es quickly, often with a rigor, and remains high; the
patient looks ill, and is either unable to sleep or the sleep is
disturbed by starting pains. The joint is held rigid in the flexed
position, and the least attempt at movement causes severe pain; the
slightest jar--even the shaking of the bed--may cause agony. The joint
is hot, tensely distended, and there may be oedema of the peri-articular
tissues or of the limb as a whole. If the pus perforates the joint
capsule, there are signs of abscess or of diffuse suppuration in the
cellular tissue. The final disorganisation of the joint is indicated by
abnormal mobility and grating of the articular surfaces, or by
spontaneous displacement of the bones, and this may amount to
dislocation. In the acute arthritis of infants, the epiphysis concerned
may be separated and displaced.

When the _joint is infected through an external wound_, the anatomical
features are similar to those observed when the infection has reached
the joint by the blood-stream, but the destructive changes tend to be
more severe and are more likely to result in disorganisation.

The _terminations_ vary with the gravity of the infection and with the
stage at which treatment is instituted. In the milder forms recovery is
the rule, with more or less complete restoration of function. In more
severe forms the joint may be permanently damaged as a result of fibrous
or bony ankylosis, or from displacement or dislocation. From changes in
the peri-articular structures there may be contracture in an undesirable
position, and in young subjects the growth of the limb may be interfered
with. The persistence of sinuses is usually due to disease in one or
other of the adjacent bones. In the most severe forms, and especially
when several joints are involved, death may result from toxaemia.

The _treatment_ is carried out on the same principles as in other
pyogenic infections. The limb is immobilised in such an attitude that
should stiffness occur there will be the least interference with
function. Extension by weight and pulley is the most valuable means of
allaying muscular spasm and relieving intra-articular tension and of
counteracting the tendency to flexion; as much as 15 or 20 pounds may be
required to relieve the pain.

The induction of hyperaemia is sometimes remarkably efficacious in
relieving pain and in arresting the progress of the infection. If the
fluid in the joint is in sufficient quantity to cause tens