efore the normal bandy condition had passed off, the result will
necessarily be either an arrest in the development of the limbs or an
increase of the bandy condition. If the child is weakly, either rachitic
or suffering from any ailment which prevents the due ossification of the
bones, or is improperly fed, the bandy condition may remain persistent.
Thus the chief cause of this deformity is rickets (q.v.). The remaining
causes are occupation, especially that of a jockey, and traumatism, the
condition being very likely to supervene after accidents involving the
condyles of the femur. In the rickety form the most important thing is
to treat the constitutional disease, at the same time instructing the
mother never to place the child on its feet. In many cases this is quite
sufficient in itself to effect a cure, but matters can be hastened
somewhat by applying splints. When in older patients the deformity
arises either from traumatism or occupation, the only treatment is that
of operation.

A far commoner deformity than the preceding is that known as
_knock-knee_ (or _Genu Valgum_). In this condition there is close
approximation of the knees with more or less separation of the feet, the
patient being unable to bring the feet together when standing.
Occasionally only one limb may be affected, but the double form is the
more common. There are two varieties of this deformity: (i.) that due to
rickets and occurring in young children (the rachitic form), and (ii.)
that met with in adolescents and known as the static form. In young
children it is practically always due to rickets, and the constitutional
disease must be most rigorously dealt with. It is, however, especially
in these cases that cod-liver oil is to be avoided, since it increases
the body weight and so may do harm rather than good. The child if quite
young must be kept in bed, and the limbs manipulated several times a
day. Where the child is a little older and it is more difficult to keep
him off his feet, long splints should be applied from the axilla or
waist to a point several inches below the level of the foot. It is only
by making the splints sufficiently long that a naturally active child
can be kept at rest. The little patient should live in the open air as
much as possible.

The static form of Genu Valgum usually occurs in young adolescents,
especially in anaemic nurse-girls, young bricklayers, and young people
who have outgrown their strength, yet have to