The Leg. 369 



close to this border. The ligature generally includes the 

 venae comites, since they are closely connected with the 

 vessel in its course. 



Ligation of the artery in the middle third of the leg. 

 An incision a little internal to the line of the vessel is 

 made; the tibialis anticus and the extensor longus digi- 

 torum identified in the manner above described ; the exter- 

 nal border of the tibia is used as a guide and the artery 

 found by keeping close to the tibialis anticus. The nerve, 

 in this situation, lies in front of the vessel and must be 

 avoided. Ligation at the lower third of the leg. An in- 

 cision is made in the line of the artery on the outer side of 

 the tendon of the tibialis anticus, and on separating this 

 from the extensor proprius hallucis, the vessel will be 

 found lying between them, or beneath the latter muscle. 

 The nerve, in this situation, lies external to the vessel, so 

 that the needle should be passed from the nerve, i.e., from 

 without inwards. Collateral circulation, after ligature of 

 the tibial, will be carried on (1) by the anterior peroneal 

 anastomosing with the external malleolar of the anterior 

 tibial, and with the tarsal, a branch of the dorsalis pedis ; 

 (2) by the calcanean, from the peroneal, communicating 

 with the external malleolar, tarsal, and with branches of 

 the external plantar; (3) by the external and internal 

 plantar with the branches of the dorsalis pedis ; (4) by the 

 internal malleolar of the anterior with the internal malle- 

 olar of the posterior tibial, and (5) by muscular branches 

 from both tibials that pierce the interosseous membrane. 



Posterior Aspect. The superficial structures of this 

 region are supplied by branches from the internal or long 

 saphenous nerve and by the external or short saphenous 

 nerve. The latter is formed by the communicans poplitei, 

 which pierces the deep fascia about the middle of the leg 

 and then receives the communicans peronei. The exter- 



