tion of the epiphysial
portion_ of the coracoid may occur up to the seventeenth year.

The _treatment_ consists in placing the arm across the front of the
chest, to relax the muscles causing the displacement, and retaining it
in that position by a sling and roller bandage.

FRACTURE OF THE UPPER END OF THE HUMERUS

It is most convenient to study fractures of the upper end of the
humerus in the following order: (1) fracture of the surgical neck; (2)
separation of the epiphysis; (3) fracture of head, anatomical neck, or
tuberosities.

[Illustration: FIG. 27.--Fracture of Surgical Neck of Humerus, united
with Angular Displacement.]

#Fracture of the Surgical Neck.#--The surgical neck of the humerus
extends from the level of the epiphysial junction to the insertion of
the pectoralis major and teres major muscles, and it is within these
limits that most fractures of the upper end of bone occur. This
fracture is most common in adults, and usually follows direct violence
applied to the shoulder, but may result from a fall on the hand or
elbow, or from violent muscular action, as, for example, in throwing a
stone. It is usually transverse, and there is often little or no
displacement, the fragments being retained in position by the long
tendon of the biceps and the long head of the triceps. When the
fracture is oblique, the fragments are often comminuted, and sometimes
impacted. The displacement of the upper fragment seems to depend upon
the attitude of the limb at the moment of fracture. When the upper arm
is approximated to the side, the upper fragment retains its vertical
position, but is slightly rotated laterally by the muscles inserted
into the greater tuberosity, while the lower fragment is drawn upwards
and medially towards the coracoid process by the muscles inserted into
the inter-tubercular groove and the longitudinal muscles of the upper
arm, and can be felt in the axilla. The elbow points laterally and
backwards, and the upper arm is shortened. The shoulder retains its
rotundity, but there is a slight hollow some distance below the
acromion. On grasping the elbow and moving the shaft, it is found that
the head and tuberosities do not move with it, and unnatural mobility
and crepitus at the seat of fracture may be detected. When the upper
arm is abducted at the moment of fracture, the upper fragment is
retained in that position by the lateral rotator and abductor muscles
inserted into it, while the lower fra