t, exhibits a
lateral curvature of the spine with the dorso-lumbar convexity to the
sound side.

[Illustration: FIG. 114.--Tuberculous Disease of Left Hip: third
stage, showing adduction and shortening.]

When adduction is pronounced, the patient is unable to restore the
normal parallelism of the limbs, and the knee on the affected side may
cross the sound limb. There is a deep groove at the junction of the
perineum and thigh, great prominence of the trochanter, and the pelvis
may be tilted to such an extent that the iliac crest comes into
contact with the lower ribs.

As a result of the pressure of the carious articular surfaces against
one another, the acetabulum is enlarged and the upper end of the femur
is drawn gradually upwards and backwards within the socket.
Examination will then reveal the existence of a variable amount of
_actual shortening_; it will also be found that the trochanter is
displaced above Nelaton's line, while above and behind the trochanter
there is a prominent hard swelling corresponding to the enlarged
acetabulum.

There may, therefore, be a combination of real and apparent shortening
together amounting to several inches (Fig. 115).

[Illustration: FIG. 115.--Advanced Tuberculous Disease of Left
Hip-joint in a girl aet. 14, showing flexion, adduction, shortening,
and iliac abscess.]

In cases of long standing, beginning in childhood, the shortening is
still further added to by deficient growth in length of the femur, and
it may be of all the bones of the limb; even the foot is smaller on
the affected side.

The most reasonable explanation of the attitudes assumed in hip
disease is that given by Koenig. If the patient walks without crutches,
as he is usually able to do at an early stage of the disease, the
attitude of abduction, eversion, and slight flexion enables him to
save the limb to the utmost extent; on the other hand, if he uses a
crutch, as he is obliged to do at a more advanced stage, he no longer
uses the limb for support, and therefore draws it upwards and medially
into the position of adduction, inversion, and greater flexion.
Similarly, if he is confined to bed, he lies on the sound side, and
the affected limb sinks by gravity so as to lie over the normal one in
the position of adduction, inversion, and flexion. Koenig's explanation
accords with the fact that in the exceptional cases which begin with
adduction and inversion we have usually to deal with a severe type of