LAMENESS: ITS CAISKS AND TREATMENT. 331 



culty encountered in biin«riii<j; to^i'ther the enel> of a broken femur or 

 humerus, the muscuhir contractions beini; even in these animals suffi- 

 ciently forcible to renew the displacement. 



It is generally, therefore, only fractures of the htuj; bones, and 

 then at points not in close proximity to the trunk, that may be con- 

 sitlered to be amenable to reduction. It is true that seine of the 

 more superficial bones, as those of the head, of the pehis, and of 

 the thoracic walls, may in some cases require special manipulations 

 and ajjpliances for their retention in their normal positions; hence 

 the treatment of thesi» and of a fractured le<? can not be the same. 



The methods of accomplishinjx reduction vary with the features of 

 each case, the manipulations being necessarily modified to meet dif- 

 ferent circumstances. If the displacement is in the thickness of the 

 bone, as in transvei"se fracture, the manipulation of reduction con- 

 sists in applying constant pressure upon one of the fragments, while 

 the other is kept steady in its place, the object of the pressure being 

 the reestablishment of the exact coincidence of the two bony surfaces. 

 If the displacement has taken place at an angle it will be sufficient in 

 order to ettect the reduction to press upon the summit, or apex, cf 

 the angle until its disaj^pearance indicates that the ]")arts have been 

 brought into coaptation. This method is often practiced in the treat- 

 ment of a fractured rib. In a longitudinal fracture, or when the 

 fragments are pres.-ed together by the contraction of the muscles to 

 which they give insertion until they so overlap as to correspond by 

 certain points of their circmiference, the reduction is to be accom- 

 plished by effecting the movements of extension, counter extension, 

 and coaptation. Extension is accomplished by making traction upon 

 the lower portion of the liml). Counter extension consists in firmly 

 holding oi- confining the upper or body portion in such manner that 

 it shall not be affected by the traction applied to the lower part. In 

 other words, the operator, grasping the limb below the fracture, 

 draws it down or away from the trtmk, while he seeks not to draw 

 away, but simply to hold the upper portion still until the broken 

 ends of bone are brought to their natural relative positions, when 

 the coaptation, which is thus effectetl. has only to be made permaiuMit 

 by the proper dressings to perfect the reduction. 



In treating fractures in small animals the stit-iigth of tlie hand 

 is usually sufficient for the retpiired manipulations. In the fractuie 

 of the forearm of a dog, for example, while the upper segment is 

 firndy held by one hand the lower may be giasjied by the othei' and 

 the bone itself made to serve the purjiose of a lever to bring aboJit the 

 desired coaptation. In such case that is sufficient to overcome the 

 musculai- contraction and correct the overlaj^ping or other malposi- 

 tion of the bones. If. however, the resistance can not bo oveicome 

 in this way. the upper segment may be committed to an a-sistanl for 



