26. The reduction, in this case, is generally attended with but little
difficulty. The acromion being drawn outward, by the upper end of the
os humeri, which, by means of a fulcrum placed under the armpit, is
made to act as a lever of the first kind, is restored, without much
trouble, to its natural contact with the corresponding surface of the
clavicle. But, it soon becomes deranged again, unless it be retained
in its place by a proper apparatus. Now, on what principle ought
this apparatus to be constructed? To prevent the displacement, which
generally occurs from without inwards, it ought evidently to act from
within outwards. Whence it follows, that the rollers in the figure
of 8 bandage, recommended in this case by all writers, instead of
preventing, actually favour the displacement (17), because they act in
the same direction with, and therefore assist, the powers that produce
it.
27. Here, in like manner as in the preceding case, the bandage of
Desault fulfils with precision the indications of cure, because, by
it, the point of the shoulder is, particularly, drawn outward; and if,
in certain cases, a slight projection of the humeral extremity still
remains, it is to be attributed to the inefficacy of the means of
execution, and not to the principles on which they are founded.