328 



for the retention of the parts after reduction would be next to impos- 

 sible. The prognosis is sufficiently grave from any point of view for 

 the luckless animal with a dislocated shoulder. 



The hip joint— This joint partakes very much of the characteristics 

 of the humero-scapular articulation, but is more strongly built. The 

 head of the thigh bone is more separated, or prominent and rounder in 

 form, and the cup like cavity or socket into which it fits is much deeper, 

 forming together a deep, true ball-and-socket joint, which is, moreover, 

 reenforced by two strong cords of funicular ligaments, which unite them 

 together. It will be easily comprehended, from this hint of the anatomy 

 of the region, that a luxation of the hip joint must be an accident of 

 comparatively rare occurrence. And yet cases are recorded in which 

 the head of the bone has been affirmed to slip out of its cavity and as- 

 sume various positions, inwards, outwards, forwards, and backwards. 



The indications of treatment are those of all cases of dislocation. 

 When the reduction is accom])lished the surgeon will be apprised of 

 the fact by the peculiar snapping sound usually heard on such occasions. 



Pseuflo luxations of the imtella. — This is not a true dislocation. The 

 stifle bone is so peculiarly articulated with the thigh bone that the 

 means of union are of sufficient strength to resist the causes which 

 usually give rise to luxations. Yet there is sometimes discovered a 

 peculiar pathological state in the hind legs of animals, the effect of 

 which is closely to simulate the manifestation of many of the general 

 symptoms of dislocations. This peculiar pathological condition origin- 

 ates in muscular cramps, the action of which is seen in a certain change 

 in the coaptation of the articular surfaces of the stifle and thigh bone, 

 resulting in the exhibition of a sudden and alarming series of symptoms 

 which have suggested the phrase of " stifle out" as a descriptive term. 

 The animal so affected stands quietly and firmly in his stall, or perhaps 

 with one of his hind legs extended backwards, and resists every attempt 

 to move him backwards, and if urged to move forwards he will either 

 refuse or comply with a jump, with the toe of the disabled leg dragging 

 on the ground and brought forward by a second effort. There is no 

 flexion at the hock and no motion at the stifle, while the circular motion 

 of the hip is quite free. The leg appears to be much longer than the 

 other, owing to the straightened position of the thigh bone, which forms 

 almost a straight line with the tibia from the hip joint down. The 

 stifle joint is motionless, and the motions of all the joints belbw it are 

 more or less interfered with. External examination of the nmscles of 

 the liip and thigh discovers a certain amount of rigidity, with perhaps 

 some soreness, and the stifle bone may be seen projecting more or less 

 on the outside and upper part of the joint. 



This state of things may continue for some length of time and until 



treatment is applied, or it may spontaneously and suddenly terminate, 



lenving everything in its normal condition, but perhaps to return again. 



Pseudo dialocatiou of the patella is likely to occur under many of 



