As to what remains, it will be sufficient to show the insufficiency of the process of reduction (22), by means of the knee placed between the shoulders, in order to demonstrate the existence of a like insufficiency in all those forms of apparatus, which, as Brasdor remarks, have for their object a continuance, during the treatment, of the effect produced by that process.
31. On the other hand, those indications will be fulfilled with exactness, by such a form of apparatus as will render permanent the action of the means of reduction which were employed by Paul of Egina, by certain Arabian physicians, and by Pare; which have been renewed by Desault, and tend to draw the shoulder upward, backward, and outward (23 and 24).
Pecceti appears, in the last century, to have had a faint view of the proper indication on this subject, when, under the article of fractures, he advises the ball to be suffered to remain under the arm during the treatment of the injury. But the figure of 8 bandage, united to this expedient, counterbalances its effect, rendering it of no avail, and Pecceti was therefore no more successful than others, in obtaining a cure of the fracture, unaccompanied by deformity.
32. An overlapping more or less perceptible never failed to accompany the consolidation or knitting of the bone, and here, as in many other cases, practitioners laboured to explain what they knew not how to prevent. The impracticability of surrounding the part, as in other fractures, with a circular bandage, appeared to Heister, Petit, and Duverney, to be the cause of this deformity. They supposed that to be a superabundant callus, which was nothing but a displacement of the fragments. These visionary hypotheses ceased to exist, as soon as this displacement was prevented by a proper apparatus.
Desault sought for this form of apparatus, as well as for his other bandages, in the multiplied application of means already known, without inventing new ones. Bandages and compresses, easy to be procured, and already rendered familiar to surgeons by daily use, served him for the construction of his apparatus, for which several machines had been already proposed.
33. The pieces of which this apparatus is composed, are,
1st. Three rollers, three inches broad; the two first, six, and the other eight, ells long, each one rolled up separately.
2dly. A bolster or pad (a, b, [Fig. 1]), made in the form of a wedge, out of pieces of old linen. Its length should be equal to that of the humerus, its breadth four or five inches, and its thickness at the base (a), about three inches.
3dly. Two or three long compresses.
4thly. A small sling for the arm, ([Fig. 5]).