8o THE SURGICAL ANATOMY OF THE HORSE 



and then on the internal lateral ligament of the elbow. In front of the 

 artery in this situation is the tendon of insertion of the biceps muscle. 

 Covering the vessel is the posterior superficial pectoral muscle. The 

 artery is accompanied by the median nerve, which lies behind it, and its 

 satellite vein, and after crossing the elbow joint it inclines slightly 

 backwards and disappears between the radius and the internal flexor of 

 the metacarpus. 



The ulnar artery is given off from the brachial at the lower border 

 of the small head of the triceps estensor cabiti muscle. It takes 

 a course downwards and backwards, and reaches the inner aspect 

 of the elbow, where it is placed between the olecranon process and 

 the inner condyle. In this situation it is accompanied by the ulnar 

 nerve which is in front of the artery, the latter having crossed 

 the nerve. Both are covered by the thin scapulo-ulnaris muscle, 

 and care should be taken not to injure them in dissecting away elbow 

 tumours of any considerable size. The artery then becomes more deeply 

 seated, and follows the tendon of the ulnar portion of the flexor perforans 

 muscle. 



Posteriorly we have the joint protected by bone, since the olecranon 

 process extends in an upward direction for a distance of from two and 

 a half to four inches above the articulation. There is therefore no 

 necessity for a posterior common ligament. 



DISEASES OF THE ELBOW 



LUXATION OF THE ELBOW 



The length of the lateral ligaments of this joint is such that 

 they keep the articular surfaces of the bones in very close apposi- 

 tion. The length and strength of these ligaments together with 

 the conformation of the articular surfaces (the joint being of the 



