Ministry of Health
Fractured clavicles are found in up to 2.9% of term infants, more frequently
on the right side. They are often silent but may be noticed later when
a palpable callous forms at a few weeks of age.
There is often minimal pain
apparent, but if the infant is uncomfortable strapping may be all that
is required for a few days.
The radiograph to the left
shows a linear lucency at the lateral one third of the clavicle.
Midshaft (diaphyseal) humeral fractures are often diagnosed at birth when a
"crack" or "snap" is heard or felt on delivery of the baby. Clinical
signs are variable - the baby may be asymptomatic, may be in pain, or may
present with a pseudoparalysis.
Treatment is by
immobilisation of the arm by the side with the elbow held at 90°.
These fractures usually heal very well over the following weeks.
The images to the left
demonstrate a humeral fracture which was suspected at delivery after a
difficult extraction. The top image shows the fracture immediately
after birth; the second image shows the fracture three weeks later, with
good callous formation. The third image shows the fracture 2
months after the initial injury with minimal angulation.
fractures are generally classified as linear, depressed, or occipital
Linear skull fractures, as in
the right parietal skull fracture shown at the left, are most common in
the parietal region. The exact incidence is difficult to determine
although they are reportedly common. The pathogenesis is thought
to be from direct compression.
There may be external signs
of injury (i.e. haematoma), but significant intracranial complications
are rare. Rarely, there is an associated dural tear which may
subsequently develop a leptomeningeal cyst.
No specific therapy is
indicated, although a follow-up radiograph at several months of age may
be useful to show healing.
Depressed skull fractures are
most commonly associated with the use of forceps, with the most common
site being the parietal bone. They may occur after pressure on
maternal pelvic structures. Although rarely associated with
epidural or subdural haemorrhage and cerebral injury, a CT scan may
nevertheless be indicated. Many depressed fractures are managed
(separation of the squamous and lateral parts of the occipital bone) may
result in intracranial injury (posterior fossa subdural haemorrhage and
cerebellar contusion). Typically, infants have been delivered
breech and are commonly depressed at delivery. Severe occipital
osteodiastasis is associated with a poor outcome.
Osteopenia of Prematurity
Poor mineralisation of bone is a relatively common finding in extremely
preterm infants, with those under 1000g and less than 30 weeks gestation at
most risk. Terminology in the literature can be somewhat confusing,
and other terms such as metabolic bone disease and rickets of prematurity
have been used interchangeably. The aetiology is complex, and is
relate to both nutritional factors (inadequate intake of minerals), hormones
(vitamin D) and to mechanical factors (lack of mechanical stress applied to
the bone). Infants most at risk are those who have been very
systemically unwell (often with chronic lung disease and receiving diuretic
therapy) and have been troubled with suboptimal nutritional intakes.
Radiologically, bone mineral density is significantly decreased. This
may manifest as "disappearing" bones (such as in the image to the left,
where the vertebral bodies and scapulae are barely visible) and in severe
cases rib or limb fractures may be seen (in the image to the left, the
posterior part of the right 7th rib shows a callous indicating a previous
Severe osteopenia is rare,
probably due to changes in nutritional and other neonatal practices.
Some infants will require long-term
although there is some evidence that regardless of how osteopenic infants
are, bone density improves with age and with adaptation to mechanical
requirements of the body.
Left humerus at 2 weeks
Comparison of right and
left humeri at 4 weeks
Resolution of lytic changes at 8
Osteomyelitis and septic arthritis may occur simultaneously in infants under
1 year of age, due to the unique nature of the vascular supply of the
neonatal skeleton (perforating capillaries are present in the epiphyseal
plate of long bones and provide a communication between the metaphysis and
the joint space). The exact incidence of osteomyelitis and septic
arthritis in neonates is not well defined. Common organisms include
Staphylococcus aureus, Group B Streptococcus, and Gram-negative enteric
organisms, but other organisms are also seen. The origin of
osteomyelitis is thought to be haematogenous.
Symptoms are generally non-specific and are often overshadowed by the
general condition of the septicaemic child. The baby may present with
a pseudoparalysis with reduced movement of the affected limb.
Swelling, erythema, and heat over the bone or joint may be present.
Early in the disease,
radiographs may be normal. Subsequently, the normal fat markings
of deep tissues may be obscured. Cortical destruction is unusual
before the second week of the illness, so in the event of Staphylococcal
septicaemia a complete
should be taken 2 weeks into the treatment (or earlier if there are
clinical signs suggesting osteomyelitis or septic arthritis).
Clinical resolution precedes radiographic resolution, but some infants
are left with significant joint or bone injury.
The images to the left show
the serial radiographs of an extremely low birth weight infant with
Staphylococcal septicaemia at 1 month of age. He had no clinical
signs of osteomyelitis or septic arthritis.
The initial skeletal survey 2
weeks into treatment suggested some lucency in the left proximal humerus
with some irregularity of the cortex suggestive of underlying
osteomyelitis. A follow-up radiograph 2 weeks later showed clear
difference between the right and left humerii. After completion of
6 weeks of intravenous flucloxacillin, there was resolution of the lytic
changes in the bone, but some evidence of sclerosis and new bone
formation around the proximal humerus.
image demonstrates bowing of a femur.
Osteogenesis imperfecta (OI) is a
generalised abnormality of bones due to problems with Type I collagen
formation. There are at least 4 recognised types, although
differentiation between types can be difficult in the newborn period.
- Type I OI is most common
and the mildest type. There is less collagen than normal, with
little bone deformity, although the bones are nevertheless fragile.
There may be bluish discolouration of the sclera of the eyes.
Type II OI is the most severe form with improperly formed collagen.
Intrauterine fractures are common, and many babies are stillborn or die
soon after delivery.
Type III OI also has severe bone deformities. Infants are often
born with fractures. Discolouration of the sclerae may not occur.
It is compatible with longer life, although people are generally of
below-average height, may have skeletal and/or respiratory problems, and
IV OI is moderately severe. Bones are fragile, and the sclerae may
be of normal colour. Bone abnormalities are mild to moderate in
severity, adults are shorter than average, and may have brittle teeth.
Treatment is largely
supportive, with referral to the Orthopaedic, Genetics, and Endocrine
services. Medical treatment with bisphosphonates may be indicated.
The images below show marked
skeletal abnormalities involving bowing of the femurs and tibias, a
fracture of the left humerus, and deformity of the right humerus.
The chest radiograph demonstrates rib fractures on the left. The
skull radiograph demonstrates Wormian bones. The bones appear
osteopenic in all films.
29 November, 2011