MEMOIR ON TENOTOMY. 587 
may happen that the operation of tenotomy will occasionally be 
performed without producing any beneficial results*. 
Towards the inferior extremity of the cannon, and nearty on a 
level with the articulation of the fetlock, is likewise situated 
another tendinous synovial bursa, called the semmoidian groove , 
which is evidently intended to facilitate the passage of the flexor 
tendons over the projecting angle of the sesamoids, and which 
never extends higher than the tubercles of the splent bones. 
In concluding these descriptive anatomical considerations, we 
have now only to point out, as clearly as we can, the position on 
either side of the tendinous region of the cannon occupied by the 
vessels and nerves which exist immediately beneath the inte- 
guments. 
In the fore legs, on the outer side, will be found the lateral vein 
of the cannon, and the plantar nerve which runs along by the side 
of this vein. They lie close together, and are maintained on the 
edge of the perforans tendon by cellular tissue. 
On the inner side, the plantar nerve accompanies the superficial 
lateral artery of the metacarpus, to which it is closely attached. 
About the spot where the operation of tenotomy should be per- 
formed, this nerve throws off a large division or branch which 
crosses the direction of the flexor tendons from above downwards, 
and rejoins the external plantar nerve beneath an acute angle. 
On this side the vein is situated much deeper, and is found almost 
in front of the perforans. 
In the hind legs, the superficial lateral artery of the metatarsus, 
instead of being situated on the inner side, creeps along a groove 
formed by the union of the external splent bone and the cannon. 
This sheltered position saves it from all possibility of receiving any 
injury during a section of one or both tendons. The disposition 
of the plantar nerves in these limbs so much resembles the 
account we have already given of them in the fore legs, that 
farther description is needless. 
Since it is admitted that all deviations of the osseous radii or 
fibres, which by their union concur to form the articulation of the 
fetlock, may be idiopathic or symptomatic, the causes which induce 
this kind of evil ought certainly to be divided into direct and in- 
direct. We shall presently perceive all the importance of this 
division in a therapeutic surgical point of view. 
Thus, while taking into consideration not only the nature of the 
work exacted from the animals, but also the peculiar conformation 
observable in some of them, which seems to render them extremely 
* There cannot be a doubt but that, when operating with a sharp instru- 
ment, it is very easy to open the cul de sac of the carpal or tarsal sheath, 
while we believe ourselves to be beneath it. 
