134 



REGIONS OF THE LEG. 



operation, before having recourse to so severe 

 and hazardous a measure as that of tying the 

 femoral or popliteal artery. 



The operation of tying the posterior tibial 

 artery in the middle of the leg will be found 

 much more difficult than either of the other 

 situations mentioned, as this vessel here 

 lies at such a depth from the surface, and is 

 covered by the gastrocnemius and internal 

 head of the solens, which in this situation is 

 attached to the tibia. To expose the artery 

 here, the leg should be bent, the foot extended, 

 and both laid on the outer side. The incision 

 must be of considerable length, not less than 

 four inches, along the inner edge of the tibia. 

 The integuments and fascia being divided, 

 (care being at the same time taken to avoid the 

 saphena vein,) the edge of the gastrocnemins 

 muscle will be exposed ; this will be easily 

 raised and drawn to one side. The soleus 

 must next be divided from its attachment to 

 the tibia, and at the bottom of this incision 

 will be discovered some dense aponeurotic 

 fibres, which are part of the deep fascia of the 

 leg. The muscular fibres in the incision must 

 now be held wide apart, and carefully sepa- 

 rated from this deep fascia preparatory to its 

 division, and immediately underneath this 

 fascia lies the artery, with its accompanying 

 veins, one on each side, with the nerve on its 

 inner or tibial side, and here situated about an 

 inch from the edge of the tibia. 



On the dead subject this operation is not 

 attended with much difficulty ; in the living, 

 however, the case is very different; the mus- 

 cles are then rigid and unyielding, and when 

 the fascia which covers them is divided, they 

 leave their natural situation, and become much 

 elevated, so as to make the situation of the 

 artery appear as a deep cavity, at the bottom of 

 which the vessel is placed. The contraction of 

 the muscles has been found in some cases so 

 great an impediment to the operation, as to 

 require the transverse division of part of the 

 muscle. The operation of cutting directly 

 from behind, through the fibres of the gas- 

 trocnemius, is obviously still more objection- 

 able, from the cause just mentioned. 



The second terminating branch of the pop- 

 liteal artery is the peroneal. This is situated 

 deeply, along the posterior part of the leg, 

 taking the direction of the fibula ; hence it is 

 sometimes called fibular. It commences about 

 an inch or two below the lower border of the 

 poplitens muscle, after perforating the tibialis 

 posticus at the commencement of its course, 

 and descends, almost perpendicularly, towards 

 the outer ankle. In this course, it lies close 

 upon the fibula, between the flexor proprius 

 pollicis and flexor digitorum communis. On 

 reaching the lower extremity of the interos- 

 seous ligament, it divides into two branches, 

 the anterior and posterior peroneal, the first of 

 which passes through the aperture at this part 

 of the interosseous ligament, and both of these 

 run to the outer side of the foot. This artery 

 is so small and so deeply seated, that its 

 wounds are rare and unimportant. Hence 

 but little has been said of its ligature, which 



would be very difficult, and could only be per- 

 formed at the middle of the external side of the 

 leg. We should then divide the same parts as 

 for the tibial, but on the opposite side, and as 

 it is enveloped in the fibres of the flexor longus 

 pollicis, we must also detach this muscle from 

 the fibula. 



Each of these arteries of the posterior region 

 is accompanied by two veins, which fre- 

 quently overlap the artery so as to conceal it 

 from view, in the operation of securing it; 

 they are also so adherent to its coats as to occa- 

 sion some difficulty in separating them, so as 

 to avoid including them in the ligature, parti- 

 cularly where the artery, as in the present in- 

 stance, is deep-seated. The best mode of 

 accomplishing this is to insinuate the aneu- 

 rismal needle first on one side, and then upon 

 the other, not attempting to bring it out on the 

 opposite side of the artery, till, by this means, 

 the lateral attachments are separated. 



The deep nerve which accompanies the 

 posterior tibial artery is the tibial, and is of 

 considerable size, being the continuation of 

 the trunk of the popliteal. It is situated, at 

 first, to the outer side of the artery, and lower 

 down it runs nearly behind it, and so close to 

 it, that without care it maybe injured, included 

 in the same ligature, or even tied for that 

 vessel. 



It may not be amiss here to observe on the 

 distinctive marks by which the nerve may be 

 recognized, when passing the ligature under 

 the artery, that besides the most essential, the 

 absence of pulsation, which may occur even to 

 the artery itself from accidental causes, the 

 inexperienced operator will find considerable 

 assistance from the following, viz. the firm, 

 round, cord-like feel of the nerve, while the 

 artery has a flattened yielding feel when 

 pressed between the finger and thumb, and 

 the whitish, somewhat glistening, and promi- 

 nent round appearance of the nerve, the artery 

 having a somewhat reddish colour, and a flat- 

 tened, thick, and riband-like appearance, as it 

 is raised upon the aneurism needle. When 

 the cut extremities of the two are seen toge- 

 ther, after an amputation, of course the round 

 open mouth of the one, and the prominent 

 stump of the other, like a tight packet of 

 thread cut across, are readily recognizable. 



The lymphatics of these deep parts accom- 

 pany the bloodvessels, and pass to the glands 

 of the ham ; hence diseases occurring in the 

 parts beneath the aponeurosis of the leg exert 

 their influence on the glands of the popliteal 

 space. 



The two bones of the leg united by the 

 interosseous ligament form an elongated fossa 

 in front which is closed in by the aponeurosis, 

 and is larger at the union of its two superior 

 thirds than at its extremities. The muscles 

 being imbedded here are difficult to cut in 

 circular amputations, at the same time that its 

 depth prevents the formation of a good flap. 

 Posteriorly, they form a gutter, or fossa, larger 

 than the preceding, but also much more shal- 

 low, excepting at the lower part. Hence the 

 deep muscles are easily comprehended in the 



