OF INFLAMMATION OF THE MUCOUS MEMBRANES.

Mucous Membranes and the skin are analogous in structure, somewhat similar in function, and sympathise closely with each other in health and in disease. Both are endowed with that peculiar degree of sensibility which enables them to bear with impunity the impressions of foreign bodies; and both are protected from the influence of these bodies by an inorganic covering; the cutis and rete mucosum by the epidermis; the corium of mucous membranes by a laminated epithelium. They are the seat of all excretions, and by them all substances are introduced from without into the system. The capillary portion of the vascular system appears to have somewhat the same arrangement in both; the distribution of blood to the mucous membranes being, however, more copious. At the commencement and extremity of the alimentary canal, they insensibly pass into each other by means of an intermediate structure, of which the prolabium may serve as an example. In particular circumstances, they change into each other, both in appearance and in function. Thus, in prolapsus of the gut or of the vagina, the discharge from the protruded mucous surface after a time subsides, the rugæ disappears, the membrane becomes thickened and indurated, and gradually assumes an appearance exactly resembling that of the skin. In natural paraphymosis, the delicate membrane which, in the healthy state of parts, lines the internal surface of the prepuce, becomes converted into a cuticular covering. In neglected and long-continued excoriation of the nates, the raw surface, which was at first tender and irritable, and discharged a serous fluid, becomes villous, less sensible, and discharges a fluid similar to a mucous secretion. In sinuses also of long duration, the secreting surface becomes changed, so as to resemble a mucous membrane, and the discharge, from being purulent or gleety, becomes mucous, or at least resembles a mucous fluid,

A mucous surface, when inflamed, has for a short time, perhaps, at first, its functions suspended; it then furnishes a secretion, increased in quantity, and but little changed in appearance from the healthy fluid; afterwards the discharge resembles purulent matter, and is termed muco-purulent. When, however, the inflammation is violent, the discharge becomes bloody, or is altogether suppressed, and the membrane is thickened. Inflammation of a mucous membrane is very apt to spread with great rapidity, in this respect resembling the corresponding affection of the skin. It is attended with a sense of itching, and a burning pain. This pain is much increased by the muscles surrounding the parts being thrown into action, as in expelling their contents, more especially if these be of an acrid quality. The membrane is thickened, and of a spongy appearance; its surface is red, and sometimes covered with flakes of lymph; occasionally it is much softened, and coated with a viscid adherent mucus; and it would appear, in many instances, that, in acute inflammation, the membrane is generally softened, whilst it becomes indurated from chronic inflammatory action. When the inflammation is violent, and consequently rapid, considerable quantities of lymph are effused either on the surface of the membrane, or into the submucous tissue: and the lymph subsequently becoming organised, the membrane is much thickened, and a contraction is the consequence. The functions of a part lined with mucous membrane are more or less deranged, in consequence of the vitiation of the secreted fluid.

In inflammation of this tissue, metastasis is also apt to occur, from one part of the membrane to another, and from the membrane to the external surface. Cynanche, for instance, often follows upon erysipelas of the face and scalp, and vice versâ.

The passages, the internal surfaces of which are invested by a mucous membrane, are those subservient to respiration, nutrition, generation, and the urinary secretions; in other words, the mucous surfaces are the Pneumogastric and the Genito-urinary. Their particular diseases will be treated of hereafter.

OF INFLAMMATION OF THE SEROUS MEMBRANES.

On such an extensive subject it is unnecessary to enter fully; not that the inquiry is uninteresting, or that a knowledge of the diseases of the internal cavities, and the mode of treating them, is not required of the surgical practitioner before he can enter into practice, with safety to his patients and comfort and satisfaction to himself, but we have a very important class of diseases to bring under review in a limited space, and it is properly the province of others to treat of internal disorders, and to describe the best mode of alleviating or curing them. It is, however, the duty of the surgeon to treat the inflammatory affections of some of the serous membranes, and the consequences of inflammatory action in most of them; and it is therefore highly necessary that he understand the symptoms, progress, and consequences of such actions. The affections of the serous membranes are principally under the management of the physician; but they not unfrequently follow wounds and surgical operations, and the diseases of several of them are purely surgical. Inflammation of a serous membrane is attended with heat and pain, aggravated by motion of the parts and by pressure; the natural secretion is increased in quantity, the process of exhalation being incited, and that of absorption weakened; the serous fluid accumulates. The secretion becomes altered in quality, and assumes a milky appearance; lymph is effused, generally mixed with purulent matter, and floats in the fluid, or adheres to the surface of the membrane, which is rough and flocculent. The adherent lymph becomes organised, being penetrated by numerous bloodvessels; and thus the original membrane is, in many instances, much thickened, chiefly from the addition of new matter, though also from enlargement of its bloodvessels and opening out of the primitive tissues, principally the subserous cellular. When inflamed serous surfaces, which have been altered, both in texture and function, in consequence of inflammatory action, remain for a short time in contact with each other, lymph is effused and penetrated by bloodvessels from each surface; thus the new deposit is organised, and forms a medium of connection. By this process the parts are intimately united to each other, and consolidated into one mass; or are merely approximated, and joined, at one or more points, by portions of lymph, in some cases thin and narrow, in others extensive and of considerable thickness; the adhering bands either extend in a straight direction, from one surface to another, or interlace, forming a sort of network. After adhesions of various kinds have been formed, they are often lengthened and attenuated in consequence of the motion of the parts, as is particularly the case with adhesions between the pleura costalis and pulmonalis. When they have been of considerable duration, they often resemble the original membrane from which they were deposited, becoming thin and transparent, smooth on their external surface, and furnishing a serous secretion. Not unfrequently, inflammatory action in this tissue terminates in suppuration; and the pus, secreted by the membrane, accumulates in the most dependent part of the cavity. By collections of matter, whether serous, sero-purulent, or purulent, within a serous cavity, the functions of the contained viscera are deranged, much impeded, and in many instances morbid actions are excited in them. The inflammation, whether it terminates in resolution, or proceeds to serous effusion, adhesion, or purulent secretion, is attended with constitutional disturbance, and the symptoms are proportioned to the original intensity of the action, and the extent and kind of its termination. The effusion of lymph, and consequent adhesion, is, however, in many circumstances, a highly salutary process, as in wounds and injuries of the hollow viscera: effusion of their contents being thereby prevented, and the patient being saved from the danger attending violent inflammation of those cavities and their coverings, caused by the escape of a greater or less quantity of irritating extraneous matter. Purulent collections also, in the solid internal viscera, are thus allowed to discharge themselves externally. The nature, symptoms, and consequences of inflammation of serous membrane, will be more fully considered under the diseases of particular parts.

OF INFLAMMATION OF TISSUES COMPOSING THE ARTICULATIONS.

Inflammation of the synovial surface occurs in consequence of wounds, bruises, or sprains, and often from exposure to cold; from the latter cause, the knee and elbow joints most frequently suffer, as they are generally more exposed to its influence, and not so well covered with muscular substance as the others. Constitutional diseases, such as certain fevers, are followed sometimes by effusion of serous fluid into joints. Purulent matter is also deposited in joints during certain forms of suppurative fever; and this is attended by rapid change of structure.

There is heat, throbbing, pain, and swelling of the part, sometimes redness of the surface, and great constitutional disturbance; the symptoms and appearances, however, vary much, according to the extent of the joint which is involved. When part of the capsule is affected, the inflammation spreads rapidly over all the surface; the synovial membranes resembling the serous in this respect, as well as in healthy structure and function. Like the serous, too, they are shut sacs, are smooth on their surface, and furnish a secretion, the synovial, for facilitating the motion between opposing surfaces; it is, however, somewhat more glairy than the serous. Neither, in their healthy state, are possessed of much sensibility, nor are ligaments, tendons, tendinous sheaths, and bursæ, which two latter textures resemble in every respect the synovial; when inflamed, they become most exquisitely sensible. The incited action of the bloodvessels is followed by increased discharge, which is less glairy and albuminous, partaking more of the serous character. When the incited action soon terminates, and the activity of the absorbents is diminished, the fluid accumulates within the joint, producing Hydrops Articuli. This accumulation of fluid in joints may take place without being preceded by any apparent inflammation, and may remain a long time without any visible change of structure in the membrane. The knee is more frequently the seat of dropsy than any other joint.

When the action is more violent, and is not actively opposed, lymph is effused on the inner surface of the membrane, or is deposited amongst the ligamentous and cellular tissues external to the joint, in consequence of which, the membrane and external ligaments become thickened, and of an almost cartilaginous consistence. Serum is effused into the more superficial cellular tissue, filling up the hollows around the joint, concealing the protuberances of the bones, and producing a globular swelling. The articulating surfaces become ulcerated, and matter forms within the capsular ligament; or the pus is deposited exteriorly to the joint, and gradually approaches the surface. But although ulceration is so prone to occur in the cartilages, the synovial membranes do not readily take on this action, unless from the progress of matter, formed within the joint, towards the surface. The synovial lining of the bursæ and sheaths of the tendons are extremely indisposed to ulcerate; and it may be remarked, that, while suppuration without ulceration is common in the synovial membranes, the cartilages, on the other hand, afford frequent instances of ulceration without suppuration, of which more particular mention will be made in the sequel. The cartilage is occasionally swelled and softened where the disease has long existed.

Along with ulceration of the cartilage, a portion of it may become dead, or either state may occur separately; and in many cases, the substance of the bone also becomes affected, of which two classes of cases may occur, viz., great inflammation on the articular surface of the bone, with separation of the cartilage by the ulcerative process in this situation; and inflammation of the medullary web, leading to atrophy of the cancelli, collections of pus therein, or even death of a portion of the spongy texture of the bone, as will be more particularly treated of in the chapter on diseases of the osseous tissue. These changes often compose the primary disease, and to them the affections of the synovial membrane and other parts succeed.

Such occurrences are attended with alarming disturbance of the constitution, with fever, and even with the most threatening and dangerous symptoms, such as delirium and coma. If the patient survive, and the matter be evacuated from the joints by openings into its cavity, hectic fever is almost certain to supervene.

An opinion has been broached lately by Mr. Key, that the ulceration of cartilage was consequent upon the increased vascularity and thickening of the synovial membrane, that the cartilage, in fact, was removed by the action of the vessels ramifying in the membrane, and the prolongations or fringes from it in its diseased condition. Occasionally these fringes correspond, in a remarkable manner, to the breach of surface in the cartilage; but again, ulceration is frequently met with far removed from the membrane. It is also seen, in cases where an opportunity is afforded of making the examination in the earlier stage of disease, that ulceration exists to some extent whilst the synovial membrane is unaffected. And certain cases, in which the cartilage is affected with hypertrophy, and the common form of atrophy of this part in old people, are altogether adverse to Mr. Key’s views. When ulceration takes place at a point removed from the attachments of the synovial membrane, it appears to proceed more frequently from the attached than from the free surface of the cartilage; then the adventitious membrane occupying the rugged spaces, and which under the microscope appears highly vascular, is connected apparently with the medullary web.

In acute inflammation of the synovial membrane, and in cases where the cartilage is ulcerated, the pain is very intense, and the spasms of the limb most distressing. This happens when the surface is ulcerated, and perhaps to no great extent. We know that in the horse an ulcerated hollow in the cartilaginous covering of the navicular bone, not so large as to contain a grain of barley, will cause such lameness and suffering as to render the animal so affected perfectly useless. If he is not destroyed at this stage, as many valuable animals have been, the mischief extends, and terminates in extensive disease of that and the neighbouring bones and articulations. It is different if the disease commence, as it sometimes does, in the human subject, in the cancelli of the bone, and on the attached surface of the cartilage, the free surface remaining some time entire and smooth. When the synovial membrane is primarily affected by chronic disease, the pain is in general trifling, often not complained of, and swelling of the part, from effusion, into the joint or neighbouring bursæ, first attracts attention, after it has existed, perhaps, in a slight degree, for a considerable time. The joint is stiff, and pain is experienced from extensive motion; on this account the patient is disinclined to use it, and it is soon tired by the slightest exertion. The swelling becomes more solid, though still remaining elastic, and the feeling of fluctuation diminishes. Effusion of lymph follows that of serum, the latter having been absorbed; the motion of the joint is still further impeded, and the articulation is distorted; the patient keeps the limb in the most easy position, generally that of partial flexion, in which it becomes almost immovably fixed. The cause of the flexed position, which is almost pathognomonic of knee disease, being preserved, seems to be that the limb is insensibly brought into it in order to take the pressure off the interarticular apparatus, the ligamenta mucosa and alaria,—these swell—the muscles of the hamstrings get contracted from habit, and a difficulty, even after the disease is completely subdued, is often enough experienced in procuring complete extension. The muscles, from disuse, shrink, the adipose substance is absorbed, the shafts of the bones also are diminished in size, get into an atrophied state, as the phrase is, and thus the whole limb is rendered slender and wasted, so as to make the swelling of the diseased articulation still more conspicuous. The bones are softened, and the muscles are of a white colour, as in the limbs of the paralytic or bedridden, and resemble more cellular than muscular tissue. The wasting of the muscles and loss of power often precede the appearance of disease; this is frequently observed in the shoulder-joint, the deltoid shrinking, and almost disappearing, before any disease in the articulation is suspected by the patient. Not unfrequently, also, this wasting occurs without obvious cause, or any affection of the joint. When the disease is advancing, the patient may feel no acute pain, but merely a reluctance to use the limb; and from this, if long continued, the muscles, and afterwards the bones, become wasted. Wasting of the limbs in children, often of one of the lower, frequently arises from disorder of the bowels, and the irritation and debility attendant on teething. This must be distinguished from the wasting accompanying diseased joint. The history of the case, the period at which the weakness of the limb was observed, and its appearance, will lead to a correct diagnosis.

The swelling is often irregular, being more protuberant at one part than another, from the fluid or the addition of solid matter being accumulated where the least resistance is afforded; but the slighter inequalities are generally filled up by œdema of the cellular texture. As the disease proceeds, matter forms in the joint, and is often attended with great pain and fever; or the pus is effused into the bursæ, into the surrounding cellular tissue, or into the filamentous tissue amongst the tendinous sheaths of the muscles in the neighbourhood; being allowed to remain without an outlet, it at length communicates with the cavity of the joint. Portions of the cartilages are absorbed, though this, as already noticed, may occur at the very commencement of the disease; the subjacent bone becomes affected by ulceration, or perhaps its vitality is partially destroyed. When matter has accumulated, a portion of the capsular ligament generally ulcerates, the pus escapes, and is ultimately discharged externally.

When the disease begins with swelling, which is of a chronic character, and produces but little inconvenience, and when the more urgent symptoms supervene after the swelling has continued for a considerable time, there is every reason to suppose that the disease has originated in the synovial membrane, or perhaps in the osseous cancelli, and this is generally met with in poorly fed and strumous subjects. But when the first symptoms have been pain and stiffness of the joint, without change of its appearance, and when the swelling has occurred after these symptoms have been of some duration, then it is probable that the cartilages are the primary seat of mischief. For the most part, however, the symptoms have a general resemblance in most chronic affections of the joints, and all the apparatus is sooner or later involved. When the cartilage has been extensively absorbed, a grating sensation is felt in moving the articular surfaces of the bones upon each other. In consequence, also, of the softening and disorganisation of the lateral and other ligaments, the affected articulation at length becomes unnaturally loose, which is owing in some measure, also, to the muscles being wasted and paralysed from pain and disuse. At an earlier stage of the disease, the joint may be rigid from deposition of lymph into the contiguous cellular tissue, and contraction of the muscles.

Purulent matter not unfrequently collects in the substance of the bones, which in all cases ultimately become softened in a remarkable manner. In many subjects, without actual disease of the osseous tissue, the heads of the bones are so altered in consistence, are so deficient of earthy matter, as to be easily cut with a knife. It has been a matter of dispute, whether, in this affection, the articulating extremities of the bones are enlarged or not; and the supposition that they are always more or less increased in size, or hypertrophied, has arisen from the extensive effusion and indurated state of the soft parts being mistaken for this enlargement. In the first stages of the disease, they are seldom, if ever, enlarged; but when ulceration of the bone has occurred, new osseous matter is deposited to a greater or less degree in the neighbourhood of the ulcer,—an attempt by nature towards a cure, but too often an ineffectual one. The bones, in strumous subjects, are often much enlarged, from collection of purulent matter in their substance giving rise to a sort of spina ventosa. I removed the upper extremity of a boy lately on account of extensive disease about the elbow. The ulna to near the wrist was swollen enormously by purulent collections in its medullary canal. In cases when the whole of the articulating extremity of the bone is not enlarged, still that portion which is more immediately concerned in the articulation is often considerably expanded.

Frequently when the knee is the seat of the disease, the lymphatic glands in the groin are enlarged; and when the elbow or wrist joints are affected, there is often a similar enlargement of the glands in the axilla: such glandular tumours have not rarely been confounded with those accompanying malignant disease, and measures which were absolutely necessary for the salvation of the patient, have thus been delayed or neglected.

When the disease is extensive, and has endured for a considerable period, hectic fever supervenes, and is aggravated after the abscesses give way. The patient becomes much weakened and emaciated, and loses his appetite; the pulse is rapid, with night sweats, diarrhœa, &c.; and from a continuation of the hectic cause, the life is endangered. In some cases, however, the health is restored, and the disease abates spontaneously; in others, the disease is arrested, and a complete cure accomplished, by the careful employment of such means as will be afterwards mentioned.

The appearances produced by inflammation and consequent disease of the synovial membrane, are the following. In the first stage, the internal surface of the capsular ligament, and the rest of the synovial membrane, is found of a red hue, its formerly colourless vessels being now made apparent, from enlargement and consequent injection with a greater quantity of red blood; and the serum within the cavity of the joint is more abundant than in the natural state. When the disease has been of longer continuance, the membrane is found considerably thickened, its usual smooth glossy surface is destroyed, it is irregularly flocculent, and frequently of a light yellow colour.

The interarticular adipose tissue also seems to be increased in volume, from being infiltrated with a serous fluid, by the discharge of which the diseased bloodvessels may have attempted to relieve themselves. When the inflammation has been intense, or of long duration, lymph is secreted, and deposited on the external surface of the membrane, forming an intimate union between it and the ligaments, and producing thickening of the external apparatus. Or the lymph is also effused on the inner surface of the membrane, to which it adheres and becomes organised; this is generally accompanied by the formation of purulent matter; the organised effusion is often so extensive as to conceal almost the whole of the synovial membrane, excepting portions of its delicate reflexions which invest the articulating cartilages. By the lymphatic deposit, to a less degree, the folds also of the synovial membrane adhere to each other, whereby the motion is still farther impeded, and the pain, when attempted, increased. Occasionally the synovial membrane is found enormously thickened, much softened in texture, and of a brown hue, when the disease has been of a very chronic character. Along with these appearances, serum is generally found effused, in a greater or less quantity, into the cellular tissue exterior to the ligamentous covering. In cases in which the matter has formed and remained long within the cavity of the articulation, the synovial membrane and the ligaments become blended into one soft mass, the internal surface of which is lined with a thick coating of lymph, as in the case of common abscess. If purulent matter is effused externally, and communicate with the joint, the capsular ligament will be found to have ulcerated and given way at certain points, forming apertures, usually of small size, and with ragged margins.

All these appearances may exist without disease of the cartilages

or extremities of the bones; but generally they are also affected at the same time. At first the surface of the cartilage is slightly irregular and rough, and the change is not observed, unless on minute inspection. Afterwards the surface is marked with small depressions, which may be numerous, and are surrounded with irregular and somewhat serrated margins. They gradually increase in depth and extent, and the subjacent bone is ultimately exposed at one or more points, as here shown. Often the greater part of the cartilage is removed by absorption; the bone is exposed, opened out in its texture, softened, of an irregular surface, and in some places excavated, containing a thin ichorous fluid; the process of ulceration has also extended to the osseous tissue. Sometimes scales of cartilage of considerable size are either completely detached, having become dead, and been thrown off by the natural process, and are found lying loose in the cavity of the articulation; or they are all but separated, adhering by one or more very slender attachments.

The incipient stage of such disease may exist without the synovial membrane being much, if at all, affected; but when the ulceration has made farther progress, all the articulating apparatus is more or less diseased. It may be here remarked, that the synovial membrane may be affected for a long period, thickened portions may extend over the cartilages, and these may have lymph upon them and yet remain intact.

The cure, resorted to by nature, and in which she may be much assisted by the surgeon, is Anchylosis, ligamentous or osseous. New bone is deposited in the neighbourhood of the disease, and the ulcers become, as it were, cicatrised; the articulating extremities of the bones are joined to each other by a firm osseous matter, either universally disposed or consisting of processes extended between the bones at various points: or again, in consequence of the effusion of lymph into the cellular tissue, and the consequent thickening and induration of that and of the fibrous tissue exterior to the joint, this connecting medium is so strengthened and concentrated as to retain the articulating surfaces in exact apposition; from one, and usually from both, of these changes, the joint is securely fixed and rendered immovable, or nearly so. In complete anchylosis, the cancellous texture of the two bones, after some time, becomes perfectly continuous, so that they in fact constitute but one bone, as seen in cut, p. 84. A very perfect specimen of anchylosed knee joint is also delineated in the cut above. But even after this happens, the disease is still apt to recur from slight causes, the bony or ligamentous union being disturbed or destroyed, and the original disease attacking the parts with fresh activity; abscesses form,—may be extensive both in size and number,—and thereby the health is again undermined. So that the patient, after undergoing much suffering and risk, preserves, perhaps only for a few years, a limb which is almost useless to him, and which must be removed at last. In other cases, the union is permanent, the disease does not return; by care and time the limb is brought into the most convenient position, and proves of considerable service.

The joints are often affected by rheumatic and gouty inflammation; and there are three species of disease, tolerably distinct in their pathological characters, generally attributed to these causes. In one there is a deposit of chalky-looking matter, composed chiefly of super-lithate of soda, on the articular surfaces of the synovial membrane and cartilage, but most abundantly in the cellular tissue outside the joint, an affection in which the cartilage is seldom known to ulcerate. In the second, the cartilages are atrophied, as if

worn away by attrition, the articular surfaces of the bone being much modified in shape, more or less denuded of cartilage, and remarkably polished and hard, so as to have been compared to porcelain, as will be described in another section. In the third, the fibrous tissue in the neighbourhood of a joint is primarily affected, the synovial membrane and cartilages not becoming involved till the disease is much advanced. It is not uncommon in the elbow of middle-aged persons who have been much exposed to the atmospherical vicissitudes, and is sometimes attributed to the effect of mercury or syphilis. The periosteum around the articular ends of the bones becomes swelled and painful; the affection is very slow in its progress; abundant deposition of adventitious bone takes place, often in short spiculæ, gradually encroaching around the joint, which ultimately becomes involved. A good specimen is here given. The disease was of twelve months’ duration, and was attributable to rheumatic inflammation supervening upon sprain. The affection involves extensively all the bones composing the articulation.

Although wounds penetrating the larger joints are attended with danger, the synovial membranes are possessed of considerable powers of reparation, and often heal readily after severe injuries. An occasional result of inflammation is adhesion between the layers of the membrane, but this is by no means so frequent as in the serous tissues. The reparative power of cartilage is so low that the best termination that can be expected from the ordinary forms of ulceration, is union between the abraded surfaces. In experiments which have been made on the lower animals, portions of cartilage which had been removed from their joints were never reproduced, but the functions of the part were soon restored by the cut surface becoming smooth. In like manner there is occasionally to be seen in museums a circumscribed indentation in human articular cartilage, as if it had been destroyed by a small ulcer in this situation, which had cicatrized without any reproduction of the destroyed tissue.