FRACTURES OF THE SACRUM. 
469 
door; in larger animals, by falling over backwards, if at the moment the 
tail is lifted. To induce oxen to move, the tail is sometimes violently 
twisted, with the result that the caudal vertebrae are fractured. In the 
tail region the inter-articular cartilages are sometimes torn through. 
Treatment is very similar to that of fracture. 
Symptoms and course. The plexus, formed by the last lumbar and 
two first sacral nerves, provides the muscles of the hind limbs with 
motor fibres, and fracture of the first sacral vertebra or of the lumbar 
vertebrae is therefore followed by paralysis in that region. The plexus 
pubo-coccygeus, which leaves the vertebral canal through the third and 
fourth sacral notches, gives motor and sensory fibres to the rectum, 
penis (N. dorsalis penis), and perineum. Fractures of the sacrum are 
therefore always attended with paralysis of the tail and rectum, and 
sometimes of the bladder, in addition to paraplegia. The symptoms 
depend on the position o£ the fracture and the changes consequent on it. 
The fact that blood is often poured into the vertebral canal, explains why 
fractures occurring further backwards than the last sacral vertebra are 
often attended with extensive disturbance. Most fractures of the sacrum 
in cattle are accompanied by weakness in the hindquarters, some with 
complete paralysis. The fragments of bone are generally displaced 
downwards, voluntary defecation is always and urination sometimes 
impossible. Fractures of the caudal vertebrae only paralyse the tail 
when the first vertebrae are affected. The tail is generally exceedingly 
mobile, and crepitation may be audible; not infrequently the skin is 
injured (compound fracture); sometimes the end of the tail remains 
hanging by a few tendinous shreds of the caudal muscles. 
So long as an animal with fracture of the sacrum is able to stand 
recovery may occur, but cure is out of the question in complete para¬ 
plegia, especially in horses ; in cattle and carnivora paraplegia renders 
prognosis doubtful. Paralysis of the urinary bladder is a very unfavour¬ 
able symptom, as, on account of the necessity for emptying the bladder 
by catheter, infection may occur, the urine decompose, and severe 
cystitis set in. A cow, however, with paralysis of the rectum, consequent 
on displacement between the first caudal and last sacral vertebrae, 
recovered completely (Harms). Fractures of the upper caudal vertebrae 
may also cause deformity and limitation of movement in the tail. 
Moller saw a calf in which, in consequence of fracture, the tail was 
twisted to one side and could no longer be freely moved. Compound 
fractures of the tail vertebrae are readily followed by necrosis; this 
always happens when the vertebrae are crushed ; the tail then feels cold, 
showing that the blood-vessels are thrombosed. Permanent paralysis is 
another frequent consequence, and is especially troublesome, because the 
tail becomes soiled by the faeces, and in cows by the urine. 
