DISLOCATIONS. 



263 



series of movements which would be simply impossible with the 

 joint in a state of integrity. Both fractures and luxations are 

 marked by deformity, but whUe in a fracture with displacement 

 there will usually be a shortening of the leg, a dislocation may be 

 accompanied by either a shortening or a lengthening. SweUing 

 of the parts is usually a well-defined feature of these injuries. 



With aU this similarity in the symptomatology of luxations 

 and fractures, there is one sign which either by its presence or its 

 absence wiU greatly assist in settUng a case of differential diag- 

 nosis, and this is the existence or lack of crepitation. It has no 

 place or cause in a mere dislocation; it belongs to a fracture, if it 

 is a complete one. If there is crepitation with a dislocation then 

 it proves that there is a fracture also. 



The prognosis of a luxation is comparatively less serious than 

 that of a fracture, though at times the indications of treatment 

 may prove to be so difficult to apply that compUcations may arise 

 of a very severe character. 



The treatment of luxations must of course be similar to that 

 of fractures. Reduction, naturally, wUl be the first indication in 

 both cases, and the retention of the replaced parts must follow. 

 The reduction involves the same steps of extension and counter- 

 extension performed in the same manner, with the patient subdued 

 by anesthetics. 



The difference between the reduction of a dislocation and that 

 of a fracture consists in the fact that in the former the object is 

 simply to restore the bones to their true normal position, with 

 each articular surface in exact contact with its companion surface, 

 the apparatus necessary afterwards to keep them in situ being 

 similar to that which is employed in fractiire cases, and which wUl 

 usually require to be retained for a period of from forty to fifty 

 days, if not longer, before the ruptured retaining Hgaments are suffi- 

 ciently firm to be trusted to perform their office unassisted. A vari- 

 ety of manipulations are to be employed by the surgeon, consisting 

 in pushing, puUing, pressing, rotating, and indeed whatever move- 

 ment may be necessary, untU the bones are forced into such rela- 

 tive positions that the muscular contraction, operating in just the 

 right directions, puUs the opposite matched ends together m true 

 coaptation, a head into a cavity, an articular eminence mto a 

 trochlea, as the case may be. The " setting" is accompamed by a 



