506 The Foot 



The internal saphenous nerve supplies the inner border of the foot 

 nearly to the ball of the great toe, but no farther (p. 358). 



In the sole the plantar nerves are distributed, the inner to three 

 toes and a half, and the external, like the ulnar nerve, to one and a 

 half. An additional plantar cutaneous branch comes through the in- 

 ternal annular ligament from the posterior tibial nerve. 



In amputation of the great toe with its metatarsal bone the 

 ridge across the base of the first metatarsal is made out the joint 

 with the internal cuneiform is close behind. A longitudinal dorsal 

 incision is made from half an inch behind this till the head of the 

 metatarsal bone is approached. The incision then divides to make a 

 racquet-shaped wound. The first metatarsal bone is then enucleated, 

 disarticulated, and removed, together with its two phalanges. 



During the operation the fol hiving structures are divided : Skin 

 and superficial fascia ; plantar fascia ; tributaries of the internal 

 saphenous vein, and branches of the internal saphenous, musculo- 

 cutaneous, anterior tibial, and internal plantar nerves ; the dorsalis 

 hallucis ; branches of the communicating, and of the internal plantar 

 arteries ; the extensor proprius hallucis ; the innermost tendon of the 

 extensor brevis digitorum ; the first dorsal interosseous muscle ; the 

 transverse ligament and muscle, the adductor, flexor brevis, and 

 abductor hallucis ; flexor longus hallucis ; tibialis anticus and peroneus 

 longus ; and fhe ligaments connecting the first metatarsal with the 

 internal cuneiform. 



Care must be taken not to wound the communicating artery as it 

 dips through the root of the first dorsal interosseous muscle. 



Amputation of the little toe with its metatarsal bone is per- 

 formed on a similar plan, the dorsal incision being begun behind the 

 articulation of the fifth metatarsal bone with the cuboid. The struc- 

 tures divided are tributaries of the external saphenous vein ; branches 

 of the external saphenous, musculo-cutaneous, and external plantar 

 nerves, and of the dorsal interosseous, metatarsal, and external plantar 

 arteries ; the outer part of the plantar fascia ; the outermost tendon 

 of the extensor longus digitorum and of the flexor longus and brevis 

 digitorum, and the fourth lumbrical ; the transversus pedis muscle 

 and ligament ; a plantar and a dorsal interosseous muscle, and the in- 

 sertions of the abductor and flexor brevis minimi digiti ; the peroneus 

 tertius and brevis, and the ligaments of the outermost tarso-meta- 

 tarsal joint. 



The web of the toes reaches about an inch beyond the head of the 

 metatarsal bones. In amputation of a toe the web makes an excel- 

 lent covering for the head of the metatarsal bone, but, in amputation 

 of the great toe, the head of that metatarsal bone requires a large flap, 

 which is best obtained from the under surface. The head of this 

 metatarsal bone should, if possible, be preserved, on account of its 

 importance in standing and walking. 



