THE ANTERIOR TIBIAL ARTERY 699 



the anterior ligament of the ankle-joint. In the upper third of its course it lies between the 

 Tibialis anticus and Extensor longus digitorum; in the middle third, between the Tibialis anti- 

 cus and Extensor propriua hallucis. At the bend of the ankle it is crossed by the tendon of 

 the Extensor proprius hallucis, and lies between it and the innermost tendon of the Extensor 

 longus digitorum. It is covered, in the upper two-thirds of its course, by the muscles which 

 lie on either side of it and by the deep fascia; in the lower third, by the integument anterior 

 annular ligament and fascia. 



The anterior tibial artery is accompanied by two veins, venae comites, which lie one on each 

 >ide of the artery; the anterior tibial nerve, coursing around the outer side of the neck of the 

 fibula, comes into relation with the outer side of the artery shortly after it has passed through the 

 opening in the interosseous membrane; about the middle of the leg it is placed superficial to it: 

 at the lower part of the artery the nerve is generally again on the outer side. 



PLAN OF THE RELATIONS OF THE ANTERIOR TIBIAL ARTERY. 



In front. 



Integument, superficial and deep fascine. 

 Anterior tibial nerve. 



Tibialis anticus (overlaps it in the upper part of the leg). 

 Extensor longus digitorum j (oyerl h s ,j hdv) 

 Extensor propnus hallucis ) 

 Anterior annular ligament. 

 Inner .tide. Outer side. 



Tibialis anticus. f Anterior \ Anterior tibial nerve. 



Extensor proprius hallucis 1 Tibial. I Extensor longus digitorum. 



(crosses it at its lower V / Extensor proprius hallucis. 



part). ^/ 



Behind. 



Interosseous membrane. 

 Tibia. 

 Anterior ligament of ankle-joint. 



Peculiarities in Size. This vessel may be very small, may be deficient to a greater or less 

 extent, or may be entirely wanting, its place being supplied by perforating branches from the 

 posterior tibial or by the anterior division of the peroneal artery. 



Course. The artery occasionally deviates in its course toward the fibular side of the leg, 

 regaining its usual position beneath the annular ligament at the front of the ankle. In two 

 instances the vessel has been found to approach the surface in the middle of the leg, being covered 

 merely by the integument and fascia below- that point. 



Surface Marking. Draw a line from the inner side of the head of the fibula to midwav 

 between the two malleoli. In this line take a point one inch and a quarter below the head of 

 the fibula, and the portion of the line below this point will mark the course of the artery. 



Applied Anatomy. The anterior tibial artery may be tied in the upper or lower part of 

 the leg. In the upper part the operation is attended with great difficulty, on account of the 

 depth of the vessel from the surface. An incision, about four inches in length, should be made 

 through the integument, midway between the tubercle of the tibia and the outer margin of the 

 fibula, and the deep fascia exposed. The wound must now be carefully dried, its edges retracted, 

 and the white line separating the Tibialis anticus from the Extensor longus digitorum sought for. 

 \Yhen this has been clearly defined, the deep fascia is to be divided in this line, and the Tibialis 

 anticus separated from the adjacent muscles with the handle of the scalpel or a director until the 

 interosseous membrane is reached. The foot is to be flexed in order to relax the muscles, and 

 upon drawing them apart the artery will be found lying on the interosseous membrane with the 

 nerve on its outer side or on top of the artery. The nerve should be drawn outward, and the 

 venae comites separated from the artery and the needle passed around it. 



To tie the vessel in the lower third of the leg above the ankle-joint an incision about three 

 inches in length should be made through the integument between the tendons of the Tibialis 

 anticus and Extensor proprius hallucis muscles, the deep fascia being divided to the same extent. 

 The tendon on either side should be held aside, when the vessel will be seen lying upon the tibia, 

 \vith the nerve on the outer side and one of the venae comites on either side. 



Branches. The branches of the anterior tibial artery are: 

 Posterior recurrent tibial. Muscular. 



Superior fibular. Internal malleolar. 



Anterior recurrent tibial. External malleolar. 



