INJURIES OF THE JOINTS 347 



with spirits of camphor or soap Hniment, ak-ohol, etc., but it must be 

 borne in mind that rest is the most important treatment. 



Luxations of the Joint (Dislocations). — While distortions of the 

 joints disappear in a short time when the luxation is reduced, if it is not 

 reduced it is lasting, for soon some anatomical change occurs that it is im- 

 possible to reduce. If both surfaces of the joint are no longer in contact, 

 it is called an entire dislocation. If they are partially in contact, it is 

 called an incomplete luxation (subluxation). 



The causes of dislocation are, as a rule, mechanical, from falling out 

 of windows, jumping from high objects, getting the foot caught, and 

 hanging, as in jumping over a fence; concussions and blows by being 

 run over by vehicles, etc. In all dislocations there is invariably laceration 

 of the capsular ligament. This membrane only remains intact in dis- 

 locations of the lower jaw. As a rule, the accessory ligaments are seldom 

 torn except in such cases where a portion of the bone is torn with them. 

 The cartilage of the joint may be torn or detached in some cases by 

 the subsequent inflammation. The ends of the bones may be unaffected 

 and in some cases broken. Other alterations are seen in the muscles and 

 tendons in the neighborhood of the joint. They are abnormally ex- 

 tended on one side and flabl^y on the other side. They may be torn, 

 lacerated, or even crushed. It is only in rare instances that the large 

 blood vessels and nerves are lacerated. The joints which are dislocated 

 are surrounded by a large quantity of blood which infiltrates the tissues 

 and is gradually reabsorbed. 



When the reduction is not performed quickly — that is to say, the 

 displaced end of the joint remains in its abnormal position — we have 

 what is called nearthrosis as a consequence of the irritation which it 

 produces in the immediate neighborhood of the joint. In such a case 

 there is slight immobility due to partial adhesions of the affected part, 

 and also due to a certain extent to atrophy of the muscles surrounding it. 

 In some cases motion of the joint is entirely lost. 



Clinical Symptoms and Prognosis. — When a dislocation has just 

 occurred, and Avhen it has been there for some time, the symptoms are 

 more marked than they are in the intermediate stage, for the reason 

 that the hemorrhage produces so much swelling as to render obscure, 

 to a certain extent, the position and character of the luxation. In 

 some cases the condition can be very easily recognized by comparing it 

 with the perfect joint on the other side; at other times, it is only by 

 careful manipulation in the region of the joint that the alteration can l)e 

 felt. We may find a projection of bone at one place and depression in 

 another, where they do not occur in the healthy side. We may even feel 

 the luxated end of the joint. In some cases where the deformity has been 

 concealed by the rapid swelling of the surrounding tissues, the leg may 



