16. From this two-fold cause of displacement, arises a two-fold indication in the arrangement and application of the apparatus. These are, 1st, to render the clavicle immoveable, by restraining every kind of motion in the shoulder and arm; 2dly, to retain the extremity of the clavicle outward, a direction opposed to that in which it has a tendency to be displaced. But if to those indications we compare the forms of apparatus hitherto used, we will readily perceive that they are insufficient to fulfil them.
17. The figure of 8 bandage, so generally in use, and all the various modifications, under which it has been revived, without being improved, fix the clavicle in the very direction most favourable to a displacement, and even do it in the very manner in which that accident is sometimes brought about; as maybe seen in the history of the case of the porter (6). This bandage does not, under any of its modifications, prevent the motions of the shoulder, because it does not restrain those of the arm, which remains free and unencumbered. Far from constituting an antagonist power to, it even co-operates with, that which has produced the displacement. (For further light on this subject, see what has been already said on the fracture of the clavicle, pages [22] and [25].)
Bell, in condemning the figure of 8 bandage, not so much because of its action being insufficient, as because of its obstructing respiration, proposes, as a substitute for it, a kind of machine analogous to the iron cross of Heister, which, being fixed by straps passing under the arm-pit, and round the neck and body, is intended to retain the parts firm and immoveable. But the motions of the arm not being restrained, nor the action of the muscles of the shoulder opposed by an antagonizing power, places this piece of apparatus in the same class with those, which, from not being devised and constructed on a proper view and conception of the causes of displacement, have no affinity to rational practice.
18. The apparatus for a continued extension, invented by Desault, for fractures of the clavicle, fulfil here all those indications in which the others fail.
By this, 1st. The aim, being firmly fixed against the side, by means of the roller (c c [Fig. 3]), can communicate no motion either to the shoulder, or the clavicle. 2dly. The shoulder itself, being forcibly drawn outward, with the upper extremity of the humerus, by the action of the kind of lever into which this bone is converted, and to which the bolster (a b [Fig. 1]) serves as a fulcrum, cannot, by its movements, derange the luxated bone. 3dly. The sternal extremity, being drawn both by the muscles which tend to displace it inwardly, and by the bandage which acts on it in an opposite direction, remains fixed between those two antagonizing forces, which thus destroy each other. Hence the apparatus of Desault, when accurately applied, offers to both of these powers of displacement, a resistance perfectly calculated to combat them.
20. We must, however, admit that this apparatus partakes of one inconvenience, common indeed to all bandages, but which is perhaps more particularly applicable to this in consequence of the numerous casts of the rollers that form it, namely, the great facility with which it becomes relaxed. Hence one cause of displacement, which the most exact and scrupulous attention cannot at all times prevent.
Case. Desault had, for a long time, the care of a patient, whose luxation, having been neglected for four days, was reduced on the fifth, by a surgeon, who, for the purpose of retaining it, employed a bandage of a particular kind. An hour afterwards, a motion of the shoulder backward, displaced the luxated extremity: a new reduction was the consequence; on the day following, another displacement, and so on in succession, for ten days, at the expiration of which, Desault being consulted, applied to the part the bandage formerly described.
On being examined the next day, the apparatus was found in a favourable state. On the day following, a slight displacement rendered necessary a new application of the bandage, which, this time, continued longer than before. But, about the expiration of the third day, the projection of the bone was again considerable. Finally, the patient recovered, with a very perceptible protuberance in front of the sternum, and a difficulty of motion, great at first, but less afterwards, and which exercise succeeded ultimately in removing.
21. The application of the apparatus differs from that intended for a fracture of the clavicle, only in this, that it is of service to place on the luxated extremity, graduated compresses,[7] calculated to make pressure backward and outward, and which are to be secured by the turns of the roller (b [Fig. 4]).