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 muscles 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 fluguier.* 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./ 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 tens, the tibialis posticus, the flexor communes 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 proportio in this respect varying considerably in diff subjects.
These two muscles, arising above by distinct heads, and having but one fuse below, form in fact but one muscle, which hleckel has named the triceps sure. 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 sionally too much for the tendon, and in ing, dancing, or other similar movements, i sometimes ruptured. After this accident, th difficulty of cure results, not so much from the injury done to the tendon itself, as from th difficulty of bringing the two ends into apposi tion. In fact, complete union never occu the utmost extension of the foot never bri the lower portion so high as the upper i tracted by the muscles. The union, howeve which is of a cellular structure, becomes suffi ciently strong to be perfectly serviceable I3oyer speaks of a partial rupture of the tend Achillis, and describes with precision the symi toms, but we apprehend this form of the acci dent is very rare.* The pathology of clubs foot, which has only of late years been clearly/ understood, shows that permanent retraction o the muscles of the calf, either primary or se condary, is its most frequent cause, and th division of the tendo Achillis and the oche tendons of this part has in consequence bee resorted to with great suecess.t The plan o operating which our experience leads us t prefer, is to insert a sharp-pointed bistou through the skin, and pass it behind the tel with its flat side towards it, till having rea its farther side, the edge is turned, and 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, th undivided tendinous fibres are pulled an stretched, and partially torn from their lat attachments, which occasions a sort of hi noise, which is not heard when the force is applied, till after the entire division of th tendon. The union here takes place in th same manner as in rupture of the tendon, MI 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 tendon, therefore the whole separation, after the division, is performed by the moving of the lower part.
The powerful muscles, now described, are never known to be ruptured themselves, the tendon, as we have seen, yielding first, but a partial rupture of their fibres is not very uncommon, and is indicated by the same pain ful symptoms as were alluded to in speaking of the anterior muscles. It is worth remarking, on the great power of these muscles, that, great as is the force required, to elevate the whole body, by acting upon the heel, yet the muscles of the calf are not nearly so soon fatigued in walking as those on the front of the leg, whose labour is merely the elevation of the foot and toes, and of this every one must be sensible after unusually long exercise on foot.