180 VETERINARY SURGICAL OPERATIONS 



above the os calcis. (4) The external plantar. (5) The 

 external saphenic. (6) The internal saphenic. All of these 

 nerve trunks are purely sensory nerves below the upper 

 third of the tibial. Above that point they may contain 

 motor fibers enough to produce permanent paralysis of cer- 

 tain muscles when surgically divided. 



INDICATIONS.— The large size of the tibial nerve 

 renders its division for surgical purposes somewhat haz- 

 ardous at all times. The area it supplies with sensibility 

 is large and includes the most important structures of the 

 pelvic limb; — the hock, the tendons, the fetlock, the foot. 

 Its division banishes the sensibility over too great a surface 

 to warrant its application for circumscribed lesion here or 

 there. If the hock is the seat of a lameness the sensibility 

 of the foot and fetlock is also uselessly sacrificed. If the foot 

 is the seat attacked with disease the others are needlessly 

 deprived of their innervation. Herein lies the greatest fault 

 with tibial neurotomy. Tibial neurotomy has been too 

 highly recommended. It is effectual in promptly dispatch- 

 ing lameness of the fetlock and hoof, but too often the relief 

 is purchased at the expense of the patient's life. For dis- 

 eases of an acute character it is positively disastrous. The 

 hoof sheds, the sesamoidean ligaments loosen from their at- 

 tachments, or the flexor tendons give way. Sometimes the 

 dissolution is an aggregation of all of these unfortunate 

 events combined. 



In spavin lameness the operation has been recommended 

 highly in conjunction with deep peroneal neurotomy. This 

 double operation, true enough, often promptly terminates 

 the limp of spavin, but, unfortunately, the whole fetlock and 

 foot being deprived of sensibility, nail pricks, treads, hoof 

 cracks, wounds from interfering, flexion crevices 

 (scratches), etc, too often enter into the situation sooner or 

 later and develop into incurable, fatal complications. In 

 view of this fact it is doubtful whether the veterinary practi- 

 tioner should recommend the operation. Certainly it must 

 not be too hurriedly resorted to. Other treatments, firing, 

 cunean tendinotomy, etc., should at least precede it. It is 

 only when these have failed that this double operation be- 

 comes a justified treatment. To recommend it as the first 

 effort in the treatment of spavin will sooner or later bring 

 the operation and operator into just disrepute. 



In chronic sesamoiditis tibial neurotomy is often of great 

 service. This condition in the hind legs is very often a 

 highly refractory one. The lameness persists in spite of 



