PLATE 41.

Various Fractures of the Forearm and Normal Epiphyseal Lines. Fig. 1.-Specimen of fracture of the forearm (right) with cohesion of the callus of both bones at the seat of fracture. This unfortunate condition is due partly to the abundance of callus and more particularly to the fact that the two fragments of each bone tend to converge. The illustration distinctly shows this abnormal direction of the four fragments. It is probable that the splint in this case was too narrow, and that the bones were forced together by the pressure of the bandage.

Fig. 2.-Isolated fracture of the radius above its middle, showing the effects of the biceps on the position of the upper fragment. This illustration, which was faithfully copied from nature (artificial specimen), represents the forearm and hand with a portion of the arm. The forearm is in pronation, but the upper fragment of the humerus is rotated outward (supination) by the action of the biceps muscle, the function of which being, as is well known, supination and flexion of the supinated forearm. The supination of the upper fragment is recognized by the position of the tuberosity on the radius, by the point of insertion of the biceps, and especially by careful examination of the line of fracture; on the lower fragment a loss of substance is seen on the lower border of the fractured surface corresponding to a slight projection visible on the upper fragment. The projection and the loss of substance are not opposite one another; the outward rotation of the upper fragment (supination) having caused the projection to move through almost 180 degrees. The lesson to be drawn from this is that even in isolated fracture of the radius the arm must be dressed in supination or midway between supination and pronation.

Fig. 3.-Epiphyses of the bones that enter into the formation of the elbow-joint, showing various centers of ossification. Frontal section, right side. The posterior sawed surface seen from in front. We see the center of ossification of the capitellum, the internal condyle, and the head of the radius.

Fig. 3 a.-Sagittal section through the upper end of an ulna from a child.

Fig. 4. Lower epiphyses of the bones of the forearm.

supination, according to general principles. For this reason the treatment of fracture of the forearm is particu

larly important and requires expert skill and conscientious attention on the part of the surgeon. The object must be to secure bony union of the fragments with each bone in good position, and unimpaired motion both of the adjacent articulations and of the two bones themselves. Care is also required not to produce any injury with the bandage. The dressing may do harm if the pressure of the circular bandage is such as to force the bones apart and bring the extremities of the fragments together at the seat of fracture in such a way as to induce complete cohesion by an abundant callus-formation (Plate 41, Fig. 1). The splint must therefore be a broad one; it may be improvised from cardboard reinforced with small strips of wood broad enough to project beyond the forearm on each side. Another important point, after careful reduction, is the primary position of the forearm. The elbow is bent at a right angle and the wrist extended; and both joints must be included in the dressing. The chief question is, however, Should the forearm be in pronation or in supination? From what has just been said, it is evident that a position in which the two bones cross each other must be avoided

at any cost. From this point of view parallel position of the bones-that is, complete supination-is the most desirable position. Another factor to be considered is the effect of the muscles on the fragments. Plate 41, figure 2, serves to remind us of the effect of the biceps on the upper fragment of the radius. This muscle is a supinator. Should the limb therefore be bandaged with the hand in pronation, while the upper fragment of the radius is in supination, the treatment would result in a very imperfect recovery with loss of supination.

Furthermore, an angular displacement of the radius at the seat of fracture may interfere with the movement or unfolding of the interosseous ligament, thereby diminishing the excursions of the bone in supination.

We conclude, therefore, that after careful reduction of the fragments, the arm is to be fixed in a position of sup

ination on a splint that must not be too narrow. The splint may be applied either to the dorsal or the volar side of the arm; or, better still, fixation may be secured by the use of two splints, a long and a short one. It is in these fractures that especial care becomes necessary to see that the splints are well padded; that the bandage is

not too tight; and that the hand and fingers are left exposed for constant inspection. For it is in such cases that neglect of these precautions, especially the application of a circular plaster-of-Paris bandage immediately after the injury, is most apt to produce gangrene and ischemia (see General Considerations). The dressing should be changed