216 OPERATIONS ON BONES. 



powerlessness -svill vary according to tlie kind of fractui-e and tlie 

 bone wliicli is injured. For example, a fracture of the cannon 

 bone without displacement, or of one of the phalanges which are 

 siH"rounded and sustained by a complex fibrous structru'e, is, in a 

 certain degree, not incompatible with some amount of resting of 

 the foot. But, on the contrary, if the shank bone, or that of the 

 forearm be the impHcated member, it would be vei-y difficult for 

 the leg to exercise any agency whatever in the support of the 

 body. And in a fracture of the lower jaw, it woiold be ob\dously 

 futile to expect it to contribute materially to the mastication of 

 food. 



A fracture seldom occurs which is not accompanied with a 

 degree of deformity, greater or less, of the region or the leg 

 affected. This is due to the exudation of the blood into the 

 meshes of the surrounding tissues and to the displacement which 

 occurs between the fragments of the bones, with subsequently 

 the swelling which follows the inflammation of the surrounding 

 tissues. The character of the deformity will mainly depend upon 

 the manner in which the displacement occurs. 



In a normal state of things the legs perform their movements 

 with the joints as their only centres or bases of action, wath no 

 participation of intermediate points, while with a fractm'e the 

 flexibility and motion which will be observed at unnatural points 

 are among the most strongly characteristic signs of the lesion. 

 No one need be told that when the shaft of a limb is seen to bend 

 midway between the joints, with the lower portion swinging 

 freely, that the leg is broken. But there are still some conditions 

 where the excessive mobility is not easy to detect with certainty. 

 Such are the cases where the fracture exists in a short bone, near 

 a movable joiut, or in a bone of a region where several short and 

 small bones are united in a group, or even in a long bone where 

 its situation is such that the muscular covering prevents the 

 visible manifestation of the symj)tom. 



If the situation of a fractui'e precludes its discovery by means 

 of this abnormal flexibiUty, other detective methods remain. And 

 after all there is one decisive sign which, though it may not avail 

 in every case, as it does not, is in cases where its testimony can 

 be secured absolute and positive beyond question. This is crep- 

 itation, or the peculiar effect which is joroduced by the friction 

 of the fractured surfaces one against another. Though discerned 



