OF THE MUSCLES OF THE UPPER EXTREMITY. 323 



patient at the same time loses the power of extending the forearm. The treatment consists in 

 relaxing the Triceps by extending the forearm, and retaining it in this position by means of a 

 long straight splint applied to the front of the arm ; the fragments are thus brought into closer 

 apposition, and may be further approximated by drawing down the upper fragment. Union is 

 generally ligamentous. 



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 

 from the large number of muscles which surround it; but the movements of pronation and supi- 

 nation are entirely lost. The upper fragment is drawn outwards by the Supinator brevis, iis 

 extent of displacement being limited by the attachment of the orbicular ligament. The lower 

 fragment is drawn forwards and slightly upwards by the Biceps, and inwards by the Pronator 

 radii teres, its displacement forwards and upwards being counteracted in some degree by the 

 Supinator brevis. The treatment essentially consists in relaxing the Biceps, Supinator brevis, 

 and Pronator radii 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. 



Fracture of the radius (fig. 184) is more common than fracture of the ulna, on account of the 

 connection of the former with the wrist. Fracture of the shaft of the radius near its centre may 

 occur from direct violence, but more fre- 

 quently from a fall forwards, the entire weight 



of the body being received on the wrist and Fig. 184. Fracture of the Shaft of the Radius. 



hand. The upper fragment is drawn up- 

 wards by the Biceps, and inwards by the 

 Pronator radii teres, holding a position mid- 

 way befween pronation and supination, and 

 a degree of fulness in the upper half of the 

 forearm is thus produced ; the lower frag- 

 ment is drawn downwards and inwards 

 towards the ulna by the Pronator quadratus, 

 and thrown into a state of pronation by the 

 same muscle ; at the same time, the Supi- 

 nator longus, by elevating the styloid pro- 

 cess, into which it is inserted, will serve to 

 depress still more the upper end of the lower 



fragment towards 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 then 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 Supinator longus, 

 and elevate the lower fragment to the level of the upper one. 



Fracture of the shaft of the ulna is not a common accident; it is usually caused by direct vio- 

 lence. Its more protected position on the inner side of the limb, the greater strength of its shaft, 

 and its indirect connection with the wrist, render it less liable to injury than the radius. It usu- 

 ally occurs a little below the centre, which is the weakest part of the bone. The upper fragment 

 retains its usual position ; but the lower fragment is drawn outwards towards the radius by the 

 Pronator quadratus, producing a well-marked depression at the seat of fracture, and some fulness 

 on the dorsal and palmar surfaces of the forearm. The fracture is easily reduced by extension 

 from the wrist and forearm. The forearm should be flexed, and placed in a position midway 

 between pronation and supination, and well-padded splints applied from the elbow to the ends of 

 the fingers. 



Fracture of the shafts of the radius and ulna together is not a common accident; it may arise 

 from a direct blow, or from indirect violence. The lower fragments are drawn upwards, some- 

 times forwards, sometimes backwards, according to the direction of the fracture, by the combined 

 actions of the Flexor and Extensor muscles, producing a degree of fulness on the dorsal or pal- 

 mar surface of the forearm; at the same time the two fragments are drawn into contact by the 

 Pronator quadratus, the radius in a state of pronation : the upper fragment of the radius is drawn 

 upwards and inwards by the Biceps and Pronator radii teres to a higher level than the ulna; the 

 upper portion of the ulna is slightly elevated by the Brachialis anticus. The fracture may be 

 reduced by extension from the wrist and elbow, and the forearm should be placed in the same 

 position as in fracture of the ulna. 



In the treatment of all cases of fracture of the bones of the forearm, the greatest care is requi- 

 site to prevent the ends of the bones from being drawn inwards towards the interosseous space : 

 if this is not carefully attended to, the radius and ulna may become anchylosed, and the move- 

 ments of pronation and supination entirely lost. To obviate this, the splints applied to the limb 

 should be well padded, so as to press the muscles down into their normal situation in the interos- 

 seous space, and so prevent the approximation of the fragments. 



Fracture of the lower end of the radius (fig. 185) is usually called Collet's fracture, from the 

 name of the eminent Dublin surgeon who f.rst accurately described it. It is generally produced 

 from the patient falling from a height, and alighting upon the hand, which receives the entire 

 weight of the body. This fracture usually takes place from half an inch to an inch above the 



