THE STUDY OF THE MUSCULAR SYSTEM 85 



163. Stifle-joint. — Independent of the disease of the bones that 

 enter into the formation of this joint (par. 113), the soft structures 

 in connexion with it are frequently the seat of injury and disease. 

 Some breeds of horses are more susceptible to contract diseases and 

 enlargements of this joint than others. Young animals— more par- 

 ticularly of the cart-horse class— are subject to big or distended 

 joints, known as ' stifled, 1 or luxation of the patella (Plate IX. t 

 No. 30). 



164. Luxation of the Patella is a partial displacement of the cap 

 of the stifle joint, and is of a hereditary nature. The young animals, 

 which suffer, as a rule, are very poor, and bad thrivers ; and when 

 they stir or walk about, the patella, or cap, slips partly off the joint 

 towards the outside, making a knocking noise. Very hilly pastures 

 are thought to favour the development of the trouble in young 

 horses. The treatment consists of repeated blistering, which some- 

 times does good, and putting on of a special shoe, thin at the heels, 

 but with a thick projecting toe. But so unsatisfactory, as a rule, are 

 the various forms of treatment that the best plan is to destroy the 

 animal, as it scarcely pays to bring it up for work, and it is of no 

 good to breed from. 



165. Dislocation of the Patella is a displacement of the patella 

 or cap of the stifle joint. Horses and cows sometimes throw off the 

 cap by jumping up too suddenly. When dislocation takes place, the 

 cap comes to the outside, on account of the ridge on the femur being 

 less on the outside than on the inside. The leg is extended behind 

 in a rigid condition, the front of the point of the toe resting on the 

 ground with the sole of the foot looking upwards and backwards 

 (Plate X.). If in the stall, the- animal must be got into the yard, a 

 neck-collar put on, and a strong rope passed through the bottom of 

 the collar, between the fore-legs, and tied round the pastern joint of 

 the dislocated limb. The foot must then be pulled forcibly forward 

 under the belly until the sole can rest flat on the ground ; the cap 

 must now be manipulated to the front and held there, when, on the 

 horse stepping forward, it readily drops into its place. A good 

 blister should be applied, and the animal tied up short for a week or 



