20. When the luxation is of long standing, it is always attended with more or less difficulty, occasioned by the adhesions of the surrounding soft parts to the articulating surfaces, by the thickening of the capsule, which diminishes the size of its opening, by the rigidity contracted by the whole part, &c. It is, in such cases, useful to employ emollient applications for some time previously to attempting the reduction, in order to produce such a relaxation, and diminution of the congestion, as may favour the efforts of the surgeon.
21. The first patient whom Desault visited at the Hotel-Dieu in quality of surgeon in chief, had a luxation forward, of more than two months standing, in which the use of these means facilitated the reduction: but they are sometimes insufficient, and then the radius remains immoveable, and the forearm performs its motions but partially.
22. It would seem as if nature, always industrious to provide, amid the disorders of our organs, some resources for the exercise of their functions, has been desirous of preventing here, the inconvenience attendant on a failure of reduction, by rendering luxations backward much more difficult than those forward. Indeed if the fore-arm be kept constantly in a state of supination, it will be much less useful, than if it were always in a state of pronation, the situation in which most of the motions necessary to our existence are performed.
§ VI.
OF THE SUBSEQUENT TREATMENT.
23. When the reduction is finished, the articulating surfaces have sometimes a great tendency to be displaced, by the different movements of the fore-arm, a tendency of which we may easily form an idea, if we observe, that in a state of pronation, the head of the ulna presses against the back part of the strained capsule, and consequently against its opening, when the luxation has been forward: a contrary state of things occurs in a luxation backward. Whence it is always prudent to avoid, for some time, the motions of pronation and supination, according to the direction of the displacement.
24. Should the tendency to displacement be very great, it will be necessary to adopt the simple method pointed out in a case already published by Desault.
Case I. The case was a luxation forward, which was easily reduced. But the easier the reduction, the more difficult was it to retain the replaced parts. This was at length accomplished, by fixing the fore-arm in a state of supination, and applying one thick compress behind the ulna, while the radius was pushed backward by another compress, placed on its anterior part, both secured by a common roller. This apparatus was continued for the space of a month, after which the reduced bones remained in their natural situation. The patient began, at first, to perform gentle motions of the wrist, avoiding those of pronation, on which he afterwards ventured by degrees, and with great caution.