DISLOCATIONS. 339 



position of the thigh bone, which forms idniost a straiglit line with 

 the tibia from the hip joint down. The stifle joint is motionless, and 

 the motions of all the joints below it are more or less interfered with. 

 External examination of the muscles of the hip and thigh reveals 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, 

 leaving evervthing in its normal condition, but perhaps to return 

 again. 



Cause. — Pseudo-dislocation of the patella is likely to occur under 

 many of the conditions which cause actual dislocation, and yet it may 

 often occur in animals which have not been exposed to the ordinary 

 causes, but which have remained at rest in their stables. Sometimes 

 these cases are assignable to falls in a slippery stall, or j^erhaps slip- 

 ping when endeavoring to rise ; sometimes to weakness in convalescing 

 patients; sometimes to lack of tonicity of structure and general de- 

 bility; sometimes to relaxation of tissues from want of exercise or use. 

 A straight leg, sloping croup, and the young are i^redisposed to this 

 dislocation. 



Treatment. — The reduction of these displacements of the patella is 

 not usually attended with difficulty, A sudden jerk or spasmodic 

 action will often be all that is required to spring the i^atella into 

 place, when the flexion of the leg at the hock ends the trouble for the 

 time. But this is not always sufficient, and a true reduction may still 

 be indicated. To effect this the leg must be drawn well forw^ard by 

 a rope attached to the lower end, and the patella, grasped with the 

 hand, forcibly pushed forward and inward and made to slip over the 

 outside border of the trochlea of the femur. The bone suddenly slips 

 into position, the excessive rigor of the leg ceases with a spasmodic 

 jerk, and the animal may walk or trot away without suspicion of 

 lameness. But though this may end the trouble for the time, and 

 the restoration seem to be perfect and j)ermanent, a repetition of the 

 entire transaction may subsequently take place, and perhaps from the 

 loss of some proportion of tensile power which would naturally fol- 

 low the original attack in the muscles involved the lesion might 

 become a habitual weakness. 



Warm fomentations and douches with cold water will often pro- 

 mote permanent recovery, and liberty in a box stall or in the field 

 will in many cases insure constant relief. The use of a high-heeled 

 shoe is recommended by European veterinarians. The use of stimu- 

 lating liniments, with frictions, charges, or even severe blisters, may 

 be resorted to in order to prevent the repetition of the difficulty by 

 strengthening and toning up the parts. 



