rognosis._--The ultimate prognosis in dislocations of the shoulder
should always be guarded. The axillary nerve may be stretched or torn,
and this may lead to atrophy of the deltoid; or other branches of the
brachial plexus may be injured and the muscles they supply permanently
weakened. In a certain number of cases traumatic neuritis has resulted
in serious disability of the limb. The movements of the shoulder-joint
may be restricted by cicatricial contraction of the torn portion of
the capsule and of the damaged muscles. A marked tendency to recurrent
dislocation may follow if abduction movements are permitted before
repair of the capsule has had time to occur.

#Dislocation of the Shoulder complicated with Fracture of the Upper
End of the Humerus.#--In these injuries the dislocation is almost
always of the sub-coracoid variety, and the most common fractures by
which it is complicated are those of the surgical neck, the anatomical
neck, or the greater tuberosity. The most common cause is a fall
directly on the shoulder, and it seems probable that the head of the
bone is first dislocated, and, the force continuing to act, the upper
end of the humerus is then broken; or the two lesions may be produced
synchronously.

When seen soon after the accident, the existence of the fracture of
the humerus is liable to be overlooked, the condition being mistaken
for dislocation alone, or for a fracture through the neck of the
scapula. On careful examination under an anaesthetic, however, it is
observed that not only is the head of the humerus absent from the
glenoid cavity, but that it does not move with the rest of the bone,
abnormal mobility and crepitus are recognised at the seat of fracture,
and the upper arm is shortened. The extravasation in the axilla is
usually greater than that accompanying a simple dislocation, and the
pain and shock are more severe. A fracture through the neck of the
scapula alone is readily recognised by the ease with which the
deformity is reduced, and the way in which it at once recurs when the
support is withdrawn. In many cases it is only by the aid of a
radiogram that an accurate diagnosis can be made (Fig. 25).

[Illustration: FIG. 25.--Dislocation of Shoulder with Fracture of Neck
of Humerus.

(Sir Robert Jones' case. Radiogram by Dr. D. Morgan.)]

_Treatment._--Unless the dislocation is reduced at once, the movements
of the arm are certain to be seriously restricted, and painful
pressure