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CHAPTER XI. 



Diseases of Bone, Joints, and Cartilage. 



(JKNERAL REMAllKS — SPLINTS — ENLAEGEMENT OF THE SPLINT BONES — SORE 

 SHINS — RINGBONE — BONE SPAVIN — OSTEOPOROSIS — RICKETS — RHEUMATOID 

 JOINT DISEASE— STIFF JOINTS AND KNUCKLING OVER — SIDE BONES. 



General Remarks. 



Inplammatiox of bone follows the same course as inflamTnation in other 

 tissues, allowing for difference in structure. It may originate, as far as I can 

 see : (1) from irritation due to the tearing away of the points of attachment 

 of the bone with tendon or ligament inserted on it ; (2 ) from direct injury, as 

 from blows ; (3) from indirect injury, as from concussion ; (4) from com- 

 pression ; (5) from changes brouglit on by chill, which changes are generally 

 ascribed to rheumatism; and (6) from infect'on. Goubaux and Barrier state 

 that " it is important to remember that tumours of bones which are the results 

 of ' work,' appear only at the points of imertion of the great articular liga- 

 ments ; because it is at these particular points that strain and distension 

 impressed on the part, spreads to the periosteum and fetsup inflammation in 

 it. The irritation extends gradually and soon finishes by invading all the 

 bony surfaces which are covered by these ligaments." This explanation, 

 though undoubtedly correct in accounting for the occurrence of splint, jarde, 

 ringbone, and probably curb, does not furnish us with the cause of sore shins, 

 navicular disease and bony tumours (enlargements) due to blows ; for the 

 inflammation in these cases does not necessarily originate at the points of 

 insertion of the ligaments of joints. 



We may have the formation of pus on the outside or inside .'urface of the 

 periosteum (the membrane which covers a bone), or in the substance of the 

 bone. When the suppuration is on the outside of the periosteum, the tissues 

 which cover the periosteum will be swollen and the pus will be watery and 

 more or less tinged with blood. If it be beneath that membrane, the pus may 

 force the thickened and inflamed periosteum aw\ay from the bone. If the pus 

 invades the fubstance of the bone, it Avill be red in colour and may give rise 

 to death of the invaded portion of the bone by reason of its interference with 

 the local circulation. Whether the pus forms on the inside surface of the 

 periosteum or in the substance of the bone, the bone, if it can be felt or seen, 

 will be found to be swollen and the part extremely painful on account of the 

 resulting pres.-^ure on the nerves. In all cases, the pus will corrode the tis.'ues 

 with which it is in contact, and thus will tend to work its way to the surface 

 by gravitation. Any dead portion of bone will in time become separated 

 from the living bone, and will become more or less dissolved by the pus which 

 surrounds it. If we have reason to fear that pus is beginning to form either 



