558 



APPLIED ANATOMY. 



with the lower fibular fragment. It is to be noted that in this fracture the foot, with 

 the small fragments of tibia and fibula, is practically loosened from the bones of the 

 leg, and the muscles of the calf being unopposed pull the foot backward and upward. 

 Therefore the displacement of the foot is not only outward, but also backward and 

 upward (Fig. 573.) 



Fracture by Inversion. This is practically the opposite of the former and is 

 not so frequent. The fibula is fractured by the traction of the external lateral liga- 

 ments which remain intact; it may break either above or below the strong inferior 

 tibiofibular ligaments. The internal malleolus may also be torn off. The displace- 

 ment is toward the inner side and upward and backward (Fig. 574). 



Treatment. -In these fractures of the ankle replacement is often difficult and 

 resultant deformities frequently cause considerable subsequent disability. For this 



reason especial efforts are to be made to reduce 

 the displacement and maintain the fragments in 

 proper position. 



There are two main points of difficulty. The 

 fractured ends of the fibula become displaced an- 

 teroposteriorly and also in the fracture by ever- 

 sion (Pott's) become pushed inward toward the 







FIG. 573. Pott's fracture of the fibula, showing eversipn of the FIG. 574. Illustrating fracture of the 

 foot, point of fracture of the fibula, and tearing off of the point of the fibula by inversion of the foot, 



internal malleolus. 



tibia. The deep fascia of the leg is attached to the fibula and its sharp broken ends 

 may get so fastened or caught in this fascia as to require an open incision before 

 they can be freed sufficiently to allow of their proper replacement. Another difficulty 

 is in the reduction of both the lateral and posterior displacement. Here it is neces- 

 sary first to relax the muscles of the calf by flexing the leg on the thigh, then by 

 pulling and direct pressure the foot can often be replaced. If this fails tenotomy of 

 the tendo calcaneus (Achillis) is to be done, which relaxes the parts still more by 

 releasing the pull of the soleus, the gastrocnemius and plantaris being already re- 

 laxed by flexion of the knee. This is sometimes necessary to prevent the persistent 



