Dislocation# is described on p. 65.

#Paralytic Deformities--Paralytic Dislocation of the Shoulder.#--The
muscles in the region of the shoulder may have their innervation
interfered with as a result of various conditions, of which
poliomyelitis and injuries of the brachial plexus at birth are the
most important. The capsular ligament of the shoulder-joint, being no
longer kept tense by the scapular muscles--especially the deltoid and
lateral rotators--becomes relaxed, and is gradually stretched by the
weight of the arm. The appearances are characteristic; the muscles of
the shoulder are wasted, the acromion is prominent, and between it and
the upper end of the humerus there is a marked hollow into which one
or more fingers may be inserted. The arm hangs flaccid by the side,
rotated medially and pronated, and moves in a flail-like fashion in
all directions, the patient having little control over it. The best
results are obtained by the transplantation of muscles, the trapezius
being detached from the clavicle and stitched to the surface of the
deltoid, and the upper arm fixed in the position of horizontal
abduction with the arm rotated laterally and supinated. Bradford
inserts a portion of the trapezius into the humeral insertion of the
deltoid. When these methods are impracticable, the upper arm may be
fixed to the trunk by some form of apparatus, or arthrodesis is
performed so that the movements of the scapula are communicated to the
upper arm; the best attitude for ankylosis is one of abduction with
medial rotation, so that the hand can be brought to the mouth.

In cases of poliomyelitis, when all the muscles governing the elbow
are paralysed while the muscles of the hand have escaped, it may be of
great service to fix this joint permanently at rather less than a
right angle. This may be effected by arthrodesis, or by removing an
extensive diamond-shaped portion of skin from the flexor aspect of the
joint and bringing the raw surfaces together, commencing the stitching
at the lateral apices of the gap.

[Illustration: FIG. 166.--Arrested Growth and Wasting of Tissues of
Right Upper Extremity, the result of Anterior Poliomyelitis in
childhood.]

#Congenital Dislocations at the Elbow.#--_The head of the radius_ may
be dislocated forwards, backwards, or laterally--usually in
association with imperfect development of the radius and of the
lateral condyle of the humerus. When the displaced head of the bone
interferes