REGION OF THE WRIST. 343 



of Joints," Dublin, 1847, that the name Colles's fracture has become generally 

 accepted. Mr. Colles placed the injury i^ inches (about 4 cm.) above the joint. 

 Mr. Smith placed it from ^ in. to i in. (6 to 25 mm. ) above the joint. Most recent 

 writers include all fractures within 4 cm. (i y 2 in. ) of the lower edge of the radius 

 under this name, though some few go still higher. When the line of fracture lies 

 more than 4 cm. above the joint it loses the characteristics of a Colles's fracture and 

 partakes of those of fractures of the shaft ; hence we will not go beyond that limit. 



The line of fracture is most commonly found, as stated by Robt. W. Smith, 

 from 6 to 25 mm. (^ to i in.) above the joint. It passes almost transversely 

 across the bone or inclines slightly downward to the ulnar side. It also lies nearer 

 the joint on the anterior surface and inclines backward and upward toward the elbow. 

 Hence the direction is from above downward and forward (Fig. 353). 



It is produced while the hand is extended (dorsally flexed) either by direct 

 transmission of the force from the palmar surface of the wrist or by tension of the 

 anterior radiocarpal ligament. 



The lower fragment is displaced upward and backward on the shaft of the 

 radius. This causes it to be tilted backward so that the articular surface is rotated 

 on a transverse axis more in the direction of the dorsum than normal and the hand is 

 also carried toward the radial side. The dorsal displacement is due to the direction 

 of the violence and not to muscular action. The radial side of the fragment is 

 displaced upward more than the ulnar because the triangular fibrocartilage retains its 



FIG. 354. Colles's fracture of the radius, showing inclination of hand toward the radial side and prominence of 

 the styloid process of the ulna. (From author's sketch.) 



radio-ulnar attachments. This prevents the ulnar side from rising, while the radial 

 side is pulled up by the radial flexor and extensor musdes. If the fracture is not 

 extremely close to the joint the brachioradialis will pull the lower fragment toward 

 the radial side and up toward the elbow. 



As the hand is attached to the radius it follows the lower fragment ; the extensor 

 muscles of the thumb, the flexor carpi radialis, and the two extensor carpi radialis 

 muscles all tend to aid the brachioradialis in producing the displacement toward 

 the radial side (Fig. 354). 



The lower fragment is displaced toward the dorsum and the upper fragment 

 toward the palmar surface. This produces the ' ' silver fork deformity' ' of 

 Velpeau. This dorsal projection is sometimes increased by the presence of the 

 "carpal tumor," a swelling due to effusion almost directly above the joint. The 

 projection of the upper fragment toward the palmar surface and the effusion in the 

 sheaths of the flexor tendons cause a protrusion on the anterior surface of the wrist 

 and a marked increase in the lower anterior radiocarpal crease. 



To reduce the deformity the upper fragment is firmly grasped with one hand 

 while with the other the hand of the patient is forcibly adducted (toward the ulnar 

 side) and then sharply flexed. This drags the distal fragment down and forward off 

 of the proximal one. To retain the fragments in position some surgeons use a pistol- 

 shaped splint to hold the hand turned toward the ulnar side and place a graduated 

 compress on the palmar surface with its base opposite the line of fracture and its 

 apex upward and another pad on the dorsal surface with its apex downward over the 

 hand. Other surgeons place the hand in a flexed position, allowing it to hang. 



