CHAPTEE XI 



DISEASES OF THE BONES 



A. PERIOSTITIS AND OSTITIS. 

 We head this section, Periostitis and Ostitis, for the reason 

 that in actual practice it is rare for one of these affections 

 to occur without the other. The periosteum and the bone 

 are so intimately connected that it is difficult to conceive of 

 disease of the one failing to communicate itself in some 

 degree to the other. Pathologically, however, and for 

 purposes of description, it is more convenient to describe 

 separately the abnormal changes occurring in these two 

 tissues. 



With the main phenomena of inflammation occurring 

 elsewhere we presume our readers are aware. Briefly we 

 may put it, that under the action of an irritant, either 

 actual injury, chemical action, or septic infection, the healthy 

 tissues around react in order to effect repair of the parts 

 destroyed. Also that this reaction involves the distribution of 

 a greater blood-supply to the part, with an abundant migra- 

 tion of leucocytes, and the outpouring of an inflammatory 

 exudate, together with symptoms of heat, pain, redness, and 

 swelling of the affected area. And that in chronic inflamma- 

 tions, owing to persistence of the cause, the process of repair 

 thus instituted does not stop at mere restoration of lost 

 tissue, but continues to the extent of forming an abnormal 

 quantity of such tissue as normally exists in the parts 

 implicated. 



The process of inflammation in bone is essentially the 

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