severe force applied directly to the point of
the thumb, driving the metacarpal against the greater multangular bone
(trapezium), and chipping off the palmar part of the articular
surface, but it may result from a blow with the closed fist. The rest
of the metacarpal slips backward, forming a prominence on the dorsal
aspect of the joint. The pain and swelling in the region of the
fracture often prevent crepitus being elicited, and as the deformity
is not at once evident, the nature of the injury is liable to be
overlooked. The fracture is recognised by the use of the X-rays.
Unless properly treated this injury may result in prolonged impairment
of function, full abduction and fine movements requiring close
apposition of the thumb being specially interfered with.

The _treatment_ consists in reducing the fracture by extension in the
attitude of full abduction and applying an accurately fitting pad over
the extremity of the displaced bone, maintained in position by a light
angular splint. This splint is first fixed to the extended and
abducted thumb, and while extension is made by pushing it downwards
the upper end is fixed to the wrist (Fig. 54 A). The apparatus is worn
for three weeks, being carefully readjusted from time to time to
maintain the extension and abduction. A moulded poroplastic splint
added on the same principle may be employed, and is more comfortable
(Fig. 54 B). Excellent results are obtained after reduction of the
displacement, by massage and movement from the first, and the support
merely of a figure-of-eight bandage (Pirie Watson).

[Illustration: FIG. 54.--A. Splint applied as used by Bennett. B.
Poroplastic Moulded Splint for Bennett's Fracture.]

#Fractures of phalanges# usually result from direct violence, and on
account of the superficial position of the bones, are often compound,
and attended with much bruising of soft parts. Force applied to the
distal end of the finger may also fracture a phalanx. The proximal
phalanges are broken oftener than the others. The deformity is usually
angular, with the apex towards the palm, and if union takes place in
this position, the power of grasping is interfered with. Unnatural
mobility and crepitus can usually be recognised, but, on account of
the swelling and tenderness, the fracture is apt to be overlooked.
Firm union takes place in two or three weeks. In oblique and
comminuted fractures, union may take place with overlapping, producing
a deformity w