142 PAETICULAR FKACTURES. 



LUXATIONS, OR DISLOCATIONS WITHOUT FRACTURE, 



Are very rare in our patients ; the most common forms are those 

 of the patella of the horse, the head of femur and carpus of the 

 dog, and that partial form which may be said to exist in what 

 is termed " knuckling over " at the fetlock in the horse. It is 

 said by some that the shoulder-joint is dislocated without frac- 

 ture in the horse, and I am inclined to think that such a thing 

 may occur, but it can only be very rarely met with ; the ana- 

 tomy of the articulation, the broad and extensive head of the 

 humerus, allowing the comparatively small glenoid cavity of 

 the scapula a freedom and extent of motion which renders dis- 

 location almost an impossibility. The following case, I think, 

 proves that the injury can take place. A horse slipped and 

 fell ; when he rose, one fore leg was found powerless, pendulous, 

 shorter than its fellow, and bulging outwards at the shoulder- 

 joint. He was taken to a stable, where he immediately lay 

 down, groaned in agony, was very restless, and unable to rise 

 to his feet. A practitioner, who was sent for, pronounced the 

 shoulder to be out; he secured the animal's other legs by 

 means of hobbles, applied ropes to the lame limb above the 

 knee and at the pastern, and had several men to pull steadily 

 at the ropes to cause extension. When all was ready, he slipped 

 his boots off, and suddenly jumped with force on the damaged 

 joint, which immediately gave a kind of crack, and the bulging 

 suddenly disappeared. The ropes and hobbles were now re- 

 moved, the horse assisted to his feet, when he was found to be 

 nearly well, and walked home, a distance of about three miles, 

 that night. I was a boy at the time, but I remember the whole 

 thing very vividly. The late Mr. Barlow was of opinion that 

 this dislocation was an impossibility; but when I mentioned 

 the above case to him, he was much struck, and confessed that 

 it was sufficient to stagger him. 



Luxation of the Patella occurs in young horses that are grazed 

 on very hilly pastures, from the mal- position in which the limbs 

 have to be constantly kept, owing to the inequality of the 

 ground. The patella is forced outwards; the internal lateral 

 ligament becomes stretched across the internal prominence of 

 the trochlea of the femur^ and is thus torn or chafed. At first, 

 the luxation is only partial, tlie patella slips in and out of its 



