THE LEG 259 



3. A lateral crural region, which includes the parts in relation to the 



lateral surface of the fibula. 



4. A posterior crural region, in which are placed the parts, on the back 



of the leg, which lie posterior to the interosseous membrane and the 

 two bones of the leg. 



ANTERIOR CRURAL REGION AND DORSUM OF FOOT. 



The anterior crural region should be dissected first, 

 and it is usual to conjoin with this the dissection of the 

 dorsum of the foot. The following parts are exposed : 



1. Superficial veins. 



2. Cutaneous nerves. 



Extensor hallucis longus. 

 Anterior tibial vessels. 



3. Deep fascia, with its inter - j 9. Perforating branch of the per- 



muscular septa, the ligamentum 

 transversum cruris, the lig. 

 laciniatum, and the lig. 



cruci- 



oneal artery. 



10. Deep peroneal nerve. 



11. Recurrent articular branch 

 atum cruris. from the common peroneal 



4. Tibialis anterior. nerve. 



5. Extensor digitorum longus. 12. Extensor digitorum brevis. 



6. Peromeus tertius. 13. Dorsalis pedis artery. 



Reflection of Skin. To place the limb in a convenient position for 

 the dissection of this region, a block should be introduced beneath the 

 knee, and the foot should be extended and fastened firmly to the table by 

 means of hooks. The skin should be reflected from the tibial and ptroneal 

 (medial and lateral] crural regions at the same time. Incisions: (i) a 

 vertical cut along the medial line of the leg and dorsum of the foot to the 

 base of the middle toe ; (2) a transverse incision across the ankle-joint ; 

 (3) a transverse incision across the dorsum of the foot at the roots of the 

 toes. 



The four flaps of skin thus mapped must now be raised from the 

 subjacent fatty tissue, and the superficial veins and nerves dissected out. 



Venae Superficiales (Superficial Veins). The arcus venosus 

 dorsalis pedis, which receives the common digital veins, should 

 in the first place be dissected. From the medial extremity of 

 this arch the great saphenous vein will be seen to take origin, 

 whilst from its lateral end the small saphenous vein proceeds. 

 Trace these vessels proximally. The former will be found to 

 pass anterior to the medial malleolus, whilst the latter ascends 

 posterior to the lateral malleolus. The great saphenous vein 

 is associated with the saphenous nerve, and the small saphenous 

 vein with the sural nerve. 



Nervi Cutanei (Cutaneous Nerves). The following are the 

 cutaneous nerves which must be secured in this dissection : 



1. N. cutaneus surse lateralis. 



2. N. suralis. 

 I 17 a 



