DISLOCATIONS OF THE THUMB AND FINGERS.
Dislocations of the Thumb are not infre quent, because of the liability of the thumb to injury from falls. The common form is back wards, but dislocation forwards may occur. The thumb consists of three bones—the metacarpal, connected with the bones of the wrist, and two phalanges (see Fig. 23, p. 62).
Now dislocation may occur at the joint be tween the wrist and metacarpal bone, or at the joint between the metacarpal bone and the first phalanx, or at the joint between the two phalanges.
The first is not common, the second and third are more common. The deformity in the second form is evident, the inner end of the first phalanx lies on the back of the outer end of the meta carpal bone, which projects strongly towards the palm. The thumb has thus got a peculiar double bend, and stands outwards sharply from the palm.
Treatment.--The difficulty in reduction is to get a large enough surface on which to make extension. If simple pulling by grasping the dislocated thumb with fingers and thumb, at the same time forcibly depressing the point of the thumb and drawing it downwards and for wards, is not sufficient, then place a clove-hitch (Fig. 56) on the thumb and pull with it. When
these have failed, then a thin strip of hard wood may be taken, 10 inches long and rather more than 1 inch wide, and shaped as shown in the figure (Fig. 60). At one end a series of holes is cut, through which strong tape about a yard long is passed, a separate piece of tape being required for each pair of holes. Loops are thus formed on one side of the wood which secure the thumb laid along the wood. Exten sion can then be practised by pulling on the wood to which the thumb is fixed ; and the reduction may be aided by bending backwards or forwards as may be required. Sometimes all these measures fail, owing, it is supposed, to the end of the bone being held by one of the muscles of the thumb, which must be cut before the bone can be returned.
Dislocation of the tip of the thumb may often be reduced by pressing the displaced end for wards with the thumb. After reduction a bandage should be applied to the thumb.
Dislocations of the Fingers are less fre quent than those of the thumb. They also are backwards and forwards, usually backwards. They are easily recognized, and should be re duced by the methods described for the thumb.