bones: diseases and accidents 271 



endings and when inflamed is very sensitive to pressure and may 

 cause lameness. This condition is often difficult to determine, and 

 even an acute observer may fail to locate the point of its existence. 

 There are three forms of j)eriostitis — aseptic, pui-ulent, and fibrous. 



ASEPTIC PERIOSTITIS. 



Aseptic periostitis when it becomes chronic causes such a bony 

 enlargement (exostosis) as is seen in the callous formation following 

 the fracture of a bone. The formation of such a tumor or enlarge- 

 ment on the surface of a bone is liable to occur in any part of the 

 bone covered with periosteum, and when found in the neighborhood 

 of a joint involving two or more bones it is likely to result in their 

 union (anchylosis). 



Treatment. — Applications of cold water to check the inflammatory 

 processes is indicated for the first few days in aseptic periostitis, fol- 

 lowed by hot fomentations to hurry resorption of fluids. Massage 

 should then be given with camphor ointment, mercurial ointment, 

 soap liniment; or Lugol's solution. In the chronic form point firing 

 or a biniodid of mercury blister will be found beneficial. 



PURULENT PERIOSTITIS. 



Purulent periostitis follows wounds which reach the periosteum- 

 und become infected, as observed in compound fractures, or it may 

 result from advancing purulent conditions in neighboring structures, 

 as in foul foot. It may also occur in the course of an infectious dis- 

 ease, when small abscesses are formed under the periosteum (sub- 

 periosteal abscess). It may lead to necrosis of the bone or a fistulous 

 track from the bone to the surface. There is usually much pain and 

 fever present, and the odor from the wound is offensive. 



Treatment. — In this form of periostitis the periosteum should be 

 freely incised, followed either by continuous irrigation or frequent 

 injection of the wound with antiseptic solutions. 



FIBROUS PERIOSTITIS. 



This form of the disease consists in the thickening of the outer 

 layer of the periosteum from the inflammation reaching it from 

 neighboring structures. This newly fomied fibrous tissue may be- 

 come ossified or may transmit the inflammation to the deeper bony 

 structures. It is frequently seen in cases where there has been an 

 intense inflammation of the skin close to an underlying bone. 



Treatment. — The treatment should follow that recommended for 

 aseptic periostitis. 



