THE REGION OF THE ANKLE AND FOOT 485 



and it can then be carried medially and slightly forwards in the 

 line of the joints until the second metatarsal is encountered. 

 The base of the second metatarsal projects backwards between 

 the medial and lateral cuneiforms, and consequently the line of 

 its articulation with the second cuneiform is posterior to the 

 other tarso -metatarsal joints. The knife is then inserted on 

 the medial side of the foot just behind the base of the first 

 metatarsal, and is carried laterally and slightly backwards 

 through the first joint until it is again obstructed by the base 

 of the second metatarsal. After division of the dorsal cuneo- 

 metatarsal ligaments, an attempt is made to flex the metatarsus 

 on the tarsus. This process puts on the stretch the strong 

 interosseous ligaments which connect the base of the second 

 metatarsal to the medial and lateral cuneiforms, and after they 

 have been divided by cutting backwards, the disarticulation 

 may be completed by cutting through the plantar cuneo- 

 metatarsal ligaments. Instead of disarticulation, the base of 

 the second metatarsal may be sawn across ; or the medial 

 cuneiform may be sawn through on a level with the second 

 cuneo-metatarsal joint, and the base of the second metatarsal 

 can then be disarticulated by division of the strong interrosseous 

 ligament which connects it to the lateral cuneiform bone. 



The intertarsal or tarso-metatarsal joints may be infected 

 with tuberculous disease from a focus in one of the tarsal or 

 metatarsal bones, as the disease requires to erode only the 

 articular cartilage. 



Injuries in the Region of the Ankle - Joint. 

 Injuries in this region commonly follow falls or twists in which 

 the weight of the body is transmitted along a line which is 

 either lateral or medial to the usual axis (p. 463). As a result 

 the foot is over-inverted or over-everted, and a slight degree of 

 adduction or abduction may be present. The precise nature 

 of the injury will depend on the position into which the foot is 

 forced by the violence, but it must be remembered that, in 

 children, a diastasis may occur instead of a fracture. These 

 injuries almost always involve the ankle-joint, and the consequent 

 swelling tends to obscure the subcutaneous bony points. 



Sprains of the Ankle usually occur following over-inversion 

 of the foot. The anterior talo-fibular and sometimes the 

 calcaneo-fibular ligaments (anterior and middle fasciculi of the 

 external lateral ligament) are torn, and in severe cases the 

 anterior part of the capsule also is ruptured. Tenderness is 



31 b 



