334 



THE INFERIOR EXTREMITY 



strongly inverted the anterior end of the calcaneus will be 

 seen to project on the surface. 



Subdivision of the Leg into Regions. In the dissection of 

 the leg four distinct regions may be recognised, viz. : 



1. An anterior crural region, in which are placed those structures which 



lie anterior to the interosseous membrane, and between the two 

 bones of the leg. 



2. A medial crural region, corresponding to the subcutaneous or medial 



surface of the body of the tibia. 



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. 



3. Deep fascia, with its inter - 



muscular septa, the transverse 

 ligament of the leg, the lig. 

 laciniatum, and the cruciate 

 ligament of the leg. 



4. Tibialis anterior. 



5. Extensor digitorum longus. 



6. Peronoeus tertius. 



7. Extensor hallucis longus. 



8. Anterior tibial vessels. 



9. Perforating branch of the pero- 



neal artery. 



10. Deep peroneal nerve. 



11. Recurrent articular branch 



from the common peroneal 

 nerve. 



12. Extensor digitorum brevis. 



13. Dorsalis pedis vessels. 



Dissection. 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 peroneal (medial 

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

 a vertical cut along the median 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 out (10, n, 12, 13, Fig. 104), 

 must now be raised from the subjacent fatty tissue, and the 

 superficial veins and nerves dissected out. 



Superficial Fascia. The superficial fascia of the front and 

 the medial and lateral sides of the leg and the dorsum of 

 the foot presents no peculiar features; and it contains as 

 a rule only a moderate amount of fat, in which lie the 

 cutaneous veins and nerves. 



