50 



SURGERY. 



also in bringing the head of the bone into such a situation that the 

 action of the muscles may draw it into its place. 



Constitutional means are often necessary to effect reduction in 

 the larger joints, such as bloodletting, warm baths, emetics, in order 

 to produce relaxation of the muscles. The local means are ex- 

 tension and counter-extension. The extension must be made gra- 

 dually, in order to overcome the action of the muscles, and to place 

 the head of the bone in such a situation as to be drawn into its place, 

 and the extension must be withdrawn suddenly, in order that the 

 muscles may leave the effect by their contraction. 



The treatment subsequent to the reduction consists in maintaining 

 the limb at rest, and applying leeches and cold applications to re- 

 move swelling and pain. Afterwards, if any stiffness remains, 

 stimulating friction may be used. 



Subluxation implies a partial removal of the head of a bone from 

 an articulating surface. Recent and old, are terms applied to luxa- 

 tions with reference to the period which may have elapsed, and the 

 changes which may have occurred by adhesions, &c. 



Compound Luxation. — This is connected with a wound in the 

 integuments, fracture of bone, laceration of large vessels, &c. The 

 same principles apply as in compound fracture. The same contin- 

 gencies of age, temperament, and constitution, will influence the 

 treatment. The question of amputation is first to be considered, and 

 then the reduction. The after treatment would be that for a wound 

 of the joint : careful closure of the wound, — prevention of inflam- 

 mation by antiphlogistic means ; if possible preventing suppuration, 

 anchylosis, and tetanus. 



DISLOCATION OF THE JAW. 



Dislocation of the jaw may be caused by spasm of the pterygoid 



muscles when yawning. 



Fig. 9. 



or by a blow on the chin 

 when the mouth is wide 

 open. The condyles are 

 pushed forwards, and rest 

 in front of the base of the 

 zygomatic process of the 

 temporal bone. 



Symptoms. — The mouth 

 gapes and cannot be shut, 

 the glenoid cavity is va- 

 cant, and there is a 

 prominence felt beneath 

 the zygoma ; — the saliva 

 trickles, articulation is pre- 

 vented, and there is great 

 pain. 



