lameness: its causes and tbeatment. 331 



culty encountered in bringing together the ends of a broken femur or 

 humerus, the muscular contractions being even in these animals suffi- 

 ciently forcible to renew the displacement. 



It is generally, therefore, only fractures of the long bones, arid 

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

 sidered to be amenable to reduction. It is true that some of the 

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

 the thoracic walls, may in some cases require special manipulations 

 and appliances for their retention in their normal positions; hence 

 the treatment of these and of a fractured leg can not be the same. 



The methods of accomplishing 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 transverse 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 effect the reduction to press upon the summit, or apex, of 

 the angle until its disappearance indicates that the parts 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 pressed together by the contraction of the muscles to 

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

 certain points of their circumference, 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 limb. Counter extension consists in firmly 

 holding or 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 trunk, 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 effected, has only to be made permanent 

 by the proper dressings to perfect the reduction. 



In treating fractures in small animals the strength of the hand 

 is usually sufficient for the required manipulations. In the fracture 

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

 firmly held by one hand the lower may be grasped by the other and 

 the bone itself made to serve the purpose of a lever to bring about the 

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

 muscular contraction and correct the overlapping or other malposi- 

 tion of the bones. If, however, the resistance can not be overcome 

 in this way, the upper segment may be committed to an assistant for 



