with supination, or with extension, it should be removed.
Congenital dislocation of both bones of the forearm is extremely rare.

#Cubitus Valgus# and #Cubitus Varus#.--When the normal arm hangs by
the side with the palm of the hand directed forward, the forearm and
upper arm form an angle which is open outwards--known as the "carrying
angle"; it is usually more marked in women in association with the
greater breadth of the pelvis and the relative narrowness of the
shoulders. When this angle is increased, the attitude is described as
one of _cubitus valgus_. This deformity may be acquired as a result of
rickets, but more commonly it is due to fracture of the lateral
condyle of the humerus, in which the separated fragment has been
displaced upwards.

_Cubitus varus_ is the reverse of cubitus valgus. It is more common,
is always pathological, and is nearly always a result of fracture of
the lower end of the humerus or separation of the lower humeral
epiphysis and subsequent interference with growth. These deformities
may be corrected by supra-condylar osteotomy of the humerus.

[Illustration: FIG. 167.--Lower end of Humerus from case of Cubitus
Varus.]

#Synostosis of the superior radio-ulnar joint# is a rare congenital
condition, in which the hinge movements at the elbow are free, but
supination is impossible; an attempt may be made by operation to form
a new joint.

#Volkmann's ischaemic contracture# of the muscles of the forearm,
resulting in the production of claw-hand, is described in Volume I.,
p. 415.

#Deformities of the Forearm and Hand.#--The _radius_ may be absent
completely or in part, frequently in combination with other
malformations. The most evident result is a deviation of the hand to
the radial side--one variety of _club-hand_. The forearm is
shortened, the ulna thickened and often bent, and the thumb and its
metacarpal bone are often absent, so that the usefulness of the hand
and arm is greatly impaired (Fig. 171). For this condition Bardenheuer
devised an operation which consists in splitting the lower end of the
ulna longitudinally and inserting the proximal bones of the carpus
into the cleft.

Congenital deficiency of the _ulna_ is extremely rare.

#Intra-uterine amputation# by constriction of amniotic bands sometimes
occurs (Figs. 168, 169).

[Illustration: FIG. 168.--Intra-uterine Amputation of Forearm.]

[Illustration: FIG. 169.--Radiogram of Arm of patient shown in Fig.
168.]

#D