LAMENESS, FROM VARIOUS CAUSES. 343 
S11FLE Out (DisLocaTion on LUXATION OF THY STIFLE 
Bone). 
The patella of the horse, or stifle bone, as it is familiarly known, 
torresponds to the knee-pan of man, and answers the same pur- 
pose; that is, to facilitate motion, and protect the two extremities 
of the bones which compose the stifle-joint. 1t is retained in situ 
at the anterior part of the inferior extremity of the thigh bone and 
superior extremity of the tibia. 
Ax accident of this character is generally accompanied with con 
riderable pain and uneasiness; but the most notable symptom is, 
the bune is thrown off its pulley-like articulatory surface, and thus 
the recti and vasti muscles (the latter being direct extensors of the 
leg or thigh, and the action of the former being similar) are, for 
the time being, paralyzed ; that is to say, their action is suspended. 
If they act at all, it is under great disadvantage, and at the expense 
of their muscular integrity. The liability to luxation of the stifle 
bone (patella) is not so great as some persons would have us be- 
lieve. The bone is secured in its position by a number of strong 
ligaments—has a complete articulatory joint of its own, whose 
capsular ligaments have strong attachments to surround them. The 
muscles, tensor vagine, rectus, vasti faschia, panniculus carnosus, 
subcellular substance and integument, all operate favorably against 
the chances of luxation. The accident, however, does sometimes 
occur—not, perhaps, from any disarrangement of the mechanical 
order of the parts by violence, such as might be operative in dis- 
location of the thigh or arm bones, but often from spasm, cramp, 
ete., of certain muscles in the immediate vicinity of the parts. 
“T think his stifle is out,” is a very common complaint made 
by horse-owners when a horse becomes lame, and the “ neighbors” 
can not discover the exact location of the same. They hastily 
conclude, if the lameness is in the hind extremity, that the “ stifle 
is out” (luxated). Here is a case in point. I received a message 
some time ago, to visit a horse said to have “ his stifle out.” On 
making examination of the foot on the lame side, I found it much 
hotter than its fellow on the opposite side. The owner, at the 
moment, remarked that there was “no trouble in the foot.” He, 
however, was nistaken; for I found that a nail nau entered the 
vosterior part of the cleft of tLe frog, which I extracted, and this 
was the sole cause of lameness. I m:ght relate a number of mis: 
