13. Normally the medial border of the foot, even when
weight-bearing, forms a longitudinal arch. The
arrangement of the metatarsals also produces an
anterior or transverse arch in the forefoot. Flattening
of the longitudinal arch is referred to as a planus
deformity or flat-foot; and a dropped metatarsal arch
as anterior flat-foot. An excessively high arch
produces a cavus deformity.
Common deformities of the toes are lateral deviation
of the big toe (hallux valgus), proximal
interphalangeal flexion of one of the lesser toes
(hammer-toe) and flexion of both interphalangeal
joints of several toes (claw-toes).
14. CONGENITAL TALIPES EQUINOVARUS (IDIOPATHIC
In this deformity the heel is in equinus (pointing
downwards), the entire hindfoot in varus (tilted towards
the midline) and the mid-foot and forefoot adducted and
supinated (twisted medially and the sole turned upwards).
It is relatively common; the incidence is 1 or 2 per 1000
birth and boys are affected twice as often as girls. The
condition is bilateral in one-third of cases. Similar
deformities are seen in neurological disorders e.g.,
myelomeningocele, and in arthrogryposis.
 The skin and soft tissues of the calf and the medial side
of the foot are short and underdeveloped. If the condition
is not corrected early, secondary growth changes occur in
the bones and these are permanent. Even with treatment,
the foot is liable to be short and the calf may remain thin.
15. Clinical features
The deformity is usually obvious at birth; the foot is both
turned and twisted inwards so that the sole faces
posteromedially. The heel is usually small and high, and
deep creases appear posteriorly and medially. In a normal
baby the foot can be dorsiflexed and everted until the toes
almost touch the front of the leg. In club-foot this
manoeuvre meets with varying degrees of resistance and
in severe cases the deformity is fixed.
 The infant must always be examined for associated
disorders such as congenital hip dislocation and spina
The tarsal bones are incompletely ossified at this age and
the anatomy is therefore difficult to define. However, the
shape and position of the tarsal ossific centres are helpful
in assessing progress after treatment.