598 
SPRAIN OF THE CORONARY JOINT. 
lameness, and by the upright position of the os suffraginis. Inflamma¬ 
tion of ligaments often extends to bones and produces exostoses, 
particularly where the ligaments are inserted into the os suffraginis and 
os coronae. 
The synovial membrane may also be affected, causing distension of 
the cavity of the joint with inflammatory exudate (hydrops articuli) 
and chronic enlargement. In other cases blood may pass into the joint 
(haemarthrosis), producing on movement a peculiar sound which has 
been likened to that made by squeezing snow in the hands (“ snowball 
sound”). Necrosis of bone occasionally occurs, and produces severe 
symptoms, or even death. 
Siedamgrotzky noticed in horses three cases of rupture of the lateral 
ligament of the hind fetlock, which recovered in three to eight weeks. 
Percival made some anatomical researches on the production of 
articular diseases, and found the fetlock-joint anchylosed in five cases, 
the coronet-joint in forty cases, and the pedal-joint in sixteen cases. 
When implicating the coronet-joint, the condition is termed ring-bone 
(see section on that disease). 
The rare occurrence of sprains in the fetlock-joint must be referred 
to the form of its articular surfaces which acts as an effective check 
on movement. Of the ginglymoid joints, the coronet suffers more 
frequently. 
Prognosis depends on the extent and duration of injury. The 
degree of pain is generally a fair criterion of the mischief, though 
the early appearance of inflammation is more significant. The imme¬ 
diate pain which accompanies “ treads” is of less importance than 
that due to strains. Although in the former cases pain may be so 
severe as to cause sweating and loss of appetite, it disappears almost 
as rapidly as it sets in, provided no grave complication occur. The 
delayed pain, due to inflammation, is of most importance in determining 
the prognosis; when appearing twelve to twenty-four hours after the 
accident it shows that grave injury has taken place, and if accompanied 
by marked fever is a grave symptom. The older the condition, the 
more slowly does resolution proceed. Hence the old rule: a sprain 
uncured in two weeks will require not less than four, and if then uncured 
will last at least a further four, and so on. Long duration predisposes 
to fresh attacks. 
Treatment. The chief indication is perfect rest, but in large animals 
is unfortunately difficult to provide for. All movement should be 
avoided, and the limb supported or fixed by firmly applying a strong 
linen bandage. During the first three days cooling applications keep 
down inflammation and modify pain, but after this time the only 
symptom justifying employment of cold is continued severe pain. 
