476 
FRACTURE OF THE PELVIS. 
the hand is placed on the outer angle of the ilium and the horse made to 
move. In mares and cows, crepitation, especially in fractures of the 
os pubis and os ischii, can be felt from the rectum or vagina by laying 
the hand on the ischiatic notch, and as the sensation is better conveyed 
by the bones than by the soft parts, it is best to examine from this point. 
Very slight crepitation can also be detected by applying the ear against 
the quarter. When the animal is lying down, crepitation may sometimes 
be produced by pressing on the outer angle of the ilium, or by moving 
the hind leg forwards; the latter is more successful in fractures of the 
tuber ischii. 
In fractures extending through the cotyloid cavity, crepitation can even 
be heard when the horse is standing by merely pressing on the muscles 
of the quarter, or by causing weight to be placed on the affected leg. 
This is explained by the fact that the muscles of the quarter are inserted 
partly in front of and partly below the point of fracture, and, in alternately 
contracting, displace the pieces of bone—a symptom that is of value both 
in prognosis and diagnosis. 
(8) Apparent deformity of the quarter is, as a rule, only seen in 
fractures of the ilium. In fractures of the outer angle, the loose piece 
of bone is drawn forwards and downwards by the oblique abdominal 
muscle, and by the tensor vaginse femoris and lies in the abdominal 
wall, so that the outer iliac angle seems to have disappeared. To detect 
this, the animal is placed with the hind feet level, and the operator, 
standing behind, compares the relative contours of the outer iliac angles. 
The larger the broken portion, the more marked, of course, will be the 
asymmetry. 
In fractures of the shaft of the ilium, the entire ilium, and especially 
its outer angle, sinks; this symptom can almost invariably be detected 
if the horse be made to stand equally on both feet. 
A peculiar change in form follows fracture of the external branch of 
the ischium; the buttock is flattened at the height of the tuber ischii, 
whilst the region of the hip-joint appears considerably swollen, and the 
ilium slightly depressed. The abnormality is discovered by standing a 
few steps behind the animal and regarding the pelvis. Fractures through 
the acetabulum or os pubis are not generally followed by changes of form 
in the quarters, though in fracture of the acetabulum a slight depression 
may sometimes be seen over the liip-joint. 
(4) The bones of the pelvis are seldom abnormally mobile, except when 
the external and internal angles of the ilium are simultaneously fractured, 
though in exceptional cases mobility is present after fracture of the shaft 
and body of the ilium. In such cases the outer angle of the ilium yields 
when pressed on, and crepitus may sometimes be detected. 
(5) In fractures of the pubis, oedematous swelling sometimes occurs 
