nefit follows the administration of salicylates.

In exceptional cases, tuberculous joint disease follows an acute course
resembling that of the pyogenic arthritis of infants. This has been
observed in children, especially in the knee, the lesion being in the
synovial membrane, and attended with an accumulation of pus in the
joint. If promptly treated by incision and drainage, recovery is rapid,
and free movement of the joint, may be preserved.

The onset and early stages of tuberculous disease, however, are more
often insidious, and are attended with so few symptoms that the disease
may have obtained a considerable hold before it attracts notice. It is
not uncommon for patients or their friends to attribute the condition to
injury, as it often first attracts attention after some slight trauma or
excessive use of the limb. The symptoms usually subside under rest, only
to relapse again with use of the limb.

The initial local symptoms may be due to the presence of a focus in the
neighbouring bone, perhaps causing neuralgic pains in the joint, or
weakness, tiredness, stiffness, and inability to use the limb, these
symptoms improving with rest and being aggravated by exertion.

It is rarely possible by external examination to recognise deep-seated
osseous foci in the vicinity of joints; but if they are near the surface
in a superficial bone--such as the head of the tibia--there may be local
thickening of the periosteum, oedema, pain, and tenderness on pressure
and on percussion.

_X-ray Appearances of Tuberculous Joints._--Gross lesions such as
caseous foci in the marrow of the adjacent bone show as clear areas with
an ill-defined margin; a sclerosed focus gives a denser shadow than the
surrounding bone, and a sequestrum presents a dark shadow of irregular
contour, and a clear interval between it and the surrounding bone.

Caries of the articular surface imparts a woolly appearance or irregular
contour in place of the well-defined outline of the articular end of the
bone. In bony ankylosis the shadow of the two bones is a continuous one,
the joint interval having been filled up. The minor changes are best
appreciated on comparison with the normal joint of the other limb.

_Wasting of muscles_ is a constant accompaniment of tuberculous joint
disease. It is to be attributed partly to want of use, but chiefly to
reflex interference with the trophic innervation of the muscles. It is
specially well seen in the extensor an