BONES DISEASES AND ACCIDENTS. 295 



Dislocations. Luxation or displacement of the bones forming a joint, 

 without fracture, is comparatively rare among cattle. It most frequently 

 occurs in the stifle joint, where dislocation of the knee-pan (patella) 

 takes place. A glance at the skeleton (Plate xxv) will show the rela- 

 tions better than they can be described. It will be observed that the 

 small irregularly shaped bone (patella) plays on the anterior rounded 

 part of the lower end of the hip bone (femur) and between it and the 

 upper end of the thigh bone (tibia). The outer ridge on the lower end 

 of the thigh bone is less prominent than the inner one, so that displace- 

 ment, when it does take place, is by slipping outward. Such an acci- 

 dent may occur from direct injury or external force, as a blow, or from 

 slipping. When it does occur the symptoms produced are somewhat 

 alarming. The animal is unable to draw the leg forward, and either 

 stands with it thrown back with the toe pointing downward, or, if it 

 should succeed in getting its weight upon it, holds it firmly on the ground, 

 fearing to move it. Examination of the outside of the joint will dis- 

 close the situation of the patella outside of its proper place. If the 

 operator is not familiar with the normal appearance of the joint it is 

 well to make a comparison between the injured and the sound one. If 

 compelled to move the animal does so with great difficulty, jerking the 

 leg which it is unable to bring forward, hopping with the other and par- 

 tially dragging the injured one. The treatment is simple. A rope 

 should be applied around the fetlock, the leg drawn forcibly forward by 

 an assistant, while the operator carefully manipulates the dislocated 

 bone, shoving it inward and forward as the leg is brought forward. If 

 successful it slips into its place with a sharp click and the animal steps 

 oft' as though nothing had happened. Unless some precaution is taken 

 the accident is liable to recur, as the ligaments have been stretched by 

 the dislocation till they no longer hold the bone with that firmness 

 messary to r.-tain it. Tii;- aMin-al >ii<ulfl !, tied Bud iln- !'.>.; fastened 

 forward, so that the animal can just stand on it comfortably, by means 

 of a rope or strap around the fetlock, carried forward between the front 

 legs around the neck and tied on the breast. Should this accident 

 occur more than once it is a good practice to apply a blister around the 

 joint, as in the formula recommended in sprain of shoulder, and observe 

 the precautions as to restraint and subsequent treatment there recom- 

 mended. With this one exception dislocations in the ox occurring inde- 

 pendently of other complications are rare. Dislocation with fracture 

 may occur in any of the joints, and where one is suspected or discov- 

 ered, lx>fore treatment is applied, examination should always IK made 

 for the other. When a fracture occurs in the vicinity of a joint the 

 force sufficient to rend the bone is likely to be partly exerted on the 

 immediate tissues, and when the bono gives way the structures of the 

 joints are likely to be seriously injn red. It occasionallyhappenstlr.it 

 the injury to the joint becomes the most important complication in the 



