Fractures
and dislocations of the upper limb in children
Introduction
It must be realised that children are not merely small adults, and this
is particularly true with fractures and dislocation of the upper limb. Although
superficially the injuries may appear to be the same, the pattern and prognosis
of the injuries are often very different. Fractures of the proximal humerus in
adults are a major problem; they are often complicated by nonunion, avascular
necrosis and a poor functional outcome, and the patient may require joint
replacement. In children the fracture usually represents an epiphyseal injury
and the prognosis is very good, often without treatment, despite significant
angulation at the fracture site. Shoulder dislocation, a common adult condition,
is very uncommon in children. Apparent dislocations in children are often due to
epiphyseal fractures and again may not require treatment. It is therefore
necessary to be aware of the ossification centres of the upper limb when dealing
with these injuries.
Ossification
A large part of the body of the scapula is ossified at birth. A
secondary ossification centre appears in the coracoid during the first year and
fuses by about the 15th year. The acromion usually develops two ossification
centres, with all ossification centres fused by about the age of 20. These may
be confused with fractures on radiographs or predispose to epiphyseal
separation. Failure of fusion of the acromion resulting in an os acromiale
occurs in about 5 per cent of the population, although there is a number
of different reports of the incidence in the literature.
The
shaft of the humerus is evident at birth, with the head appearing by about 6
months. The greater and lesser tuberosities appear around the age of 2 and 5 years,
and fuse by the age of about 6 to produce a conical growth plate. In children
under the age of 6 fracture through this growth plate is usually a Salter and
Harris type I injury, as before the tuberosities fuse the growth plate is more
transverse. In the older child a Salter and Harris type II fracture occurs
through the conical growth plate. The proximal growth plate accounts for 80 per
cent of the humeral growth.
There
are six ossification centres around the elbow and the usual order of appearance
is shown below in Table 22.1, together with the approximate time of appearance.
In general ossification centres appear earlier in females than males.
The
shafts of both the radius and ulna are evident at birth.
General
principles
With any childhood injury the possibility of child abuse must always be
considered. In general this does not apply to injuries around the shoulder, as
most of these injuries occur in those over 5 years old, an age at which
child abuse resulting in fractures is uncommon. In the under 5 year old a
proximal humerus fracture is rarely due to child abuse, although clavicle
fractures especially in those under 18 months should be viewed with suspicion.
Spiral fractures of the humerus in young children should also be considered as
nonaccidental injuries, although distal humeral fractures and elbow fractures in
general are usually not due to child abuse. If, however, the mechanism of injury
does not fit the history given or there was a significant delay in presentation,
then nonaccidental injury should be considered.
In
a child of any age, an open fracture must be treated by operative debridement
and stabilisation of the fracture site. In children, as in adults, polytrauma is
a relative indication for surgical treatment.
Epidemiology
The risk of at least one fracture up to the age of 16 in a boy has been
reported to be 42 per cent. In girls the quoted figure