r ano-rectal fistulae. They are
best dealt with by complete excision, and as primary union cannot be
expected, the wound should be treated by the open method.

CHAPTER XVIII

DEVIATIONS OF THE VERTEBRAL COLUMN

LORDOSIS--KYPHOSIS--SCOLIOSIS

Three main deviations of the vertebral column are described:
_Lordosis_, in which it is unduly arched forwards; _Kyphosis_, in
which it is unduly arched backwards; and _Scoliosis_ or lateral
deviations, in which the spine deviates to one side of the middle
line.

#Lordosis# or _anterior curvature of the spine_ with the convexity
forwards, is chiefly met with in the lumbar region as an exaggeration
of the natural curvature. A minor degree of lordosis sometimes occurs
as a peculiarity in the conformation of the individual and may be
present in several members of the same family; also in street-hawkers
and others who carry weights suspended in front of them; in very obese
persons; in those who suffer from large abdominal tumours, such as
fibroids; and in pregnant women. In its more marked and typical forms
it is met with as a compensatory deviation when the pelvis is tilted
forwards in association with flexion of one or of both hip-joints.
Illustrations of this association are found in congenital dislocation
of the hip, particularly when this is bilateral, in tuberculous
disease of the hip when recovery has occurred with ankylosis in the
flexed position, and in Charcot's disease of the hip. The resuming of
the erect position with tilting of the pelvis from flexion at the hip
is necessarily attended by an exaggeration of the forward curvature of
the lumbar spine. Its relationship to the erect posture is readily
demonstrated by noting its partial or complete disappearance when the
patient is sitting and the tilting of the pelvis is thus eliminated.

Lordosis elsewhere than in the lumbar segment is met with as a
compensatory deviation to kyphotic or backward curvature of the spine:
in Fig. 211, for example, a kyphotic projection in the mid-thoracic
region has led to a lordosis in the cervico-thoracic segment above,
and in the thoracico-lumbar segment below, the forward curve being
again a necessary outcome of the resuming of the erect posture. The
absence of a compensatory lordosis in such a condition would warrant
the inference that the patient had been bed-ridden.

#Kyphosis# or _posterior curvature of the spine_ with the convexity
backwards, is met with at all periods