the disease, associated with grave osseous lesions--precisely those
cases in which the patient is compelled from the outset to lie up or
to adopt the use of crutches. Further, the transition from the
abducted to the adducted position usually follows upon such an
aggravation of the symptoms that the patient is no longer able to walk
without the assistance of a crutch.

During the third stage the other signs and symptoms become more
pronounced; the patient looks ill and thin, he is usually unable to
leave his bed, his sleep is disturbed by startings of the limb, and
the rigidity of the joint and the wasting of the muscles are well
marked. The temperature may rise slightly after examination of the
limb, or after a railway journey.

#Abscess Formation in Hip Disease.#--The formation of abscess is not
related to any stage of the disease; it may occur before there is
deformity, and it may be deferred until the disease is apparently
cured. Its importance lies in the fact that if a mixed infection with
pyogenic organisms occurs, the gravity of the condition is greatly
increased.

An abscess may appear _in the thigh_ in front or behind the joint. The
_anterior abscess_ emerges on one or other side of the psoas muscle;
from the resistance offered by the fascia lata, the pus may gravitate
down the thigh before perforating the fascia. It has occasionally
happened that when such an abscess has been opened and become infected
with pyogenic organisms, the femoral vessels have been eroded, and
serious or even fatal haemorrhage has resulted. The _posterior abscess_
appears in the buttock and may make its way to the surface through the
gluteus maximus; more often it points at the lower border of this
muscle in the region of the great trochanter, or it may gravitate down
the thigh.

Abscesses which form _within the pelvis_ originate either in
connection with the acetabulum or in relation to the psoas muscle
where it passes in front of the joint. Those that are directly
connected with disease of the acetabulum may remain localised to the
lateral wall of the pelvis, or may spread backwards towards the hollow
of the sacrum. They may open into the bladder or rectum, or may ascend
into the iliac fossa and point above Poupart's ligament (Fig. 115), or
descend towards the ischio-rectal fossa. The abscess which develops in
relation to the psoas muscle may be shaped like an hour-glass, one sac
occupying the iliac fossa, the other filling up S