Specific Varieties.-These have their special general symptoms, tuberculosis, syphilis, etc. Locally, the symptoms are practically the same as in the preceding varieties. (See table below for further information.) Tubercular osteomyelitis is rare except as occurring near joints and as being a part of tubercular arthritis.

What is the treatment of suppurative osteomyelitis ?

Early diagnosis and prompt chiselling of the bone, both for the acute and chronic forms. If sinuses have formed, all dead bone should be removed by free incision and use of the chisel, gouge, or sharp spoon. The resulting cavity should be packed with iodoform gauze and allowed to heal by granulation. Or the skin-edges may be sutured, and the cavity allowed to fill with blood, which subsequently becomes organized. This is known as Schede's "bloodclot" method. If non-suppurative, wet dressings and careful regulation of the bowels will be sufficient. It must be remembered that this form may run into suppuration. Hence if the symptoms become severer or the process lasts for more than four or five days, operation should be resorted to.

Treatment of the Specific Varieties.-If tubercular, the focus should be removed as early as possible by operation. If syphilitic and if it is secondarily infected with pus, operation is indicated. Otherwise, use regular antisyphilitic constitutional treatment. is understood, of course, that pure syphilitic osteomyelitis occurs in nodes, which are simply the well-known gummata of the bone. Give a definition of caries and necrosis.

(a) Necrosis is a mass of dead bone of comparatively large size. It is the result of acute suppurative, of acute serous, or of sclerosing osteomyelitis. In the two last instances it is absorbable by fatty degeneration. In the first it must be removed by operation. Necrosis may also be caused by direct traumatism or by embolism of the regional artery.

(b) Caries is a mass of minute particles of dead bone. It is the result of chronic osteomyelitis, whether the latter be specific or nonspecific. If non-specific, the caries is non-specific, and does not have pus mixed with it unless the osteomyelitis is suppurative. Tubercular caries and syphilitic caries are examples of specific If uncomplicated, these varieties are often called caries sicca. (For other varieties of caries see table.)

caries.

The following table gives a brief synopsis of bone inflammations, and includes certain varieties which are not considered in the text:

A physiological variety al-
ways occurs in uncompli-
cated repair of simple frac-
tures, and is followed by
"productive" osteomyelitis.
(See text.)

(See text.) This may at
times cause nodes under the
periosteum.

(a) Excess of bone tissue Any primary bone in- As is seen, this is really a
and lime-salts. More com- flammation.

Joint-neuro-process goes on in the ab

sorption of the temporary callus in repair of fractures.

Part of an acute general
tuberculosis.

Syphilitic tissue and caries
sicca, if uncomplicated by
pus.

Tubercle tissue. Caries
sicca if without pus. If
not near the joints, sub-
periosteal nodes are often
present. (See text.)

Discuss Pott's disease.

This is tubercular osteomyelitis of the bodies of the vertebræ. It occurs usually in children. The bony tissue is gradually replaced by tubercle tissue, and softening results, causing various deformities of the spine, especially the so-called angular curvature, or a flexion of the spine due to coalescence of the vertebral bodies, which produces undue prominence of the spines. Recovery with ankylosis may take place at this stage, but more commonly "tubercular pus "forms (see Chronic Abscess aud Tubercular cellulitis), which burrows more or less extensively and may burst spontaneously. Psoas abscess and retropharyngeal abscess are examples of collections of pus complicating Pott's disease. Death may follow soon or not for years.

What are the symptoms of Pott's disease?

Pain in the affected region, with rigidity (and inability of selfsustainment rapidly following), extremely marked on movement and pressure; deformity; and later, the symptoms of the abscess if it forms. Paralysis, both motor and sensory, of the nerves running from the vertebræ affected may occur in extreme cases. What is the treatment of Pott's disease?

Rest and immobilization by means of the plaster jacket, jurymast, and other apparatus. Should an abscess form and danger of spontaneous opening be imminent, it should be opened and drained. Otherwise it may be left alone, though some recommend incision in any event or injection with iodoform emulsion.

DISEASES OF JOINTS.

Give a general description of joint inflammation.

As is known, the structures which make up a joint are bone, cartilage, ligaments, synovial membrane, and, in some cases, fibrocartilage. Hence a joint inflammation is an inflammation of all of these structures. This is called arthritis. The inflammation may begin in any one of the above-mentioned parts, but sooner or later all are involved. The synovial membrane, however, when inflamed seems to prove an exception to this rule; that is, inflammation may or may not extend from it to the rest of the joint. If such an extension takes place, we have an arthritis, as already stated. If the inflammation remains confined to the synovial membrane, it is called a synovitis. Thus we have two main classes of joint inflammations-viz. the varieties of synovitis and the varieties of arthritis.

How are synovitis and arthritis respectively classified?

The varieties of synovitis and arthritis are the same as those of inflammation of bone or other part of the body-i. e. they are specific and non-specific-and each of these in its turn may be acute or chronic.

Compare briefly the symptoms and lesions of arthritis and synovitis.

Lesions. In synovitis there is but one inflammation—i. e. that of the synovial membrane. In arthritis there is a combination of inflammations-viz. osteomyelitis, synovitis, chondritis, and cellulitis (of the ligaments).

Symptoms. Other things being equal, those of arthritis are more severe than those of synovitis, both local and general. The latter, of course, are simply those of septicemia, and are of a varying degree of severity. The local symptoms, common to both synovitis and arthritis, are pain, tenderness, swelling, heat, redness, loss of function, and pain on passive and active motion. A differential diagnosis is based on two points-viz. the character of the swelling and bony crepitus. Thus, in acute cases, if the swelling is marked so as to give fluctuation, and if there is no thickening nor infiltration of the tissues surrounding the joint, the process is probably a synovitis. If, on the other hand, the swelling is evidently due to inflammation of the ligaments and peri-articular connective tissue, shown by boggy feeling and readiness to pit on pressure, and if the bones are somewhat enlarged, it is an arthritis.

In chronic cases, if on passive motion or on crowding the ends of the bones together bony crepitus is obtained, the process is of course an arthritis. This symptom is sometimes obtained in acute cases, and is equally significant of arthritis. This crepitus must not be confounded with that due to exudation of fibrin, which is common in both synovitis and arthritis.

Other points of differential diagnosis must be obtained from the previous history, causation, number of joints involved, etc.

In tubercular arthritis the process may have begun either in the synovial membrane or in one or other of the ends of the bones, as a tubercular synovitis or tubercular osteomyelitis respectively. If in the former, the process may remain as such. If in the latter, extension to the joint sooner or later invariably takes place. Discuss in detail the various varieties of synovitis and arthritis. This rather comprehensive question may be answered by reference to the following tables :