A fracture of the lower end of the radius _with forward displacement of the carpal fragment_, was first described by R. W. Smith of Dublin (_Colles' fracture reversed_, or #Smith's fracture#) (Fig. 47). It is nearly always due to forcible flexion, as from a fall on the back of the hand. Like Colles' fracture, it may be transverse or slightly oblique, impacted, or comminuted. The deformity is characterised by an elevation on the dorsum running obliquely upwards from the ulnar to the radial side of the wrist, and caused by the head of the ulna, which remains in position, and the distal end of the proximal fragment. Below this, over the position of the distal radial fragment, is a gradual slope downwards on to the dorsum of the hand. Anteriorly there is a prominence in the flexure of the wrist, and the distal fragment may be felt under the flexor tendons. The hand deviates to the radial side, and thereby still further increases the prominence caused by the lower end of the ulna. The radial styloid is displaced forward, upward, and to the radial side, and the ulnar styloid may be torn off. [Illustration: FIG. 47.--Radiogram of Smith's Fracture. (Sir George T. Beatson's case.)] When the deformity is not well marked, this injury may be mistaken for forward dislocation of the wrist, for fracture of both bones low down, or for sprain of the joint. The _treatment_ is carried out on the same lines as in Colles' fracture. _Longitudinal fractures_ of the lower end of the radius opening into the joint usually result from the hand being crushed by a heavy weight or in machinery. They are often compound and comminuted. #Separation of the lower epiphysis# of the radius, which is on the same level as that of the ulna and lies above the level of the synovial membrane of the wrist-joint, is comparatively common between the ages of seven and eighteen, especially in boys, and is caused by the same forms of violence as produce Colles' fracture. Although clinically the appearances in these two injuries bear a general resemblance to one another, separation of the epiphysis may usually be identified by the directly transverse line of the dorsal and palmar projections, the folding of the skin observed in the palmar depression, the absence of abduction of the hand and the ease with which muffled crepitus can be elicited (E. H. Bennett). The deformity is readily reduced, and the fragments are easily retained in position. This injury is often complicated with fracture of the shaft or styloid process of the ulna, or with dislocation of the radio-ulnar joint, and it is not infrequently compound, the lower end of the shaft being driven through the skin on the palmar aspect immediately above the wrist. Impairment of growth in the radius seldom occurs; when it does, it results in a valgus condition of the hand (Fig. 48), calling for resection of the lower end of the ulna.