THE POSTERIOR TIBIAL ARTERY. 645 



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 Tiw3? r I Posterior tibial nerve, 



upper third. y ) lower two-thirds. 



Behind. 



Integument and fascia. 

 Gastrocnemius. 

 Soleus. 



Deep transverse fascia. 

 Posterior tibial nerve. 



Behind the Inner ankle the tendons and blood-vessels are arranged in the 

 following order, from within outward : 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, an I 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 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 haying 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 

 vena? 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 Achillis. 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- 

 tion, the 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. 



