Hence appears, both the necessity of placing a solid body, as Desault did, before the whole of the limb, to prevent its flexion, and the insufficiency of the apparatus proposed by Duverney and others, who directed to lay a thick compress on the fracture, to surround the elbow then by a circular one, to secure the whole by a kind of figure of 8 bandage, similar to that used in blood-letting, and, finally, to place the limb on a pillow, without further precaution.
55. Position alone evidently acts only on the lower fragment, which it directs towards the upper one. But it is also necessary to draw the upper fragment towards the lower one, and fix it there, and this is certainly the most difficult point; because, the triceps muscle having a constant tendency to contract, opposes its action to the approximation of the fragments, and indeed prevents it, if, as in the means usually proposed and adopted, the pieces of the bandage glide easily over each other.
56. These considerations determined Desault to search for some means which, being more efficacious than those already in use, might better fulfil the indications of the fracture. He accordingly invented the apparatus which we are about to describe; some ideas of this apparatus are indeed borrowed from other bandages. The success which attended the use of it at the Hotel-Dieu, will, without doubt, introduce it generally into rational practice, where the insufficiency of the old forms of apparatus is acknowledged.
1st, The fore-arm being placed in the position already directed (53), two assistants retain it in that situation, while the surgeon applies on its lower part the end of a roller five or six yards long, and about four inches wide, wet with some discutient liquid, making with it, at first, one or two circular turns to fasten it. Then ascending from below upwards, he covers the whole of the fore-arm with oblique and reverse turns moderately tight.
2dly, Having arrived at the joint, he stops, and makes an assistant draw the skin of the elbow upwards, lest, being loosened and wrinkled by means of the extension, it might get between the fragments, and create an impediment to their reunion. Then, taking hold of the olecranon, he draws it down towards the ulna, and passes behind it, as a substitute for his fingers which have hitherto kept it firmly fixed, a cast of the roller, which he brings from the anterior part of the fore-arm above the elbow. Descending again with the roller along the external side of the arm, and returning across the anterior part, he pursues again the same course, so as to make the casts of the roller lie on each other, and surround the elbow like a kind of figure of 8.
3dly, The surgeon proceeds now by oblique turns, to the upper part of the arm, where he fixes the roller, by a circular turn, and gives it into the hand of an assistant. He next applies along the arm and fore-arm, a splint very strong, but a little bent at the place which corresponds to the joint, in order to prevent too great an extension of the limb: then, resuming the roller, he employs it, in a descending direction, to secure the splint.
4thly, The apparatus being applied, the limb is placed on a pillow, so as to be equally supported throughout its length, and is protected by hoops from the weight of the bed-clothes.
57. To the bandage which we have just described, Desault added formerly a strip of linen, to be placed all along the posterior part of the arm, secured first at its upper end by circular casts, which began above; this strip was secured afterwards by oblique casts, as far as to the place where it met theolecranon, separated from the ulna. Here, the surgeon quitting the roller, took hold of the bit of linen, and drew it downwards, and along with it the circular casts of the roller, together with the muscles on which these casts were applied, and also the fragment which the muscles drew upwards. An assistant then secured it here, while the surgeon, after having made some casts in form of the figure of 8, descended to the inferior part of the fore-arm, where the end of the strip was made fast by tight circular turns. (Seefracture of the rotula.)
58. The intention of this additional piece of apparatus, was to draw down the superior fragment, to prevent the circular casts of the roller from separating by their relaxation, and, by that means, to retain the fragments in apposition. But, on the one hand, may not the superior fragment be drawn by the hand, as well as by a roller employed for the purpose? And, on the other, if the circular casts of the roller be liable to become relaxed, why not the strip of linen also? These considerations induced Desault to lay it aside, and use the bandage in the form just described.
59. The advantages it offers are far from being equivocal. 1st, The limb is kept in a state of invariable extension by the anterior splint, and, on this account, there can be no displacement on the part of the inferior fragment. 2dly, The bandage, which accurately envelopes the whole limb, restrains the action of the muscles by compressing them, and prevents in part the contractions of the triceps; while the casts in the form of the figure of 8, applied with skill andprecision, hold down the superior fragment, and render it difficult for it to be displaced. 3dly, Without the application of a roller over the whole limb, a swelling, more or less considerable, would probably be the effect of the constriction at the elbow, which must necessarily be somewhat tight, because, as the turns of the roller, in form of the figure of 8, act on the olecranon obliquely, if they be too loose, they will slip and not perform the office of retention.
60. Like all kinds of apparatus composed of rollers, this ought to be frequently examined, lest, by becoming relaxed, it should not make sufficient resistance to the triceps, which is always disposed to draw itself upwards. There can be no period fixed on for the reapplication of the apparatus; the moment it begins to become slack, it ought to be renewed: three or four times during the course of the treatment are generally sufficient. Should a considerable swelling give reason to suspect that the constriction is too great, it will be necessary to remove the bandage in order to apply it anew.
61. The period necessary for the reunion of fractures of the olecranon varies, according as the bandage is more or less exactly kept in its place. Among ten cases of this kind, collected in the Hotel-Dieu, four united in twenty-four days, three in twenty-eight, and three in thirty-two. Hence, taking the mean term, all other circumstances being alike, the process of cure requires about twenty-six days.
62. When this is completed, it is necessary to impress on the limb motions of flexion and extension, gradually increased every day. This is, as Davidproperly observes, the most certain method of avoiding a stiffness, and even an anchylosis, too often the consequence of this fracture.
63. But that illustrious practitioner, in recommending this salutary remedy, has erred with regard to the mode in which it operates. To consume, by degrees, a superabundant callus in the interior of the articulation, and thus reduce it to a level with the articulating surfaces, is not, as he conceives, the effect which these motions produce. This opinion, founded on the ancient doctrine of an osseous juice, is refuted by the dissection of many bodies of patients that died during the treatment, and in which Desault discovered no trace, either of an effusion of osseous juice, during the reunion, or of its superabundance after this reunion had been completed.
The exercise communicated to the limb, appears to act principally by removing the congestion of the tendons and membranes surrounding the joint, which, being at first irritated by the fracture, are thrown into a state ofengorgement; and further by dissipating a kind of numbness which affects the muscles after they have remained too long in a state of rest.
64. But whatever may be its mode of action, it ought to be gradually increased, according to the state of the parts, and continued for at least twenty days, a period sufficiently long to restore to the limb, in general, its natural motions.
65. It is seldom that after this methodical treatment, the patient is exposed to an anchylosis, a thing inevitable in such cases, according to most authors, A celebrated surgeon, believing the long continuedextension of the fore-arm to be the cause of this accident, has advised here to abandon every kind of bandage, and to commit the cure entirely to nature. But this doctrine, contrary to the general principles of the reunion of divided parts, has not in its favour the result of experience, which proves that, under such neglect, the stiffness in the parts near to the joint is always as great as in other cases, that the reunion is more tedious and more deformed, and that sometimes it cannot be accomplished at all. The analogy of the inconveniences and disadvantages attributed to the method of Foubert, in fractures of the neck of the os femoris, constitutes another argument against this method, which is now almost entirely abandoned.
66. To the cases already published, proving the success of that which we have proposed, let us add one more, reported by Maublanc.
Case IV.Silvan de la Noue, aged thirty, fell on his elbow, having his fore-arm bent, while the shoulder of the same side supported a heavy load. Acute pains at the instant of the fall; a sudden inability to extend the fore-arm; a considerable swelling appears almost immediately, around the joint; and a superficial echymosis at the hind part.
During the night the pains were augmented, the swelling increased, and, on the day following, February 9th, 1791, the patient was received into the Hotel-Dieu.
From the presence of the signs formerly mentioned (43), Desault recognized the fracture, and applied the apparatus (56), notwithstanding the swelling and echymosis, persuaded that the compression madeby this apparatus on the tumefied parts, was the most effectual mode to remove the enlargement.
Next day, pains almost gone; swelling diminished; on the fifth day, the bandage become loose, by the almost entire disappearance of the swelling; a new application of it; the joint wet frequently with vegeto-mineral water.
Seventh day, usual regimen allowed; ninth day, a slightly bilious disposition; evacuants somewhat active administered, to remove it.
Thirteenth day, a third application of the apparatus; echymosis entirely gone.
Thirtieth day, the consolidation complete; the apparatus laid aside; from this time motions gradually impressed on the limb.
Fifty-eighth day, the patient discharged, free in all his motions, except a little stiffness, which exercise will soon remove. Since that time, it has been understood that the limb had completely recovered its natural functions.
§ I.
1. The solidity and security of joints are increased in proportion as the extent of their motions is diminished. This inverse proportion of these two properties to each other, is in a particular manner remarkable in the upper extremities, where the connexion of the humerus with the scapula, of the fore-arm with the humerus, and of the bones of the wrist among themselves, appear, in regular gradation, to acquire the one as they lose the other: hence, their predisposition to luxations is extremely different. We will examine those to which the fore-arm is subject.
2. An angular ginglymus unites to the humerus the bones of the fore-arm, which are again connected with each other by a double lateral ginglymus. Eminences and depressions, reciprocally receiving and received, constitute the first kind of articulation, where, proceeding from without inwardly, we find, 1st, the small head of the humerus, entering or rather joining the upper articular cavity of the radius, which moves on it: 2dly, the external groove of the humerus, receiving the rim of the same cavity of the radius: 3dly, a projection which, rising from the external edge of the coronoide19cavity, extends to the corresponding edge of that of the olecranon, and is receivedinto the external depression of the sigmoid cavity:204thly, the large groove of the humerus, receiving the middle eminence of this same cavity: 5thly, a considerable projection, obliquely applied to the internal depression which receives it.
3. These numerous connexions secure the solidity of the joint, which is still farther strengthened before by the coronoid apophysis, together with the fleshy and tendinous extremities of the biceps, and brachialis muscles, and by the olecranon behind; at the inferior part, by the anconeus; on the sides by two ligaments which descend from the two tuberosities, and strong muscular fasciæ running from the same parts. The whole articulation is also surrounded by a thick capsule, strengthened by numerous accessory fibres. With such powers of resistance, how can this joint suffer a luxation? Yet next to that of the os humeri, it is perhaps most frequently subject to this accident.
§ II.
4. Writers have admitted in general four kinds of displacement; backward, forward, outward, and inward. But all these are not alike frequent, as is proved by experience, and demonstrated by the relative situation of the parts.
5. In a backward direction the olecranon and the radius may pass up behind the humerus, as thecoronoid apophysis offers but little resistance in consequence of its slight curvature. On the other hand, the kind of hook formed by the olecranon, prevents it and the radius from passing before the lower articulating extremity of the humerus, and therefore, without a fracture of the olecranon, a luxation in that direction is impracticable: at the sides, the two lateral ligaments, but more particularly the reciprocal joining or interlocking of the uneven articulating surfaces, present almost insurmountable obstacles to luxations laterally. Whence it follows, that luxation backward is much more frequent than the others; compared to lateral luxations, it is, at least, in the proportion of ten to one: with luxations forward, no comparison can be made; neither Petit nor Desault having ever met with such.
6. An external force produces the whole of these luxations, but according to each, this force must vary. In a fall sideways, suppose the hand be applied to the ground, with the arm extended, to save the body. It is evident that the resistance of the ground will tend to make the bones of the fore-arm pass upwards over the humerus, while the weight of the body pushing that bone downward and forward, will make it glide over the coronoid apophysis. Thus, the capsule, being distended before by the humerus, and behind by the bones of the fore-arm, will give way in one or the other place, or in both, as Desault observed in a man, who fell on his side, as he was carrying a heavy load: the weight of the body increased by the load, had such an effect, that the bones overlapped each other nearly two inches.
7. It appears from this, that a state of extension is the position most favourable to a displacement backwards; a doctrine by no means conformable to that of most practitioners, who consider a state of flexion as necessary to the accident. But, then, in what direction should the fall take place, in order that the olecranon may pass upwards? Applied as it is against the side of the cavity that receives it when the arm is extended, would not this apophysis prevent such passage? Whatever may be the mode of displacement, the olecranon, in passing upward and backward, may incline a little to the one or the other side.
8. I have already said, that without a fracture of the olecranon, no luxation forward can occur (5). But what cause can act with sufficient power on the parts to produce both accidents at the same time? It would be necessary that a fall which had produced a fracture should be succeeded by another fall; but in such a case, the fore-arm would be half-bent, and it is in a state of extension alone (7) that the luxation can take place.
9. Lateral luxations, that is, luxations at the sides have been divided into complete, when the two articular ranges of the arm and fore-arm, have lost their connexion entirely, and incomplete, when only one bone or one part of a bone has been separated from its natural connexion with the humerus. But what cause can act with sufficient force to produce the first kind of luxation, namely, that which is complete? In such an accident so great would be the extent of the wreck and ruin of the part, thatwithout doubt amputation would be the only resource.
10. The second kind of lateral displacement is the result of a stroke which forces violently the extremity of the fore-arm outward or inward. A footman, says Petit, in falling from a carriage, had his arm entangled between the spokes of the wheel, and suffered in consequence a luxation outwards. Another produced one inwardly, by being thrown from his horse, and falling with his arm under him, on rough ground. Strokes of this kind may, as that author remarks, vary in a singular manner. But, in general, in all of them, the fore-arm must represent a lever of the first kind, where the power acts on the end next the hand; the resistance being in the joint, and the fulcrum in the middle.
§ III.
11. To form an idea of the signs or appearances of a luxation backwards, let us examine, for a moment, the natural situation of the olecranon, and the condyls of the humerus. As these eminences are easily felt under the skin, a knowledge and recollection of their situation will serve as a standard of comparison, to judge of the changes they experience in a luxation. When the fore-arm is extended, the olecranon is on a level with the internal condyl, and a little above the external one. In a state of flexion, it descends below this level, and is then farther below the internal than the external condyl. Ineither situation, it is nearer to the first than to the second, the radius separating it from the latter.
12. But, when a luxation has taken place, this apophysis, still remaining on a level with the two condyls, even although the fore-arm be half-bent, is oftentimes separated from the internal one, and driven towards the other: a preternatural protuberance announces this change of position of the olecranon. The coronoid apophysis, whose posterior surface glides in the large groove of the humerus, corresponds to this groove now only with its anterior surface: sometimes the olecranon cavity21receives its extremity. The radius passes backward over the small head of the humerus. At the fold of the arm, a transverse protuberance, more perceptible on the internal side, announces the presence of the displaced articular extremity of the os humeri. Over this extremity are reflected the biceps and the brachialis muscles in a state of violent distension. These muscles, greatly irritated by such distension, continue in a state of habitual contraction, in consequence of which, they keep the fore-arm half-bent. Nor can the anconeus muscle, which is necessarily relaxed, act so as to prevent this semiflection. Severe pains would be the consequence of attempts to extend the fore-arm; the limb is in a state of pronation; yet I find among the cases collected by Desault, several examples where supination existed; this state is explained by the relaxed condition of the pronator muscles. At the level of or opposite to the coronoid cavity is a depression or hollow manifesting the absence of the apophysis of that name.
13. Should chance give rise to a luxation forward, an anterior projection of the two bones of the forearm, and above all, of the coronoid eminence, a depression corresponding to the olecranon cavity, the extremity of the humerus carried backward and downward, the rigid extension of the fore-arm, a protuberance behind formed by the fractured olecranon (5), and severe pains, necessarily resulting from attempts to bend the limb, &c. would constitute the principal characteristic signs of the displacement.
14. In lateral luxations, a protuberance at the internal or external side of the articulation, always shows of what kind it is. If the displacement be to the internal side, the olecranon is then situated behind the small tuberosity: the middle protuberance of the os humeri bears on the radius, which is sometimes placed even behind the internal articular eminence of that bone, which then rests on the external depression of the great sigmoid cavity. Hence, as Petit judiciously observes, arises the direction of the fore-arm outward, the above eminence presenting a manifest obliquity in that direction. In this luxation, the ulna has been known to lose entirely its connexion with the humerus, and the radius to be brought into contact with the internal condyl of that bone. This is what some authors call a complete luxation. Others reserve that name for cases where, the two articular ranges have lost their correspondence or apposition entirely.
15. In a luxation outwards, the olecranon corresponds to the external condyl; the middle projection of the humerus, to the internal depression of the great sigmoid cavity; the small head of this bone, to the external depression; the radius projects outwards; and the humerus makes a protuberance inwardly.
16. After all, these changes of situation vary remarkably, and it belongs to theory rather than practice, to trace their history, with precision. In general, luxations outwardly happen more frequently than those inwardly, a circumstance which is fully explained by the structure of the joint. In both, the lateral ligaments are almost always lacerated.
A swelling more or less considerable accompanies all the different kinds of luxation, and is sometimes carried so far as to involve the diagnosis in great uncertainty, particularly when the displacement is not very great. This phenomenon (the swelling), seems, in general, to correspond, in a direct ratio, to the force with which the articulation resists. Indeed the violence, and consequently the irritation, are always in proportion to the resistance of the parts.
§ IV.
17. The means of reduction vary according to the different kinds of displacement. They are all, however, founded on nearly the same principles, and it will be easy to form proper ideas of them, when we shall have given an account of the means necessaryto be employed in luxations backward, of which the others are only modifications.
Here genius seems to have been as prodigal of resources, as nature has been of obstacles. Indeed, to accomplish the reduction, we sometimes see the surgeon placing his elbow in the fold of the affected arm, interlocking his fingers with those of the same limb, and, then, bending with his whole force, both his own fore-arm, and that of the patient, to effect at the same time extension, counter-extension, and reduction or conformation: at another time we see him fixing the fold of the injured arm against some resisting body, such as a bed-post; and while an assistant, then, pushes the displaced olecranon against this body, he himself, pressing on the shoulder with one hand, and grasping the fore-arm with the other, bends it forcibly, in order, by that means, to produce a replacement: again, a body of some size, being placed in the fold of the arm, serves as a fulcrum, on which the fore-arm, being suddenly flexed, moves and acts like a lever of the first kind, of which the power, being applied at the extremity next the hand, draws it backward and upward, and by that means pushes in a contrary direction its luxated end, where the resistance is made. On some occasions, the fore-arm of the diseased side, bent at a right angle, is placed on a horizontal table, and, while the lower extremity of the humerus is thus resting on the table, the surgeon pushes it backward with one hand, and with the other, taking hold of the extremity of the fore-arm, draws it in a contrary direction.
18. The ancients employed the three first modes. Pare has had engravings of them made: Scultel has also given figures of them as practised by Hippocrates. The Arabians knew of no other modes, nor did their descendants, who were only compilers from them. The practitioners of our own day still continue their use. But, in general, they are chargeable with the numerous inconveniences and faults of producing intense pain, of not being completely under the direction of the surgeon, of bringing the point of luxation too near to the place on which counter-extension is made, and of bruising and doing violence to the parts: nor do they disengage, by means of previous extension, the luxated ends of the bones, to facilitate their replacement in their natural situations.
This last charge is not applicable to the last of the processes proposed by Petit. But, here, the extending forces are most commonly insufficient; the surgeon, having both his hands engaged, is not able to act on the joint to assist in the replacement: and the counter-extension made is too near to the point of luxation.
19. In common cases, Desault employed a method as simple and more efficacious, which few writers have recommended, and none have described with accuracy.
The patient is, indifferently, either seated or standing. The fore-arm being half-bent, an assistant takes hold of the extremity next the hand, to make extension; another, to make counter-extension, takes hold of the humerus a little below its middle, with both hands, the fingers crossing before, and the thumbsbehind. The extension is made gradually, and when it begins to move the olecranon, and draw it from the place it accidentally occupies, the surgeon, to aid in the reduction, grasps the lower end of the humerus with both hands, crosses his fingers in the fold of the arm, applies his thumbs to the olecranon, and drawing the first backward, pushes at the same time the latter forward; thus, he favours, on the one hand extension, and on the other counter-extension, and in that way finishes the reduction.
20. This method is most commonly practised with success, in recent luxations, where we have oftentimes seen the reduction effected at the Hotel-Dieu, by the simple process of pushing, as just mentioned, the olecranon forward, the humerus being held backward, without any previous extension, while the fore-arm was merely supported by the assistants.
21. But the luxation being oftentimes of long standing, presents very great difficulties. What means must then be employed? It is an established principle, that the force with which a power acts, is in direct proportion to its distance from the point of resistance. Augment this distance, and the extending forces, being doubled and even trebled, will more easily dislodge the luxated extremity. But this indication is fulfilled, by two long straps, formed each of a towel folded several times, one of which is fixed above the wrist, and the other round the humerus a little below its middle. Extension is then made at their extremities, and is almost always sufficient, when aided by skilful efforts of the surgeon (19), to accomplish the reduction. The application of a strapround the humerus is never necessary, unless when the resistance is very great; because, in counter-extension, it is requisite only to withstand or bear against the efforts of extension, but not to act in a contrary direction.
22. But in cases of this kind, the strap, placed, as we have directed, round the lower part of the humerus, has sometimes the disadvantage of compressing too much the brachialis and the biceps muscles, and thus preventing them from acting; this inconvenience is particularly felt in old luxations, where great force is employed; for, the more active then the contraction of these muscles is, the more it will aid the surgeon in his efforts to draw the bones into their natural situation, when once disengaged by extension, from that which they had accidentally occupied. If, in such a case, we impede the contraction of these muscles, how can they fulfil this office?
23. It was this which, in certain cases, induced Desault to place his counter-extension under the armpit, by means of a strap passing, as in the luxation of the humerus, over a ball previously fixed in this hollow, and crossing, not on the top of the opposite shoulder, but behind that of the diseased side. By this contrivance the humerus was drawn or rather held back, by a force acting perfectly in the line of its direction. But is not this force situated too near to the centre of motion? The strap for making extension, fastened at the wrist, answers very well, as has been already mentioned (21).
24. Should the luxation be forward, the extension must be directed according to the state and positionin which the fore-arm is found, which is always extended. The hands of assistants alone (19), or straps (21), may then serve to make the extension, which the surgeon must aid, by grasping, in a direction the reverse of that in the preceding case, the lower extremity of the humerus, that is, by crossing his fingers behind, and placing his thumbs on the coronoid apophysis, to push it downward and backward.
25. The strap for counter-extension, would in such a case, always afford the greatest advantage, by being placed exactly as in luxations of the humerus, that is, by running to, and crossing on, the opposite shoulder; the direction or course of the fore-arm, which is necessarily in a state of extension, sufficiently explains this; finally, the reduction of the luxation must be succeeded by the reduction of the olecranon (5), and by the application of a proper apparatus to retain the whole.
26. The reduction of lateral luxations, differs but little from that of luxations backwards. The displaced extremities must be first dislodged by previous extension (19). The surgeon, then, taking hold of the lower part of the arm, places his fingers before, and with his thumbs, crossed on the olecranon, pushes that apophysis forward and inward, if the displacement be outwardly, but forward and outward if it be inwardly. Does the case prove very difficult, recourse must be had to the other means (21 and 23). The hands of the surgeon must still, according to the direction of the displacement, assist the extension made by the straps.
§ V.
27. Luxations of the fore-arm have, oftentimes, a great disposition to occur anew, after having been reduced, whether they be recent, or of long standing. Extension readily dislodges the olecranon and the radius, and replaces them perfectly in their natural situation; but if any thing interrupt them, the displacement is sometimes immediately renewed: suppose the parts even remaining in contact, the slightest motion may derange this contact, and give rise to a necessity for a new reduction, more difficult, oftentimes, than the first. Hence it is always prudent to employ a retentive apparatus for some time.
28. But, on what principle and for what purpose ought it to be applied? The motions communicated to the fore-arm by external bodies, but, more particularly, the action of the muscles inserted in the bones that have been reduced, are here the causes of their displacement. Hence, 1st, to render the limb immoveable; 2dly, to push the articular ends of the bones in a direction opposite to that in which they are drawn by the muscles, and have a tendency to be displaced: such is the twofold indication of the bandage; an indication not fulfilled by the kind of bandage and the sling which Petit proposed, and which leave the arm free to move, and the muscles free to act.
29. Desault employed the following apparatus: 1st, The arm and fore-arm are first covered by oblique turns of a roller, intended both to protect them from the impression of splints, and to diminish the power and action of the muscles, by the pressure made on them: 2dly, Behind the olecranon is to be placed a thick compress, designed to retain it downwards, and which must be secured by a strong splint, situated behind, and curved at the elbow, to accommodate it to the flexion of the fore-arm: 3dly, On the sides are placed two other splints, chiefly necessary in lateral luxations: 4thly, The whole is to be secured by the remaining part of the roller, by which the arm and fore-arm are already covered.
In this bandage, the immobility of the arm is secured by the splints, while the olecranon is pushed by the compress, in a direction the reverse of that of its displacement. But these circumstances constitute the double indication that was to be fulfilled (28).
30. The period at which these means may be dispensed with, is undetermined. It belongs to the surgeon to examine and ascertain, when the natural connexions of the joint are sufficiently confirmed. Then motions, at first gentle, are to be impressed on the limb; being afterwards gradually increased, they remove by degrees that stiffness, which usually follows a dislocation, particularly an old one. But if it has existed too long, to give the limb motion, is then the only resource: the new attachments or adhesions, contracted by the articulating surfaces in their displaced state, render reduction impracticable. We must then confine ourselves merely to increasing theextent of the motions, which the displaced fore-arm is yet capable of performing.
31. There is, in general, all other things being favourable, a hope of accomplishing the reduction, till the end of the second month after the accident. Desault succeeded in it, at even a later period. What trouble or hardship is it, at last, to try extension? Should no other end be gained, but merely to bring the bones nearer to their natural cavities or situations, even without actually replacing them, this will aid their movements, the extent of which is inversely proportioned to their distance from these cavities.
1st, Most authors who have written on the luxations of the fore-arm, have omitted considering separately those confined to the radius alone. Some detached observations may be found here and there, on the luxations of the upper extremity of this bone, which Duverney alone has treated at some length. Those of its lower extremity, though more frequent, and more easily produced, appear to have almost entirely escaped the attention of the French practitioners, who have transmitted nothing to us on that point, owing, no doubt, to their having had no knowledge of it from experience. But since, at thepresent day, a sufficient number of facts are collected on the subject, some account of these displacements cannot be a matter of indifference to the art, and it may be traced with as much precision as the accounts of other similar accidents.
§ I.
2. The radius, the moveable agent in pronation and supination, rolls on the ulna its fixed basis or abutment, by means of two small articulating surfaces, the one at its upper end, slightly convex, broad within, and narrow without, corresponding to the small sigmoid cavity, in which it is lodged; and the other at its lower end, concave, semicircular, and fitted to the convex edge of the ulna, which it receives. Hence two kinds of articulation different from each other, with respect to their motions, the connexion of their surfaces, and the ligaments which strengthen them. Let us specify these differences; they will serve to shed light on those that exist between the displacements of the two extremities of the radius.
3. At its upper end, the radius, in performing pronation and supination, moves only on its own axis; at its lower end, it rolls round the axis of the ulna: therefore, being farther removed from their centre, its motions must have both a greater range and greater force, in the latter case than in the former. The head of the radius, turning on itself within the annularligament, cannot distend it in any direction or part. The cellular membrane attached to this ligament is alone slightly stretched, but being loose and elastic, it yields without resistance. At its lower end, on the contrary, the radius, turning from without inwards during pronation, keeps the capsule posteriorly in a state of tension, and draws it against the immoveable head of the ulna, which tends to pass through it, if the motion be forcible. The same phenomenon occurs in a contrary direction, during supination; the radius is directed backward, and the ulna inward. Being in this case distended before, and relaxed behind, the capsule is disposed to laceration anteriorly.
4. In addition to this disposition, the ligaments of the two articulations are disproportioned in their strength. Thin and weak at the lower articulation, thick and firm at the upper one, they are in this respect strikingly different. The head of the radius, resting against the small but firmly fixed head of the humerus, finds there, in most of its movements, an obstacle to displacement. On the contrary, its lower end, drawing along with it in its movements, the bones of the carpus which are connected with it, derives from them no solid support.
§ II.
5. It follows from what has been said (3 and 4), 1st, that the lower articulation of the radius is not only exposed to the action of more causes of displacement, but possesses fewer means of resisting those causes, and that, from the threefold consideration of its motions, the ligaments which connect its articulating surfaces, and their relation to each other, it must be frequently subject to luxations: 2dly, that for reasons the very reverse of these, its upper articulation must be very seldom subject to luxation.
6. Indeed, what cause is there to produce luxation in this latter joint. Is it from a forcible exertion of pronation or supination that this accident can occur? Surely not: for, on the one hand, as the lower articulation offers less resistance than the upper one, it is evident that, in either state of motion, it being the weakest, will be displaced first, and the motion being thus checked, can no longer operate to the displacement of the other. On the other hand, however forcible the motion may be, there will be in the upper articulation, nothing but a rotation of the bone on its own axis (3). How, then, without being carried forward, backward, &c. can the head be displaced? Indeed, it would be necessary that all the fastenings or bonds of attachment muscular and ligamentous, should be first broken. But these are too strong, andthe motion is too weak. Can the displacement be produced by a blow impressed on the radius from below upwards? By no means: because the head of the humerus making, in this case, a solid resistance will not permit it to escape from the capsule (4). Can it arise from a violent extension or flexion of the fore-arm? No. This effort being altogether confined to the ulna, affects the radius in but a very faint degree.
7. It appears from hence, that the accidental luxation of the upper end of the radius, suddenly produced by external causes, must, if it ever occur, be extremely rare. But it is not so with respect to luxations which take place slowly in this joint, particularly in children, where, in consequence of repeated efforts, the ligaments become relaxed. But this kind of displacement, being almost always complicated with a swelling of the joint, and sometimes not to be reduced by the expedients of art, cannot be comprised in my present plan.
9. But experience would seem to have at times exposed the fallacy of these considerations and reasonings, founded merely on the structure of the parts. Duverney relates some instances of luxations of the head of the radius, produced suddenly by external causes. Two other practitioners are also of opinion that they have witnessed similar displacements. But did they examine the subject with all that attention which it required? A similar case was reported to the Academy of Surgery, by one of its associates; but doubts were entertained with regard to its reality: and, ultimately, there were so few facts in its favour,and such strong presumptions against it, that Desault was induced to deny the luxation altogether, till its reality should, by new proofs, be more certainly established.
After all, if it should occur, the same signs which announce the luxation, when the ligaments, in consequence of being gradually relaxed or in some way distended, permit the head of the radius to be insensibly displaced, would then appear as the sudden effect of external violence.
§ III.
9. The causes which produce the displacement of the lower end of the radius, are the same with those that give rise to other similar affections. 1st, The convulsive action of the pronator and supinator muscles, is doubtless a rare cause of the accident, since Desault never met with an instance of it. 2dly, The action of external bodies, which, by forcibly and suddenly producing the motions of pronation, rupture the posterior portion of the capsule, or, by those of supination, lacerate its anterior portion.
10. Hence two kinds of displacement, the one forward, the other backward. The first is somewhat frequent; the second is much less so. The latter was never seen by Desault but once, and that was in thecorpse of a man who had had both his arms luxated, but respecting the circumstances of which he could receive no information. The other kind occurred frequently in his practice, of which five examples have been already published. The difference no doubt arises from this circumstance, that the greater part of our powerful motions are performed only in the direction of pronation. This appears to be proven by the following circumstances.
11. If, in several dead bodies, we lay bare the bones of the fore-arm, still united by their ligaments, and push the extremity of the radius forcibly backwards, that is, in the direction of supination, a laceration will as readily occur in the anterior part of the capsule, as it will in its posterior part, when, by forcibly pushing the same extremity forward, the motion of pronation is performed. Hence the difference does not arise from the structure, but from the direction of the motions impressed on the limb.
§ IV.
12. The signs which characterize a luxation of the radius forward, are, 1st, The constant pronation of the limb: 2dly, An inability in it to assume the state of supination, and even severe pains arising from attempting it: 3dly, A protuberance larger than common, formed behind, by the small head of the ulna passing through the capsule: 4thly, The end of the radius being situated more anteriorly than natural: 5thly, The constant adduction, and almost constantextension of the wrist: 6thly, The semiflexion of the fore-arm, and very often of the fingers: this position is generally assumed by the fore-arm, in affections of the bones that form it, and, in the present case, cannot be changed without considerable pain: 7thly, A swelling more or less extensive, which sometimes appears around the articulation, at the moment of the accident, and which never fails to occur afterwards, unless the reduction be immediately effected. This occurrence may conceal the state of the articulation, and make the accident be considered, at first sight, as a sprain, as Desault witnessed in certain cases, where the disease had been mistaken by the surgeons who were first called to the persons injured. It is easy to conceive of the sad consequences of this mistake, which, by preventing any effort at reduction, gives the articular surfaces time to form adhesions, and thus oftentimes renders the mischief irreparable.
13. If to these signs be added, the severe pains experienced by the patient, the circumstances of the fall, in which the fore-arm is violently drawn into a state of pronation, we will have a view of every thing that can here aid the practitioner in his diagnosis.
14. Most of the foregoing signs, taken in the opposite sense, would characterize a luxation of the radius backward, should it occur: such, for example, as a forced supination of the limb, an inability as to pronation, the pains that would result from this movement if performed by force, the tumour formed anteriorly by the extremity of the ulna, the posterior situation of the large head of the radius, and the abduction of the wrist.
15. The dead body, in which Desault observed this kind of displacement (9), being dissected with care, exhibited in the articular parts, the following diseased state. The tendons of the flexor muscles, pushed outwards, adhered to one another and to the skin; a substance of a cellular texture filled up the sigmoid cavity of the radius, and occupied the place of the cartilage which naturally invests it: the inter-articular ligament, which passes between the ulna and the os pyramidalis, scarcely touched the head of the ulna, having followed the radius backwards; and the head of the ulna, situated before the sigmoid cavity of the radius, rested on one of the ossa sesamoidea, to which it was attached by a capsular ligament.
§ V.
16. Extension so important in the reduction of other luxations, renders scarcely any service in this: impulsion alone answers the purpose. If the displacement be forward, it is reduced in the following manner: The patient sits or stands indifferently; the latter position, however, has sometimes this advantage over the former, that by placing the part to be operated on more on a level with the hands of the surgeon, it gives him both more readiness and more force in his motions: one assistant supporting the elbow, separates the arm a little from the body; while another taking hold of the hand and fingers, gives them also an equable support.
17. The surgeon grasps the extremity of the fore-arm, with both hands, one placed on its internal, and the other on its external side, so that his two thumbs may meet before, between the ulna and the radius, and the fingers behind. He then exerts himself to separate the two bones from each other, by pushing the radius backward and outward, and retaining the ulna in its place; in the mean time the assistant who supports the hand, endeavours to move it in the direction of supination, and consequently to draw the radius, with which it is connected, into the same state. Being thus pushed in a direction opposite to that of its displacement, by two forces, the one exerted directly on it, and the other acting indirectly, the radius is forced outwards, and the ulna, returning through the opening in the capsule, is replaced in the sigmoid cavity.
18. Should a luxation of the radius backwards ever occur, the same process executed in an inverse direction, would serve the purposes of reduction. The surgeon with his fingers would have to press the extremity of the radius forward and inward, while a forcible pronatory movement impressed by the assistant on the hand intrusted to him, would favour the effort and finish the reduction.
19. The disappearance of the signs (12...14) of the luxation bespeak its reduction. In general the pain is entirely removed; sometimes a perceptible sound, or report, caused by the passage of the bone through the opening in the capsule, announces the replacement.
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.
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 whichhe afterwards ventured by degrees, and with great caution.
25. These gentle motions frequently repeated, when a displacement is no longer to be apprehended, remove that unavoidable rigidity which, for some time, occupies the parts around the joint. It is advisable, for some time, to apply on the hand and extremity of the fore-arm, compresses wet with some discutient liquor, to prevent the swelling resulting perhaps from the inactivity and sprain of the parts. This was the practice of Desault.
I will close this memoir by two cases, extracted from the Journal of Surgery, in order to confirm, by experience, what has been already settled in theory.
Case I.Desault was called to visit a child five years old, supposed to be labouring under a fracture of the arm. He learnt from the parents of the child, that, as it was lying in a very low bed, a young man who was playing with it, had taken hold of its fore-arm, and drawn it towards him, twisting it forcibly at the same time in the direction of pronation; that the effort had been accompanied by a report, and the child had immediately experienced an acute pain throughout the whole limb, but more particularly along the posterior part of the fore-arm.
When Desault saw the patient, no swelling had as yet supervened; the arm was removed from the body, and carried a little forward, while the fore-arm, half-bent, was kept in a state between pronation and supination. There existed, at its lower and back part, a preternatural tumour, formed by the head of the ulna carried behind the sigmoid cavity of the radius. Thehand was a little extended, and in a state of adduction. The patient carefully preserved that position, and, as soon as it was changed, or the part affected touched, manifested signs of the most acute pain.
From these appearances, Desault discovered immediately a luxation of the radius forward, which was reduced in the manner already mentioned (16 and 17). By this process, the bones, being a little separated from each other, were replaced with facility. The suffering of the patient was immediately at an end; the limb resumed its natural state, and performed its functions as freely as before; lest some congestion might be the consequence, the injured parts were covered by compresses wet with camphorated spirits; these were secured by a bandage moderately tight, and no accident whatever supervened.
Case II.On the 29th of January, 1789, Madeleine Fuser, a washer-woman, thirty-four years of age, had the lower extremity of the radius luxated forward.
Just as she had finished wringing a sheet, another washer-woman, who was assisting her to wring it, giving it a forcible jerk, did violence to her left arm, which was at the time in a state of strong pronation.
The woman experienced immediately a severe pain, accompanied by a sensation as if something had been torn. The sheet dropt from her hand, and she fell on the ground. Believing that she had received only a sprain, she neglected to apply for aid, and did not enter the Hotel-Dieu till the sixth day after the accident.
There was then a little swelling at the lower part of the fore-arm and at the wrist: the latter was extended and in a state of adduction; the fingers were bent. This woman suffered but little, when her hand was supported and kept still; but the pains became severe, when she attempted to move it. It was plainly perceived that the radius was placed before the ulna, and that the bones overlapped each other.
Process of reduction the same as in the preceding case. It was accompanied by a kind of report, and its completion was clearly announced by the restoration of the natural shape of the limb, and by the freedom of its motions. Compresses wet with vegeto-mineral water were applied to the wrist.
This patient remained fifteen days in the hospital, at the end of which, she performed with ease the motions of the wrist and hand.
§ I.
1. The os femoris, being in man, a moveable support for the weight of the whole body, appears to be better secured than the other bones, from accidents that might affect its continuity. The numerous masses of muscle that immediately surround it; the thick and compact layers or fasciæ that form its more exterior covering; and an articulation loose, and ready to yield, in every direction, to the motions impressed on it, all seem, on the one hand, calculated for its preservation.
2. But, on the other hand, being visibly curved in its middle, bent at its upper end almost at a right angle, longer in proportion in man than in quadrupeds, placed, in most falls, between the ground which resists, and the weight of the body which presses on it; it would seem, from these latter circumstances, to be less calculated to resist external force. And, if to these considerations be added those of the causes which have an immediate action on it, it will be easy to perceive, that, in a comparative scale of the bones most exposed to fractures, it holds, next to the bones of the leg, one of the highest grades. The proportion which its fractures bear to those of the leg, is, according to the observations of Desault, as one to three; but to that of most other bones it is equal if not superior.
3. The os femoris, being in its body irregularly cylindrical and curved behind, becomes larger towards its lower end, where it terminates in two articulating masses, which rest immediately on two corresponding surfaces of the os tibiæ; changing its direction above, it inclines towards the acetabulum, and inserts into that cavity a round head, supported by a neck which is entirely enclosed in the capsule of the joint.
4. From this different conformation of its different parts, arises such a variety in the fractures which occur in it, that they cannot be treated of under the same head. Hence the division into fractures of the body and of the extremities, which is borrowed from anatomists, and will be followed in the present memoir, where we will consider in order,
1st, The fractures of its body,2dly, Those of its upper extremity,3dly, Those of its lower extremity.
§ II.
5. The os femoris may be fractured indifferently at any point between its condyls and its neck. But the part where this accident most frequently occurs, is about the centre of the curve of the bone, where most of the motions and shocks impressed on it by external violence expend their force.
6. Whatever may be the seat of the fracture, its direction is sometimes transverse, but most frequently oblique, a variety which does not affect the real nature of the disease, but which possesses, as to its consequences, a very important influence. As in other affections of the kind, so here, the bone is sometimes affected alone, and, at other times, to a fracture simple or complicated by means of splinters, is added an injury done to the surrounding soft parts. Hence result compound fractures, differently varied, according to the nature of the parts affected, and to the extent and other circumstances of these affections. But, as Petit observes, this bone is less frequently shattered or crushed into several pieces, than those that are more superficially situated.
7. Extraneous causes are known to render falls more frequent in man than in other animals, and to multiply in him the fractures of the lower extremities, by multiplying the action of external bodies on these extremities. This action may be exerted on the os femoris in two modes. Sometimes only passive, it merely offers a resistance to the power which puts the bone in motion; thus, in a fall, the os femoris, being pressed between the ground which resists, and the weight of the body that bears on it, bends beyond the extent of its flexibility or pliancy, and finally gives way. At other times the influence of external bodies is actively and directly exerted in this accident: thus a stone, or a piece of timber, falling on the thigh, fractures the bone, in consequence of communicating to it a degree of motion greater than its power of resistance.
8. In common, the first mode of division is by a true counter-stroke, similar to that which fractures the clavicle, the ribs, &c. In the second mode, the fracture is always direct. The middle part of the bone is generally broken in a counter-stroke: wherever the direct stroke is received, that is the place of the fracture which it produces; the division, most frequently oblique in the first case, is sometimes perpendicular or transverse in the second. From a counter-stroke result most commonly simple fractures, while compound ones are usually owing to a direct stroke.
§ III.
9. In whatever manner a fracture of the os femoris may have occurred (7), its existence is characterized by the following signs: severe local pain at the instant of the accident; a sudden inability to move the limb; a preternatural mobility occurring in some particular part; a crepitation sometimes distinct, when the two fragments are rubbed against each other; and a deformity, which may be considered under the threefold relation, of length, thickness, and direction.22These signs, being common to most fractures,exhibit but few circumstances peculiar to those of the os femoris, except that of the deformity. Respecting this circumstance, in particular, it is essentially necessary to possess accurate ideas, because, having an incessant tendency to recur, especially in oblique fractures, it must constitute a primary object of attention during the treatment.
10. It may be laid down as a general principle, that all fractures of the os femoris are accompanied with some deformity; the exceptions to this rule are too few to be worthy of notice. If this deformity be considered in relation to length, it will be found that, in oblique fractures, the limb is always shorter than that of the opposite side, a circumstance which plainly points out an overlapping of the fragments. But, on examining the place of fracture, it is easy to discover, that this overlapping arises from the inferior fragment mounting upwards on the superior one, which itself remains immoveable. Now, what power, but the contraction of the surrounding muscles, can communicate to the inferior fragment a motion from below upwards? Attached, on the one hand, to the pelvis, and on the other to this fragment, to the rotula, the tibiæ, and the fibula, these muscles have on the former their fixed, and on the latter their moveable points, and, drawing the leg, the knee, and the inferior portion of the thigh upward, they produce the displacement and shortening either mediately or immediately. In this displacement, the adductores, the semi-tendinosus, the semi-membranosus, the rectus anterior, the rectus internus, &c. are the principal agents.
11. The following case communicated to Desault by a surgeon, who had been formerly his pupil, proves how great the influence of this cause is; a cause which is indeed generally acknowledged, but not sufficiently attended to by practitioners, with a reference to permanent extension. It is this that induces me to relate the case.
Case I.A carpenter falling under the ruins of his scaffold, was immediately taken up and carried home, where a surgeon discovered an oblique fracture of the os femoris, but without any displacement. The thigh, which appeared even a little longer than the other, was fixed in an apparatus too slack to prevent muscular action. Next day, the length of the thigh was the same, but the whole extremity was in a paralytic state, accompanied by an entire inability to discharge urine.
The moxa was proposed. The patient being placed in the position directed by Pott, for fractures of the os femoris, the fire was applied; some movements were the consequence; the application being repeated on the sixth day, the muscles instantly recovered their power of action, and then the shortening of the limb became evident, and still returning immediately after being removed by extension, rendered it necessary to have recourse to an apparatus calculated for permanent extension.
12. In this case, the muscular influence is evident. Indeed the shock having produced a temporary suspension of the excitability of the part, the fragments remained in place and in proper contact with each other: but the moxa having awakened the excitability again in the muscles of the thigh, theyresumed their action and caused, as usual, the inferior fragment to mount on the superior.
13. Hence it follows, 1st, that it is principally to the action of the muscles that we must attribute the displacement, in the longitudinal direction of the bone; 2dly, that, as that action, being the effect of an inherent power, is constantly exerted, the limb must have a constant tendency to this displacement, particularly in oblique fractures, where the two extremities of the bone represent two inclined plains, which readily glide along each other.
14. To this must be still added another cause, which operates injuriously in the course of the treatment. However solid the bed may be on which the patient lies, the nates or buttocks, being the most projecting part of the body, soon form a depression in it; hence arises an inclination or descent of the plain or surface on which the body lies. The body therefore sliding downwards, pushes before it the superior fragment, and makes it overlap the inferior one. In consequence of this, the muscles, being irritated by the points of the bones, increase the force of their contractions, and, as we have already observed (10), draw the inferior fragment upwards. This double movement of the two ends of the bone in contrary directions, produces only a single effect, namely, the overlapping of these ends, but carries this overlapping to a higher degree.
15. Transverse fractures are less exposed to displacement, in the longitudinal direction of the bone, because the fragments when in contact, support each other. In such a case, the inferior fragment, drawn by the muscles, finds a point of resistanceagainst the superior one, while the latter, when pressed downward by the weight of the body, pushes the former before it, and thus both preserve their relative position.
16. A deformity of the fractured os femoris, in the direction of its cross-diameter or thickness (9), always accompanies that in its longitudinal direction, and sometimes exists alone. This takes place when, in a transverse fracture the two ends of the bone, losing their contact, are carried, the one outward, and the other inward, or when the one remains in its place, while the other is separated from it. In such a case, the superior fragment is not, as in the preceding one, immoveable by means of muscular action; because the action of the pectineus, the psoas, the illiacus, and the first adductores, derange its natural direction, and contribute to its displacement.
17. The deformity of the limb, in relation to its direction, in other words, the crookedness of the limb (9) is either the result of the stroke which fractured it, or, what is more common, of the ill directed efforts of those who lift and carry the patient, and, by an improper position, bend the two fragments, so as to make them form an angle with each other. Desault was once called to a patient, whom he found seated on a bed, in such a manner, that the upper part of the thigh was in a horizontal position, and the lower, hanging with the leg in almost a perpendicular one. Doubtless the triceps femoralis, equally attached to both fragments, bends them by its contraction, and produces a change in the direction of the limb.
18. Whatever may be the kind of the deformity, whether in a longitudinal or lateral direction, the inferior fragment may either preserve the natural position in which it is placed, or experience a rotatory motion on its axis outwards, which is a common occurrence, or inwards, a circumstance which is more rare. This rotation always renders the displacement more serious, and ought to have an influence, as I shall presently observe, on the means of reduction.
§ IV.
19. Fractures of the os femoris, though seldom very distressing, in common cases, from any accidents that immediately accompany them, are sometimes rendered so, by inconveniences which are the consequences of them, when they are oblique. Celsus declared, that a shortening of the limb, more or less considerable, was always the result of such fractures. Most authors have copied and repeated this assertion, and, even at the present day, the opinion is advocated by a great number of practitioners. It must be acknowledged, that, if we compare the natural powers that are engaged in producing displacement (10...15), with the artificial resistance made by most of our forms of apparatus, we will perceive that there is between the two forces so great a disproportion in point of strength, that the former can never yield to the latter. But, is it in the nature of all forms of apparatus to be unable to overcome the force of the displacing powers? Cannot an equilibrium be established,so as to retain the fragments in contact? The remainder of the present memoir will throw some light on this problem, which will become less difficult of solution, if we call to mind, that the action of muscles, though very powerful at first, diminishes afterwards by degrees, in consequence of their being kept in a state of permanent extension; that even a weaker power may, by acting constantly, accomplish ultimately, what could not have been effected at once, by another power much stronger, if only momentarily applied; and that compression made by circular bandages, tends also to diminish the force and prevent the action of muscles.