^ig- 193' Region of the Ankle and Dorsum of Foot. Left. 



Preparation from a girl aged 75 years. The Fascia of the Leg and Dorsum 



of the Foot has been removed, but the Superficial Veins and the Anterior An- 



milar Ligament have been preserved. 



The open network of superficial fascia which occurs in this situation, con- 

 tains little fat, but is rich in a Venous Plexus which terminates on the inner side 

 in the Long Saphenous Vein, and on the outer side in the Short Saphenous Vein. 

 The Fascia extending from the leg to the foot is considerably strengthened above 

 and over the ankle by the Superior and Anterior Annular Ligaments. The latter 

 is formed by a series of fibres which run from the Internal Malleolus outwards 

 and downwards to the outer border of the foot, these fibres are crossed by another 

 series of fibres which run frorn the inner border of the External Malleolus. These 

 fibres are no independent structures but thickenings of the Fascia; they can only 

 be displayed artificially (cf. Fig. 193). 



The Extensor Muscles present the same relations as in the Leg. On the 

 inner side, the Anterior Tibial Muscle is inserted into the Scaphoid and base of 

 the first Metatarsal Bone, externally to this the Long Extensor of the Big Toe 

 runs to the terminal phalanx of the Big Toe, next the Long Extensor of the Toes 

 to the 4 outer Toes, and lastly the Peroneus Tertius (Third Peroneal) Muscle to 

 the Tubercle of the 5th Metatarsal Bone. Arising from the first part of the upper 

 and outer surface of the Os Calcis, deep to the Tendon of the Long Extensor of 

 the Toes, lies the Short Extensor of the Toes, with its obliquely directed tendons 

 which blend with the Long Extensor Tendons to form the dorsal aponeurosis of 

 the toes. Between the Metatarsal Bones appear the Dorsal Interosseous Muscles. 



At the mid-point between the 2 Malleoli and between the tendons of the Long 

 Extensors of the Toes and Big Toe is situated the Anterior Tibial Artery ; in its 

 continuation below the Anterior Annular Ligament it is called the Dorsal Artery 

 of the Foot which runs over the middle Cuneiform Bone onwards into the 1st 

 interosseous space, where it anastomoses with the External Plantar Artery. 



The Anterior Tibial Artery gives off to each Malleolus — a Malleolar 

 Branch — , the Dorsal Artery of the Foot, to both inner and outer sides of the 

 Foot a Tarsal Artery. 



The Anterior Tibial Nerve generally on the inner side of the Dorsal Artery 

 of the Foot, supplies tlie Short Extensor Muscle of the Toes and gives a Cutaneous 

 Nerve to the contiguous sides of the Big Toe and the 2nd Toe. 



On either side of the Extensor Tendons and between the tendinous bundle 

 and each Malleolus is a space of considerable importance, because at these points 

 the Capsule of the Joint is only covered by Skin and Superficial Fascia without 

 any accessory strengthening fibres. 



At no other place is the joint so exposed or so readily accessible. Moreover 

 by a bulging of these spaces an effusion into the joint will be first observed. 



