THE LEG. 



549 



be included because they are so firmly bound to the artery and membrane as to be 

 separated only with difficulty (Fig. 561). 



In the Middle Third. The incision having been made in the line of the artery, 

 the septum between the tibialis anterior and extensor longus digitorum is usually vis- 

 ible as a depressed line. Flex the foot to relax the tendons, and on drawing the 

 extensor digitorum outward the upper part of the extensor longus hallucis is seen, it 

 also is drawn outward and the artery is found lying on the membrane with the nerve 

 in front of it. 



In the Lower Third. Here, above the flexure of the ankle, the artery lies 

 on the tibia between the 

 tibialis anterior and the 

 extensor longus hallucis. 

 The nerve is to its outer 

 or inner side or in front 

 of the artery. Flexing the 

 foot allows the tendons to 

 be more readily separated, 

 and movement of the foot 

 and big toe will assist in 

 identifying the muscles. 



Posterior Tibial 

 Artery. Ligation. The 

 line of the posterior tibial 

 artery is from the middle 

 of the popliteal space to 

 the middle of the line join- 

 ing the internal malleolus 

 and internal tuberosity of 

 the calcaneum; at this lat- 

 ter point it divides into 

 the internal and external 

 plantar arteries (Fig. 562). 



In the Middle of the 

 Leg. The incision should 

 be made 2 cm. ( ^ in. ) 

 behind the edge of the 

 tibia, avoiding the long 

 saphenous vein. If the 

 edge of the gastrocnemius 

 comes into view draw it 

 outward, incise the soleus 

 muscle through its entire 

 thickness, dividing the 

 tendinous fibres in the 

 body of the muscle. Sep- 

 arate the edges of the 

 incision and seek for the 

 artery on the obliquely 

 running fibres of the flexor 

 longus digitorum muscle. 

 The nerve is to its outer 

 side. The artery lies di- 



Line for posterior 

 tibial artery 



Gastrocnemius 



Soleus 



Posterior tibial artery 

 Posterior tibial nerve 



Soleus 



Posterior tibial tendon 

 Flexor longus digitorum 



Posterior tibial artery 

 Posterior tibial nerve 



Internal malleolus 



Internal tuberosity of os calcis 



FIG. 562. Ligation of the posterior tibial artery. 



rectly over the outer edge of the tibia, which can be felt with the finger. It is covered 

 with a thin fascia. The ligature is passed from without inward. 



Low Down in the Leg. The incision may be made midway between the inner 

 edge of the tibia and the edge of the tendo calcaneus (Achillis). The artery lies 

 beneath the deep fascia on the flexor longus digitorum muscle with the nerve to the 

 outer side. The muscle has fibres as low down as the malleolus and the artery is to 

 the outer side of its tendon. If the artery is sought behind the ankle then it has the 



