particularly in young subjects.

The #supra-condylar# fracture usually results from a fall on the
outstretched hand with the forearm partly flexed, from a direct blow,
or from a twisting form of violence. The line of fracture is generally
transverse, or but slightly oblique from behind downwards and
forwards, so that the lower fragment is forced backward together with
the bones of the forearm, simulating backward dislocation of the
elbow; the lower end of the upper fragment lies in front (Fig. 33).

[Illustration: FIG. 33.--Radiogram of Supra-condylar Fracture of
Humerus, in a child aet. 7.]

_Clinical Features._--The elbow is flexed at an angle of 120 deg. or 130 deg.,
and the forearm, held semi-pronated, is supported by the other hand.
Around the seat of fracture great swelling rapidly ensues. The
olecranon projects behind, but the mutual relations of the bony points
of the elbow are unaltered. The lower end of the upper fragment may be
felt in front above the level of the joint, as a rough and sharp
projection, and this sometimes pierces the soft parts and renders the
fracture compound. Movement at the joint is possible, but unnatural
mobility may be detected above the level of the joint. Crepitus and
localised tenderness may be elicited. The displacement is readily
reduced by manipulation, but usually returns when the support is
withdrawn. The arm is shortened to the extent of about half an inch.

In rare cases the obliquity of the fracture is downward and backward,
and the lower fragment is displaced forward.

The #inter-condylar# fracture is a combination of the supra-condylar
with a vertical split running through the articular surface, and so
implicating the joint. The condyles are thus separated from one
another, as well as from the shaft, by a T- or Y-shaped cleft. As such
fractures usually result from severe forms of direct violence, they
are often comminuted and compound. In addition to the signs of
supra-condylar fracture, the joint is filled with blood. The condyles
may be felt to move upon one another, and coarse crepitus, which has
been likened to the feeling of a bag of beans, may be elicited if the
fragments are comminuted.

[Illustration: FIG. 34.--Radiogram of T-shaped Fracture of Lower End
of Humerus.]

#Separation of the lower epiphysis# of the humerus is met with in
children of three or four years of age, but it may occur up to the
thirteenth or fourteenth year. The more common lesion, how