MEMOIR III.
ON THE LUXATION OF THE CLAVICLE.
§ I.
1. The clavicle, which forms a moveable abutment for the shoulder, and receives and sets bounds to most of the movements of that part, and of the arm, exhibits at its extremities, two articulations, essentially different from each other in their form, dispositions, and uses. These differences give rise to differences equally essential with regard to the dislocations to which they are subject.
2. On the sternal extremity, a small surface, convex from above downwards, and concave from before backwards, is fitted, by means of an intervening cartilage, to a much smaller surface of the sternum, concave and convex in opposite directions.
One capsule, two ligaments, viz. the interclavicular and costo-clavicular ligaments,[5] and the anterior portion of the sterno-cleido-mastoideus muscle, strengthen the connexion of these two surfaces, and tend, on one hand, to prevent their luxation, while, on the other, this luxation is favoured and facilitated by the following circumstances: 1st, the disproportion between the dimensions of the two articulating surfaces; 2dly, the mobility of the joint; and 3dly, by this joint’s constituting a kind of centre for the motions of the arm.
3. On the humeral side, an elliptical surface, slightly convex, and inclined downwards, is immediately joined to a corresponding surface of the acromion, elliptical also, a little concave and directed upwards. Hence two kinds of inclined plains, which would be very liable to dislocations, by sliding easily over each other, were they not firmly secured by a capsule, by accessory fibres, by the intersection of those of the deltoid and trapezius muscles, and, above all, by two ligaments, the rhomboid and the conoid.[6]
Having laid down these preliminary considerations, let us proceed to examine, in particular, each kind of luxation to which the clavicle is subject.
LUXATION OF THE STERNAL EXTREMITY.
§ II.
OF THE CAUSES AND DIFFERENT KINDS OF DISPLACEMENT.
4. The sternal articulation of the clavicle experiences different changes, according to the different movements of this bone. If these movements be in a backward direction, the articulating surface is turned forward, straining the anterior part of the capsule, the corresponding ligament, and the extremity of the sterno-cleido-mastoideus muscle. If, on the other hand, they be in a forward direction, the posterior ligament, and the adjacent portion of the capsule are overstretched. In motions directed upwards, the costo-clavicular ligament, and the external and inferior part of the capsule, and in those directed downwards, the inter-clavicular ligament, and the internal portion of the capsule, experience a similar degree of tension.
5. Hence it follows, 1st. That the natural movements of the shoulder may be regarded as predisposing causes of luxation, because at the part where tension is excessive, the ligaments are disposed to give way, and suffer the sternal extremity to escape: 2dly. That the efficient causes will be, all external forces acting on the clavicle in such a way as to increase its motions beyond their natural degree, and beyond the resistance which the ligaments are capable of making. Thus a fall on the point of the shoulder, forcing it suddenly backward and inward, produces a luxation forward. But, in general, as the strength of the articular ligaments is superior to the resistance of the clavicle itself, a fracture takes place more frequently than a luxation, in the proportion of nearly six to one.
Though falls on the point of the shoulder are oftentimes productive of luxation of the clavicle, they are not the exclusive causes of that accident. Desault has seen the sternal extremity forced from its cavity by the knee being pushed violently against the middle of the back, while the shoulders were drawn at the same time backwards.
Case I. A porter dislocated his clavicle in the following manner. He was carrying a very heavy burden, suspended from his shoulders by cords that passed under each arm-pit. Being desirous of resting himself by the way, he placed on a block the burden he carried, which slipping backward, drew his shoulders in the same direction, and at the instant of his attempting to retain it and prevent it from falling, produced a luxation of the clavicle.
7. It follows from what has been said respecting the different states of the articulation, during its various motions (4), that the clavicle is not equally liable to be luxated in every direction. Inclining naturally backward, but a very slight degree of motion in that direction is necessary, to effect a luxation forward. To produce a luxation backward or inward, it is necessary, on the other hand, that the humeral extremity of the bone should make a sweep at least three times the extent of that required in the preceding case. Besides, motions in this direction are accompanied with pain, particularly if they be made by force. Luxation downward is prevented, on the one hand, by the cartilage of the first rib, which presents to the bone an insurmountable barrier. On the other hand, to produce this kind of luxation, it would be necessary for the external extremity of the clavicle to be forced upwards, an occurrence very seldom occasioned by falls. Luxation upward, or over the superior edge of the sternum, must be the effect of a stroke, which, by depressing the point of the shoulder, and forcing it at the same time forward, presses the sternal extremity against the internal and superior part of the capsule, which, being thus lacerated, suffers a luxation to take place. But such a derangement of the articulating surfaces is very rarely produced by falls. Whence it follows, that of the different kinds of luxation of the clavicle, that in a downward direction is altogether impracticable. Those backward and upward, though possible, occur but rarely in practice; while that in a forward direction, on the contrary, is not an unfrequent accident. This tends to confirm the observations of practitioners, and particularly of Desault, whose immense collection on the subject furnishes examples of the last kind of luxation only.
8. In these luxations, there is for the most part, a rupture of the capsular ligament, and an escape of the bone through the opening. But sometimes the ligament is only preternaturally distended, and then the luxation is incomplete.
§ III.
OF THE SIGNS.
9. But whatever may be the causes or kind of the luxation, its diagnosis is always easy. If it be forward, the direction of the stroke which the shoulder has received, furnishes, at first, some ground of suspicion. The accident is certainly known by the appearance of a hard and unnatural protuberance in front of the sternum, and behind the extremity of the sterno-cleido-mastoideus muscle, by the existence of a sensible depression or hollow at the joint, and by the situation of the shoulder, which is pushed further backward, and is less projecting and more approximated to the trunk, than in its natural state. Add to these, a difficulty in performing motions in a forward direction, which, when somewhat forced, reduce, in proportion as they are accomplished, the size of the protuberance formed by the displaced end. The head is always inclined towards the side where the luxation exists; an attitude which relieves the painful drawing or tension produced in the sterno-mastoideus muscle, by the humeral extremity pushing it forward.
10. A protuberance over the superior edge of the sternum, a difficulty in raising the shoulder, the pain which results from attempting such a motion, the diminution of the protuberance which it occasions, the absence of the sternal extremity from its natural cavity, the approximation of the shoulder to the thorax, and its depression and diminished projection, compared to its usual state, afford evidence of a luxation upwards.
11. A luxation inward or backward, would be characterized by a projection of the shoulder exteriorly, by a difficulty in performing motions in a backward direction, by the alarming effects, which, as Petit remarks, the compression of the trachea would doubtless produce, and by a depression or hollow at the joint, more perceptible here than in the two preceding cases.
12. These appearances will be more or less striking, accordingly as the membranes, lacerated or only distended, offer a greater or less resistance.
§ IV.
OF THE REDUCTION.
13. To reduce a luxation, is, in general, to make the bone re-enter its cavity, by retracing, or returning along, the same route which it followed in escaping from it. Now, in a forward luxation, the displacement is from behind forward, in an upward one from below upward, in an inward or backward one from before backward, but, in each of the three, it is more particularly from without inward. In the first case, therefore it is backward, in the second, forward, in the third downward, but, in each of the three, more particularly outward, that the powers for producing extension must be directed.
14. Hence the method generally employed by most practitioners, recommended by almost every author who has written on the subject, adopted by Petit, Duverney, Heister, &c. and which consists in placing the knee between the shoulders of the patient, as a point of resistance, by the aid of which the shoulders may be drawn backward, fulfils only half of the indication of cure; because at the time that the humeral extremity is drawn backward, it is not directed sufficiently outward.
Hence a difficulty of replacing the bone sometimes occurs, a difficulty always removed, when, pursuant to the method employed by Desault in fractures of the clavicle (see Desault’s method), the arm is made to serve as a lever of the first kind, to carry backward and outward, the head of the bone, which is displaced in the opposite directions, when the luxation is forward. This method possesses the advantage, not only of giving the powers of extension a proper direction, but also of increasing them to a degree even beyond what is necessary for effecting a reduction, by removing them further from the resisting force. Hence it is unnecessary to adopt any particular measures for restoring and preserving the form of the part, as the extension is alone sufficient for that purpose.
These principles, evidently applicable in effecting a reduction, are still more strikingly so in the means destined for retaining it. Let us apply what I have just said, to a case of dislocation in a forward direction. It will be easy to transfer it afterwards to the other kinds of luxation.
§ V.
OF THE MEANS OF RETAINING A REDUCTION.
15. Few luxations are so speedily reduced, but few are more easily displaced again, than that of the clavicle. This disposition is the reverse of that of most other luxations, which are reduced indeed with difficulty, but seldom afterwards suffer a displacement. The cause of this we find, 1st, in the extreme mobility of the clavicle, to which all the motions of the arm are communicated; 2dly, in this further consideration, that most of the muscles, which have their insertion towards the shoulder, tend to draw this bone inward, when the ligaments, in consequence of being either broken or distended, as happens in this accident, do not offer a sufficient resistance.
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]).
A second precaution, not less essential, is, to push the humeral extremity of the clavicle, a little forward, and fix it in that direction, in order that the sternal being directed backward, may be removed from the place[8] through which it has a tendency to escape.
22. Desault almost always obtained complete success by this process, and by the most accurate attention to prevent the relaxation of the bandage. In the mean time, a stiffness, more or less considerable, always remains in the joint for a long time after the reduction, and it is not unfrequently a month or two before the part recovers its usual facility of motion.
The following cases, collected by Brochier, confirm the doctrine for which I have been contending.
Case II. A man luxated the clavicle by falling on the point of his shoulder, and forcing it backward. He was immediately brought to the Hotel-Dieu, where Desault demonstrated to his pupils, that the head of the bone, carried in front of the sternum, was removed nearly an inch from its natural cavity, the ligaments of which were no doubt lacerated.
Here, as in the fracture of the clavicle, the application of the bandage answered the purpose of reduction, and removed the protuberance formed by the extremity of the bone.
The patient, being strong and vigorous, and having received besides a violent contusion, was bled twice, and confined to a low diet. On the following day, no derangement; on the fourth day, a slight displacement of the bone, the rollers a little relaxed, bandage applied anew. Eighth day, no sensible displacement. Eleventh day, some swelling around the joint; compresses, wet with vegeto-mineral water, ordered to be frequently renewed. Twentieth day, the swelling almost gone, and no disposition to a displacement; the apparatus was removed; motions at first difficult, and contracted. Twenty-ninth day, more free and easy. Thirty-fourth day, returned to their natural state.
Case III. Mary Rivert luxated her clavicle, on the seventh day of January 1789. Being brought some time afterwards, to the Hotel-Dieu, she was treated in the same manner as the foregoing patient, and with the same result, except that a very slight protuberance remained at the extremity of the bone, and the confined state of the motions continued a little longer. Desault related, in his lectures, other instances of cures being performed without the least remaining deformity.
After all, even supposing the method just proposed, to possess no other advantage, than that of diminishing the protuberance of the bone, which, under other modes of treatment, is almost inevitable, and by that means preventing the motions of the part from being confined, it would still, without doubt, be a great step towards the perfection of the art.
23. Should a luxation backwards occur, the same process of reduction should be adopted, with this difference, that the extension ought to be made forward and outward; and the same apparatus should be applied for retaining the parts, except that the humeral extremity ought to be directed a little backward, in order that the sternal extremity, being carried forward, may be removed from the place of laceration in the capsule.
In like manner, should the bone be luxated upwards, it would be necessary to draw the arm outwards, and elevate slightly the point of the shoulder, for the purpose of depressing the sternal extremity.
LUXATION OF THE HUMERAL EXTREMITY.
§ V.
OF THE KINDS OF LUXATION.
24. Luxations of the humeral extremity of the clavicle, take place, according to Petit, in two ways, 1st, under, and 2dly, over the acromion. If we attend to the disposition of the articulating surfaces, the superior of which rests obliquely on the inferior; if we examine, in particular, the relative position of the corocoid apophysis with respect to the clavicle, it will be difficult to conceive how the first kind of luxation can occur, without being accompanied by a fracture. Yet some facts added by Desault to the doctrine of Petit, on this point, seem to demonstrate the possibility of the clavicle sliding under the acromion. As to luxations forward and backward, the mobility of the shoulder, the facility with which it yields to motions impressed on it in these two directions, and the want of a resisting power, make the two bones that compose it, move together, still preserving their relative position.
The luxation upward, then, is that which ought chiefly to occupy the attention of the practitioner. Yet even this is less frequent than the luxation of the sternal extremity, on account of the very great strength of the retaining ligaments, which, when this luxation occurs, must be, if not lacerated, at least very much distended.
§ VI.
OF THE MECHANISM AND THE APPEARANCES.
25. A fall on the point of the shoulder is the most frequent cause of this luxation. The two articulating surfaces, representing an inclined plain, slide along each other, in such a manner, that that which belongs to the acromion is pushed inward, while that of the clavicle is directed outward. The capsule being stretched, gives way, and then the displacement is manifested by a preternatural protuberance over the acromion; by a stiffness in the motion of the shoulder; by the direction of this part, which is evidently drawn inward and downward; by the inclination of the head of the patient to the side affected; by a bending of the body; and by severe pains in the luxated part. These characters are essentially distinct, and ought to have prevented the error of Galen, who mistook a case of this kind for a luxation of the os humeri downward. Hippocrates and Ambrose Pare have foreseen the possibility of this mistake and even warned young practitioners to be on their guard against it. But, as citizen Sabattier judiciously observes, the position of the head of the humerus, under the arm, in a luxation of that bone, will remove all uncertainty respecting the nature of the injury.
§ 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.