SPRAIN OF THE CORONARY JOINT. 895 



are favoured by irregular pavement, high calkins or heels, narrow- 

 ness of the chest, and lameness. The condition is therefore commonest 

 in large cities, and during the winter. Less frequently the foot is 

 caught in deep ground, or between fixed objects like railway-metals. 

 The commonest complications are fractures of the os coronae ; next 

 to these come fractures of the suffraginis. 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 versd,. 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, 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 (periarthritis), generally last four to six weeks, 

 and may be followed by imperfect recovery or chronic lameness. 

 In severe cases the diseased ligaments are apt to contract and impede 

 free movement of the joint, which is also distorted. Excessive 

 volar flexion may then occur, especially after inflammation of the 



