does not become smaller; nor is it felt to refill when the pressure is removed during two or three beats of the heart, as in aneurism; and a bruit, if present, is not so distinct. Portions of expanded bone, moreover, may be felt in parts of the tumor, and there may be glandular enlargement and other general signs of malignancy. From an inflammatory condition of a neighboring joint a tumor of the end of the bone may generally be distinguished by the absence of signs of inflammation; by the swelling being less regular in contour than in a joint affection, and apparently being connected more intimately with one of the bones entering into the articulation than the other; and by a careful review of the history of the case.

Treatment.-Periosteal growths, unless the glands are much enlarged and there is evidence of dissemination having occurred, call for amputation of the limb, or removal, if practicable, when growing from the bones of the head or trunk. Small growths, however, may at times be dissected off the shafts of the long bones, and the surface of the bones scraped, gouged away, or destroyed by the actual cautery. Endosteal growths, if small, may in some cases be enucleated, but usually, like the periosteal variety, call for amputation. The treatment of sarcomata of the jaws and of other special regions are described under Tumors of the Jaws, etc.

CARCINOMA is now generally believed never to occur as a primary growth in bone. It may spread to the bone, however, from the skin or mucous membrane, as seen, for example, in some cases of squamous epithelioma of the leg or lip, or be deposited there in the course of the general dissemination following on primary carcinoma of other tissues or organs, as the breast or liver. In the latter case it is seldom discovered till after death, unless it gives rise to spontaneous fracture. Treatment. Where epithelioma has spread to the bone, free and early removal with the knife before the glands have become affected is the only treatment that holds out a prospect of success. In the case of a limb, amputation well above the disease is generally called for; although, where the bone is but little involved, a free sweep of the growth and the gouging away of the underlying bone may under some circumstances be advisable.

CYSTS IN BONE are rare, except in the jaws. Hydatid cysts are occasionally met with, but require no special description. The sanguineous or blood-cysts formerly described were probably sarcomatous tumors in which hemorrhage had taken place.

ANEURISMS IN BONE are occasionally met with, and vascular erectile tumors, consisting of anastomosing vessels, and somewhat resembling nævi of the soft tissues, sometimes occur in the bones

of the skull. The majority of pulsating tumors in bone, however, are of the nature of soft sarcomata.

DISEASES OF JOINTS.

SYNOVITIS, or inflammation of the synovial membrane, may be acute, subacute, or chronic.

ACUTE SYNOVITIS.-Cause.-Generally a slight injury, as a sprain or over-exertion of a joint, or exposure to cold and wet in a gouty or rheumatic subject. Synovitis, moreover, especially in the knee, often occurs during an attack of gonorrhea, and is sometimes seen in the earlier stages of syphilis. It is well known as a symptom of acute rheumatism and pyæmia, in which latter affection rapid suppuration and implication of the other tissues of the joints occur.

Pathology. The synovial membrane becomes red and congested and loses its lustre, the synovial fringes turgid, and the synovial fluid increased in quantity, and slightly turbid from admixture with inflammatory products. Resolution may now occur, or the inflammation may become chronic, or it may spread to the cartilages, bones, etc., and terminate in suppuration and the probable disorganization of the joint (see Acute Arthritis).

Signs.-The joint is hot, excessively painful, especially on movement and pressure, and, if the inflammation is very intense, the skin may be slightly reddened, and the tissues around oedematous. The joint is usually held flexed, that is, with the capsule and ligaments relaxed-the position of greatest ease. Where the joint is superficial the swelling is well marked, the outline of the synovial membrane being distinctly mapped out. Thus in the knee, the joint perhaps most commonly affected, the synovial membrane can be seen extending upward under the crureus and vasti, and bulging on either side of the ligamentum patellæ. The patella itself is raised from the condyles of the femur, and on making pressure on it the fluid is displaced, and the patella can be felt to strike against the condyles (riding of the patella). In the elbow, the synovial membrane can be seen extending under the triceps and on either side of the olecranon; in the ankle, bulging beneath the extensor tendons and behind the malleoli. Feverish symptoms varying in intensity according to the severity of the inflammation are generally present. The inflammation may now gradually subside or assume the chronic form. Should, however, suppuration occur, and the other tissues of the joint become involved, the pain, swelling, and adema increase, and the skin becomes of a dusky red, while a chill or distinct rigor ushers in a more severe type of inflammatory fever.

Treatment. The joint should be placed at absolute rest on a splint, and the patient, in the case of the hip, knee, or ankle, confined to bed. In applying the splint, care should be taken that the limb is in the position best suited for future use should ankylosis ensue; thus, the knee should be straight and the elbow bent at a right angle. Where the joint has already been drawn into a faulty position, this must be rectified, the patient being placed under an anesthetic, as the manipulation may be attended with intense pain. Cold, by means of evaporating lotions or Leiter's tubes, may in slighter cases be applied to the joint. When, however, the inflammation is very acute, half-a-dozen leeches, followed by hot applications, should be substituted for the cold, with liniments of belladonna and opium to assuage pain. Where there is much distention, and the synovial membrane threatens to give way, the joint should be aspirated, or, if suppuration occurs, laid freely open and drained antiseptically. Amputation may be called for should the patient's powers fail under the long-continued suppuration that at times ensues.

SUBACUTE SYNOVITIS.-The term subacute is applied to less severe cases of acute synovitis. But as one form of the disease differs from the other in degree rather than in kind, and as the causes, symptoms, and treatment are similar, no special description is required.

CHRONIC SYNOVITIS.—Causes.-Similar to those of the acute form of which it is often a sequel. When occurring in strumous subjects, it probably nearly always depends on the presence of the tubercle bacillus, and will be described under strumous disease of the joints.

Pathology. The synovial membrane is slightly thickened, and the synovial fluid increased in quantity; but there is little or no change in the cartilages or the other tissues, though, if the disease is neglected, it may run on to total disorganization of the joint. At times, the synovial membrane becomes greatly distended with clear serous fluid, a condition known as hydrops articuli, and in this state it may remain for years without any further change ensuing; or, after long periods, the synovial membrane may become thickened, and little masses of cartilage form in its hypertrophied fringes. In other instances pouch-like protrusions of the synovial membrane may extend along the muscles and other tissues, often to some distance from the joint, where they give rise to bursa-like swellings (Morrant Baker's cysts).

Signs.-The joint, as in the acute affection, is swollen, and the synovial membrane slightly thickened; but there is little or no heat, there may be no pain, and the skin is unaltered in appear

ance.

The patient, however, complains that the joint feels weak and stiff on movement, but he does not suffer from starting-pains at nights. In hydrops articuli the synovial membrane is greatly distended but not thickened, and, save a sensation of weakness and want of security in the joint on walking, the affection gives no trouble. In what may be termed the bursal variety of chronic synovitis, in addition to the joint affection, more or less tense fluctuating and translucent swellings occur in the neighborhood of the joint. On pressure, these swellings become less tense, and some of the fluid contained in them can at times be forced back into the joint.

Treatment. The indications are (1) to prevent further irritation by placing the joint at perfect rest, (2) to promote the absorption of the inflammatory products by pressure and counterirritation, and (3) to remove any stiffness that may remain on the subsidence of the inflammation by passive movements, shampooing, or the breaking down of fibrous adhesions. Thus, the joint should be fixed in an accurately fitting poroplastic or a moulded leather splint, or a plaster-of-Paris bandage; and the limb, if a joint of the upper extremity is affected, should be carried in a

sling. In the case of the lower extremity, the patient, if unable to lie up, may wear a Thomas's hip or knee splint, according to the joint affected, and be allowed to get about on crutches with a patten fixed to the boot of the sound limb (Figs. 52, 53, and 54). Pressure may be applied by strapping the joint with ammoniacum and mercury plaster, or with Scott's dressing, or by means of a Martin's bandage. Counter-irritation may be effected either with the liniment of iodine, small flying blisters, or the actual cautery. Rest, however, though most essential in the treatment, should not be continued too long, lest the joint become stiff. Should this happen, friction, shampooing, and passive movements must be sedulously used, or, if all signs of inflammation have ceased, the adhesions may be broken down under an anæsthetic. In the meantime, the patient's general health must not be neglected, and any constitutional tendency to gout, rheumatism, etc., should be corrected by appropriate remedies. During convalescence a stay at Buxton, Harrowgate, Wiesbaden, or some other suitable spa, may be of benefit. In hydrops articuli the treatment recommended above may first be perseveringly tried; this failing, the joint may be aspirated and pressure reapplied. Should it refill, it may be injected with iodine, or in very severe cases laid open and drained.

ACUTE ARTHRITIS is the term applied to a general inflammation of all the tissues of a joint. It may begin in the synovial membrane, in the articular ends of the bones, or in the tissues around, but in whatever way it begins the whole joint rapidly. becomes involved in the inflammatory process.

The causes are very various, and include those given under acute synovitis. Among the most frequent causes, however, may be mentioned penetrating wounds, infective periostitis or osteomyelitis, epiphysitis, the bursting of an abscess in the soft parts or in the end of the bone into the joint, pyæmia, and the continued and the exanthematous fevers.

Pathology.-The course of the disease differs somewhat according to its cause and mode of origin. In a typical case beginning in the synovial membrane and running on to complete disorganization of the joint and subsequent ankylosis the following changes occur: The inflammation rapidly spreads from the synovial membrane to the bones and surrounding soft tissues; the cartilages are destroyed; the ligaments are softened; the articular surfaces are displaced by the action of the muscles; and the joint is converted into the cavity of an abscess (Fig. 55). The capsule of the joint now gives way, allowing the inflammatory products to escape. The soft tissues break down into pus, and the abscesses open externally, forming sinuses leading down to