FEACTUKES IN GENERAL. 295 



COURSE OF UiNION.— The following are the stages of the union of a broken 

 bone. (1) The period of inflammation and exudation lasting for about three 

 days. (2) Tlie external and (if the bone be hollow) internal encasing of the 

 broken ends by soft material, which is completed in about the twelfth day. 

 (3) The conversion of the soft encasing material into bone, which holds the 

 parts together for the time being, and which is called the provisional callus. 

 This stage wiU be finished at about the end of a month. (4) The formation, 

 between the broken ends, of material, which on becoming converted into 

 bone (definite callus), completes the union of the separated parts, and 

 which commences after the provisional callus has become sufficiently strong 

 to check movement in the part. This process would probably require 

 a couple of months for its full accomplishment, but it cannot take place 

 if movement in the broken ends of the bone be set up from time to time. 

 (5) The absorption of excess of callus, which requires several months to 

 complete its course, and even then is almost certain to leave more or less 

 roughness and thickening of bone. 



The foregoing details hold good in compound fracture, in which repair is 

 generally delayed by suppuration. 



FIBROUS UNION OF FRACTURE AND FALSE JOINT.— In fibrous 

 union, the reparative material which is formed between the broken ends, 

 instead of becoming converted into bone, is changed into fibrous tissue, 

 usually on account of the disturbing influence of frequent movement. In 

 false joint, fibrous tissue forms a capsule round the broken ends, which, by 

 rubbing against each other while being thus held together, make a more or 

 less effective joint. 



GENERAL SYMPTOMS OF FRACTURE.— Sudden and great 

 lameness ; deformity of the part with or without abnormal 

 mobility ; pain ; and fever. Grating (crepitus) may be felt, or 

 even heard when the broken surfaces rub together. When there 

 is fracture without displacement, there is often very little to show 

 what is amiss as long as the animal is kept quiet. The symptoms, 

 thpn, are somewhat similar to those of violent sprain. Here, the 

 absence of injury to other parts will generally help us in our 

 investigation. When feeling the part, great care should be taken 

 not to separate the divided ends, if there be no displacement ; nor 

 to convert a simple fracture into a compound one, which is far 

 more dangerous and more difficult of cure, by reason of the entrance 

 into the wound of putrefactive germs from without, as well as by 

 the increased extent of the injury. 



GENERAL TREATMENT OF FRACTURES.— If there be dis- 

 placement, the broken ends of the bone should be brought together, 

 and the part placed in as natural a position as possible. If there 

 be compound fracture, the wound should be thoroughly syringed 

 out with some suitable antiseptic (p. 67), which will disinfect it 

 as well as clean it. Drainage (p. 75) should be secured, and the 

 wound should be treated antiseptically (p. 74) until it becomes 

 healed. All completely separated fragments of bone, in the case 

 of comminuted compound fracture, should be removed ; but those 



