e or epiphysial separation in the
region of the knee; and a paralytic form, usually combined with
flexion, in cases of spastic paralysis. Finally, genu valgum may be a
result of various forms of osteomyelitis of the lower end of the
femur, or of disease in the knee-joint, such as tuberculosis,
arthritis deformans, or Charcot's disease.

#Genu Varum--Bow-knee.#--In this deformity, which is the converse of
genu valgum, the leg joins the thigh at an angle which is open
medially. It is almost invariably bilateral, is of rachitic origin,
and is frequently associated with bow-legs (Fig. 141). The tibia takes
a greater share in its production than the femur. Although an ungainly
deformity, it is much less frequently the source of complaint than
knock-knee, because it scarcely interferes with locomotion--as a
matter of fact, the subjects of bow-knee, although short in stature,
are unusually sturdy on their legs. An extreme example of the
deformity is shown in Fig. 141.

[Illustration: FIG. 141.--Bow-knee in Rickety Child.]

Treatment is carried out on the same lines as in genu valgum.

#Rickety Deformities of the Bones of the Leg--Bow-leg.#--These
deformities are common in children; are nearly always bilateral and
symmetrical, and may be associated with knock-knee or bow-knee. They
may occur before the child is able to walk, the bones bending in the
attitude in which the limbs are habitually placed--over the nurse's
knee, for example, or as they are crossed underneath the child in
sitting. In children who are able to walk, the curve is due to the
weight of the body acting on the softened bones. In either case, the
bending may be increased by the traction of muscles, and sometimes by
the occurrence of greenstick fracture. The most common deformity is a
uniform curvature of the bones laterally and forwards, or a more
acute bend in the lower thirds of their shafts. In some cases the
chief curvature is forwards. The ungainliness in walking may be added
to by flat-foot. Backward curving of the upper end of the tibia has
been already described as one of the causes of genu recurvatum. The
most extreme deformities are met with in rickety dwarfs.

_Treatment._--Under the age of six, and particularly in children, who
are actively growing, the bones will probably straighten if the child
is treated for rickets and kept off his feet; well-padded lateral
splints are applied as recommended for knock-knee, and these should be
taken off a