THE TREATiMENT OF SPAVIN. 77 



In neurectomy of the tibial, the point selected is at the external 

 surface of the lower part of the thigh, approximately at the same 

 height as the former. The anterior tibial nerve is situated on the deep 

 surface of the anterior extensor of the phalanges, between this muscle 

 and the thin muscular portion of the flexor metatarsi which separates 

 it from the tibial artery, and from its large satellite vein — vessels 

 which lie directly on the anterior surface of the tibia, where they 

 are surrounded by a thick layer of connective tissue. 



The method is as follows : — The point of operation being prepared, 

 the skin and subjacent aponeurosis are incised for a distance of two 

 and a half to three inches, opposite the external margin of the anterior 

 extensor of the phalanges. This muscle is separated from the lateral 

 extensor, then from the muscular portion of the flexor metatarsi, on the 

 anterior surface of which the tibial nerve is readily discovered. A 

 fragment of this, three quarters of an inch to one and a quarter inches 

 in length, is excised. The wound is closed by a few cutaneous sutures, 

 with or without providing for drainage. The operation is eas}-. It is, 

 however, always necessary to proceed methodically, and to take care 

 not to injure the tibial vein, which thrusts the muscular portion of the 

 flexor metatarsi prominently forwards as soon as the anterior extensor 

 of the phalanges is reflected. 



This double neurectomy has proved successful when all other 

 methods had failed. Bosi reported six favourable cases, and more 

 recently Frohner has described others. Nevertheless it is not without 

 danger, trophic changes in the extremities, local sloughing, and loss of 

 the hoof sometimes occurring. 



I may summarise the treatment of spavin as follows : — At first, when 

 the disease is still latent, prolonged rest and blisters ; later, when 

 spavin is apparent, firing in deep penetrating points, and when the 

 exostosis is large, section of the internal terminal tendon of the flexor 

 metatarsi. Should improvement only be partial, repeat the firing ; 

 finally, if repeated firing fails, you may, after warning the owner of 

 possible risk, perform neurectomy of the sciatics. 



The heredity of certain organic conditions which favour the pro- 

 duction of spavin suggests the only prophylactic measure applicable in 

 our practice, viz. to avoid breeding from animals with this disease, or 

 from those with specially defective hocks. 



