ion, if it
persists, or if there is reason to suspect that it is purulent, it
should be withdrawn without delay; an exploring syringe usually
suffices, the skin being punctured with a tenotomy knife, and, as
practised by Murphy, 5 to 15 c.c. of a 2 per cent. solution of formalin
in glycerin are injected and the wound is closed. In virulent infections
the injection may be repeated in twenty-four hours. Drainage by tube or
otherwise is to be condemned (Murphy). A vaccine may be prepared from
the fluid in the joint and injected into the subcutaneous cellular
tissue.

Suppuration in the peri-articular soft parts or in one of the adjacent
bones must be looked for and dealt with.

When convalescence is established, attention is directed to the
restoration of the functions of the limb, and to the prevention of
stiffness and deformity by movements and massage, and the use of hot-air
and other baths.

At a later stage, and especially in neglected cases, operative and other
measures may be required for deformity or ankylosis.

#Metastatic Forms of Pyogenic Infection#

In #pyaemia#, one or more joints may fill with pus without marked
symptoms or signs, and if the pus is aspirated without delay the joint
often recovers without impairment of function.

In #typhoid fever#, joint lesions result from infection with the typhoid
bacillus alone or along with pyogenic organisms, and run their course
with or without suppuration; there is again a remarkable absence of
symptoms, and attention may only be called to the condition by the
occurrence of dislocation.

Joint lesions are comparatively common in #scarlet fever#, and were
formerly described as scarlatinal rheumatism. The most frequent clinical
type is that of a serous synovitis, occurring within a week or ten days
from the onset of the fever. Its favourite seat is in the hand and
wrist, the sheaths of the extensor tendons as well as the synovial
membrane of the joints being involved. It does not tend to migrate to
other joints, and rarely lasts longer than a few days. It is probably
due to the specific virus of scarlet fever.

At a later stage, especially in children and in cases in which the
throat lesion is severe, an arthritis is sometimes observed that is
believed to be a metastasis from the throat; it may be acute and
suppurative, affect several joints, and exhibit a septicaemic or pyaemic
character.

The joints of the lower extremity are especially apt to suffer; th