lyzed and wasted, and the flexors, which exert in most instances a superior power, being contracted, shortened, and atrophied. Anchylosis of the bodies of the vertebræ has already been alluded to as the mode in which a cure takes place after caries of their structure and ulceration of the intervertebral ligaments. It is clear from this that when the destruction of these parts has been at all extensive, the avoidance of the deformity of angular curvature is impossible. Anchylosis of some of the less important joints occurs almost naturally in old age. Some rare instances are recorded in which all the joints of the body became spontaneously anchylosed.

CHRONIC RHEUMATIC ARTHRITIS.

The chronic inflammatory nature of this affection is extremely well marked, but the essential dependence of it upon rheumatism is not so well demonstrated. It occurs not only after an attack of acute rheu matism, but after injuries and bruises, and sometimes without apparent cause. It is very frequent in the hip, the shoulder, the knee, and the articulations of the hand. When it is fully established in the hip-joint, it is said, by Mr. R. Adams, rarely or never to extend itself to the other articulations. Sometimes both hips only are attacked. When the knee is the seat of the disease, or the shoulder, other joints will, generally, be found more or less implicated. In the case of the knee, Mr. R. Adams recognizes a first stage, "marked by evidences of subacute inflammation, such as pain, heat, considerable swelling. This is followed by a second period, in which the heat and swelling diminish, but the pain continues." The disease in the hip and shoulder is described by the same author as of a more chronic character from the commencement, not being attended with any sensation of increased heat, or appearance of distension. A very marked diagnostic sign of this affection is, that pressing the articular surfaces together, and moving them, so as to produce crepitus, does not cause any uneasiness. A similar attempt in ulceration of the cartilages, or in articular caries, would cause severe pain. We quote, from Mr. W. Adams's communication to the Pathological Society, the following account of the appearances ordinarily observed in the advanced stages of chronic rheumatic arthritis:"In the hip-joint.-1st. Great enlargement and irregularity of shape of the head of the femur, which assumes a mushroom-like form, in consequence of real or apparent flattening of its upper part, and nodulated masses and flattened ring-like layers of new bone, surrounding the edge of its articular cartilage, and extending to a variable distance over its articular surface. To this mushroom-like form, the apparent shortening of the neck, in consequence of its upper part being concealed by the overhanging margin of new bone at the edge of the articular cartilage, also contributes. 2dly. Absence of articular cartilage to a greater or less extent, and the eburnation of the bony surface. 3dly. Nodulated masses of new bone, from the size of a hemp-seed to that of a walnut, attached by thin peduncles to the synovial membrane on the neck of the bone, or to that of the capsular ligament-more or less spherical

when small, but flattened and irregular when of large size. In the os innominatum.-1st. Increased capacity of acetabulum. 2dly. Ossification of the fibro-cartilaginous rim, or cotyloid ligament. 3dly. Absence of articular cartilage to a greater or less extent, and eburnation of the exposed bony surface. 4thly. Irregular osseous growths (stalactitic osteophytes) on the surface of the bones external to, and immediately surrounding the joint. In the knee-joint, the appearances were essentially similar to those in the hip; new osseous growths, of irregular form, surrounded the margins of the articular cartilages of the femur and tibia; and pedunculated osseous growths, in considerable numbers, and of all sizes, were attached to the synovial membrane, both in the notch and lining the capsule. In addition, however, the articular cartilages on the condyles of the femur presented a thickened, nodulated appearance, in their central parts." Mr. R. Adams, describing the condition of the shoulder-joint, says: "The capsular ligament is occasionally increased in thickness, and its fibres are hypertrophied; and it is generally more capacious than natural, showing that effusion of synovia to a considerable amount had existed, although the external signs of this phenomenon are not usually evident. When the interior of the synovial sac is examined, it will be found to present evidences of having been the seat of chronic inflammation. Bunches of long organized fringes hang into the interior of the synovial sac; and many of these vascular fimbria, which in the recent state are of an extremely red color, surround the corona of the head of the humerus. We also notice rounded cartilaginous productions, appended by means of membranous threads attached to the interior of the various structures which compose the joint." The size and shape of these bodies is various. The long tendon of the biceps muscle is very commonly adherent to the superior extremity of the bicipital groove, while that portion of it which normally passes upwards, and takes its attachment to the upper margin of the glenoid cavity, is destroyed. The articular surface of the humerus is very much enlarged, and extends itself over the greater and lesser tuberosities, and even over the highest part of the bicipital groove. The head appears to be in a line with the shaft of the bone, instead of being directed upwards, inwards, and backwards. The cartilage is more or less completely removed, the bone in some parts eburnated, in others porous. Nodules of bone, vegetations, as Mr. R. Adams terms them, are thrown out around the margin of the head. The glenoid cavity of the scapula becomes much enlarged, and, losing its oval shape, assumes a more circular form. This, however, depends much on the position which the head of the humerus occupies. The depth of the articular cavity is increased by osseous productions thrown out around its margins; its encrusting cartilage is removed, and the surface in part is covered by porcellaneous deposit, in part remains porous. The enlarged head of the humerus comes into immediate contact, in many cases, with the under surface of the coraco-acromial vault, causing absorption and wasting of the tendons of the supra-spinatus and biceps, and the upper part of the capsular ligament. The acromion process, the outer extremity of the clavicle, and the coracoid process, in most cases become enlarged, though their under surfaces are worn and ebur

nated by the friction and pressure of the head of the humerus. Occasionally, however, they are found atrophied, or altogether removed. It is a remarkable circumstance, particularly noticed by Mr. R. Adamsfrom whose article, in the Cyclop. of Anat. and Phys., we have taken the foregoing account-that, in many cases, the acromion process is traversed in the line of junction of its epiphysis, "by a complete interruption of its continuity, as if fractured." This has been considered by several observers, as well as the destruction of the long tendon of the biceps, to be the result of accidental violence. Cruveilhier is quoted by Mr. R. Adams as describing the bones of the carpus, in a case of chronic rheumatic arthritis of the wrist-joint, to be so confounded together into an irregular mass that it was difficult to say which part each took in the construction of the carpal region. The radius and the ulna undergo like changes to those which have been described above; the lower surface of the latter, confronting the cuneiform bone, becomes smooth and polished, the inter-articular fibro-cartilage having been removed. The nature of the changes taking place in this disease have been admirably investigated by Mr. J. Adams, from whose communication to the Pathological Society, 1850-51, p. 156, we extract the following account. Rokitansky regards the morbid process as an inflammatory rarefaction, attended with swelling and softening of the bone. "After furnishing an osseous exudation within the texture of the bone, and all around, an exudation which may be distinguished by its form and chemical composition, it terminates in consecutive induration." Mr. Adams, from his examinations, arrives at a different conclusion. He believes the process to consist: "1st, in hypertrophy of the articular cartilage, generally occurring at the circumferential margin, but occasionally taking place towards the central parts of the articular surfaces. The new growth of cartilage takes place principally, if not entirely, near to the articular surface." It is very similar, though not quite identical with the original cartilage, a fibrillated character of the matrix, and the scattered, solitary, or imperfectly grouped arrangement of the nuclei being the principal points of difference." 2dly, "in the development of true osseous tissue in the hypertrophied cartilage, ossification commencing either in the newly-formed cartilage or at the junction of the new with the old cartilage. Ossification proceeds more rapidly in the newly-formed and forming cartilage, for its growth is probably simultaneous with the advancing ossification than in the old articular cartilage; so that considerable masses of new bone are formed, altering the configuration of the articular extremities, whilst a layer of articular cartilage remains in its normal position. More slowly, but as perfectly, ossification takes place in this imbedded layer of articular cartilage. The process resembles the normal process of ossification in temporary cartilage in the intercellular matrix being the primary seat of earthy impregnation, and in the enlargement of the cells in the immediate vicinity of the bone."

Effects of Dislocations.-The most common cause of dislocations is a violent strain or injury to the part; but they may also come to pass spontaneously, either from abnormal relaxation of the ligaments, or from destruction of them in consequence of disease and muscular inac

tion. Dislocation, it is affirmed, may also occur congenitally. What we wish to notice here is, the changes which take place in the articulating surfaces when a dislocation has taken place and remained a long time unreduced. Rokitansky describes these as follows: "The capsule becomes enlarged, and the place of its insertion altered; the articular cavities of the bones increase in size, and undergo various changes in form; and corresponding alterations are produced in the articular heads or prominences. In other cases, in which the dislocation is complete, the capsule wastes, and the bony cavities diminish in size, or are filled with masses of new osseous substance; the displaced head of the bone loses its character, and a new joint is formed. The cellular structures which surround the dislocated head inflame, and frame a new capsule around it, which, for the most part, fits closely, is of fibroid structure, and has a serous lining; whilst the pressure of the head, in its new position, occasions a shallow, articular excavation beneath it. In other cases, instead of an excavation beneath the head, a mass of callus springs up around it, and forms either a hollow to receive it or a level surface, which the head may be flattened in order to fit; or, lastly, the callus may project, and that which was the articular head be excavated to receive it. Sometimes the quantity of new bone deposited around a dislocated head is very abundant, and retains it firmly in its place. In dislocations of long standing, the pressure upon the vessels and nerves interferes with the nutrition of the luxated bone, and, like the soft parts, it is found in a state of atrophy."

Morbid Conditions of Bursa.-These small synovial sacs are liable to be affected much in the same way as larger. They may be attacked by inflammation, more or less acute, or quite chronic, resulting from rheumatism, the abuse of mercury, or some other constitutional affection, or excited by violence or long-continued pressure. The effusion which takes place may, in cases of a chronic kind, be a simple synovial or serous fluid; but, when the inflammation is more acute, it is either a turbid serum, with flakes of fibrinous matter floating in it, or actual pus. Suppuration sometimes is produced artificially, for the purpose of causing the obliteration of the cavity of the bursa. The matter sometimes makes its way directly to the surface of the skin, and is discharged; but it often, also, escapes into the surrounding cellular tissue, and diffuses itself over a considerable extent. Sir B. Brodie describes this as being of common occurrence after inflammation of the bursa patellæ, so that an abscess is formed between the skin and the fascia," covering the whole of the anterior part of the knee, and liable to be confounded with inflammation of the synovial membrane of the joint. When severe inflammation supervenes, after the puncture of a large bursa, so much constitutional disturbance is sometimes occasioned that the patient dies. This is more likely to occur in persons who are in a state of bad health. The walls of an inflamed bursa sometimes become prodigiously thickened by the organization of layers of fibrinous effusion. There is a specimen in the Museum of St. George's, in which the walls of an enlarged bursa patellæ are more than half an inch thick, while the cavity, which is comparatively small, is traversed by reticulating laminæ of false membrane. When the inflammation has been of long standing," Sir B. Brodie says,

"it is not unusual to find, floating in the fluid of the bursa, a number of loose bodies, of a flattened oval form, of a light-brown color, with smooth surfaces, resembling small melon-seeds in appearance. There seems to

Fig. 356.

Enlarged bursa over the patella, the result of pressure. Housemaid's knee.

of frottement, and are Brodie.

be no doubt that these loose bodies have their origin in the coagulated lymph which was effused in the early stage of the disease; and I have had opportunities, by the examination of several cases, to trace the steps of their gradual formation. At first, the coagulated lymph forms irregular masses, of no determined shape, which afterwards, by the motion and pressure of the contiguous parts, are broken down into smaller portions. These, by degrees, become of a regular form, and assume a firmer consistence, and at last they terminate in the flat oval bodies which have been just described." The synovial sheaths surrounding the flexor tendons of the fingers, as they pass under the annular ligament, are not unfrequently the seat of increased secretion of fluid, and of the formation of small bodies, compared by Mr. R. Adams to grains of boiled rice. "They are found in vast numbers in the same cyst, mixed with a more or less considerable quantity of glairy synovial liquid." They occasion, as they move to and fro, a distinct sensation quite identical with those described by Sir B.

What are called ganglions, are small collections of fluids in bursal cavities of new formation. They are most frequent on the back of the wrist and forearm. They do not seem to arise from inflammation, but rather to be of the nature of simple cysts. They are slightly movable, indolent, and painless, and appear to be situated "in the reticular tissue, which immediately covers the sheath of the extensor tendons." To the latter they are connected firmly, to the skin but loosely. The consistence of their contents varies from that of limpidity to that of thick jelly-like matter. According to Velpeau, these cysts occasionally communicate with the articular synovial cavity.

1 Some fluid of this kind, which we examined, was coagulated, in great measure at least by nitric acid; it contained a few nucleated granulous corpuscles.