THE LEG 273 



brevis, and ends on the dorsum of the foot in a gangliform 

 enlargement. Branches proceed from the ganglion for the 

 supply of the extensor digitorum brevis, and the numerous 

 articulations in the neighbourhood. One fine filament can, 

 in most cases, be traced to the second dorsal interosseous 

 muscle. The terminal swelling resembles closely the corre- 

 sponding enlargement in which the dorsal interosseous nerve 

 of the upper extremity ends. 



The Transverse and Cruciate Ligaments (O.T. Anterior 

 Annular Ligament). The dissector should again examine 

 these ligaments, and the arrangement of the structures which 

 pass under them. The transverse ligament is attached to the 

 fibula by its lateral end, and to the tibia by its medial 

 extremity. By dividing its fibular attachment, and throwing 

 it medially, it will be seen to give a separate and distinct 

 sheath to the tibialis anterior. 



The crticiate ligament is the more important of the two. 

 Its attachments have already been noted (p. 261). Examine 

 the manner in which it holds the tendons in position. It 

 consists of two layers, and these, by separating at certain 

 points -and becoming reunited at others, form three distinct 

 compartments. Through the most medial passes the tendon 

 of the tibialis anterior ; through the intermediate one passes 

 the tendon of the extensor hallucis longus ; and through the 

 lateral are transmitted the tendons of the extensor digitorum 

 longus and peronaeus tertius. As the tendons pass through 

 the compartments of the ligaments, and for some distance 

 proximal to the transverse and distal to the cruciate ligament, 

 they are surrounded by mucous sheaths. Lastly, note the 

 position of the anterior tibial vessels and the deep peroneal 

 nerve as they pass under cover of the ligaments. They 

 lie between the extensor hallucis longus and the extensor 

 digitorum longus (Fig. 96). 



LATERAL CRURAL OR PERONEAL REGION. 



The peroneal or lateral compartment of the leg should now be opened by 

 dividing, in a longitudinal direction, the fascia which covers it. Enclosed 

 within it are : 



1. The peronaeus longus. 



2. The peronaeus brevis. 



3. The termination of the common peroneal nerve. 



4. The superficial peroneal nerve. 

 VOL. I 18 



