THE FOOT AND ANKLE. 1463 







upon the interosseous membrane, while in its distal third it winds on to the front 

 of the tibia, to terminate at a point opposite the ankle-joint, midway between the 

 two malleoli. Incisions to expose the vessel should strike the lateral border of the 

 tibialis anterior, which corresponds to a line drawn from a point midway between 

 the lateral condyle of the tibia and the head of the fibula, to the termination of 

 the vessel. 



When the muscles of the calf are thrown into action, a groove is seen between 

 the two heads of the gastrocnemius, the fleshy fibres of which extend a little distal 

 to the middle of the leg. The fleshy fibres of the soleus extend to the junction 

 of the middle and distal thirds of the leg, and project beyond the margins of the 

 gastrocnemius. The narrowest part of the tendo calcaneus is situated opposite the 

 bases of the malleoli, and it is there that the tendon is divided in the operation 

 of tenotomy. The small saphenous vein, which lies a little to the lateral side of 

 the tendon, gradually reaches the middle of the calf, along which it runs proximally 

 to the middle of the popliteal fossa. The great saphenous vein and the saphenous 

 nerve lie along the medial margin of the tibia. 



The course of the posterior tibial artery is mapped out by drawing a line from 

 the distal angle of the popliteal fossa, at the level of the distal border of the 

 tuberosity of the tibia, to a point midway between the medial malleolus and the 

 tendo calcaneus. To expose the vessel in the proximal half of the leg, an incision 

 is made parallel to and \ in. posterior to the medial margin of the tibia ; after 

 retracting the medial border of the gastrocnemius and dividing the tibial origin 

 of the soleus, the artery is found lying on the tibialis posterior. In exposing the 

 artery below the soleus, divide two layers of deep fascia and keep the knife 

 directed towards the tibia. 



The peroneal artery is given off 3 in. distal to the head of the fibula ; incisions 

 to expose the vessel are made in the direction of a line extending from the 

 posterior border of the head of the fibula to a point midway between the lateral 

 malleolus and the tendo calcaneus. 



THE FOOT AND ANKLE. 



The tip of the lateral malleolus is situated \ in. distal and f in. more 

 posterior than that of the medial malleolus. Proximal to the lateral malleolus is 



Fibula 

 Line of ankle-joint 





Extensor digitorum brevis 

 Tendon of flexor digitorum 

 longus to tifth toe 

 Second metatarso- 

 phalangeal joint 



Fifth metatarso-phalangeal joint' Base of fifth metatarsal \ \ Lateral malleolus 



Peronseus brevis . Trochlear process 



Greater tubercle of calcaneus Peronseus longns 



FIG. 1123. LATERAL ASPECT OF FOOT AND ANKLE. 



the triangular subcutaneous surface of the fibula, the apex of which corresponds 

 to the distal end of the extensor-peroneal intermuscular septum. 



The line of the ankle-joint can be felt on either side of the extensor tendons, 

 and when the foot is extended the anterior part of the proximal articular surface 

 of the talus forms a visible prominence distal to the anterior crest of the distal end 



