FRACTURES OF THE PELVIS. 731 



IV.— FRACTURES OF THE PELVIS. 



Fractures of the pelvis are commonest in the larger animals, 

 particularly in horses, and are caused by falls on smooth pave- 

 ments, by collisions, sometimes by the animal's legs slipping from 

 under it, or by the horse making a sudden turn when being ridden. 

 Since asphalt has been extensively laid down fractures of the pelvis 

 in horses have greatly increased in frequency and often occur even 

 without the animal falling. Trasbot saw fracture of the ilium in 

 a race-horse produced while galloping. The pelvis may also be 

 fractured by casting the horse on hard ground, if the pelvis fall first ; 

 the animal's chest should first touch the bed. Stockfleth noted 

 a case of fractured pelvis from violent struggling in hobbles. 

 Fractures of the outer angle of the ilium are also caused by passing 

 through narrow doorways, by kicks or by heavy objects falling on 

 the bone ; the skin is often simultaneously injured and a compound 

 fracture results ; with few exceptions, other pelvic fractures remain 

 subcutaneous. In the mare, however, Moller saw perforation of the 

 vagina by a splinter of the ischium. 



In cows fractures of the pelvis may be caused by violent attempts 

 to effect delivery. Similar injuries occur during coitus and after falls. 



Whilst in large animals the weight of the body or violent 

 muscular action is responsible for these fractures, in dogs and the 

 smaller animals they generally result from external violence, as 

 from being run over, severely kicked, or crushed in narrow passages 

 or in doorways. This explains why multiple fractures of the pelvis 

 are frequent in small animals, but comparatively rare in large ones. 



For the purpose of diagnosis and prognosis, fractures of the pelvis 

 may be divided into two groups : — 



(1) Pelvic fractures without division of the pelvic girdle (Fig. 

 450). These comprise fractures of the external (1) or internal (2) 

 iliac angle, fractures of the tuber ischii (6), transverse portion of 

 the os pubis (4), and external portion of the ischium (4a). The 

 external angle of the ilium is the most frequent seat. It need scarcely 

 be said that such injuries are less grave than the following group, 

 though they may, nevertheless, cause incurable lameness — as, for 

 example, when they involve the acetabular margin of the hip-joint. 

 Jess mentions a case where a horse fell several times and then 

 suddenly died. On post-mortem examination the tuberosities of 

 the ischium were found to be broken, the posterior portions of the 

 bodies of the pubic bones and the shaft of the ilium fractured. 

 Death had resulted from haemorrhage. 



