those
produced during birth; and (3) those acquired after birth.

Palsies of children: _Anterior Poliomyelitis_. Cerebral palsies:
_Spastic paralysis_.

THE LOWER EXTREMITY: Congenital dislocation of hip--Snapping
hip--Paralytic deformities--Contracture and ankylosis of hip--Coxa
vara and coxa valga--Congenital dislocation of knee and
patella--Genu recurvatum--Paralytic deformities--Contracture and
ankylosis of knee--Genu valgum and genu varum--Congenital
deformities of leg--Bow-leg--Club-foot: _Talipes equino-varus_;
_Pes equinus_; _Pes calcaneus_; _Pes calcaneo-valgus and varus_;
_Pes cavus_; Flat-foot and pes valgus--Painful affections of
heel--Metatarsalgia--Hallux valgus and bunion--Hallux
varus--Hallux rigidus and flexus--Hammer-toe--Hypertrophy of
toes--Supernumerary toes--Webbed toes.

THE UPPER EXTREMITY: Congenital absence of clavicle--Elevation of
scapula--Winged scapula--Congenital paralytic deformities of
shoulder--Deformities of elbow--Club-hand--Deformities of
wrist--Madelung's deformity--Deformities of fingers--Dupuytren's
contraction--Polydactylism.

The surgery of the extremities is so largely concerned with the
correction of deformities that it is necessary at the outset to refer
briefly to some points relating to the time and mode of origin of
these.

1. _Congenital deformities_--that is, those which originate _in utero_
and are present at birth--are comparatively common and may be due to a
variety of causes. Some result from errors of development--for
example, supernumerary fingers or toes, and deficiencies in the bones
of the leg or forearm. A larger number are to be attributed to a
persistent abnormal attitude of the foetus, usually associated with
want of room in the uterus--for example, the common form of club-foot
and congenital dislocation of the hip. Less frequently amniotic bands
so constrict the digits or the limbs as to produce distortion, or even
to sever the distal part--_intra-uterine amputation_. Lastly, certain
diseases of the foetus, and particularly such as affect the
skeleton--for example, achondroplasia--cause congenital deformities.

2. _Deformities originating during birth_ are all traceable to the
effects of injuries sustained in the course of a difficult labour.
Examples of these are: wry-neck resulting from rupture of the
sterno-mastoid; lesions of the shoulder-joint and brachial plexus due
to hyper-exte