RHEUMATOID ARTHRITIS. 211 



constitutional originating in sedentary pursuits, sudden exposure 

 to cold when the body has been over-heated, or as a sequel to 

 rheumatic fever ; the local, from habitual over-exertion of a par- 

 ticular joint, or from accident." 



Symptoms. — A singular rigidity in the affected joints, which, 

 when first moved, emit a crackling sound. The crackling sen- 

 sation, felt as well as heard in the human patient, and the 

 rigidity of the limbs, followed by pains, are very considerable at 

 the moment the patient commences to move about, particularly 

 in the morning, after the repose of the night ; and in some cases 

 there are painful spasms of the muscles. 



The veterinarian frequently finds both these symptoms, namely, 

 the crackling noise and the painful and spasmodic uplifting of 

 the limbs, especially the hind ones, in many of his patients, 

 whose joints present the other symptoms of the disease in man 

 — the swelling, pain, and tenderness to the touch. 



The swelling in and around the affected joints, w^hich is 

 noticed in the earlier stages of the disease, arises principally 

 from the increased effusion into the synovial sacs of the articu- 

 lation, a result of the chronic synovitis w^hich at this period 

 exists. In the later stages of the affection, exostotic growths 

 can be occasionally felt through the integuments. — (See Photo- 

 lithograph, Plate II., Pigs. 1, 3, and 5.) These spring from the 

 margins of the articular surfaces, as weU as from the periosteum 

 and bone in the neighbourhood of the diseased joint. In the 

 tibio-femoral articulation (stifle-joint) rims of new bones can be 

 seen to range themselves along the margin of the condyles of 

 the femur and tibia. — (See particularly Pig. 3 in the same 

 plate.) 



Articular rigidity, or false anchylosis, is not an unusual con- 

 sequence of the disease ; but true anchylosis, or the complete 

 fusion together of two bones, is exceedingly rare ; nor does the 

 disease in its ordinary course proceed to suppuration. 



The synovial bursse in the neighbourhood of the affected joint 

 are occasionally found distended, and synovial cysts become, as 

 it were accidentally, developed in the areolar tissue surrounding 

 the affected articulation, having no communication with the 

 diseased joint. As the disease advances, the fluid contained 

 in these cysts may become absorbed, and the sacs converted into 

 solid tumours. 



