622 INFLAMMATION OF POSTERIOR LIGAMENTS OF CORONET-JOINT. 
avoiding injury to the ulnar artery and vein which accompany the 
nerve. 
The nerve being isolated is divided at the upper angle of the wound, 
and a fragment about 1J inch • in length is excised. The wound is 
cleansed and the skin brought together with a few small sutures. 
Double neurectomy of the median and ulnar nerves is not often per¬ 
formed. Neurectomy of the median alone often has serious drawbacks. 
It should be reserved for old-standing chronic affections of the fore limb, 
and—particularly in dealing with valuable animals—should not be tried 
until all other methods of treatment, especially firing, have proved 
unsuccessful. 
Loss of the hoof, thickening of the subcutis, fracture of the os pedis, 
and gelatiniform degeneration of the flexor tendons are not uncommon 
sequelae; the first most frequently results when there are large exostoses 
on the front of the joint, near the coronet. Perhaps loss of the hoof 
is due to the coronary band being bruised between the exostosis and the 
hoof. To avoid this contretemps , the toe of the hoof should be freely 
pared, whilst the heels are preserved. If needful, shoes with thick 
heels or high calkins are applied. Loss of the hoof also follows 
neglected corns, or pricks in shoeing; the injury not being detected 
owing to the animal showing no signs of lameness. 
INFLAMMATION OF THE POSTERIOR LIGAMENTS 
OF THE CORONET-JOINT. 
The deep sesamoidal and the postero-lateral ligaments correspond physio¬ 
logically to the suspensory ligament of the fetlock-joint. In common with 
the capsular and lateral ligaments they fix the coronet-joint; the latter also fix 
the pedal-joint when the limb is loaded. On account of the slight develop¬ 
ment and flattened shape of the upper articular surface of the os coronee, the 
fixation of the pastern and coronet bones throws a severe strain on the 
limiting apparatus of the joints, which is greatest in the case of the lateral 
ligaments. These, therefore, become diseased, forming ring-bone; the poste¬ 
rior ligaments of the coronet-joint also become affected, and more frequently 
than is generally supposed. 
Causes. The condition is produced by over-extension, sometimes 
accompanied by partial rupture, resulting from excessive dorsal flexion 
of the coronet-joint. Attention should, therefore, first be given to the 
position of the hoof. Low heels and long toes are almost always the 
active causes. Heavy horses in mounting hills bring about a similar 
condition of things ; the leverage of the toe becomes greater. If the 
general direction of the phalanges (phalangeal axis) be not parallel with 
that of the walls of the hoof (hoof axis), but more upright, there is 
danger of straining, not only the different portions of the inferior sesa¬ 
moidal ligament and the antero-lateral and postero-lateral ligaments, 
