Part 21

On opening the body, the parts in the neighbourhood of the joint were evidently tumefied, and the capsule was stretched from above downwards. The head of the os femoris was situated on the external edge of the acetabulum. The capsule, though greatly elongated was still in a state of tension; and the articular cartilage was swollen to such a degree, as nearly to fill up the cavity. The quantity of synovial fluid was less than natural.

7. This case, taken at a period of the disease not far advanced, fully confirms the inference deducible from the two preceding ones, respecting the cause of spontaneous luxations. Here, indeed, the capsule not having given way, the swelling having only just commenced, and the synovia existing in but small quantity, the progress of nature was evident. Here, also, occurred a sign not noticed by Petit; namely, the elongation of the limb, which always, in such cases, precedes its contraction.

From what we have said, it appears, 1st, that the efficient cause of spontaneous luxations of the os femoris, is a swelling of the articular cartilages, which alters and destroys their organization: 2dly, that the presence of this swelling must necessarily render fruitless all attempts that might be made to replace the head of the bone in its cavity: 3dly, that the change in the organization of the cartilages, renders astringents, discutients, and other external means applied for the purpose of removing the tumefaction, entirely useless: 4thly, that here, as in many other cases, art ought to confine itself to the palliation of effects, and not attempt the removal of causes.

MEMOIR XIII.

ON THE FRACTURE OF THE ROTULA.

§ I.

1. The rotula, a sort of bony production of the sesamoid kind, attached to the tendon common to the extensors of the leg, represents a moveable pulley, intended to slide on that formed by the separation of the condyls of the os femoris. It protects the joint which it covers, and, in point of structure, use, and situation, greatly resembles the olecranon, from which it differs only in this, that, instead of being a continuation or process of the tibia as the olecranon is of the ulna, it is only attached to that bone by a strong and thick ligament which is inserted into its tuberosity. Hence it follows, that between the injuries of the one and the other, there must be a great analogy: and indeed most of the signs characteristic of fractures of the olecranon, are characteristic also of those of the rotula, and the treatment which, in such cases, is suitable for the former, differs but little from that required by the latter.

§ II.

OF THE VARIETIES AND CAUSES.

2. Fractures of the rotula may, in general, assume any direction, transverse, longitudinal, or oblique: but the first kind occurs in practice much more frequently than the others; and so great indeed is the disproportion, that it has almost exclusively attracted the attention of authors, in the numerous forms of apparatus invented to retain the fragments.

3. A shattering of the bone, the effect of a violent blow; a contusion; an echymosis; an effusion of blood into the adjacent soft parts; one or more wounds of the soft parts, with or without an opening into the joint; a swelling, the degree of which varies greatly, according to the state of the fracture, and the disposition of the subject, but which is constantly present; a double division of the bone, one of which, being longitudinal, forms an angle with the other, which is transverse; and a concomitant fracture of the condyls of the os femoris, or of the tibia: such are the varieties and complications, of which the fracture under consideration is susceptible.

4. But this fracture may be produced in two modes. 1st, by the action of external bodies: 2dly, by that of the extensor muscles. The first mode of division takes place in falls on the knee, or when a body in motion strikes against it, and, in this case, there is no counter-stroke, the rotula being too small for such an occurrence, and always sustaining the fracture where it receives the blow. In the second, the fall is only subsequent to the fracture, and, as Camper has well observed, is most frequently the effect of it. For instance, the line of gravity of the body is, by some cause, removed behind it; the anterior muscles contract themselves to bring it forward again; the extensors act on the rotula; it is broken, and a fall ensues. Again, the leg is suddenly thrown into a state of violent extension; the extensors act with great force; a fracture is the consequence, and the patient falls. A soldier once fractured his rotula in kicking at his serjeant; thus the olecranon, in like manner, has been broken by throwing a stone. A man, in the Hotel-Dieu, fractured the rotula of each knee, in the operating room, by means of convulsive motions, produced by the operation of lithotomy.

5. The action of external bodies, can alone produce a longitudinal fracture, as when a person falls on a sharp projecting piece of timber: but this may also produce a transverse fracture. On the other hand, muscular action can never give rise to any but the latter kind, since the direction of this fracture is at a right angle with that of the extensors. A fracture resulting from the action of external bodies, is oftentimes accompanied by a wound, a contusion, or a shattering of the part (2); a fracture, arising from muscular action, is always simple, except as to a swelling around the joint. The latter cause may, instead of fracturing the rotula, rupture the common tendon of the muscles, or, what is more common, the inferior ligament. Desault has seen many examples of this: Petit has also observed several, and Sabatier has sometimes met with them. External violence seldom produces this double accident.

§ III.

OF THE SIGNS AND THE DISPLACEMENT.

6. In longitudinal fractures the diagnosis is always accompanied with more or less difficulty, because the extensor muscles, drawing by their contractions the two fragments equally upwards, and the inferior ligament holding them equally down, tend to keep them in apposition, and to prevent them from separating. Sometimes also the ligamentous production which covers the rotula, remains entire and serves to keep the fragments together. It will be necessary, therefore, should the existence of such a fracture be suspected, to move the two sides of the rotula in opposite directions, by pressing them to the right and to the left, in order to arrive at certainty on the subject. Should a wound exist, as is oftentimes the case (5) the diagnosis is less difficult.

7. If the division be transverse, the diagnosis becomes then as plain and easy, as it is difficult and obscure in cases where it is longitudinal. In such a case, a considerable separation or space exists between the two fragments, sensible to the touch, when the hand is placed on the knee. In this separation, the fragments are not displaced by the same means. The superior fragment being attached to the extensors, is drawn upwards with great force by these muscles, the action of which the rotula no longer resists. The lower fragment, on the other hand, being attached only to the inferior ligament, is not moved by any muscle, and cannot be displaced in any other way than by the motions of the leg with which it is still connected.

8. Hence it follows, 1st, that, in a state of extension, the separation is the least possible, because it is then produced on the part of the superior fragment only; 2dly, that in a state of flexion it is greatest, because then both fragments concur alike in producing it; 3dly, that it may be increased or diminished by varying the degrees of flexion.

9. This fracture is further characterized by the following circumstances, namely, a practicability of moving the fragments transversely in opposite directions, and of producing, by that means, some degree of crepitation, provided they be first brought close together; by the pain which accompanies these motions; by the swelling common to every kind of fracture of the rotula, and which, if very great, may involve the other signs in more or less uncertainty; by a difficulty of standing; and an almost entire loss of the power of walking, in consequence of the extensors being no longer able to communicate motion to the leg, unless when the fracture exists very low down, near to the inferior ligament.

10. The touch will always discover in what part of the bone the fracture is situated, which, if it be oblique, will partake more or less of the characters of the longitudinal or the transverse, accordingly as it approaches to the one or the other.

§ IV.

OF THE PROGNOSIS.

11. Many authors have pretended that fractures of the rotula cannot be cured, and it even appears that the Academy of Surgery adopted this opinion, on receiving a memoir from a Flemish physician, which contained several facts tending to establish that principle. But what do these facts prove? That in some particular cases, reunion did not take place, but they do not show that this was owing to the nature of the fracture.

12. But, what, in such cases, could prevent a cure from taking place? The structure of the rotula differs, say they, from that of the other bones. Now, admitting this difference of structure to be real, it certainly approaches to the structure of tendons to which indeed it bears a strong affinity. But, who does not know, that, when tendons are divided, they unite as readily as bones? Besides, is not the power of reunion common to every part endowed with life? I have already shown, when treating of other fractures that communicate with joints, what credit is due to those hypotheses so often revived but never confirmed, nay even clearly proved to be unfounded, such as, an effusion of callus into the joint, a failure of reunion from a want of periosteum on the posterior part of the bone, the synovia diluting the matter of callus, and thus preventing it from being duly prepared, &c.

13. The inflammation of the articulating surfaces and of the ligaments around the joint, ought to have more influence in constituting an unfavourable prognosis, than any circumstance that authors have mentioned. But experience proves, that, when judiciously treated, these fractures are not accompanied by that accident, and even that the swelling, which for the most part attends them, always yields more or less speedily, when a bandage, uniformly applied, presses equally on all parts around the joint, and thus forms a kind of discutient, while at the same time it retains the fragments.

14. Pare, Fabricius of Hilden, and a number of other writers, have pretended, that some degree of lameness must always be the consequence of this fracture. But, from what causes must this lameness so certainly arise? Is it from a want of reunion in the part? I have already shown (11 and 12) that this apprehension is wholly unfounded. Is it from an anchylosis? This accident cannot take place, except either in consequence of inflammation occurring in the articulating surfaces, (and I have already shown how that may be avoided, 13) or of a stiffness in the ligaments, and I shall hereafter make it appear that that may be readily prevented by motion. Is it from the fragments being drawn asunder, and in that state united by an intermediate substance of too great an extent? I shall prove, that a bandage properly constructed, is always sufficient to keep these fragments in contact.

From these considerations it appears, that writers have, in general, without sufficient cause, given an unfavourable prognosis, in relation to fractures of the rotula, which have, indeed, a great affinity to other affections of the same kind.

§ V.

OF THE REDUCTION AND THE MEANS OF MAINTAINING IT.

15. I have already observed (7), that the causes of the separation of the fragments are, as far as respects the upper one, the contraction of the extensor muscles; and, in relation to the lower one, the flexion of the leg; whence it follows, that the means of preserving contact between these fragments are 1st, all those that are calculated for the prevention of muscular action; 2dly, such as may keep the limb in a state of permanent extension. Hence two leading curative indications must be fulfilled by the bandage constructed for fractures of the rotula: the last of these indications presents in general but little difficulty; but, with regard to the other, the case is different. To fulfil the latter, it is necessary first, to weaken the contractile force of the muscles, and by that means diminish the effort which they make to draw the superior fragment upwards; and then, to oppose to them a proper mechanical resistance, which, by acting in a direction the very reverse of that in which they act, may countervail their efforts.

16. But the force of contraction is diminished, 1st, by throwing the muscular fibres into a state of relaxation; this end is best attained by bending the thigh on the pelvis: 2dly, by making compression over the whole limb, by means of a circular bandage, which, by confining the muscles, tends to restrain and weaken their action. Thus it is known that the advantage of the bandage employed to unite transverse wounds, consists chiefly in that compression which, by diminishing muscular action, prevents the retraction of their edges. Another advantage resulting from the bandage in this case is, that it prevents the swelling of the limb.

17. As to the mechanical resistance, which must act in a direction opposite to that of the contraction of the muscles, and, by that means, prevent the displacement of the superior fragment, it cannot, in the present case, be of the same nature as in fractures of the thigh, the clavicle, &c. where permanent extension is practised. The superior fragment offers too small a purchase for any extending forces to act on. This resistance must be made, then, by placing some body above this fragment, and retaining it in that situation with a force sufficient to hinder the fragment from rising upwards: such as a few turns of a roller drawn tight, a bit of leather, some hollow compresses, &c.

18. It is evident from the foregoing principles, that every bandage intended to retain a transverse fracture of the rotula, ought to be calculated to maintain the following state of things: 1st, the extension of the leg on the thigh; 2dly, the flexion of the thigh on the pelvis; 3dly, a uniform compression over the whole limb; and, 4thly, some mechanical resistance properly secured above the superior fragment: the three last expedients relate to the displacement of that fragment alone; while the first has a relation to that of the lower one. Let us examine whether or not the bandages, hitherto employed by different authors, be calculated for these purposes.

19. M. Valentin, believing that position alone was sufficient to retain the fragments in contact, neglected the application of apparatus entirely, which he even considered as hurtful, in consequence of the swelling it produced; but experience soon proved the insufficiency of this method. The slightest movement, or the least effort on the part of the patient, made the extensor muscles contract, which, drawing the superior fragment upwards, separated it from the lower one; and, as the time of reunion is in direct proportion to the distance of the fragments from each other, it must, under such treatment, have been necessarily tedious, and sometimes must have even failed altogether.

20. As to a swelling being produced by the bandage, this never occurs, unless when some openings are left, through which the integuments protruding become tumefied: but, when the pressure is uniform throughout, when the fluids find throughout an equal resistance, this accident is not to be apprehended, as is proved by the practice of Desault, who never met with it; on the contrary, a bandage properly constructed and applied, is calculated to prevent swelling (16).

Mere position, then, though always of service in this affection, is not alone sufficient, because it fulfils only the first of the indications or principles laid down with respect to every form of apparatus for transverse fractures (18), namely, that which relates only to the lower fragment; while those that relate to the upper one, remain still to be fulfilled.

21. Most authors have employed, with a view to these, a kind of figure of 8 bandage, known in art by the name of _Kiastre_,[32] and approved of by Petit, Heister, &c. This is made of a roller formed into two balls, which are brought across each other alternately under the ham, passing over two hollow or forked compresses, that enclose the two fragments of the rotula.

[32] I know not of any English term equivalent to this. T.

But the unequal pressure which this makes on the unequally projecting parts of the knee, renders its application extremely painful, particularly below, where the pasteboard covering applied by Louis, immediately on the skin, afforded but a feeble protection to the tendons of the flexors. Besides, it did not prevent the swelling, which is indeed a necessary consequence both of this unequal pressure, and of the openings left between the casts of the bandage. This swelling is taken notice of by all writers, and is, according to them, one of the troublesome circumstances attending the fracture. The third indication is not all fulfilled (18).

22. The extensor muscles, not being at all compressed, will act with their whole force on the upper fragment, and, on the slightest effort of the patient, overcome the resistance of the bandage, the action of which, being oblique with respect to the fragment, is inconsiderable, unless it be drawn very tight, and thus a displacement will again occur. This obliquity of the turns of the roller obliges the surgeon, either to draw it very tight, in which case a swelling is inevitable, or to make it but moderately tight, and then the apparatus will be insufficient to resist the action of the muscles.

23. Most of the objections to the ancient apparatus for fractures of the rotula, apply also both to that proposed by Ravaton in his surgery, and to that which Bell employs in his practice. Both of these, while they fail in making sufficient resistance to muscular action, as well as in fulfilling the third condition laid down as necessary to every bandage (18), contribute to the swelling, and can rarely produce a perfect contact between the fragments. Thus Bell has well observed, that the reunion is rarely perfect, and that there is always a separation more or less perceptible.

24. The complication, the intricacy, the expense, and other more weighty inconveniences of the machine described by Garengeot in his treatise on instruments, and employed, for the first time, by Arnaud, and also of that which was proposed and used by Solingen, have, long since, entirely banished them from among the means of reduction.

25. Some practitioners have advised the uniting bandage used in cases of transverse wounds, which is formed, as is well known, of two small rollers or strips placed in the longitudinal direction of the limb, one of them having holes in it, to which the divisions of the other are fastened. Both of these are first secured by circular turns; being then drawn in opposite directions so as to meet, they draw the parts on which they are applied in the same directions. But the action of this bandage is confined to the integuments, and would have of course but a feeble influence on the fragments beneath. It is also attended with this further inconvenience, that by wrinkling the integuments, and throwing them into folds, it might press them down between the fragments, and thus prevent their contact. Besides, it is liable to most of the objections urged against the preceding one.

26. This view of the means employed by different practitioners, to counteract the causes of displacement in this fracture, are sufficient to convince us, that the difficulties hitherto experienced in the treatment of it, have arisen from the feebleness of the former, and the strength of the latter. So great indeed have been these difficulties, that some authors, conceiving a reunion impossible, have, in conformity to such an opinion, though contrary to all the rules and principles of the profession, advised us to abandon the patient to himself. But I have already exposed the fallacy of that opinion, respecting the want of a healing power in the rotula (12), an opinion which, if generally adopted, would give rise to consequences of the most serious nature. In the present case, as in all other fractures, the contact of the fragments ought to be the chief object of the surgeon’s efforts.

27. But ought this contact to be perfect and exact? Several authors, particularly Bell, have conceived, that the motions of the limb can be performed as well with a slight separation of the fragments. Pott even declares that such a separation will enable the patient, after his recovery, to walk with more ease. Flajani advances the same opinion in a dissertation on the subject.

From this doctrine arose a new mode of treatment, which consisted in not suffering the fragments to be at rest. They were accordingly, during the cure, put frequently in motion, the more effectually to prevent an anchylosis, which is sometimes the consequence of this fracture.

28. But, on the one hand, it is difficult to conceive, on what this opinion of these authors can be founded; while, on the other, reason declares, in the plainest and most forcible terms, that the more the state of a bone, after it has been broken, differs from its natural state, the less free will be the exercise of its functions, and, that the perfection of the treatment of fractures consists, in leaving behind it no vestige of the accident.

29. This truth was frequently confirmed in the experience of Desault, who had an opportunity of seeing numerous fractures of the rotula, both in the Hotel-Dieu, and in his private practice. He always observed, that, when the separation of the fragments was considerable, and the ligamento-cartilaginous substance uniting them was of some extent, standing and walking were performed with much difficulty; that the patient was exposed to frequent falls, from the want of a proper correspondence, in point of strength and motion, between the two limbs; and that, on the contrary, the less extensive the separation and the substance that filled it up were, the more free and easy were the motions of the part, which still remained, however, somewhat defective and imperfect, unless every vestige of the division was obliterated.

Paul of Egina long since observed, that, when no means of reduction were employed, though the patient might walk tolerably well on a level surface, he could not, without difficulty go up an ascent.

30. From what has been said, it follows, 1st, that in the treatment of this fracture, the perfect contact of the fragments ought to be the principal object of the practitioner; 2dly, that the kinds of apparatus employed by different authors, are but ill calculated for the attainment of this end, because they fulfil but imperfectly the indications formerly laid down (18). Let us see whether or not the apparatus of Desault be any better suited to this purpose.

31. The bandage, which he employed in this case, analogous to that for fractures of the olecranon, is composed, 1st, of one splint, two inches broad, and long enough to reach from the tuberosity of the ischium, to a little above the heel; 2dly, of two rollers, five or six yards long, and nearly three inches wide; 3dly, of another single roller, with two holes about the middle of it, a little longer than the injured limb of the patient, along the fore part of which it must be extended.

32. Every thing being arranged for the application of the apparatus,