60 SURGERY. 



DISLOCATION AT THE ANKLE. 



This accident is usually the result of severe force, and accom- 

 panied by fracture of the malleoli. The displacement may be for- 

 ward, backward, inward, and outward. 



Dislocation of the tibia inivard is the most frequent, and owing 

 to a fracture of the external malleolus, the foot is everted and the 

 internal malleolus greatly projects. 



Reduction is effected by extension of the foot and flexion of the 

 leg, so as to relax the gastrocnemius muscle. Dislocation of the 

 tibia outward is occasioned by a fracture of the internal malleolus, 

 and the deformity is the reverse of the last. Dislocation backwards 

 may result from a fracture of the posterior extremity of the astra- 

 galus, in which instance the foot is inverted as in varus ; this is 

 more rare than dislocations forward, which result from fractures of 

 the lower end of the fibula. There is danger of suppuration and 

 gangrene, especially if connected with an external wound. Ampu- 

 tation will often be the best resort, particularly when the constitution 

 of the patient is bad. 



DISLOCATION OF THE BONES OF THE FOOT. 



The astragalus is more frequently dislocated than any bone of 

 the tarsus ; and it may either be forward or backward. Unless re- 

 duction can be effected, which is difficult, excision of the bone may 

 be necessary, or amputation at the ankle. Dislocation of the other 

 bones of the tarsus are usually compound injuries, and are to be 

 treated upon general principles. 



INJURIES OF THE HEAD. 



THE SCALP. 



Contusion of the scalp may be very severe, on account of its 

 being stretched over the resisting bony surface of the cranium, and 

 being frequently connected with a lacerated wound. Owing to its 

 vascularity, great swelling will occur from extravasation of serum or 

 blood ; in many instances a fluctuating tumour being produced be- 

 neath the integuments. The swelling which results being readily 

 depressed in the middle, may give rise to the idea of a fracture, 

 which is to be carefully diagnosticated. 



The treatment will require cold applications. In no instance is a 

 coawulum of blood to be evacuated by incision or puncture ; but ab- 

 sorption is to be promoted and depended upon, even if slow and 

 tedious. It may be that the clot will produce inflammation and 

 suppuration ; then a free incision should be made, and the exit of the 

 pus favoured. Healthy granulation contracts the cavity, and the 

 wound unites by the formation of a cicatrix. 



