REGIONS OF THE LEG. 



133 



tendon, therefore tlic 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. 



Between the gastrocnemius and the soleus 

 is the plantaris tendon, a long slender slip, 

 which, after crossing between the muscles, runs 

 on the inner side of the tendo Achillis, to its 

 insertion. The belly of this little muscle is 

 under the outer head of the gastrocnemius, 

 close to the origin of which it arises. Authors 

 describe the symptoms attendant upon rupture 

 of this tendon, but the diagnosis of injury to 

 so small and deep-seated an organ must be so 

 uncertain, that we should be much more in- 

 clined to refer them to an injury of some of 

 the fibres of the great muscles of the calf, es- 

 pecially when we compare the power of the 

 plantaris with that of its tendon, the passive 

 strength of the latter appearing greatly superior 

 to the active force of the former.* Between 

 the lower part of the tendo Achillis and the 

 tendons of the deep layer of muscles, there is 

 a considerable layer of cellular tissue, con- 

 taining fat, and this is often the seat of trouble- 

 some chronic inflammation; and if suppuration 

 follows, the abscess is often very difficult of 

 healing, from the constant movement of the 

 tendon, and the result is a troublesome sinuous 

 ulcer, which can only be healed by keeping 

 the foot entirely at rest. 



The deep muscles, bound down in the pos- 

 terior interosseal space, by the inter-muscular 

 layer of the aponeurosis, are found lying in this 

 order; the flexor digitorum communis, placed 

 innermost, upon the back of the tibia; the 

 flexor longus pollicis, on the fibula, and the 

 tibialis posticus between them, and partly con- 

 cealed by them. Upon this last muscle are 

 situated the posterior tibial vessels and nerves. 

 As they all of them have to pass nearly behind 

 the inner ankle, the two outermost are gradu- 

 ally approaching to the flexor communis, as 

 they descend, till they are nearly in contact one 

 with the other. As all these tendons, either 

 primarily or secondarily, act upon the ankle- 

 joint, their action is retained after rupture or 

 division of the tendo Achillis, so that the 

 power of extension of the foot still remains, 

 though in a feeble degree. 



The arteries of this region are the posterior 

 tibia! and peroneal, and are given off from the 

 termination of the popliteal. The anterior ti- 



Src Dictiounaire des Sciences Medicales, ar- 

 ticle Jambc. 



bial also has here a course of a few lines, from 

 its origin, till it perforates the interosseous liga- 

 ment. The posterior tibial maybe considered as 

 the continuation of the trunk of the popliteal. 

 It commences about an inch below the origin 

 of the anterior tibial, and where the popliteal 

 divides into this artery and the peroneal. The 

 course of the posterior tibial may be defined 

 by a line drawn from the middle of the ham, 

 to a spot half an inch behind the inner mal- 

 leolus. In this course it is accompanied by 

 two veins, one on either side, also by the poste- 

 rior tibial nerve ; in the upper part of the leg, 

 this nerve lies to the inner or tibial side of the 

 artery ; it soon, however, passes over it, and 

 inferiorly it lies to its outer or fibular side. 



The posterior tibial artery is covered, in the 

 upper and middle thirds of the leg, by the gas- 

 trocnemius and soleus muscles, but in the lower 

 third only by the integuments, and by the su- 

 perficial and deep fasciae of the leg. In the 

 upper third of its course, this artery rests upon 

 the tibialis posticus muscle, in the middle 

 third upon the flexor digitorum communis, 

 and in the inferior third some fat and cellular 

 membrane separate it from the tibia, and from 

 the internal lateral ligament of the ankle-joint. 



In the inferior third of the leg, the posterior 

 tibial artery runs nearly parallel to the inner 

 edge of the tendo Achillis ; between the os 

 calcis and malleolus interims, it lies nearly in 

 contact with the sheath of the flexor digitorum 

 communis.* The only branch of surgical in- 

 terest given off by this artery in the leg is the 

 nutritious artery of the tibia, which comes off 

 about its upper third, and in amputation at 

 this part sometimes bleeds freely. 



In putting a ligature upon this artery, the 

 difficulties attendant upon the operation vary 

 according to the situation at which we seek for 

 it. It is favourably circumstanced for opera- 

 tion in the inferior third of its course, being 

 covered in the two upper thirds by the muscles 

 of the calf. It may require to be tied for a 

 wound in the sole of the foot, or for one behind 

 the inner ankle. In either of these cases the 

 artery may be found and tied with facility be- 

 hind the inner malleolus. (See ANKLE-JOINT, 

 REGION or.) When, however, it is deemed de- 

 sirable to tie it at the lower third of the leg, it 

 will be readily found by an incision of from 

 two to three inches in length, performed mid- 

 way between the inner border of the tibia and 

 the tendo Achillis. After the division of the 

 integuments, the superficial fascia, and the 

 deep fascia, the artery will be met with di- 

 rectly under the incision. Its accompanying- 

 veins sometimes completely conceal it ; the 

 nerve is here on the fibular side of it. 



In case of secondary hemorrhage after this 

 operation, or in case of aneurism of the pos- 

 terior tibial artery, forming in consequence of a 

 wound of the artery in this situation, it may be 

 necessary either to tie this vessel higher up in 

 the leg, or to tie the popliteal femoral artery 

 itself; it has been deemed prudent to give the 

 patient the chance of success from the former 



* See article ANKLE-JoiNT, REGION or. 



