Supply of Toes 505 



upon by the upper leather of the boot or shoe. Careful padding 

 and strapping of the toe, or, in more extreme cases, division of the 

 tendons, sometimes cures this deformity, but when the lateral ligaments 

 have slipped behind the head of the metatarsal bone, nothing short of 

 excision of the head of that bone, or amputation of the toe, will effect a 

 cure. The deformity is often hereditary ; it is doubtful if wearing tight 

 boots is often accountable for it. 



The inter-phalangeal articulations of the foot are like those of the 

 hand (p. 289). 



The great mobility which naturally exists between the astragalus and 

 the scaphoid, and between the astragalus and os calcis, is necessarily 

 at the expense of the strength of the union between the astragalus 

 and those bones. So, as the result of great violence, the interosseous 

 (astragalo-calcanean) ligament may be ruptured, and the os calcis, 

 scaphoid, and the other bones of the foot shifted inwards, outwards, 

 or even in the antero-posterior plane. The dislocation of the foot is 

 called subastragaloid. 



A modification of Syme's amputation is performed on this prin- 

 ciple : the heel-flap being made as usual, but the ankle-joint not 

 being opened. A short dorsal flap is made, the os calcis is removed 

 with the rest of the foot, and the heel-flap is brought round the 

 astragalus. 



THE CUTANEOUS VESSELS AND NERVES OF THE FOOT 



The venous arch on the dorsum receives tributaries from the backs 

 of the toes, and empties itself by the internal and external saphenous 

 veins. The direct communication between the saphenous veins 

 enables one of them to do the work of both when inflammation and 

 plugging have rendered its fellow impervious. 



The arteries on the dorsmn of the toes are smaller than the plantar 

 digital branches. The three outer clefts, and the outside of the little 

 toe are supplied by the dorsal interosseous branches of the metatarsal 

 of the dorsalis pedis. The innermost cleft, and the inner side of the 

 great toe, are supplied by the dorsalis hallucis (p. 494). 



On the under aspect the three outer clefts and the outer side of 

 the little toe are supplied by the digital branches of the external 

 plantar artery ; the innermost cleft and the inner side of the great 

 toe get branches from the communicating branch of the dorsalis 

 pedis. 



Nerves. The dorsum is chiefly supplied by branches of the 

 musculo-cutaneous, but the cleft between the great and second toes 

 receives the ending of the anterior tibial nerve, the inner side of the 

 great toe getting its branch from the musculo-cutaneous. Along the 

 outer side of the foot and little toe twigs are derived from the external 

 saphenous. 



