THE PLANTAR NERVES 187 



has, however, been performed, with successful results. The operation is 

 described in Chapter VI., which deals with tendons. 



THE PLANTAR NERVES 



In general these nerves in their course and distribution resemble the 

 corresponding nerves of the fore limb. In the hind limb, however, the 

 large metatarsal artery does not run down alongside either of the plantar 

 nerves. It is placed on the outer side of the limb, some distance in front 

 of the external plantar nerve, and between the large and outer small 

 metatarsal bones. Following the course of the nerves are the internal 

 and external metatarsal veins, behind which the corresponding plantar 

 nerves are found. Two small arteries, which are unnamed, descend from 

 the tarsal arch. These run down the limb, one in front of each plantar 

 nerve, and between it and the corresponding metatarsal vein. These arteries 

 usually terminate in the inferior third of the metatarsal region, and not 

 infrequently one of them is absent. Regarding the point at which the 

 plantar nerves of the hind limb divide into the digitals, Craig made observa- 

 tions on a number of cases, and found that all divided below the level of the 

 button of the splint bone. It was also found that in a number of cases the 

 oblique branch which usually connects the internal and external plantar 

 nerves was absent, and that the average point at which this branch (in 

 those cases in which it was present) was detached from the internal plantar 

 nerve, was two and a third inches above the lower extremity of the 

 internal small metatarsal bone, whilst it joined the external plantar nerve 

 at a point which was on an average half an inch below the level of the 

 button of this bone. Consequently he recommended that the incision in 

 external plantar neurectomy in this limb should commence about a 

 quarter of an inch below the button of the external metatarsal bone, and 

 should extend in the downward direction vertically for a length of an inch 

 and a quarter. In operating on the internal plantar nerve the incision 



