5. Two different processes have been long in use for the reduction of
fractures of the acromion. One consists in elevating the arm almost to
a right angle with the body, in order, as Heister remarks, to throw
the deltoid muscle into a state of relaxation, and then to be able,
with the fingers, to place the fragments in their natural situation.
In the other mode, the humerus is suffered to retain the position it
has assumed, that is, to hang down the side; the surgeon then taking
hold of the elbow, pushes it vertically from below upwards, in such
a manner, that the head of the bone, pressing against the acromion,
elevates and replaces it.
6. Petit seems to have adopted indiscriminately these two methods, one
of which, however, is greatly superior to the other. Indeed, it is
evident, that if the humerus be removed from the trunk, its head will
necessarily sink down in the glenoid cavity. Being thus separated from
the fractured apophysis, it leaves beneath it a hollow or vacancy,
into which the fragment will be pushed, should it be in any measure,
compressed by the casts of the roller, during the application of the
bandage.
7. On the other hand, if the arm still fixed against the side, be
pushed upwards, it will afford to the acromion a solid point of
support, which, during the application of the apparatus, will prevent
its displacement downwards. This consideration is unquestionably of
moment, during the process of reduction; but ought more particularly,
to command the attention of the practitioner, in the choice of means
destined to maintain the reduction.
§ III.