Ligation of Dor sal is Pedis 495 



Xifg-ation of the dor alls pedis. An incision of two inches is 

 made over the artery in the line running from the middle of the ankle 

 to the base of the first space, through the skin and the superficial 

 and deep fasciae. The tendon of the special extensor of the great toe 

 is not the guide to the artery, which is running at some distance on its 

 outer side ; the guide is the inner belly and tendon of the short ex- 

 tensor of the toes. This latter closely overlaps the dorsalis pedis, and 

 is beginning to cross it from the outer side. The artery is thus to be 

 looked for close on the inner side of, or just beneath, that part of the 

 extensor brevis digitorum, and a second layer of deep fascia, which 

 binds the artery to the tarsus, has to be divided before the vessel is 

 quite cleared. On either side is a vein, and to the outer is the an- 

 terior tibial nerve. The ligature is to be passed from the outer 

 side. 



Branches. Various tarsal branches anastomose with the malleolar 

 and plantar arteries, and the outermost of them may be also joined by 

 twigs of the anterior peroneal. The metatarsal branch runs over the 

 bases of the metatarsal bones, under the extensor brevis digitorum, 

 and gives off dorsal interosseous branches, which run along the three 

 outer spaces. These slender vessels divide at the clefts of the toes, 

 and receive there the anterior perforating branches from the digitals 

 of the external plantar. At the hinder end of the spaces the dorsal 

 interosseous arteries are joined by the posterior perforating twigs of 

 the external plantar. The outermost interosseous artery gives a 

 branch along the outer side of the little toe. 



The dorsalis hallucis comes from the bifurcation of the dorsalis 

 pedis, and runs on the first dorsal interosseous muscle to the cleft, both 

 sides of which it supplies. It also sends a branch under the tendon of 

 the extensor proprius hallucis to the inner side of the great toe. 



The communicating- branch descends between the heads of origin 

 of the first dorsal interosseous muscle to become continuous with the 

 external plantar, and so to form the plantar arch. It supplies also 

 the inner side of the great toe and the adjacent sides of the great and 

 second toes on their plantar aspect, the internal plantar artery failing 

 to reach so far forwards. 



THE BONES OF THE LEG 



The tibia has three centres of ossification, that for the shaft 

 appearing early in foetal life. The upper epiphysis consists of the 

 tubcrosities and the tubercle, and begins to ossify at birth. The 

 centre for the lower end appears in the second year and joins the 

 shaft soon after puberty. The upper epiphysis joins at manhood, that is 

 when the growth of the leg is perfected. The upper junction-cartilage, 

 therefore, has more concern with the growth of the bone than the 

 lower for it is in active increase for several years longer and must 



