176 THE SURGICAL ANATOMY OF THE HORSE 



states the following case, which was reported by Franck, in which the 

 anterior set of nerves was paralysed owing to the presence of a neuroma: 

 " The patient, a seven-vear-old gelding, showed gradually advancing 

 atrophy of the gluteal muscles of the left side, which became so marked 

 as to result in five months in the bones being almost denuded of muscle 

 and appearing almost like an osteological preparation ; the muscles of 

 the thigh and lower thigh also suffered severely. At first there was 

 only insecure gait, but this symptom, always marked when the horse was 

 turned, gradually became aggravated. Finally the lower part of the limb 

 was kept permanently flexed, and during forced exercise was slid along 

 the ground and set down with a tapping, insecure movement. The 

 backward portion of the stride was shortened. On post-mortem examina- 

 tion a neuroma the size of a pigeon's egg was found on the anterior 

 gluteal nerve four inches from its point of exit." 



When the muscles supplied by the gluteal nerves are paralysed the 

 animal loses the power of abducting the limb, and if compelled to move, 

 the limb is carried with the foot much too close to the mesial line. The 

 limb is carried forward by the action of the crural muscles, the flexors of 

 the hock and the extensors of the interphalangeal joints, and whilst this 

 is being done there is a tendency for the foot of the affected limb to 

 strike that of the limb opposite. Any alteration in the conformation ot 

 the part as a result of atrophy of the muscles is easily detected, and 

 becomes visible to the eye particularly if the animal be viewed from 

 behind and the two quarters compared. The usual treatment for 

 paralysis should be adopted. 



THE POSTERIOR TIBIAL NERVE 



This is the direct continuation of the internal popliteal nerve, 

 the inferior border of the popliteus being the line of demarcation 

 between the two. The first portion of the posterior tibial nerve is 



