Part 46

13. But what can be the immediate cause of these tumours? Are they, as some allege, an aggregation or crystallization of particles of matter conveyed into the interior of the joint by the synovia, in the same manner as the rudiments of a stone are conveyed into the bladder by the urine? Their organic appearance and the vessels that pervade them, are unfavourable to such an opinion. Can they be, agreeably to the conjecture of Theden, articular glands bruised by means of strokes or falls? Or are they, as some authors will have it, portions of the cartilage of the joint, detached by the same causes? How then will their spontaneous formation be explained?

But why trouble ourselves about the cause, provided we can remedy the effects? Nature conceals from us the means, and discloses to us nothing but the results. Theories are fluctuating; but experience is still the same: let us search, then, by an attention to facts, for that which we cannot learn from first principles.

§ IV.

OF THE SIGNS.

14. The phenomena which announce the presence of foreign bodies in the joint of the knee, are sometimes clothed in a character of such evidence, that they cannot be mistaken; at other times, the nature of the disease eludes the most accurate researches: the cause of this variety may be easily perceived.

As the joint presents different depressions and eminences, and as the bodies, being usually loose and detached, may travel through its whole extent, they produce different effects, according to the particular situations which they occupy. If lodged in a depression, they are not compressed, and cannot, of course, give rise to any troublesome affection. If they bear on an eminence, such as the condyls, or the posterior part of the rotula, they are forcibly compressed, and must derange, in some measure, the functions of the joint. Hence the precise nature of the affection cannot be at all times derived from the state of the symptoms.

15. Sometimes the patient can stand and walk with perfect freedom and ease, while, at other times, a sudden pain seizing him, obliges him to sit down, or even causes him to fall, if there be nothing at hand to support him. This pain subsists for a longer or shorter time. One motion produces it, and sometimes another, made in an opposite direction, removes it. But in common it is of some continuance, and then the patient is obliged to keep his bed.

16. If the state of the joint be examined, it will be found more or less swollen, when the pain is very acute. When the pain ceases, the swelling in part disappears. It is never sufficient to prevent the fingers, when drawn along the external surface of the joint, from discovering the presence of the foreign body, when it forms a protuberance under the integuments. It is then found sometimes above the rotula, by the side of the tendon of the extensor muscles, and that is the place where it usually produces least pain; at other times, it is lower down, in front of the condyls, and by the side of the rotula. It is occasionally found immediately behind the tendon of the extensor muscles; in this case so acute is the pain, that the patient is generally unable to stand. But it is when it is situated behind the rotula, near to the projecting ridge which runs across its posterior surface, that it gives rise to the most serious affections.

17. The body passes from one place to another, on the least motion, and sometimes, as Bell observes, the patient, on changing his position during sleep, is awakened by severe pain, in consequence of the foreign body being moved by this change. It happens, in certain cases, that it disappears, and lies concealed for some time, in the back part of the joint. During this period the joint performs all its functions with freedom and ease. Desault made this remark, in the case of a captain of dragoons, from whom, for the first time in his practice, he extracted one of these bodies, and who, for six months previously, had been able to perform all the motions of the joint freely, without pain. This person, experiencing no uneasiness, considered himself perfectly cured, when the body suddenly reappeared, in consequence of a hasty extension of the leg.

18. If the body, when projecting under the integuments, be gently compressed, it yields to the pressure, changes its situation, and, according to the impression it has received, moves either to the internal or the external side of the joint, or reciprocally from one side to the other, passing also behind the rotula, behind the inferior ligament, or sometimes behind the tendon of the extensor muscles. In these alternate displacements, it may in some cases be turned round, in such a manner that its anterior surface will take the place of its posterior one, and then resume its primitive situation. Desault met with an instance, in which the patient himself was in the habit of turning the body round in this manner.

19. Bell, in conformity to the distinction of articular concretions into cellular and solid, attributes to each division its peculiar signs. In the first case, the pains, being rather obtuse than sharp, are constant; in the second, they are extremely acute, but disappear and return at intervals. Supposing the division to be a real one, cases of the last description certainly occur much more frequently than those of the first.

§ V.

OF THE TREATMENT.

20. From what has been said it follows, 1st, that these cartilages floating through the joints, do mischief mechanically (14), by coming into contact with the articular surfaces: 2dly, that to obviate this mischief, it is necessary either to prevent their contact, by fixing the bodies in a spacious part of the joint, and thus doing constantly what nature does on certain occasions, or to extract them through an opening made into the articular cavity.

21. Hence, art can have recourse to but two methods of cure, all hope of discussing these tumours by external applications being, as Bell observes, entirely extinguished.

22. The first method was proposed by Middleton and Gooch, who having brought the foreign body into a situation where it produced no pain, endeavoured to confine it there a length of time sufficient to make it form adhesions with the corresponding part of the capsule. As we are not informed of the result of the experiments of these two physicians, we are left to our own conjectures on the subject.

23. Are these foreign bodies capable of forming adhesions? Supposing they are, will the internal surface of the capsule attach itself to them at the pleasure of the surgeon? Even admitting the existence of both these conditions, by what means can the bodies be kept stationary for a length of time sufficient for the formation of these adhesions? Will they not be displaced by the slightest motion? Besides, experience seems to be unfavourable to the expedient. I have already said (17) that, in a certain case, the foreign body disappeared for six months, remaining, no doubt, during that whole time, in the same place: but, if it could not, on that occasion, form adhesions, if a motion was sufficient to produce its reappearance, can we expect that art will be more fortunate in her attempts?

24. But, even admitting that the foreign body does form these adhesions with the capsule, if it should increase in size in the part of the joint which it occupies, becoming in a short time disproportioned to its extent, it will impede motion as before, and produce, by degrees, nearly the same affections.

25. From these considerations it follows, that the only expedient which can promise a radical cure is, the extraction of the foreign body. In the performance of this extraction, an incision must first be made through the integuments and the capsule.

26. This operation, simple and easy in itself, has given rise to apprehensions as to its consequences, which have long prevented practitioners from undertaking it.

It was in former times a maxim in surgery, that wounds of the joints are, if not mortal, at least extremely dangerous, in consequence of their admitting air into contact with the articulating surfaces. But observation has demonstrated the fallacy of this doctrine, and Desault in particular, has thrown great light on the subject, as I have frequently had occasion to mention in the course of this work: so that, at the present day, it is clearly ascertained, that, if judiciously treated, these wounds are seldom productive of serious consequences.

27. Hence it follows, that the operation we are considering, when skilfully performed, never gives rise to any dangerous or disagreeable affections. Experience has proved the truth of this assertion in the practice of Theden, Simson, Gooch, Broomfield, Bell, and Desault, the latter of whom performed the operation five times with complete success. The only case in which he was less fortunate, was that of a man, in whom the wound of the integuments closed up at first without any accident, but which was succeeded by two abscesses, one in the thigh, and the other in the leg, but without any affection of the interior of the joint. This patient was subject to a wandering rheumatism, which oftentimes attacked the lower extremities, and was perhaps in the present case the chief cause of the unfavourable occurrences.

28. It is to the English that we are indebted for the first operation performed for the extraction of these bodies. An account of this is given in the Transactions of a society in Edinburgh. Since that, the operation has been frequently repeated, and more than ten instances of it were already on record, when Desault first performed it in France. His method, somewhat different from that of others, was as follows.

1st, The patient must be laid on a bed, or seated on a high chair. The first position, however, is to be preferred, because when it is adopted, the patient need not be moved after the operation.

2dly, The leg is extended on the thigh, in order to relax the anterior part of the capsule of the joint.

3dly, The surgeon then searches for the foreign body, moves it to the internal side of the joint, against the attachment of the capsule, and secures it between his thumb and the fore-finger of his left hand, while an assistant draws the skin over the fore part of the rotula.

4thly, Taking then a common bistoury, he makes, on the protuberance formed by the body, a longitudinal incision of an extent proportioned to its size, through both the integuments and the capsule, so as to lay the body bare at the first stroke.

5thly, Sometimes the body escapes immediately of its own accord, in consequence of the compression made on it by the fingers. If its passage out be not spontaneous, a small scoop or a taper-pointed spatula passed under it, answers the purpose of extracting it. But, in the introduction of these instruments, it is necessary to avoid touching the articulating surfaces with their ends, lest, by being irritated, they might swell, and give rise to troublesome accidents.