FRACTURE OF THE PELVIS. 
479 
(2) Fracture of the shaft of the ilium without much displacement may 
in quiet animals be followed by complete restoration to usefulness; 
otherwise lameness remains, or continually returns after severe exertion, 
and restricts the animal to walking work. As the result depends on the 
amount of displacement and the nearness of the fracture to the joint, 
prognosis should be preceded by rectal examination. Prognosis is, 
however, generally doubtful, and is the more unfavourable the more 
patent the deformity of the croup, the greater the depression of the 
ilium, and the nearer the fracture to the acetabulum. Marked atrophy 
of muscle is also an unfavourable symptom. Stockfleth saw continuous 
lameness due to formation near the joint of a large callus, which 
interfered with movement of the upper trochanter. 
(3) Fractures of the transverse branch of the os pubis or external 
branch of the os ischii are also grave. Union proceeds slowly, and 
often remains incomplete, resulting in the formation of a callus fibrosus; 
fractured of the pubis often recur, especially if the animal soon after¬ 
wards becomes pregnant. Fracture of the external branch of the 
ischium often fails to unite, and the animals are only of use for slow 
work. In a case of Holler’s there was still marked crepitation after 
eight weeks, but complete union occurred in four months, and the 
animal could be put to trotting work. The fact that pain is not severe 
favours movement and displacement of the fragments, and interferes 
with recovery. 
(4) Fractures of the tuber ischii generally require months to unite, 
and sometimes result in the toe being dragged and the M. biceps femoris 
thrust out of position during movement. 
(5) Fractures through the obturator foramen are most dangerous on 
account of the risk of injury to the larger blood-vessels and of fatal 
bleeding. Otherwise they are rather more hopeful than the following, 
because, though rare, yet union may occur, and the animal become 
capable of slow work. Many horses, however, are unable to bear 
the continual standing on the other foot, and if not killed, die from 
decubitus. 
Division of the pelvic girdle close to the symphysis pubis and parallel 
with it sometimes produces little disturbance; but union is always slow 
and incomplete, while in many cases it altogether fails to occur. Laser 
saw a case where the bladder had been nipped between the pieces of 
bone. Such fractures tend to recur, especially if the animal be moved 
too early, or give birth to a foal. 
(6) Fractures of the acetabulum are the most dangerous, because as a 
rule the margin of the cotyloid cavity is broken into several pieces ; hence 
prognosis is always unfavourable. 
Fracture of the pelvis through the sacro-iliac symphysis is also 
