132 



REGIONS OF THE LEG. 



anastomoses form an important part of that 

 system of collateral circulation by which the 

 stream of blood is continued to the leg and 

 foot, after the obliteration of the popliteal 

 artery. 



The anterior tibial artery may require to be 

 tied in case of wound or aneurism. In wounds 

 of the dorsal artery of the foot, it may be advi- 

 sable to put a ligature at the lower third of the 

 leg, when the anterior tibial is running between 

 the tendons. Its course may be here ascer- 

 tained by feeling its pulsation, or by observing 

 the line of the tendon of the extensor proprius 

 pollicis, on the fibular side of which it here lies. 

 When about to tie it higher up, the incision in 

 the integuments and fascia must be the more 

 free in proportion as it is nearer the knee ; and 

 it may sometimes be advisable even to divide 

 some of the fibres of the fascia transversely, to 

 permit more freely the retraction of the muscu- 

 lar sides of the cut. In dissection, we so easily 

 separate the inuscles and expose the artery, 

 that we may underrate the difficulty attending 

 the operation of tying it. The depth at which 

 it lies in this part, the constant contraction of 

 the muscles, and the difficulty of retracting the 

 sides of the incision, occasioned by the strong 

 aponeuroses, all constitute considerable obsta- 

 cles to the operation. This artery was subcu- 

 taneous in a case related by Pelletan, and is 

 occasionally very small indeed, or even abso- 

 lutely wanting. The first anomaly we have se- 

 veral times seen in dissection, and an instance 

 of the latter is related by Huguier.* In these 

 cases a large branch of the peroneal, which had 

 passed through the interosseous ligament a 

 little above the ankle-joint, supplied the place 

 of the lower part of the artery. In a case 

 which was met with by Velpeau, he found this 

 artery not perforating the interosseous ligament 

 at all, but winding round the fibula just below 

 the head of this bone, and in company with the 

 musculo-cutaneous nerve.f 



The artery is accompanied by two veins, one 

 placed on each side, throughout its course. 

 The anterior tibial nerve, which is a branch 

 from the peroneal, runs on the fibular side of 

 the artery first, and then obliquely crosses it, 

 sometimes again passing outwards, towards the 

 lower part of the leg. The deep-seated lym- 

 phatics following the course of the vessels, 

 deep-seated disease of the front of the leg may 

 produce alteration of the glands of the ham. 

 A lymphatic gland is found in front of the an- 

 terior tibial vessels, a little below the opening 

 of the interosseous ligament through which 

 the vessels pass. 



In the posterior region of the leg the mus- 

 cles are arranged in two distinct layers, the 

 superficial, composed of the gastrocnemius, 

 soleus, and plantaris ; the deep, of the popli- 

 teus, the tibialis posticus, the flexor communis 

 digitorum, and flexor longus pollicis. The 

 gastrocnemius becomes tendinous, considerably 

 higher in the calf than the soleus, sending off 



its broad thin tendon about the middle of the 

 leg, to unite with that of the soleus, about the 

 junction of its middle and lower thirds. The 

 soleus, beginning its origin lower than the 

 last muscle, from the bones of the leg, con- 

 tinues its muscular fibres lower in proportion, 

 in this respect varying considerably in different 

 subjects. 



These two muscles, arising above by their 

 distinct heads, and having but one insertion 

 below, form in fact but one muscle, which 

 Meckel has named the triceps surce. Their 

 common tendon is of a strength proportioned 

 to that of the muscles themselves, and is 

 therefore exceedingly powerful. Notwithstand- 

 ing; the combined action of the muscles is occa- 

 sionally too much for the tendon, and in leap- 

 ing, dancing, or other similar movements, it is 

 sometimes ruptured. After this accident, the 

 difficulty of cure results, not so much from the 

 injury done to the tendon itself, as from the 

 difficulty of bringing the two ends into apposi- 

 tion. In fact, complete union never occurs, 

 the utmost extension of the foot never bringing 

 the lower portion so high as the upper is re- 

 tracted by the muscles. The union, however, 

 which is of a cellular structure, becomes suffi- 

 ciently strong to be perfectly serviceable. 

 Boyer speaks of a partial rupture of the tendo 

 Achillis, and describes with precision the symp- 

 toms, but we apprehend this form of the acci- 

 dent is very rare.* The pathology of club- 

 foot, which has only of late years been clearly 

 understood, shows that permanent retraction of 

 the muscles of the calf, either primary or se- 

 condary, is its most frequent cause, and the 

 division of the tendo Achillis and the other 

 tendons of this part has in consequence been 

 resorted to with great success.f The plan of 

 operating which our experience leads us to 

 prefer, is to insert a sharp-pointed bistoury 

 through the skin, and pass it behind the tendon 

 with its flat side towards it, till having reached 

 its farther side, the edge is turned, and the 

 tendon is divided in the withdrawal, without 

 more division of the skin than the mere punc- 

 ture. If the tendon is kept tense during the 

 operation by the forcible flexion of the foot, 

 and is not quite divided at one stroke, the 

 undivided tendinous fibres are pulled and 

 stretched, and partially torn from their lateral 

 attachments, which occasions a sort of hissing 

 noise, which is not heard when the force is not 

 applied, till after the entire division of the 

 tendon. The union here takes place in the 

 same manner as in rupture of the tendon, but 

 the treatment proceeds upon a somewhat diffe- 

 rent principle, since it is in this latter case the 

 intention to keep the divided ends apart, and 

 the foot is therefore placed at right angles, 

 while, in the ruptured tendon, the foot is ex- 

 tended, in order to approximate the ends as 

 much as possible. The extreme contraction of 

 the muscle, in club-foot, leaves no possibility 

 of further retraction of the upper part of the 



137. 



: See Velpeau's Anatomy of Regions, p. 474. 

 See Velpeau's Mcdecine Operatoire, torn. iii. 



* See Uoyt 

 .95. 

 t See Listen's Practical Surgery, p 



Maladies Chirurgicales, torn. ii. 

 154. 



