THE POSTERIOR TIBIA L ARTERY. 589 



PLAN OF THE RELATIONS OF THE POSTERIOR TIBIAL ARTERY. 



In front. 

 Tibialis posticus. 

 Flexor longus digitorum. 

 Tibia. 

 Ankle-joint. 



Inner side. / \ Outer side. 



Posterior tibial nerve, p ^j or Posterior tibial nerve, 



upper third. V t lower two-thirds. 



Behind. 



Integument and fascia. 

 Gastrocnernius. 

 Soleus. 



.Deep transverse fascia. 

 Posterior tibial nerve. 

 Abductor hallucis. 



Behind the Inner ankle the tendons and blood-vessels are arranged, under 

 cover of the internal annular ligament, in the following order, from within out- 

 ward: First, the tendons of the Tibialis posticus and Flexor longus digitorum, 

 lying in the same groove, behind the inner malleolus, the former being the most 

 internal. External to these is the posterior tibial artery, having a vein on either 

 side : and, still more externally, the posterior tibial nerve. About half an inch 

 nearer the heel is the tendon of the Flexor longus hallucis. 



Peculiarities in Size. The posterior tibial is not unfrequently smaller than usual, or 

 absent, its place being supplied by a large peroneal artery which passes inward at the lower end 

 of the tibia, and either joins the small tibial artery or continues alone to the sole of the foot. 



Surface Marking. The course of the posterior tibial artery is indicated by a line drawn 

 from a point one inch below the centre of the popliteal space to midway between the tip of the 

 internal malleolus and the centre of the convexity of the heel. 



Surgical Anatomy. The application of a ligature to the posterior tibial may be required 

 in cases of wound of the sole of the foot attended with great haemorrhage, when the vessel 

 should be tied at the inner ankle. In cases of wound of the posterior tibial it will be necessary 

 to enlarge the opening so as to expose the vessel at the wounded point, excepting where the 

 vessel is injured by a punctured wound from the front of the leg. In cases of aneurism from 

 wound of the artery low down, the vessel should be tied in the middle of the leg. But in 

 aneurism of the posterior tibial high up it would be better to tie the femoral artery. 



To tie the posterior tibial artery at the ankle, a semilunar incision, convex backward, should 

 be made through the integument, about two inches and a half in length, midway between the 

 heel and inner ankle or a little nearer the latter. The subcutaneous cellular tissue having been 

 divided, a strong and dense fascia, the internal annular ligament, is exposed. This ligament is 

 continuous above with the deep fascia of the leg, covers the vessels and nerves, and is intimately 

 adherent to the sheaths of the tendons. This having been cautiously divided upon a director, 

 the sheath of the vessels is exposed, and, being opened, the artery is seen with one of the venae 

 comites on each side. The aneurism needle should be passed round the vessel from the heel 

 toward the ankle, in order to avoid the posterior tibial nerve, care being at the same time taken 

 not to include the vense comites. 



The vessel may also be tied in the lower third of the leg by making an incision, about three 

 inches in length, parallel with the inner margin of the tendo Aehillis. The internal saphenous 

 vein being carefully avoided, the two layers of fascia must be divided upon a director, when the 

 artery is exposed along the outer margin of the Flexor longus digitorum, with one of its venae 

 comites on either side and the nerve lying external to it. 



To tie the posterior tibial in the middle of the leg is a very difficult operation, on account of 

 the great depth of the vessel from the surface. The patient being placed in the recumbent posi- 

 tionrthe injured limb should rest on its outer side, the knee being partially bent and the foot 

 extended, so as to relax the muscles of the calf. An incision about four inches in length should 

 then be made through the integument a finger's breadth behind the inner margin of the tibia, 

 taking care to avoid the internal saphenous vein. The deep fascia having been divided, the 

 margin of the Gastrocnemius is exposed, and must be drawn aside, and the tibial attachment of 

 the Soleus divided, a director being previously passed beneath it. The artery may now be 

 felt pulsating beneath the deep fascia about an inch from the margin of the tibia. The fascia 

 having been divided, and the limb placed in such a position as to relax the muscles of the 

 calf as much as possible, the veins should be separated from the artery, and the aneurism 

 needle passed round the vessel from without inward, so as to avoid wounding the posterior 

 tibial nerve. 



