Chap, xxiii.] THE ANKLE AND FOOT. 477 



(the tip of the malleolus) is drawn towards the 

 middle line, the fulcrum is secured by the tibio- 

 fibular ligaments, and the shaft breaks at the other 

 end of the lever, some few inches above the end of 

 the bone (Fig. 54, c). It will be seen that in. the 

 fracture due to eversion the upper end of the lower 

 fragment is displaced towards the tibia, while, in the 

 lesion due to inversion, it is displaced from that bone. 

 From a careful examination of all the cases of frac- 

 ture of the lower end of the fibula admitted into the 

 London Hospital during the time I held the post of 

 surgical registrar there, I convinced myself that the 

 lesion is much more frequently due to eversion than to 

 inversion of the foot. I think it may be said that a 

 fracture of the lower end of the fibula due to simple 

 inversion of the foot is not possible unless the ex- 

 ternal lateral ligament remains entire. 



In the outward luxation, better known as Pott's frac- 

 ture, the condition is such as has just been described in 

 connection with the effects of eversion of the foot upon 

 the fibula. That bone is always broken some two or 

 three inches above the malleolus, the deltoid ligament 

 is torn, or the tip of the inner malleolus wrenched off. 

 The astragalus is so rotated laterally that the foot is 

 much everted, its outer edge is raised, while its inner 

 edge rests upon the ground. The inferior tibio- 

 fibular ligaments remain intact. If they yield, an 

 unusual form of fracture or dislocation is produced, 

 as already stated. Boyer relates a case, considered 

 to be unique, where the foot was luxated outwards, 

 but without any fracture of the fibula. That bone, 

 however, had been forced upwards entire, and its 

 head dislocated from the articular facet of the tibia. 

 A horizontal dislocation outwards, without rotation of 

 the foot and without fracture of the fibula, is possible 

 if the inferior tibio-fibular ligaments are entirely torn. 



In Dupuytrerfs fracture (a rare injury) the fibula 



