m, or from direct violence, but may be
caused by a fall on the lateral side of the elbow.

The epiphysis, especially in young children, may be separated without
being displaced, or the displacement may be incomplete.

When the epiphysis is completely separated from the shaft, the
clinical features closely resemble those of fracture of the surgical
neck, and the diagnosis is made by a consideration of the age of the
patient, and the muffled character of the crepitus, when it can be
elicited. The upper end of the diaphysis forms a projecting ridge
which may be felt below and in front of the acromion. The diagnosis
can usually be established by the use of the X-rays (Fig. 30).
Dislocation is rare at the age when separation of the epiphysis
occurs.

Reduction is often difficult on account of the periosteum and other
soft tissues getting between the fragments, and on account of the
small size of the upper fragment. Union almost invariably results, but
the growth of the limb may be interfered with and its shape altered,
especially when the injury occurs at an early age and its nature is
overlooked.

_Treatment._--This injury is treated on the same general lines as
fracture of the surgical neck. General anaesthesia is almost always
necessary to secure satisfactory reduction, and retention is most
easily secured if the patient is confined to bed with the upper arm
fixed in the fully abducted position. Operative treatment is called
for in exceptional cases.

#Fractures of the Head, Anatomical Neck, and Tuberosities of
Humerus.#--These fractures are met with as accompaniments of
dislocation of the shoulder, and as results of gun-shot injuries,
blows, or falls.

In sub-coracoid dislocation the _head_ of the humerus may be indented
by coming in contact with the anterior edge of the glenoid cavity (F.
M. Caird).

The _anatomical neck_ may be fractured in an old person by a direct
blow on the shoulder. In a few cases the fracture is entirely
intra-capsular, the head of the bone remaining loose in the cavity of
the joint. As a rule, however, the fracture passes laterally and
implicates the tuberosities. In some cases there is impaction, and in
others comminution of the fragments. The use of the X-rays has shown
that in many cases in which prolonged stiffness has followed a severe
blow of the shoulder, there has been a fracture of the anatomical
neck.

The _tuberosities_ may be implicated in other fractures in this region