APPLIED ANATOMY OF THE UPPER EXTREMITY 



501 



shown in Fig. 364, the lower fragment is drawn upward and forward, causing a considerable 

 prominence in front, and the upper fragment projects backward beneath the tendon of the 

 Triceps muscle. 



Fracture of the olecranon process (Fig. 375) is a frequent accident. The detached fragment 

 is displaced upward, by the action of the Triceps muscle, from half an inch to two inches; the 

 prominence of the elbow is consequently lost, and a deep hollow is felt at the back part of the 

 joint, which is much increased on flexing the limb. The patient at the same time loses, more 

 or less, the power of extending the forearm. The treatment consists in relaxing the Triceps by 

 extending the limb, and retaining it in the 

 extended position by means of a long straight 

 splint applied to the front of the arm; the 

 fragments are thus brought into close appo- 

 sition, and may be further approximated by 

 drawing down the upper fragment. The frag- 

 ments may be wired together and thus prevent 

 the formation of a ligamentous union, as is 

 generally the case when wiring is not em- 

 ployed; passive motion must be instituted at 

 the end of the third week to prevent ankylosis. 



Fracture of the neck of the radius is an 

 exceedingly rare accident, and is generally 



caused by direct violence. Its diagnosis is somewhat obscure, on account of the slight deformity 

 visible, the injured part being surrounded by a large number of muscles; but the movements of 

 pronation and supination are entirely lost. The upper fragment is drawn outward by the 

 Supinator [brevis], the extent of displacement being limited by the attachment of the orbicular 

 ligament. The lower fragment is drawn forward and slightly upward by the Biceps, and inward by 

 the Pronator teres, its displacement forward and upward being counteracted in some degree by 

 the Supinator. The treatment essentially consists in relaxing the Biceps, Supinator, and Pro- 

 nator teres muscles by flexing the forearm, and placing it in a position midway between pronation 

 and supination, extension having been previously made so as to bring the parts in apposition. 



FIG. 376. Fracture of the shaft of the radius. 



FIG. 377. Fracture of the lower end of the radius. 



In fracture of the radius below the insertion of the Biceps, but above the insertion of the 

 Pronator teres, the upper fragment is strongly supinated by the Biceps and Supinator, and at 

 the same time drawn forward and flexed by the Biceps; the lower fragment is pronated and 

 drawn inward toward the ulna by the Pronators. Thus, there is extreme displacement with 

 very little deformity. In treating such a fracture the arm must be put up in a position of 

 supination, otherwise union will take place with great impairment of the movements of the 

 hand. In fractures of the radius below the insertion of the Pronator teres (Fig. 376), the upper 

 fragment is drawn upward by the Biceps and inward by the Pronator teres, holding a position 

 midway between pronation and supination, and a degree of fulness in the upper half of the fore- 

 arm is thus produced; the lower fragment is drawn downward and inward toward the ulna by 

 the Pronator quadratus, and thrown into a state of pronation by the same muscle; at the same 

 time, the Brachioradialis, by elevating the styloid process, into which it is inserted, will serve to 

 depress the upper end of the lower fragment still more toward the ulna. In order to relax the 

 opposing muscles the forearm should be bent, and the limb placed in a position midway between 

 pronation and supination; the fracture is then easily reduced by extension from the wrist and 

 elbow; well-padded splints should be applied on both sides of the forearm from the elbow to 

 the wrist; the hand, being allowed to fall, will, by its own weight, counteract the action of the 

 Pronator quadratus and of the Brachioradialis, and elevate the lower fragment to the level of 

 the upper one. 



