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Conditions
Scoliosis |
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| Scoliosis refers to a condition where the spine (which
is normally straight when viewed from the front or back) develops a lateral, or
side-to-side, curve: |
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The individual vertebrae also rotate towards the centre
of the curve. If the main, scoliotic curve is present in the thoracic spine (where the
ribs are attached), this rotation will cause the rib cage to distort – not only from
side-to-side as you would expect from scoliosis, but also from front-to-back. As a result,
the ribs on the inside of the curve will stick out at the front and, on the outside of the
curve, they’ll stick out at the back.
Why does this happen?
In general, the causes of scoliosis are poorly understood. Idiopathic scoliosis (a form of
the condition which isn’t, itself, caused by another condition) tends to run within
families – as a result, it would appear that genetics are involved, although the
underlying mechanisms aren’t very clear. However, despite the fact that the causes
are largely unknown, it is relatively easy to classify the type of scoliosis that a
patient has:
- Idiopathic: infantile; juvenile; adolescent
- Idiopathic: adult
- Congenital (present at birth)
- Neuromuscular
- Degenerative
Idiopathic, genetic scoliosis accounts for about 80% of all cases, and is far more
common in girls (88%) than boys (12%). It can be sub-classified into infantile, juvenile
and adolescent types, depending upon the age of onset; of these, adolescent scoliosis is
by far the most common form. Note: idiopathic, adult scoliosis is simply the result of
scoliosis that isn’t, or wasn’t, fully corrected during childhood.
Congenital deformities are generally more severe, and are due to failures in spinal
formation – for example, incomplete formation of one, or more, vertebrae, can result
in wedge-shaped bones that laterally distort the spine; in some cases, the vertebrae
actually fail to separate, or segment, resulting in solid bars or blocks of bone.
Neuromuscular scoliosis is not idiopathic – it is caused by other,
neuromuscular conditions, including cerebral palsy; spina bifida; and muscular dystrophy.
In the elderly, degenerative changes in the spine can lead to scoliosis. For example, an
osteoporotic fracture may cause one of the vertebrae to collapse, resulting in a loss of
height of some 15-20% – if the collapse is even, the normal curvature of the spine
will be maintained. However, if the collapse is uneven (as it often is), a
wedge-shaped vertebra is produced – if this slopes from side-to-side, then a
scoliotic curve will develop. Degenerative scoliosis can also be caused by: thinning of
the inter-vertebral discs; weak muscles; and weak ligaments. The condition is most likely
to occur in the lumbar spine – this area bears the most weight and therefore tends to
degenerate faster than either the cervical or thoracic spine. |
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How is it diagnosed?
In visual terms, scoliosis is fairly easy to diagnose – the lateral curve in the
spine is often very noticeable. If the condition is present in the thoracic spine, the rib
cage will also rotate; as a result, the ribs on the inside of the curve will stick out at
the front, and those on the outside will stick out at the back. In addition to this, the
ribs on the inside of the curve are squashed together, whilst those on the outside display
increased separation: |
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Providing a full diagnosis, however, is slightly more
complex. For example, the primary (or structural) scoliotic curve is often accompanied by
secondary curves – these are usually developed by the patient to compensate for the
distribution of weight over the primary curve (without a secondary curve, they might fall
over). Primary and secondary curves can be distinguished by asking the patient to bend
over to the side – structural curves are largely unchanged, but secondary curves
straighten significantly in order to maintain balance.
In addition to this, one needs to determine the severity of the condition. This is defined
by an angle referred to as the Cobb angle (the same angle that is used to measure kyphosis); this time, however,
the angle is used to measure a side-to-side curve as opposed to one that goes from
back-to-front. X-rays are used to measure the Cobb angle – a normal, healthy spine
should display an angle of 0°, although angles of less than 25° are considered
relatively small. |
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What are the consequences for back pain?
Irrespective of the cause, scoliosis can be very painful.
In general terms, however, the pain is roughly proportional to the size of the curve
(measured by the Cobb angle). As the primary angle increases, so does the size of any
secondary curve – in turn, this leads to increased muscle fatigue and pain. In
addition to this, nerve root compression is relatively common: as the primary curve
increases, the vertebrae are pushed closer together (on the inside of both the primary and
secondary curves); as a result, the spinal nerves become compressed – this can
lead to intense pain, in addition to (other) sensory and motor symptoms. For example, in
severe cases of lumbar scoliosis, the patient may experience partial, or complete,
paralysis of the feet and/or legs; patients with thoracic scoliosis may develop heart
and/or lung problems as one side of the rib cage becomes compressed.
In addition to this, the increased pressure, on the inside of both the primary and
secondary curves, can lead to bulging or
herniated discs; scoliosis will also accelerate the degenerative changes in the spine
and lead to secondary conditions (such as osteoarthritis).
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What are the risk factors?
To reiterate: idiopathic, genetic scoliosis accounts for about 80% of all cases, and is
far more common in girls (88%) than boys (12%). For most people, hereditary factors, and
sex, are therefore primary risk factors. For adults with idiopathic scoliosis, the risk
factors are similar, but they also include the type of treatment (if any) they were given
as children.
Degenerative scoliosis is largely caused by osteoporosis;
as a result, overweight, post-menopausal women tend to be most at risk. |
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Can it be treated?
The classical approach to treatment includes: observation; bracing; and, in extreme cases,
surgery. In our opinion, however, the only
conditions that require surgery are vertebral fractures, and cancer of the spine; instead,
we believe that scoliosis can be treated by non-invasive decompression of the spine
(either by using the backrack™ or,
for larger curves, by visiting a specialist trained in orthopaedic medicine). Irrespective of the treatment, however, there
are a number of observations that appear to hold true:
- Adolescent curves > 40° are difficult to control with braces.
- Adult curves > 50° will continue to progress at a rate of 1% per year.
- Children with large curves are more at risk from deterioration, than adults with small
curves.
Taken together, the goal of treatment is to keep adolescent curves at < 50°.
However, it should be noted that bracing is only temporarily effective – curves
generally return to their previous angle, soon after the brace is removed.
The surgeon’s approach to scoliosis, is to correct the curve using instrumentation
(rods and screws), and then to fuse the vertebrae together – this prevents them from
moving back to their original positions, but it also prevents all other forms of movement.
Our views on spinal surgery are well
documented on this website.
For cases of degenerative scoliosis, the best possible form of treatment lies in
prevention; for example, if osteoporosis can be prevented (generally by eating well, and
taking regular, weight bearing exercise) then the chances of developing osteoporotic
scoliosis are vastly reduced. |
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