CHAPTER IV. 



FRACTURES AND DISEASES OF BONES. 



CAUSES OF FRACTURE SYMPTOMS — MODES OF UNION TREATMENT OP 



FRACTURES — COMPOUND FRACTURES SEPARATION OF EPIPHYSES 



FALSE JOINTS AND NON-UNION. 



A FRACTURE is said to occur in three ways : — Isf. By external 

 violence, operating directly upon the injured part: 2d. By 

 external violence, producing such concussion upon the bone 

 as not to break it where the force is applied, but at some 

 other part: 3d. By inordinate action of the muscles, as in 

 broken back. But some bones are more liable to fracture than 

 others. The bones of the pelvis, shoulders, thighs, pasterns, legs, 

 vertebrae, and of the face and skull, seem to be more frequently 

 broken than the other bones of the horse. In the dog, the 

 lea and thi^h bones. Althouoh bones are fractured in animals 

 of aU ages, it is worthy of notice that the bones of the old are 

 more readily broken than those of the young. 



Bones are rendered liable to fracture from trivial causes by a 

 previously diseased condition. The navicular bone, by a peculiar 

 atrophy or caries. The os pedis, by atrophy and fragility, induced 

 by chronic inflammation ; and the pelvic bones, by a degenerative 

 disease, partaking of the nature of fragilitus ossium and necrosis. 



A solution of continuity of bone (fracture) may be transverse, 

 oblique, or longitudinal, according as it is at a right or an acute 

 angle with, or parallel to, the long axis of the part of the bone 

 in which it is situated. A fracture is said to be simple when 

 a bone is broken at one part, without any injury of soft parts ; 

 compound or open, when there is an open wound communicat- 

 in<y with the broken bone ; comminuted, when the bone is 

 broken into several fragments ; complicated, when, together 



