498 THE INFERIOR EXTREMITY 



In Hallux Valgus the great toe becomes excessively 

 adducted and overrides or underlies the second toe. The 

 condition is caused by the wearing of faultily made boots or 

 shoes, which in addition to being too short, have the point of 

 the toe in line with the third instead of in line with the first 

 digit. The toes, therefore, are approximated to one another 

 in the narrow toe of the boot. Once the normal alignment of 

 the great toe is altered, the distortion is increased by the action 

 of the long flexor and extensor tendons. In pronounced cases, 

 these tendons and the lateral metatarso-phalangeal ligament 

 become shortened and the medial part of the head of the first 

 metatarsal is rendered unduly prominent. A bursa, which 

 subsequently develops into a bunion, is formed over the bone. 



The condition may be improved by the resection of the 

 distal two-thirds of the head of the first metatarsal. A semi- 

 lunar incision, the base of which is directed towards the sole, 

 is made over the prominence, and the skin and fascia are elevated 

 together and retracted downwards. The adventitious bursa 

 is dissected free except at its proximal part, so that it can be 

 turned inwards between the first phalanx and the cut surface 

 of the metatarsal. It is stitched in this position, after the head 

 has been excised. 



Hallux valgus may be associated with a deformity of the 

 second toe, known as " Hammer Toe." The latter condition 

 may be present alone, affecting the lateral four digits of each 

 foot, and it is then not infrequently congenital in origin. It 

 may, however, be acquired, independently of hallux valgus, 

 by the wearing of boots or shoes which are too short. 



The metatarso-phalangeal and the distal interphalangeal 

 joints are hyper-extended, while the proximal interphalangeal 

 joint is acutely flexed. The prominent head of the first phalanx 

 may be excised through a dorso-lateral incision. The skin and 

 the dorsal extensor expansion, which forms the dorsal ligament 

 of the joint (cf. p. 93), are divided and retracted to the medial 

 side. The proximal interphalangeal joint is thus widely opened, 

 and after the lateral ligament has been divided and the second 

 phalanx still further flexed, the head of the first phalanx may 

 be dislocated into the wound. 



Hallux Rigidus, which is not uncommonly associated with 

 flat foot, is due to collapse of the longitudinal arch of the foot. 

 Under normal conditions the long axis of the first metatarsal is 

 directed forwards and downwards, whereas the long axis of the 



