268 The Elbow Joint 



been dissecting dangerously near to it. The lower end of the humerus 

 having been cleared of the attachment of the lateral and the anterior 

 ligaments, and other indefinite fibres, is thrust out of the wound and 

 sawn off. The olecranon process is cleared of the insertion of the 

 anconeus, and of fibres of origin of the flexor carpi ulnaris. The 

 lower part of the coronoid process is then cleared of the insertion of the 

 brachialis anticus (and of fibres of origin of the flexor sublimis digi- 

 torum), but as much as possible of the process and of the insertion of 

 the brachialis should be left ; the ulna is then sawn across. The head 

 of the radius is also removed. The arm had better not be fixed on a 

 splint after the operation, as the surgeon desires to obtain a fibrous 

 ankylosis, not a bony one as in the case of the knee, and, therefore, 

 the sooner that he begins to move it, the better. 



THE FORE- ARM, WRIST, AND HAM) 



Surface marking-s. From the olecranon process the posterior 

 border of the ulna may be traced down to the styloid process, and 

 the head of the bone may be made out between it and the inferior 

 radio-ulnar joint. In the groove between the styloid process and the 

 head of the ulna runs the tendon of the extensor carpi ulnaris, and in 

 the gap corresponding to the radio-ulnar articulation passes the special 

 extensor tendon of the little finger. 



The tendon of the flexor carpi ulnaris may be traced along the 

 front of the inner side of the fore-arm to the pisiform, and on flexing the 

 wrist, so as to slacken that tendon, the sesamoid bone may be moved 

 at its arthrodial joint with the cuneiform. Along the radial side of the 

 ulnar flexor tendon runs the ulnar artery, but its pulsations cannot be 

 made out as readily as those of the radial artery, first, because the 

 vessel is overlapped by the tendon, and, secondly, because the finger 

 compresses the ulnar artery not against firm bone, as in the case 

 of the radial, but against the less resisting mass of the flexor profundus 

 digitorum. 



On the radial side of the groove in which the artery descends 

 are the tendons of the flexor sublimis, and in the middle line of the 

 wrist, and quite superficially, is the tendon of the palmaris longus. 

 Close to the outer side of the last tendon is that of the flexor carpi 

 radialis, immediately on the ulnar side of which is the median nerve 

 under cover of the tendon of the palmaris longus. About \ in. ex- 

 ternally, in the groove on the ulnar side of the radial styloid process, 

 is the radial artery, which here rests upon the pronator qu.idr.itus, and 

 lower down on the radius itself. The tendon of the supinator longus 

 can just be made out descending to the root of the styloid process. 



Proceeding outwards and backwards, one encounters the prominent 

 ridge of the tendons of the extensors ossis and primi, just beneath 

 which the radial artery and its veins are winding. The fleshy bellies 



