122 THE SURGICAL ANATOMY OF THE HORSE 



In the early stages there is heat in the part, and the animal flinches 

 when the area is palpated. Moreover, the patient is lame. In these 

 cases fomentations should be applied. But the condition usually becomes 

 chronic. The walls of the swelling become harder and thicker, lame- 

 ness, excepting in cases where the swelling is very large, disappears, and 

 the affection is more unsightly than injurious. The fluid contents may 

 be removed with an aspirator, and a solution of iodine injected, or the 

 swelling may be fired and blistered, but rarely is treatment effective in 

 removing or even materially reducing the enlargement. 



THE FLEXOR TENDONS OF THE METACARPUS 



A further reference to the plate illustrating ulnar neurectomy 

 (Plate XXXII.) will reveal the fact that there are two tendons which obtain 

 insertion into the upper border of the pisiform bone. These are the 

 tendons of the flexor metacarpi medius and flexor metacarpi externus 

 muscles. The tendon of the middle flexor, which is the more powerful, 

 is wholly inserted into the pisiform bone, whilst that of the external 

 flexor bifurcates just above the pisiform bone, having an additional slip 

 of insertion in the form of a flat band of fibres which runs obliquely 

 downwards and forwards to the head of the external small metacarpal 

 bone. 



These powerful tendons act in antagonism to the thick tendon of the 

 extensor metacarpi magnus, and their action, as their names imply, is to 

 flex the knee. In the normal condition of the tendons they are of such 

 length that when the foot rests upon the ground, and the flexor muscles 

 are in a condition of relaxation, the long axis of the large metacarpal 

 bone is in a straight line with the long axis of the radius. But when 

 the tendons are abnormally short, as they frequently are either from 

 congenital malformation or as a sequel to a serious sprain, we have the 

 condition commonly known as " bent knees," when the axes of the 



