( extracted from the web site of SCOLIOSIS RESEARCH SOCIETY)
In Depth Review of Scoliosis:
Introduction / Diagnosis
/ Radiographic Imaging
Treatment
of Adolescent Idiopathic Scoliosis
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When one views
a normal spine form behind, the back appears straight and the trunk
symmetrical. When the normal spine is viewed from the side, curves are seen
in the neck, upper trunk and lower trunk. The upper trunk has a gentle
rounded contour called kyphosis and the lower trunk has a reverse direction
of the rounded contour called lordosis. Certain amounts of cervical (neck)
lordosis, thoracic (upper back) kyphosis and lumbar (lower back) lordosis are
normally present and are needed to maintain appropriate trunk balance over
the pelvis (Fig. 1a&b). Deviations
from this normal alignment may reflect abnormal kyphosis or lordosis or, more
commonly, scoliosis. |
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Scoliosis Scoliosis
is defined as a side-to-side deviation from the normal frontal axis of the body
(Fig. 2a&b).Although
traditional, this definition is limited since the deformity occurs in varying
degrees in all three planes: back-front; side-to-side; top-to-bottom. |
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Clinical Clinical
evaluation focuses on history and physical examination findings.
Consideration is given to circumstances surrounding the patient's birth,
delivery and development histories. Was the pregnancy full term? What was the
child's birth weight? When did the child begin to walk?--are some of the
important guide posts which are sought. Abnormalities in these areas may lead
one to consider neuromuscular or congenital etiologies. With congenital
anomalies, if one congenital anomaly is found, others are sought, e.g.,
kidney abnormalities are often associated with congenital scoliosis.
Intermittent backache may occur with idiopathic scoliosis, but complaints of
pain radiating into the legs, night pain, or systemic complaints (for example
changes in bowel or bladder habits) are highly abnormal and are not common
complaints in patients with idiopathic scoliosis and usually require further
study. A family history of spinal deformity is looked for since certain types
of spinal deformity are more prevalent within families. |
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Physical
examination centers on assessment of trunk symmetry. The Adam's forward bend
test is done with the patient bending forward with arms extended and knees
straight. Asymmetry of the trunk when viewed from the front or the back as
well as abnormal increases or decreases in lordosis or kyphosis when viewed
from the side are assessed (Fig.3). This test is used during school
screening for scoliosis. The test is sensitive to detect trunk asymmetry but
it is not specific for spinal deformity. A common finding that is often
misinterpreted as spinal deformity is truncal asymmetry from unequal trunk
muscle development on the patient's dominant hand side. Further
physical findings depend on the patient's deformity location and magnitude.
Shoulder heights may be uneven and there may be an increased space between the
elbow and trunk because of trunk deviation (Fig.4). Prominence of a "hip",
pelvis or breast may be seen. Examination of the skin overlying the spine
assesses the presence of dimples, sinuses, hairy patches and skin
pigmentation changes. The effect of any limb length inequality is tested with
the patient standing on blocks to level the pelvis or seated on a flat
surface. Neurological examination includes evaluation of the function of the muscles
and nerves of the upper and lower limbs. |
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Initial
imaging evaluation of a patient suspected of having scoliosis is by
a standing posterior-anterior thoracolumbar spine radiograph done on
a single long film. Modern radiographic techniques minimize radiation
exposure (Fig.5). A standing
side view radiograph of the thoracolumbar spine is suggested if significant
deformity is present in the front-to-back (sagittal) plane. Radiographs
are assessed for spinal column contour and to rule out congenital, developmental,
degenerative or neoplastic abnormalities. The amount of each deformity
is calculated using a standard, reproducible measurement technique.
An estimate of skeletal maturity is made by assessment of the growth
areas at the upper pelvis and hips (Fig.6). Specialized
imaging studies such as (CT scans or magnetic resonance imaging (MRI))
may occasionally be needed. Magnetic resonance imaging is done to evaluate
the spinal cord and spinal nerves (Fig.7). As with
all studies, MRI is done for a specific indication and correlated with
clinical examination. Myelography, a radiographic study which uses an
injected dye to provide contrast to study the spinal canal and its contents,
has been largely replaced by magnetic resonance imaging techniques.
CT scans are used to provide improved definition of abnormalities of
vertebral size, shape or number (Fig.8). |
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Congenital
Scoliosis Congenital
scoliosis is caused by abnormal vertebral formation. Vertebral absence,
partial formation or lack of separation can cause asymmetrical growth and
resultant deformity (Fig.9). Patients with
congenital scoliosis require a renal ultrasound to rule out renal anomalies
such as a single kidney which is the most common associated finding. Magnetic
resonance imaging may be necessary to rule out suspected associated
abnormalities of the spinal cord or spinal nerves if clinical neurologic
examination findings are present. The treatment of congenital scoliosis is
individualized and dependent upon the type of vertebral malformation. Early
surgical intervention may be required to prevent deformity progression. Neuromuscular
Scoliosis Spinal
deformity is common and often severe in patients with neuromuscular disease
especially in those patients who do not walk because of their underlying
neurological disease. Seating modification and bracing in the vast majority
of cases have no long-term effect on the natural, i.e., untreated course, of
spinal deformity in neuromuscular disease. Such techniques may improve
sitting ability but do not alter curve progression. Surgical correction and
stabilization are done to prevent curve progression. With modern spinal
instrumentation and surgical techniques, most patients do not require
post-operative immobilization with braces or casts. In patients with muscular
dystrophy, the curve often increases when walking ability diminishes.
Surgical intervention is indicated for progressive spine deformity in
patients with muscular dystrophy while pulmonary function is still adequate,
i.e., preferably when the curves are less than 30° (Fig.10). Myelodysplasia (spina bifida) often
produces major progressive deformities from both paralytic and congenital
factors, particularly in patients with high levels of paralysis. Progressive
spinal deformity in patients with cerebral palsy often leads to difficulty
with seating and care, especially in patients who do not walk (Fig. 11). |
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Idiopathic
Scoliosis - Infantile; Juvenile; Adolescent Idiopathic
scoliosis is considered in three age groups: Infantile--from birth to three
years of age, juvenile--from greater than three years of age through nine
years of age and, adolescent from 10-18 years of age. The adolescent type is
the most common and represents about 80% of this type of scoliosis. In
addition to the amount of spinal deformity, the patient's physiological age
is assessed, i.e., is growth completed or is there more potential spinal
growth (Fig.12). In the
latter case, potential curve progression is related to the time remaining
until maturity. Curve progression is often associated with degenerative
intervertebral disc disease and degenerative joint disease of the spine in
middle-aged or older patients or may be due to significant previously present
undiagnosed or untreated scoliosis. Idiopathic
scoliosis treatment is patient-age dependent. In patients with infantile
scoliosis (0-3 years) left-sided curves are commonly seen, particularly in
boys and may resolve spontaneously with growth (Fig.13). Observation
treatment is done with repeat evaluation every four to six months. Use of
orthoses (braces) and surgery is uncommon. Juvenile idiopathic scoliosis (3-9
year olds) may rapidly progress especially in children over the age of five
and may require orthotic (brace) management (Fig.14). Surgery is
indicated if the curve is unable to be controlled by orthotic means. Although
surgery in a significantly skeletally immature spine will produce some
decrease in ultimate spine height, it is better to have a shorter spine with
more normal alignment than a progressive curve where height is lost because
of deformity. The most
common of all types of scoliosis is adolescent idiopathic and is seen with
equal frequency in boys and girls at low curve magnitudes. Girls, for unknown
reasons, have a significantly higher risk for development of curve
progression than boys. Pulmonary and cardiac function are not impeded with
lumbar curves and significant changes of pulmonary function are not seen in
patients with thoracic curves until the curve reaches a level greater than
70° , i.e., a severe curve. This amount of curve and subsequent cardiac and
pulmonary changes are often seen later in life in untreated idiopathic
infantile and juvenile scoliosis patients and present a threat to life.
Patients with adolescents onset idiopathic scoliosis do not usually have such
compromise unless severe curves develop. The time of highest risk for curve
progression in adolescent idiopathic scoliosis occurs around puberty, i.e.,
when the growth rate is the fastest. Pulmonary and cardiac function tests
which require patient cooperation may be required to assess lung and heart
function in some cases of severe scoliosis, especially pre-operatively. |
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Treatment
choice in adolescent idiopathic scoliosis is determined by a complex equation
which includes the patient's physiologic (not chronologic) maturity, curve
magnitude and location and potential for progression. Thoracic curves are at
higher risk for progression than thoracolumbar curves or lumbar curves.
Patients whose curves are of consequential magnitude prior to onset of their adolescent
growth spurt are at significant risk for curve progression. Treatment options
include observation, bracing or surgery. General guidelines include
re-evaluation every 4-6 months (often including a PA erect T-L spine
radiograph) for patients who are skeletally immature (but still not fully
skeletally mature) and have curves less than 25° . In patients who are more
skeletally mature with curves less than 45° similar observation should be
carried out to assess any evidence of interval change at 6 months. Brace
(orthotic) management of adolescent idiopathic scoliosis is used in children
with spinal deformity and curve magnitudes of 25-40° who are skeletally
immature and with significant growth remaining. The primary goal of brace
management is to stop curve progression. Any amount of curve correction at
the end of brace treatment must be considered a "bonus." The
orthoses used are usually underarm or higher reaching Milwaukee-type styles (Fig.15). The type of braces and amount of
time the braces are worn daily vary according to the orthopaedist's choice (Fig.16). Brace
removal for participation in sports is strongly encouraged. An alternative to
full-time brace wear is the use of a night time "bending" brace for
management of a single curve. The termination of successful brace use is
determined by the achievement of skeletal maturation, usually indicated by
the patient not having further changes in height (and no curve progression)
and evidence of maturity on skeletal radiographs. Surgery for
idiopathic scoliosis is suggested when curve magnitude is 50° or more in
either the previously untreated patient or in one who fails brace treatment.
Surgery is undertaken with two goals in mind. The primary one is to prevent
spine deformity progression and the secondary one is to diminish spinal
deformity. The natural history of idiopathic scoliosis during adulthood is
one of continued progression if the curves tend to be more than 50° at the
end of growth. The surgical procedure most often used to correct idiopathic
adolescent scoliosis is a posterior spinal fusion with instrumentation and
bone grafting (Fig.17). With
current instrumentation techniques, post-operative casting and bracing are
not required in most idiopathic scoliosis cases. Patients are rapidly
ambulatory and usually discharged from hospital within 5-7 days
postoperatively with progressive resumption of routine daily activities,
including return to school (Fig.18). There is no
scientifically documented role for exercises, manipulation or electrical
stimulation in the management of scoliosis. |
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Diagnosing Similar imaging
guidelines exist as described for scoliosis. With the patient erect,
radiographs are taken to show side-to-side alignment. Spinal radiographs are
sometimes taken with the patient erect and supine are helpful to document
flexibility of a rigid deformity. Specialized imaging studies (CT scan, MRI,
bone scan) are used as required. Clinical Pertinent
historical points include those previously mentioned for scoliosis
assessment. Examination includes the forward bend test and the patient is
viewed from the side to see if the normal spine contours are present (Fig.19). Prominence of the patient's thoracic
kyphosis or failure to reverse their lumbar lordosis with bend requires
further investigation. Postural
"Round Back" Postural
"round back" is defined as an increase in thoracic kyphosis while
standing. Curve flexibility is seen when the patient "stands tall"
or, when prone or supine, the "deformity" resolves (Fig.20). This non-progressive condition is commonly
seen in middle school children, especially girls, and almost always resolves
by itself and requires no specific treatment. Parental "nagging"
should be avoided. Scheuermann's
Disease
Scheuermann's
disease is a condition of unknown cause which produces an increased thoracic
kyphosis (>40° ) with true structural changes within the thoracic vertebra
with 5° of wedging in each of three adjacent vertebrae measured on side-view
radiographs (Fig.21). This localized
deformity is usually painless. Treatment is dependent upon the magnitude of
the deformity, pain complaints and patient maturity. Observation is done for
deformity of less than 60° and brace treatment for curves between 60° and 80°
if the patient is skeletally immature. Surgery is rarely required. A subtype
of Scheuermann's disease occurs in the lumbar spine, usually in male patients
during late adolescence who are involved in heavy lifting tasks. The changes
of the vertebra and disc are considered to reflect the physical stress
effects. Treatment is by elimination of the offending activity. Congenital
Kyphosis/Lordosis Sagittal
plane deformities may be due to congenital defects of vertebral formation or
failure of vertebral segmentation (Fig.22). Deformities due to congenital
vertebral formation failure are predictably progressive and require early surgical
treatment. Because of potential associated renal anomalies, renal
ultrasonographic assessment is recommended. MRI of the spinal canal may also
be needed to rule out associated spinal cord abnormalities (Fig.23). Summary Spinal
deformity is due to a myriad of causes. Scoliosis, kyphosis and lordosis are
descriptive and not diagnostic terms and efforts must be made to establish
the deformity's cause. The etiology of the most common type of spinal
deformity, adolescent idiopathic scoliosis, is unknown, but it is strongly
familial. Initial radiographic examination for scoliosis requires a standing
back-to-front (PA) thoracolumbar spine radiograph on a single film. Sagittal
plane concerns are evaluated by side view radiographs (Fig.24ab). Treatment
varies according to the deformity's cause, location, magnitude, patient
maturity and evidence of progression. Treatment decisions are based
on a complex equation taking such factors into account. Modern bracing
techniques provide cosmetic braces which allow patients to continue
their routine activities including sport participation. Modern methods
of surgical management allow for patients' rapid mobilization and return
to routine daily activity. |
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