SPRAIN OF THE CORONARY JOINT. 
597 
in large cities, and during the winter. Less frequently the animal is 
caught in deep ground, or between fixed objects like railway-metals. 
The commonest complications are fractures of the os coronas; next to 
these come fractures of the pastern. The lateral ligaments of the 
coronet-joint are most exposed to sprain. 
Symptoms. Lameness appears suddenly following a slip ; the animal 
avoids placing weight on the limb, and movement is often painful. 
The foot is rested, and held in a position of volar flexion. Pain is 
evinced, both on passive rotation of the joint and when the animal 
is turned round. At a later stage, weight may be placed on the limb 
when the animal is in the stable or on level ground, though attempts to 
turn are followed by distinct recurrence of lameness. This is due to the 
fact that moving on level ground produces little tension in the articular 
ligaments. The affected part is warm and- swollen, and there is often 
marked pain on pressure. 
Careful examination of the separate joints usually reveals the position 
of injury, especially if the fetlock-joint be fixed and the coronet rotated, 
or vice versa. Passive rotation of the fetlock-joint, however, does not 
produce so marked an effect as that of the two lower joints, because the 
form of its articular surface effectively limits movement. It is often 
difficult to discover whether the pedal or coronet joint is affected, but 
luckily the question is of no practical moment. 
Course and results. Sprains and the inflammation resulting from 
them vary greatly in extent and intensity. A slight slip may produce 
violent momentary pain, in consequence of strain of the ligamentous 
apparatus, though such usually disappears with proper rest in twenty- 
four to forty-eight hours, when the condition may be regarded as cured. 
When sprain is complicated with rupture of ligaments, great pain is 
shown, but often diminishes rapidly, and may even disappear for a short 
time. It returns after some hours, however, and then continues. The 
second attack results from inflammation, and is in direct relation to its 
intensity and extent. When the strain and rupture are still more 
severe, pain continues longer, and inflammatory symptoms (increased 
warmth and swelling) appear early.- Slight cases completely recover 
within a period varying from a few days to several weeks, according to 
their gravity, but a disposition to fresh injury exists, which is directly 
proportional to the changes in the joint. Cases of extensive and intense 
inflammation of the joint, consequent on injury to ligaments (peri¬ 
arthritis), generally last four to six weeks, but may be followed by com¬ 
plete recovery. In severe cases the diseased ligaments are apt to con¬ 
tract and impede free movement of the joint, which is also distorted. 
Excessive volar flexion may then occur, especially after inflammation of 
the fetlock-joint. Limitation in the movement of the joint is shown by 
