FRACTURES OF THE UPPER EXTREMITY. 401 



applied to the front of the arm ; the fragments are thus brought into close 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 

 bv 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 prona- 

 tion and supination are entirely lost. The upper fragment is drawn outwards by the Supinator 

 Brevis, its 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. 251) is more common than fracture of the ulna, on account of 

 the connection of the former bone*with the wrist. Fracture of the shaft of the radius near its 

 centre may occur from direct violence, but 



more frequently from a fall forwards, the Fig. 251. Fracture of the Shaft of the Radius, 

 weight of the body being received on the wrist 

 and hand. The upper fragment is drawn up- 

 wards by the Biceps, and inwards by the Pro- 

 nator Radii Teres, holding a position midway 

 between pronation and supination, and a de- 

 gree of fulness in the upper half of the forearm 

 is thus produced ; the lower fragment 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 Supinator Longus, by elevating 

 the styloid process, into which it is inserted, will serve to depress the upper end of the lower 

 fragment still more 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 supinatiou ; 

 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 

 violence. The more protected position of the ulna 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. The fracture usually occurs a little below the middle, 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 de- 

 pression 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 very common accident; it may 

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

 sometimes 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 palmar 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 prouation ; 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 

 requisite to prevent the ends of the bones from being drawn inwards towards the interosseous 

 space ; if this point is not carefully attended to, the radius and ulna may become anchylosed, 

 and the movements 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 iuterosseous space, and thus prevent the approximation of the fragments. 



Fracture of the lower end of the radius (Fig. 252) is usually called Colles' s fracture, from the 

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

 by the patient falling upon the hand, which receives the entire weight of the body. This frac- 

 ture usually takes place from half an inch to an inch above the articular surface, if it occurs in 

 the adult ; but in the child, before the age of sixteen, it is more frequently a separation of the 

 epiphysis from the diaphysis. The displacement which is produced is very considerable, and 

 bears some resemblance to dislocation of the carpus backwards, from which it should be care- 

 fully distinguished. The lower fragment is drawn upwards and backwards behind the upper 

 fragment by the combined actions of the Supinator Longus and the flexors and the extensors 

 26 



