CAUSES OF FRACTURE. 79 



with the fracture, there is serious injury of the adjoining 

 structures, as laceration of vessels, open joint, or serious con- 

 tusion of the tissues; fracture with wound, when the wound 

 does not communicate with the fracture; impacted, when one 

 fragment is lodged in the other ; and partial, when the con- 

 tinuity of only a part of the bone is broken. This last variety 

 has been called by some lending, with partial fracture, and 

 by others green-stick fracture. Bending may take place with- 

 out fracture, but this, as well as bending with partial fracture, 

 is very rare in our patients, although I have seen it both in 

 dogs and young horses. 



THE SYMPTOMS OF FRACTURE. 



When fracture occurs in one or more bones of a limb, the 

 symptoms are — great lameness suddenly manifested, obvious 

 deformity (with some exceptions, to be mentioned), preternatural 

 mobility, crepitus, and inability to bear weight upon that limb. 

 These are the general symptoms; the particular ones, as well 

 as the causes of the several fractures, will be hereafter described, 

 and it will therefore be unnecessary to refer to them under this 

 head. 



MODES OF UNION. 



The injury inflicted in a fracture is rarely limited to the bone. 

 The two or more fragments, driven in opposite directions, pene- 

 trate and wound the adjacent tissues, giving rise to more or less 

 less hsemorrhage. If the skin is broken, suppuration generally 

 foUows, and the repair is attended with difficulty ; but if the 

 injuries are subcutaneous, and the air has no access to the 

 damaged part, the repair is more easily effected. 



The extravasation of blood about fractures is not only uncer- 

 tain in amount, but unequal in the several tissues. Its presence 

 is useful for diagnosis, particularly in the diagnosis of fracture of 

 the humerus. 



A ridiculous idea has prevailed amongst horsemen, that 

 fi^actured bones in the horse never unite. This is incorrect, 

 and, owing to the same tendency that produces splints, spavins, 

 &c., the process of union and repair is a very rapid and efficient 

 one, provided the solution of continuity does not extend into a 



