PERIOSTEOTOMY IN SPA.YIN. 
735 
is directed towards the joint, and the back pressed with the fingers of the 
left hand, while, by gently rocking the instrument, it is made to penetrate 
the bones of the joint. The tendon of the flexor metatarsi muscle and 
the periosteum part with a distinct “ crunching ” sound. The same 
process is repeated in the posterior pocket of skin, the sharp edge of the 
knife, however, being directed forwards. After wiping away the small 
amount of blood which escapes from the wound, the surface is rinsed with 
a disinfectant, and an antiseptic dressing applied. The bandage should 
be carried down as far as the fetlock, so as to obtain a firm hold. The 
horse is then allowed to rise, and is placed in the 
stable. If, during the next few days, the bandage 
become soaked through with blood, it should be re¬ 
newed, otherwise it is left in position for six to eight 
days, when the skin wound will be found to have closed. 
By the exercise of moderate care in operating, pus 
formation can be avoided; and even should it occur, 
it seldom entails grave consequences, for, on account 
of the flat position of the knife while making the 
incision, there is little danger of opening the joint, 
and thus producing dangerous arthritis. 
The horse must be rested for at least four to six 
weeks after operation, and during this time move¬ 
ment, as far as possible, avoided. Some operators 
even recommend fastening the animal up short to 
prevent it lying down. 
Moller discovered by experiment that both the inner 
tendon of the flexor metatarsi and the periosteum of 
the cuneiform bones are divided in this operation ; not 
infrequently the internal lateral ligament is also partly 
cut through. The above method produces active 
periostitis and thickening of the internal ligaments 
of the joint, which favour periarticular exostosis and 
union of the smaller joints in a much higher degree than simple opening 
of the bursa and other operations. 
Bad results are rare. For a short time exostoses are actively produced, 
but greatly diminish after a month or two, and may finally leave no trace 
of operation. 
It is not pretended that this procedure cures all cases of spavin, but 
the objections raised against it in no way detract from its undoubted 
value. 
There need be no fear of using the knife, even when the exostosis is 
small. In such cases, to make sure of sufficiently dividing the perios¬ 
teum, knives of greater curvature may be used; these penetrate more 
a b 
Fig. 268. — Perios¬ 
teotomy knives. 
