94 CLINICAL VKTERINARY :^IEDICINE AND SURGERY. 



incision ; for this purpose the assistants have only to increase or 

 diminish the pull on the limb. You know that in certain animals 

 operation is rendered difficult by an abnormal arrangement of the 

 radial veins, but this is rare. I return to our patient. 



After excising about three quarters of an inch of the nerve I placed 

 a fragment of gauze in the wound to act as a drainage-tube, and over it 

 I united the skin with a couple of sutures. On rising the horse 

 appeared a little less lame than before operation. Next day the 

 sutures were cut, the gauze removed, and the parts treated with anti- 

 septic lotions like an open wound. Healing occurred towards the end 

 of the second week. Unfortunately the result was bad. Lameness 

 was still too marked for the horse to work. 



Peters, and after him others, showed that division of the median 

 nerve alone may remove lameness resulting from bilateral lesions, — that 

 is to say, occupying both sides of one of the lower parts of the leg, 

 or encircling these regions. The results are explained b}' the pre- 

 ponderating influence of the median nerve in the innervation of struc- 

 tures below the knee, a preponderance due to the fact that at a variable 

 point in the forearm the nerve terminates by di\iding into two branches, 

 one of which is continued as the internal plantar nerve, while the other 

 joins the ulnar at the upper border of the pisiform bone, beneath the 

 tendon of the middle flexor, and is continued as the external plantar 

 nerve. 



In hospital you have seen horses with various chronic affections, 

 like strained tendons, splints, cartilaginous ringbones, and periostitis of 

 the phalanges, in which lameness has been removed, or certainly dimin- 

 ished, by dividing the median nerve. 



But others occur in which section of the nerve fails to remove lame- 

 ness caused by lesions on the outer side of the limb, or at times even 

 on the inner. The persistence of pain and lameness in the latter case 

 is explained by the existence of recurrent fibres. Under such circum- 

 stances, ulnar neurectomy, first practised by Vennerholm, often proves 

 useful. As, in our patient, severe lameness continued after radial 

 neurectomy, division of the ulnar was resorted to. 



Throughout the whole extent of the forearm the ulnar cutaneous 

 nerve, accompanied by the ulnar artery and vein, is situate between 

 the oblique and external flexors of the metacarpus, and immediately 

 under the fascia uniting them. By palpation with the finger tips the 

 muscular interspace which fixes the line of operation is readily dis- 

 covered. 



