§ VII.
OF THE REDUCTION AND THE MEANS OF RETAINING IT.
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.
MEMOIR IV.
ON FRACTURES OF THE ACROMION, AND OF THE LOWER ANGLE OF THE SCAPULA.
§ I.