the knee-joint. It has been torn in breaking down adhesions 

 in cases of fibrous ankylosis of the knee, and is in danger of being wounded, and, in fact, has been 

 wounded, in performing Macewen's operation for osteotomy of the lower end of the femur for 

 genu yalgum. In addition, Spencer records a case in which the popliteal artery was wounded 

 from in front by a stab just below the knee, the knife passing through the interosseous space. 



grnal eprrfiyle 



emiu^t5uter head), 

 ntans. 



