FRACTURE OF THE LOWER END OF THE RADIUS (COLLES'S FRACTURE).—ThiS is, after fracture of the ribs, the commonest of all fractures. It is generally pro duced by a fall upon the palm of the hand. The line of fracture runs irregu larly across the bone within an inch of its articular edge. In the young it com monly follows the epiphysial line. The lower fragment is tilted back and im pacted. It may be comminuted. The upward displacement is not great, but the tilting and crushing carry the styloid process of the radius to a higher level than that of the ulna, which is made prominent by the shifting over of the carpus. The periosteum on the back of the radius remains untorn. The styloid process or shaft of the ulna may be broken. Rarely the, internal lateral liga ment is torn.
The characteristic symptoms are the so-called "silver-fork" deformity, a back ward displacement of the whole hand and the lower end of the radius, producing a swelling over the back of the wrist and a deep crease in the front. The styloid process of the ulna is prominent and lower than that of the radius. Crepitus and mobility are usually absent. There is a line of tenderness along the line of fracture.
The diagnosis from dislocation is given under that heading.
Treatment. — The simplest way to break up the impaction is for the sur geon to grasp the forearm firmly just above the fracture. With the other hand he then grasps the injured hand, placing his thumb lightly on the back of the lower fragment. Dorsal flexion is made
until the patient complains of pain, and then with a sudden movement the dorsal flexion is increased and simultaneously strong pressure is made on the lower fragment. In a moment the fracture begins to give, the dorsal is quickly ex changed for palmar flexion, the wrist being pried backward, and the resultant crepitus announces the dissolution of the impaction. Inspection should then show that the "silver-fork" deformity has dis appeared. The impaction once thor oughly broken up, the bones tend to re main reduced, and should be immobil ized by anterior and posterior wooden splints, which need not extend so far up the forearm as for fractures of the shaft (q. v.). Massage is very useful to shorten the convalescence and can best be used if, instead of wooden splints, molded plaster ones are used, extending from the middle of the forearm to the metacarpo phalangeal joint both in front and be hind. The hand is most comfortable in slight dorsal flexion. Its position bears no particular reference to that of the fragments. A simple band of adhesive plaster around the wrist is said to de crease the prominence of the ulna, and, indeed, seems to be the only splint neces sary in some few cases. The fingers must be exercised after the tenth day.