792 LUXATION OF THE ELBOW-JOINT. 



are less often reported than the successes, and the former probably 

 exceed the latter at Least tenfold. Complicated fractures are treated 

 on general principles. 



III.— LUXATION OF THE ELBOW JOINT. 



In large animals, luxation of the elbow-joint is impossible without 

 previous rupture of the powerful lateral ligaments ; in the horse, 

 fracture of the ulna is then usually produced. According to Rigot, 

 luxation occurs during flexion, on account of the force acting on the 

 ulna. It is exceedingly rare in animals. Such cases have, however, 

 been described in the horse. In one the internal lateral ligament 

 was ruptured in consequence of a fall. The limb could be abducted 

 to an abnormal degree. The horse recovered almost perfectly ; 

 in five weeks only a slight " swinging leg " lameness was noticeable. 



A mule carrying a very heavy load of barley slipped and fell. 

 The left leg, from the elbow downwards, was doubled under the 

 body, and when the animal was lifted the head of the radius and 

 the ulna were thrust to the inner side of the inner condyle of the 

 humerus ; that is to say, the lower extremity of the humerus over- 

 lapped the upper end of the radius. 



In another case a horse fell on its left side, with the corresponding 

 leg in a doubled-up position ; on rising the fore-arm pointed obliquely 

 forwards and outwards, the limb below the fetlock hung limply 

 downwards. In this instance the head of the radius was outside 

 the condyle of the humerus. 



Luxation of the radius outwards in dogs has been referred to the 

 fact that the articular surfaces slope downwards and inwards, and 

 the internal lateral ligament is particularly strong. 



Distortion is very uncommon, on account of the effective limiting 

 apparatus of the joint — the strong lateral ligaments and beak of 

 the ulna. Hertwig insists that in carnivora both complete and 

 incomplete displacement may occur in the elbow-joint, and either 

 inwardly or outwardly, without fracture. Moller only saw such 

 displacements as congenital conditions, occurring simultaneously 

 in both limbs, and associated with deformity both of the elbow- 

 and knee- joints. The animals are generally killed as hopeless 

 cripples. 



The diagnosis of displacement is not difficult, as there is always 

 extensive rupture of soft tissues. 



Prognosis and course. In carnivora, cases do well provided they 

 are treated early and the joint is not involved. The mule and one 



