930 LUXATION OF THE FEMUR. 



external angle of the left ilium was about two inches lower than 

 the right. At the point where the lower trochanter should have 

 appeared, a depression about as wide as three fingers was visible. 

 On careful examination the lower trochanter could be detected just 

 in front of the biceps femoris ; a weak crepitation sound was produced 

 by moving it. As the horse was not brought back after the first 

 examination, its further progress could not be observed. 



III.— LUXATION OF THE FEMUR. 



In the horse the depth of the articular cavity and strength of 

 the ligamentum teres tend to prevent displacement of the femur. 

 Rigot and others altogether deny that displacement occurs, though 

 recorded cases clearly show that it may occasionally happen. It is 

 certain that complete luxation cannot occur without rupture of 

 the ligamentum teres. The pubio-femoral ligament derived from 

 the prepubic tendon of the abdominal muscles sometimes remains 

 intact after luxation, but the capsular ligament and surrounding 

 muscular tissue are always ruptured. Incomplete luxation can 

 scarcely occur in the horse, and reported cases in the cow are open 

 to doubt. 



In the horse the neck and articular head are more easily broken 

 than displaced, but in oxen and other animals the conditions rather 

 favour luxation, the articular cavity being natter, and the ligamentum 

 teres weaker. Luxation of the femur occurs in dogs. Fiedler noted 

 a case in a foal, where the epiphysis was also separated. 



In making post-mortem examinations of horses, Falke repeated^ found 

 the ligamentum teres ruptured. In an old animal that had shown no 

 lameness prior to death, the ligamentum teres was absent. The points 

 where the ligament is inserted into the head of the femur and acetabulum 

 appeared deepened and smooth, but not a trace of the ligament was visible, 

 and the pubio-femoral ligament, though normally developed, ended before 

 entering the joint-cavity. The transverse cotyloid ligament was normally 

 developed ; the posterior portions of the gluteus parvus were interspersed 

 with connective tissue. Probably luxation or violent distortion of the 

 coxo-femoral joint had long before taken place, causing rupture of the 

 ligamentum teres and of the muscle. Falke, experimenting on dead 

 bodies, found that luxation was in one instance produced by a pull of 

 8 cwt., and in another of 16 cwt. In each instance the head of the bone 

 and the cotyloid cavity remained intact, but the ligamentum teres and the 

 capsular ligament were ruptured. It is therefore quite certain that the 

 femur may be luxated without injury to the articular surfaces. Bucher's 

 observations show that rupture of the ligamentum teres is often followed 

 by severe lameness. Two horses which he saw with this rupture were 

 unable to support weight on the diseased limb. One rested the point 

 the other the side of the toe, on the ground ; the hock was excessively 



