INJURIES OF THE JOINTS. 285 



joint, too much for the Dorrnal condltioD, the animal evinces great 

 pain on movement. This dislocation is easily corrected. The 

 joint may be moved freely, but as soon as the animal stands upon 

 its feet again the displacement recurs. This is due to the annu- 

 lar ligament, which holds the joint to the forearm in place, being 

 torn. If this dislocation is not reduced and left for some time, the 

 leg will be held constantly in a flexed position, and the animal 

 will not use it. 



In cases of lower dislocation of the joint the animal walks upon 

 three legs, and on examination we find that the lower end of the 

 bone of the forearm is displaced in a posterior direction, and more 

 rarely in an anterior direction. This dislocation is easily reduced, 

 but on the slightest movement reappears again. The prognosis is 

 not favorable, as it is a rather difficult condition to treat. The 

 weak ligaments (the annular ligament and transverse ligaments) 

 do not heal quickly, and the dislocation has a tendency to become 

 chronic, especially in the upper joint. 



Teeatjient. In the treatment of the upper joint the forearm 

 becomes extended and the legs should be crossed and an attempt 

 made to push the forearm backward and outward into its normal 

 position. It must then be held there by means of a tight bandage. 

 This bandage must be changed once a day, as it is apt to produce 

 tenderness of the skin from being so tight. If the dislocation 

 affects the lower joint, the bone of the forearm will have to be 

 pushed into its normal condition with more or less force and a sili- 

 cate of sodium bandage applied. 



Dislocation of the Patella. Stockfleth states that the patella 

 may become dislocated on both sides, but not upward, and that 

 the dislocation is generally on the inner side, on account of the 

 forced extension of a very much flexed tarsus and a tendency of 

 the muscles to turn inward. This is seen occasionally in circus 

 dogs (grayhounds) making high jumps. In cases of inside dislo- 

 cation the patella lies ou the inner side of the joint where it moves 

 on the tibia, and in external dislocation it lies on the outside of 

 the external condyle. 



Inner Dislocation of the Patella. In the early stages, shortly 

 after the dislocation occurs, the animal holds its leg iu a very flexed 

 position. The hock is flexed and the heel turned outward. At 

 the joint the patella may be found lying sideways, and is easily 



