PLANTAR NERVES 



709 



At the usual point of election for tibial neurectomy, i. e., about a handbreadth above the 

 level of the tuber calcis, the nerve lies in areolar tissue and fat in a fascial compartment formed by 

 the special fascia of the deep flexor in front and by the common fascia and the accessory or tarsal 

 tendon of the semitendinosus and biceps femoris behind and internally. 



At its origin the tibial nerve gives off a muscular branch (Ramus muscularis 

 distalis), the divisions of which pass between the two heads of the gastrocnemius 

 and radiate to supply that muscle, the popliteus, the soleus, and the fiexors of the 

 digit. Small cutaneous twigs are also detached along the course of the nerve. 



Anterior digital extensor 

 Anterior tibial vessels 



Deep peroneal nerve 



Superficial peroneal 



nerve 



Intermuscular septum 

 Fibrous band 



Lateral extensor 

 Intermuscular septum 



Peroneus tertius 



Deep head of deep 



flexor (Flex. hall. 



longus) 



Tibialis posterior 



N. cutaneus surce 

 Recurrent tarsal artery 

 and vein 

 Soleus 



Tibialis anterior 



Saphenous vein 

 Saphenous artery 



Posterior tibial vessels 



Tendon of long digital 

 flexor or flexor accessorius 



Recurrent tibial vein 

 Recurrent tibial artery 

 - Tibial nerve 



Tarsal tendon of biceps femoris 

 and semitendinosus 



Gastrocnemius tendon 



Superficial flexor tendon 



Fig. 527. — Cross-sectiox of Distal Third of Left Leg of Horse. 



The deep fascia is shown by red hne. 



Plantar Nerves 

 The plantar nerves, internal and external (N. plantaris medialis, laterahs), 

 result from the bifurcation of the tibial nerve in the lower part of the leg (Figs. 

 458, 459). They continue at first in the same direction and relations as the parent 

 trunk, in direct apposition and inclosed in a common sheath. At the hock they 

 diverge at a very acute angle and descend in the tarsal canal behind the deep flexor 

 tendon in company wnth the plantar arteries. The internal plantar nerve supplies 

 cutaneous nerves to the inner aspect of the tarsus and metatarsus, descends along 

 the inner border of the flexor tendons behind the superficial plantar metatarsal 

 vessels, and is otherwise arranged like the corresponding volar nerve of the fore 

 limb. The external plantar nerve deviates outward between the two flexor 

 tendons to reach their outer border. It supplies a branch to the suspensory 



