311 



siirfa,ces. If the displacemeut has taken plaec at an angle it will be 

 sufficient in order to effect the reduction to x)ress upon the summit or 

 apex of the angle until its disappearance indicates that the parts have 

 been brought into coaptation. This method is often i)racticed in the 

 treatment 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 thej^ so overlap as to correspond by 

 certain i)oints 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 i^ortion of the limb. Counter-extension consists in firmly 

 holding or confining the upper or bodj' portion in such a manner that 

 it shall not be affected by the traction applied to the lower; in simj)ler 

 language, holding it motionless against the force exercised in the 

 extension. 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 simi)ly to hold still the upper portion 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 per- 

 manent 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 a case that is sufficient to overcome the muscular 

 contraction and correct the overlapping or other malposition of the 

 bones. If, however, the resistance can not be overcome in this mode, 

 the upper segment may be committed to an assistant for the manage- 

 ment of the counter extension, leaving to the operator the free use of 

 both hands for the further manipulation of the case. 



But if the reduction of fractures in small animals is an easy task, it 

 is far from being so when a large animal is the x>atient, whose mus- 

 cular force is largely greater than that of several men combined. In 

 such a case resort must be had not only to superior numbers for the 

 necessary force, but in many cases to mechanical aids. A reference 

 to the mode of proceeding in a case of fracture with displacement of 

 the forearm of a horse will illustrate the matter. The j)atient is first 

 to be carefully cast, on the uninjured side, with ropes, or a broad 

 leather strap about 18 feet long, passed under and around his body 

 and under the axilla of the fractured limb and secured at a point 

 oiDposite to the animal and toward his back. This will form the 

 mechanical means of counter extension. Another rope will then bo 

 placed around the inferior part of the leg below the point of frac- 

 ture, with which to produce extension, and this will sometimes be fur- 

 nished with a block or pulleys, in order to augment the power when 



