vertebral problems in tof.oa and vacterl
DESCRIPTION
ÂTRANSCRIPT
Vertebral problems in TOF/OA and
VACTERL
Text created in association with Robert Dickson, Professor and Head of the Department of
Orthopaedic Surgery, the University of Leeds.
What is a vertebra?
A vertebra is is one of many bones making up the spinal column or backbone. Our vertebrae are
divided up into five types according to their location:
Cervical vertebrae are found below the base of the skull, in the neck
Thoracic vertebrae are in the chest and each carry an articulation with a rib
Lumbar vertebrae are designed to allow the flexibility that we have in the small of the back
Sacral vertebrae are fused together to form the sacrum, which forms a joint with our pelvis
Coccygeal vertebrae make up our ‘coccyx.’
Between the vertebrae are found structures which are commonly referred to as the ‘discs’ – more
correctly ‘invertebral discs.’ These form the joints between the ‘vertebral bodies.’
The spine is, however, more than merely a flexible support for our torso; it houses the spinal cord
through which the nerves carrying signals to and from our body run.
The cord runs through the spinal canal, within the vertebrae, and nerves emerge from it to our
muscles, and return to it carrying sensory information from our skin and other body organs.
Vertebral anomalies
Children are sometimes born with vertebrae which are only partly formed, (‘hemivertebrae’ or
‘wedge vertebrae’ – see illustration below) or vertebrae which are fused together (‘block
vertebrae’). The so-called ‘butterfly vertebra’ is actually two hemivertebrae which have occurred at
the same level.
Missing or extra vertebrae – often associated with an extra pair of ribs if located in the thoracic
region of the spine – do not generally cause deformity or other problems.
Another group of problems which wdo not cause a gross deformity but can be equally problematic
are those which involve the shape of individual vertebrae in different ways –␣such as extra
projections from the bone’s surface –␣and any abnormalities in the structures surrounding the
spinal cord.
Do anomalies matter?
The significance of vertebral anomalies is related to two things: their ability to cause spinal
deformities, and their ability to create neurological problems.
Spinal deformities
A visible deformity of the spine may be present at birth, as a direct result of the deformity causing
a bend in the spine, or it may become obvious as the child grows, the unbalanced forces which the
anomaly exerts on the surrounding vertebrae causing them to grow abnormally.
Types
There are three categories of spinal deformity:
Scoliosis: a side-to-side curving of the spine when viewed from behind
Kyphosis: a forwards bending of the spine when viewed from the side
Lordosis: a backwards bending of the spine when viewed from the side.
These deformities may co-exist, and may be mild or severe in their appearance and effect on the
individual’s life. If severe they may affect the function of organs in the chest (the heart and lungs)
– however this is unlikely to develop after a child has reached the age of 5 years. An individual’s
ability to sit or stand can also be affected simply due to the amount of deformity present.
Neurological problems
Muscular weakness or loss of sensation may result from spinal deformities if they put pressure on
the spinal cord, but can also be caused by abnormalities in the shape of individual vertebrae
(either co- existant with spinal deformity or in its absence) or from various problems affecting the
relationship of the spinal cord to the vertebrae (discussed under ‘spinal dysraphism’).
Spinal deformity
Fortunately scoliosis is not painful at any stage throughout life. Sometimes kyphosis in
adolescence can be painful but that usually settles at the end of spinal growth.
Assessing vertebral anomalies and spinal deformity
In assessing a child with congenital vertebral anomalies who has a spinal deformity, several
questions are asked: how bad is the deformity now? (and – if severe – is it causing neurological or
cardiorespiratory signs?) and is it likely to get worse?
Whilst the current status of a deformity can be evaluated using a combination of physical
examination and radiography (X-rays), it is not always possible to predict which anomalies are
going to progress. Absent or additional vertebrae will not push the spine out of alignment and are
therefore unlikely to cause deformity. However, multiple anomalies may either cancel one another
out, or have an additive effect, and while most solitary hemivertebrae will not cause deformities
which are progressive, this depends on their location in the spine – so each individual case needs
to be assessed by an experienced orthopaedic surgeon.
Reassessment at regular intervals may be required for many children – and may need to be
continued for many years, since the adolescent growth spurt is often a time when progression
occurs rapidly.
The Cobb angle
This is a measurement of the amount of deformity present, and is measured from radiographs (X-
rays). A surgeon may take many views at a range of angles in order to see the deformity from
different directions. An increasing Cobb angle is indicative of a worsening deformity.
Idiopathic scoliosis
Scoliosis can develop in the absence of congenital vertebral anomalies; this is called ‘idiopathic
scoliosis.’ TOF/VACTERL children may suffer this form of deformity – which can become apparent
at varying ages and may either resolve spontaneously or progress and require treatment.
Treatment of spinal deformities
Where a visible deformity is the only problem, and progression is not an issue, a decision may
need to be made regarding how acceptable the deformity is to the individual (and/or the family). If
it is acceptable, then no surgery will be required.
If a deformity is progressing rapidly or the underlying anomaly is of a type likely to worsen
dramatically, then surgical intervention will be advised to halt this progression. The issue of
acceptibility (as above) may also be relevant in order to decide whether only a halting of
progression will be sufficient, or whether the spine additionally needs to be straightened from its
current position.
A deformity which is already causing problems for the chest organs or the spinal cord will
inevitably require surgical treatment to straighten the spine.
The exact surgical procedure will vary depending on the nature of the problem(s). Surgery may be
required on the back or the front of the spine (or both), depending on where the anomaly lies and
where it is having its effect on growth/deformity. The operation may involve removal of bone,
grafting of bone from other locations in the body (often a rib or the rim of the pelvis) in order to
cause vertebra to be fused together, or use of metal implants and screws. For some children,
staged procedures will be necessary (i.e. one operation followed by another at an interval of a
week or two afterwards) and some individuals may need to be prepared to undergo operations at
different ages.
Whereas body casts and splints are sometimes sufficient for the management of idiopathic
scoliosis, there is no evidence that they are effective for children with congenital vertebral
deformities, although they may in certain instances be useful for a short period before surgery.
Traction devices may also be used for the same purpose in some patients. Bracing may be used
for a while post-operatively, to support the surgical repair.
Immediately after surgery, the child will require meticulous nursing care. With time, increasing
movement will be encouraged and it is often surprising how quickly recovery progresses.
Restriction of activities is often necessary for some months, with regular follow-up checks essential
to ensure continued improvement.
Spinal dysraphism
This is a term which refers to a number of different conditions with a common feature; they are all
possible causes of ‘spinal cord tethering.’
After birth, the spinal cord extends further down the spinal column than it does in adulthood. This
means that during a child’s growth, the end of the cord ‘migrates’ up the spinal column until it
reaches its final position, between the 1st and 2nd lumbar vertebrae.
Anything which prevents this movement will put the cord under tension, and this has become
known as ‘tethering.’
A small proportion of children with congenital vertebral anomalies may have a degree of tethering,
so it is important to assess for this during growth – and especially important to make adequate
checks prior to surgery to correct deformities, since straightening of a deformed spine may
increase any tethering, with potentially serious consequences.
Causes of tethering
Various problems can cause tethering, but the most common are:
Tethered conus
The tapered end of the spinal cord is known as the ‘conus.’ This continues as the ‘filum terminalie’
which is attached to the coccygeal vertebrae. A shortening of the filum - usually associated with a
thickening which can be seen on a special X-ray (a myelogram – where a contrast material is
injected around the spinal cord so that it can be seen on a radiograph) will restrict the migration of
the cord with growth.
This problem is also known as ‘fatty filum.’
Diastematomyelia
This is a congenital anomaly which projects into the spinal cord and may even cause it to be split
into two. Since 10% of children with congenital spinal anomalies may have diastematomyelia, this
must be excluded by careful examination of radiographs.
Intraspinal lipoma
This is a fatty area within the spinal canal.
Dermoid cyst
This is a cystic structure which is comprised of tissues originating from the skin; it may extend
down to the spine.
Spinocutaneous fistula
This much rarer problem is a connection between the skin and the structures around the spinal
cord. It is a serious condition due to the risks of infection.
Signs of tethering
Indications that a child has cord tethering may arise in various ways.
Skin
An abnormally hairy patch of skin, a dimple (e.g. sacral dimple), a port wine stain or an area of
scarring which is present at birth may all alert a doctor to possible causes of tethering. These
problems act like a ‘warning sign’, indicating that further investigations are required and that
additional signs may develop as the child grows unless corrective surgery is undertaken. Other
problems usually do not present until the 2nd or 3rd year of life:
Problems
VACTERL children may also have renal or anorectal problems which contribute to a lack of urinary
control, however spinal cord tethering can also affect this function.
Lower limb abnormalities
These either have the appearance of a ‘club foot’ or take the form of a limp due to an discrepancy
in the size of the limbs.
X-rays will show abnormalities of the spinal column, however a proper diagnosis cannot be made
until a surgical exploration has been undertaken.
Treatment of tethering
Where the only problem is a tethered conus, this can be relatively easily released at surgery
simply by cutting through the restricting filum.
Other problems will require more involved sugery to remove the offending structure(s).
Usually the surgeon will also inspect the filum when operating on problems further up the spine to
ensure that there are not additional problems further down the cord. This can be performed using
an endoscope (flexible telescope) which is inserted down alongside the spinal cord.
As with spinal deformities, follow-up is important to ensure that no further problems are
encountered.
Additional resources:
The Scoliosis Association offers comprehensive information and a source of support for families of
children with scoliosis.
Scoliosis Association (UK)
2 Ivebury Court
323-327 Latimer Road
London W10 6RA
Tel: 020 8964 1166
Fax: 020 8964 5343
Website:
http://www.scoliosis.org.uk