Chapter VI: Part 6

35. The ulna, less frequently broken, in general, than the radius, scarcely ever suffers alone from falls on the wrist or hand. Most commonly its fracture is direct, and occurs, in particular, in cases where a person in falling, extends the fore-arm for the purpose of supporting himself, and strikes its internal part against some resisting body.

The division, though it does take place occasionally in all parts of the bone, occurs most frequently near to the lower end, where its slender size, compared to that of its upper end, its more projecting situation, and its thinner covering of soft parts, act as predisposing causes.

36. In whatever part it may exist, the touch must readily detect it, when the fingers are drawn along the internal surface of the ulna, which lies almost immediately under the skin. If moved in contrary directions, the fragments will also, by their mobility and crepitation, disclose the nature of the injury. A depression more or less perceptible is observed on the internal part of the fore-arm, produced by a displacement of the fragments, which are carried towards the radius, more particularly of the inferior fragment, as Petit has well observed, the superior one remaining almost immoveable.

§ XI.

OF THE REDUCTION, AND THE MEANS OF MAINTAINING IT.

37. The reduction does not differ from that of the radius (31), except in this, that the assistant who makes the extension, must place the hand in the opposite state, namely, that of abduction, in order that the fragments may be brought into contact, while the surgeon assists in this process, by pushing the broken ends of the bone in a direction opposite to that of their displacement.

As in the foregoing case, three splints are sufficient for the apparatus, where the radius, being unbroken, performs the office of a fourth.

The exercise of the limb, after the consolidation of the bone, is in general less necessary here, than in fractures of the radius (34), because the ulna, being an immoveable point of support for the motions of rotation, concurs in them only in a passive manner.

FRACTURE OF THE OLECRANON.

§ XII.

REMARKS ON THE OLECRANON.

38. The ulna is surmounted, at its upper end, by a considerable appendix, curved before, where it corresponds to the articulation of the fore-arm, and is covered with cartilage; convex behind, where there is nothing to separate it from the external integuments, and is attached at its upper end to the strong tendon of the triceps muscle, which appears to be incorporated with it. This appendix resembles greatly, in its structure, form, and uses, the rotula, from which it would differ in nothing, if the inferior ligament of the latter were ossified, so as to form a bony continuity between it and the tibia. It is exposed to fractures, perfectly similar to those of the rotula, but which differs so essentially from the other fractures of the ulna, as to call for a separate examination.

39. The ancients appear to have had but little knowledge of fractures of the olecranon, respecting which they have transmitted nothing to us, unless with Dalechamps, we find cause to recognize a reference to this affection in the following passage of Paul of Egina: _Cubitus frangitur ... circa partem ad cubiti gilbum_.

Most of the moderns have spoken of it only in a vague manner; no one has described with accuracy the signs which characterize it; and few have given satisfactory ideas on its treatment. Petit has not spoken of it separately, and Duverney, who concludes with it his article respecting fractures of the fore-arm, has but imperfectly described for it a bandage which is in itself equally imperfect. Bell does not give us, on this point, an exposition of either his opinions or his practice.

Yet this fracture is by no means so rare as to justify the silence of authors, and its treatment merits a degree of attention beyond that which is requisite in most other fractures.

§ XIII.

OF THE VARIETIES AND CAUSES.

40. The olecranon suffers fractures at its base and at its summit, but more frequently in the first, than in the second situation. The division, though very generally transverse, is sometimes oblique. Desault met with an instance of an oblique fracture of the olecranon in a man, who had sustained a violent blow on his fore-arm from a club.

41. The causes which produce it are, either muscular action, a circumstance that very rarely occurs, or the direct action of external bodies, which is by far the most common case. The reverse of this is true with regard to fractures of the rotula, which are almost always produced by the contraction of the muscles attached to that bone.

42. The olecranon has been at times separated from the ulna, by the act of throwing a stone with great force. In such cases, the fracture has been produced by the immediate action of the triceps muscle. This is the first mode of division.

The second occurs when a violent blow is received on the elbow, or, more particularly, from falls on that part: for example, if, when descending a flight of stairs, our heel slip and we fall backwards, the arm is suddenly thrown behind to save the body. In such a case, the olecranon striking forcibly against one of the steps, and being pressed between it and the weight of the body, is broken. In this way was the disease produced in a majority of the patients attended by Desault for fractures of the olecranon.

§ XIV.

OF THE SIGNS.

43. We meet here with the same appearances and state of things, which constantly occur in fractures of the rotula. The triceps extensor, finding no longer in the continuity or sound state of the ulna, a resistance to its contractions, draws upwards the short fragment to which it adheres, produces between it and the lower one an interval more or less perceptible, and gives rise to the greater part of the other characteristic signs of the affection: these are, 1st, An interval or space between the fragments, corresponding to the posterior part of the articulation. This interval may be increased at pleasure, by increasing the flexion of the fore-arm, or by making the patient contract the triceps muscle, and may be again diminished, by bringing the arm into a state of extension: 2dly, An inability in the patient to extend the fore-arm spontaneously, which is the necessary result of the separation of the triceps from the ulna: 3dly, A constant semiflexion or half-bent state of the fore-arm, produced by the contractions of the biceps and brachialis internus muscles, to which no antagonists are now opposed: 4thly, An elevation, more or less perceptible, of the olecranon above the condyls, which, on the contrary, rise above it, when, in a natural state of the parts, the fore-arm is half-bent: 5thly, A facility of moving the upper fragment in every direction, without communicating any motion to the ulna; 6thly, A peculiar sensation experienced by the patient, to whom it seems, when he makes an effort to extend the fore-arm, as if some body or substance were detached or broken off from his elbow, and carried upwards. The patient may realize the justness of this sign, by comparing it with what he feels on attempting to extend the opposite fore-arm, placed in the same position.

44. If to these signs be added the circumstances which accompany the accident, the severe pain that is always felt, the crack which is sometimes heard by the patient, and the possibility of producing a perceptible crepitation, by rubbing the fragments in contrary directions, after having first brought them together, it will be difficult to be mistaken respecting the existence of the fracture, which indeed the swelling of the part alone can conceal from the practitioner, if, as sometimes happens, it be considerable. But then, being soon dispersed, either spontaneously, or by the action of discutients, it leaves the accident unmasked, accompanied by the signs just enumerated.

45. To the swelling is oftentimes added, an echymosis more or less considerable, when the accident has been produced by a fall on the elbow. But by this, no change is effected in the essential characters, which are always sufficient to distinguish a fracture from a luxation backwards, with which it has been sometimes confounded, as appears from many examples recorded in different works.

§ XV.

OF THE PROGNOSIS.

46. I will not dwell on the question, so much agitated of late, namely, whether or not the olecranon be susceptible of consolidation or reunion. Already has it been hundreds of times answered by experience. What could theory add to the conviction already impressed on us from that quarter? It was by exhibiting to the crowd of pupils who attended his clinical lectures, fractures of this kind perfectly reunited, that Desault refuted the weak arguments, of the periosteum not being able, in consequence of not covering the anterior surface of the olecranon, to produce a union between its fragments, of the synovia mixing with the matter of callus, diluting it, weakening it, preventing it from becoming sufficiently hard for the purpose of reunion, &c. We will only observe, that these ideas are borrowed from a theory which modern experiments have proven to be unfounded, and which, were it true, would be applied in the present case quite unphilosophically, since it would deny to certain parts of man the power or property of restoration or being healed, a property common to all the component parts of beings endowed with life, and which even constitutes one of their essential and discriminative characters.

47. Is the consolidation of the olecranon effected in the same mode as in other bones? The observations of many practitioners, Camper in particular, seem to prove that a ligamento-cartilaginous substance is always the medium of the union of fragments. Desault once found this substance in a corpse, but it was in a case where the fracture had been improperly treated, and where, of course, no inference could be drawn with regard to ordinary cases.

48. But of what import to us are the means which nature employs? The indication is still the same. The fragments must be always kept in contact, that the reunion may be immediate, and that, as David observes, in his memoir on motion and rest in surgical diseases, the apophysis may not, by becoming too long in consequence of the space occupied by the callus, impede the extension of the forearm on the os humeri.

§ XVI.

OF THE MEANS OF CONTACT BETWEEN THE FRAGMENTS.

49. There are no fractures, the treatment of which demands more attention, or is surrounded with more difficulties, than that of the olecranon. Here art cannot, as in the thigh, and the clavicle, oppose to the ever active power of the natural muscles, a constant resistance produced by the action of a kind of artificial muscle, consisting in permanent extension. The superior fragment, being too small to give any purchase to extending forces, can be only pushed downwards, and kept in that position with a greater or less degree of stability and firmness, while the ulna, so to speak, is drawn to meet it. Whence it follows, that extension here is of little use, and that it is chiefly by position or attitude, aided by a judicious conformation, that the reduction is effected.

50. The position has varied in the hands of different practitioners. Some have proposed that, in which the fore-arm is half-bent, so as to form a right angle with the os humeri. The example mentioned by David, is not the only one where recourse has been had to this. But, by rejecting the general principle respecting the reunion of parts, which requires them to be kept in perfect contact, this mode is exposed to a double inconvenience. The reunion is extremely slow in being accomplished, and, when ultimately obtained, is accompanied by the loss of one part of the movements of the limb, in consequence of the length of the callus. This callus must necessarily fill up the whole space that intervened between the fragments during the treatment, and being thus added to the natural extent of the olecranon, lengthens this appendix to such a degree, that, in extending the fore-arm, its summit or upper end comes too soon into contact with the cavity in the os humeri destined to receive it.

51. This practice appears to have been chiefly owing to an opinion then in existence, that an anchylosis being the necessary consequence of the fracture, it was proper to place the arm in that position in which it would be most likely to be still of some service.

52. We must not, however, by throwing the fore-arm into the greatest possible degree of extension, allow it to be drawn into the opposite extreme. From this error the same inconveniencies would result. In such a case, should the fragments touch each other, and press too hard at their posterior edges, they must inevitably leave an intervening vacuity or space between their anterior edges. Hence a greater thickness of callus on the one side than on the other, and consequently an impediment more or less troublesome in the motions of the joint. If the inferior fragment do not touch the superior one, it sinks into the olecranon cavity, leaves the other behind it, and hence another source of irregularity in the consolidation.

53. Between these two extremes (50 and 51), it remains to choose a middle course, and that position will be best, in which the fore-arm shall be, so to speak, in a state between semi-flexion and extension. By this the fragments, being brought into perfect contact, will experience no obstacle to a reunion, which will be therefore both speedy and uniform.

54. But it would be useless to place the limb in a proper position, if no means were made use of to retain it there. Being immediately submitted to the action and influence of a multitude of causes, it will lose its position, and the work of nature being interrupted, the consolidation will be retarded.

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 the olecranon, 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. (See fracture 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 and precision, 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 David properly 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 of _engorgement_; 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 continued extension 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 made by 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.

MEMOIR IX.

ON THE LUXATION OF THE FORE-ARM.

§ 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 coronoide[19] cavity, extends to the corresponding edge of that of the olecranon, and is received into the external depression of the sigmoid cavity:[20] 4thly, 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.

[19] Not generally named in English works of anatomy.

[20] _Echancrure sigmoide._

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.

OF THE KINDS AND CAUSES OF DISPLACEMENT.

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 the coronoid 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, that without 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.

OF THE SIGNS.

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. In either 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 cavity[21] receives 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.

[21] That deep depression in the os humeri, which, in a natural
state of the parts, receives the upper end of the olecranon process.
TRANS.

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.

OF THE REDUCTION.

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 necessary to 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 thumbs behind. 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 strap round 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 position in 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.

OF THE MEANS OF MAINTAINING THE REDUCTION.

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 the extent 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.

MEMOIR X.

ON THE LUXATIONS OF THE RADIUS OVER THE ULNA.

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 the present 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.

OF THE DIFFERENCES IN POINT OF STRUCTURE BETWEEN THE TWO ARTICULATIONS OF THE RADIUS WITH THE ULNA.

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 annular ligament, 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.

DIFFERENCES IN THE LUXATIONS OF THE RADIUS; DIFFICULTIES OF THAT AT ITS UPPER END.

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.