I02 THE SURGICAL ANATOMV OF THE HORSE 



tion with the inferior extremity of the large metacarpal bone. To this 

 bone the three already united bones are connected by means of the two 

 lateral fetlock ligaments (which must not be confused with the lateral 

 sesamoidean ligaments) and the anterior common ligament. 



The lateral fetlock ligaments run from the large metacarpal bone to 

 the suffraginis, and each gives off a slip of attachment to the sesamoid 

 bone of its corresponding side of the limb. 



The anterior common ligament is in the usual form of a four-sided 

 sheet, which covers the front of the joint, running from the large meta- 

 carpal bone above to the suffraginis below, and blending with the lateral 

 ligaments. This ligament supports the synovial membrane by its pos- 

 terior surface, and its anterior face is crossed vertically by the tendon of 

 the extensor pedis muscle, and towards its outer side by the tendon of the 

 extensor suffraginis muscle. A small synovial bursa is interposed between 

 the extensor pedis tendon and the anterior common ligament. 



The superior sesamoidean or great suspensory ligament arises, as 

 already mentioned, from the posterior surface of the lower row of carpal 

 bones and the upper extremity of the metacarpals, and runs along the 

 channel formed by the large and small metacarpal bones. A short dis- 

 tance above the fetlock joint this ligament splits up into two divisions 

 which run round the fetlock joint, one on either side the limb, to gain its 

 anterior aspect, passing obliquely across the lateral surfaces of the os suffra- 

 ginis. At the front of the limb they become inserted into the tendon of 

 the extensor pedis. Each division, as it passes round the side of the 

 fetlock, gives off a small slip of insertion to the sesamoid bone. 



The relations of the ligament, from its origin to its point of division, 

 are as follows : 



Anteriorly to it are the metacarpal bones ; behind it we have at first 

 the check ligament, and subsequently the perforans tendon ; whilst 

 laterally it is related to the small metacarpal bones, the skin, and subcu- 

 taneous fascia. 



This ligament represents one of the plantar interosseous muscles of 



