LAMENESS IN THE HIND LEG 201 



shaft of the bone, by passively moving the leg to and from the 

 medial plane (adduction and abduction). 



Fracture of the trochanter major is signalized by local swelling 

 and evidence of pain; the forward stride is shortened because 

 this movement tenses the tendon of the gluteus major (maximus) 

 which is attaclicd principally to the trochanter. 



Treatment.— Reduction of femoral fracture in the horse is 

 practically impossible, and retaining the broken bones in coapta- 

 tion is not possible by means of mechanical appliances. Conse- 

 ciuently, prognosis is unfavorable in fracture of the body of the 

 femur. When union of bone occurs, there results shortening of 



Pig 47 — Same bone as in Fig. 46 after about six months' treatment. In this 

 case Dr. Merillat employed a weight to counteract muscular contraction. It 

 is noticeable that very little provisional callus has formed in this case, and 

 in spite of unusual ingenuity and good facilities for caring for the subject, 

 union of bone did not occur. 



the leg and animals are rendered permanently lame. If the 

 immediate region of the head of the bone is involved as well as 

 in case of fracture of the condyles, an incurable arthritis ensues. 

 Where the trochanters are broken, chronic lameness and 

 muscular atrophy is the result. Therefore, it is evident that, 

 because of the manner of function of the femur, the leverage 

 afforded by its great trochanter and its heavy muscular attach- 

 ments, fractures of this bone in the horse do not terminate favor- 

 ably. 



Luxation of the Femur. 



Etiology and Occurrence. — Uncomplicated femoral luxation 

 is of less frequent occurrence in the jiorse than in the other 



