Scoliosis is a side-to-side curvature of the spine.
- When viewed from the rear, the spine usually appears
- Scoliosis is a lateral (side-to-side) curve in the spine,
usually combined with a rotation of the vertebrae.
(The lateral curvature of scoliosis should not be confused
with the normal set of front-to-back spinal curves visible
from the side.) While a small degree of lateral curvature
does not cause any medical problems, larger curves can cause
postural imbalance and lead to muscle fatigue and pain.
- More severe scoliosis can interfere with breathing and lead
to arthritis of the spine (spondylosis).
- Approximately 10% of all adolescents have some degree of
scoliosis, though fewer than 1% have curves which require
medical attention beyond monitoring. Scoliosis is found in
both boys and girls, but a girl's spinal curve is much more
likely to progress than a boy's. Girls require scoliosis
treatment about five times as often. The reason for these
differences is not known.
Causes & symptoms
- Four out of five cases of scoliosis are idiopathic, meaning
the cause is unknown.
- While idiopathic scoliosis tends to run in families, no
responsible genes had been identified as of 1997.
- Children with idiopathic scoliosis appear to be otherwise
entirely healthy, and have not had any bone or joint disease
early in life.
- Scoliosis is not caused by poor posture, diet, or carrying
a heavy bookbag exclusively on one shoulder.
classified according to age of onset:
- Curvature appears before age three.
- This type is quite rare in the United States, but
is more common in Europe.
- Curvature appears between ages 3 and 10.
- This type may be equivalent to the adolescent type,
except for the age of onset.
- Curvature appears between ages of 10 and 13, near
the beginning of puberty.
- This is the most common type of idiopathic scoliosis.
- Curvature begins after physical maturation is
Causes are known for three other types of scoliosis:
• Congenital scoliosis
- due to congenital birth defects in the spine, often
associated with other organ defects.
• Neuromuscular scoliosis
- due to loss of control of the nerves or muscles which
support the spine.
- The most common causes of this type of scoliosis are
cerebral palsy and muscular dystrophy.
• Degenerative scoliosis
- may be caused by degeneration of the discs which
separate the vertebrae or arthritis in the joints
that link them.
- Diagnosis for scoliosis is done by an orthopedist.
- A complete medical history is taken, including questions about
family history of scoliosis.
- The physical examination includes determination of pubertal
development in adolescents, a neurological exam (which may
reveal a neuromuscular cause), and measurements of trunk
- Examination of the trunk is done while the patient is standing,
bending over, and lying down, and involves both visual
inspection and use of a simple mechanical device called a
- If a curve is detected, one or more x rays will usually be
taken to define the curve or curves more precisely.
- An x ray is used to document spinal maturity, any pelvic tilt
or hip asymmetry, and the location, extent, and degree of
- The curve is defined in terms of where it begins and ends,
in which direction it bends, and by an angle measure known as
the Cobb angle.
- The Cobb angle is found by projecting lines parallel to the
vertebrae tops at the extremes of the curve; projecting
perpendiculars from these lines; and measuring the angle of
intersection. To properly track the progress of scoliosis,
it is important to project from the same points of the
spine each time.
- Occasionally, magnetic resonance imaging (MRI) is used,
primarily to look more closely at the condition of the spinal
cord and nerve roots extending from it if neurological problems
- Treatment decisions for scoliosis are based on the degree of
curvature, the likelihood of significant progression, and the
presence of pain, if any.
- Curves less than 20 degrees are not usually treated, except
by regular follow-up for children who are still growing.
- Watchful waiting is usually all that is required in adolescents
with curves of 20-30 degrees, or adults with curves up to 40
degrees or slightly more, as long as there is no pain.
- For children or adolescents whose curves progress to 30
degrees, and who have a year or more of growth left, bracing
may be required.
- Bracing cannot correct curvature, but may be
effective in halting or slowing progression.
- Bracing is rarely used in adults, except where pain is
significant and surgery is not an option, as in some elderly
- Two general styles of braces are used for daytime wear.
- The Milwaukee brace consists of metal uprights attached to pads
at the hips, rib cage, and neck. The underarm brace uses rigid
plastic to encircle the lower rib cage, abdomen, and hips.
- Both these brace types hold the spine in a vertical position.
- Because it can be worn out of sight beneath clothing, the
underarm brace is better tolerated and often leads to better
- A third style, the Charleston bending brace, is used at night
to bend the spine in the opposite direction. Braces are often
prescribed to be worn for 22-23 hours per day, though some
clinicians allow or encourage removal of the brace for exercise.
- Bracing may be appropriate for scoliosis due to some types of
neuromuscular disease, including spinal muscular atrophy,
before growth is finished.
- Duchenne muscular dystrophy is not treated by bracing,
since surgery is likely to be required, and since later
surgery is complicated by loss of respiratory capacity.
- Surgery for idiopathic scoliosis is usually recommended if:
• The curve has progressed despite bracing
• The curve is greater than 40-50 degrees before growth
has stopped in an adolescent
• The curve is greater than 50 degrees and continues
to increase in an adult
• There is significant pain.
- Orthopedic surgery for neuromuscular scoliosis is often done
- The goals of surgery are to correct the deformity as much as
possible, to prevent further deformity, and to eliminate pain
as much as possible.
- Surgery can usually correct 40-50% of the curve, and sometimes
as much as 80%. Surgery cannot always completely remove pain.
- The surgical procedure for scoliosis is called spinal fusion,
because the goal is to straighten the spine as much as possible,
and then to fuse the vertebrae together to prevent further
- To achieve fusion, the involved vertebra are first exposed,
and then scraped to promote regrowth. Bone chips are usually
used to splint together the vertebrae to increase the
likelihood of fusion.
- To maintain the proper spinal posture before fusion occurs,
metal rods are inserted alongside the spine, and are attached
to the vertebrae by hooks, screws, or wires. Fusion of the
spine makes it rigid and resistant to further curvature.
- The metal rods are no longer needed once fusion is complete,
but are rarely removed unless their presence leads to
- Spinal fusion leaves the involved portion of the spine
permanently stiff and inflexible. While this leads to some
loss of normal motion, most functional activities are not
strongly affected, unless the very lowest portion of the spine
(the lumbar region) is fused. Normal mobility, exercise,
and even contact sports are usually all possible after spinal
fusion. Full recovery takes approximately six months.
- Although important for general health and strength,
exercise has not been shown to prevent or slow the development
- It may help to relieve pain from scoliosis by helping to
maintain range of motion. Good nutrition is also important
for general health, but no specific dietary regimen has been
shown to control scoliosis development.
- In particular, dietary calcium levels do not influence
- may relieve pain, but it cannot halt scoliosis development,
and should not be a substitute for conventional treatment of
- Acupuncture and acupressure may also help reduce pain and
discomfort, but they cannot halt scoliosis development either.
- The prognosis for a person with scoliosis depends on may
factors, including the age at which scoliosis begins and
the treatment received. More importantly, mostly unknown
individual factors affect the likelihood of progression and
the severity of the curve.
- Most cases of mild adolescent idiopathic scoliosis need no
treatment and do not progress. Untreated severe scoliosis
often leads to spondylosis, and may impair breathing.
- There is no known way to prevent the development of scoliosis.
- Progression of scoliosis may be prevented through bracing or