1 82 THE SURGICAL ANATOMY OF THE HORSE 



it arrives at the hock, when it follows the course taken by the large meta- 

 tarsal artery, its size being now very much reduced. It terminates in 

 cutaneous filaments, which are distributed to the skin on the outer side of 

 the metatarsal region. 



During its course the anterior tibial nerve gives off short, thick 

 branches which supply the extensor pedis and the flexor metatarsi muscles, 

 and near the inferior extremity of the tibia it detaches a number of small 

 articular filaments which are distributed to the hock joint. It also supplies 

 the extensor brevis. 



ANTERIOR TIBIAL NEURECTOMY 



Owing to the articular branches supplied by this nerve to the hock 

 joint, the operation of anterior tibial neurectomy has been commonly 

 performed in the treatment of cases of spavin which do not improve 

 under the ordinary methods of treatment by counter-irritation, &c. 



There are two seats in which this operation has been practised, which 

 may be termed respectively the upper and lower. The upper seat has 

 been commonly selected in this country, the object being to seize the 

 nerve in the most accessible position for operation. 



Upon examining the limb we find that the nerve is most superficially 

 placed where it dips in between the extensor pedis and peroneus muscles 

 on the outer aspect of the limb just below the stifle joint. An inspection 

 of the part will reveal the fact that the contour of the belly of the extensor 

 pedis muscle may be distinctly seen, since it forms a prominent and well- 

 defined bulging of the skin. Behind this elevation is another which is 

 less prominent, and which is slightly more elongated from above to 

 below. This indicates the position of the peroneus muscle. Taking 

 a vertical course upwards from the line of apposition of the two 

 muscles, we feel the head of the fibula, and this is our guide, for the 

 seat in which this nerve can be most easily picked up is that recom- 



