Scoliosis and Spinal Deformity Flashcards
Which one of the following statements about angle X is LEAST accurate?
a. Only applies to coronal plane deformity
b. Requires identification of proximal and
distal end vertebrae
c. The largest angle defines the major (structural) scoliosis curve
d. Can be reduced in a non-structural curve by side bending
e. Is a reflection of the sagittal balance
a. Only applies to coronal plane deformity
The Cobb angle (X) is obtained on the frontal PA
radiograph and is calculated by finding the vertebrae that are maximally tilted at the cranial and caudal portions of the curve being evaluated (proximal and distal end vertebrae). Lines are drawn parallel to the superior endplate of the proximal end vertebrae and parallel to the inferior endplate of the distal end vertebrae; 90° perpendicular lines are then drawn for each of these lines so that they intersect. The angle created by these two intersecting lines is the Cobb angle. The apex of a curve is the most lateral vertebral body on frontal radiographs and is considered cervical if its apex is between C2 and C6, cervicothoracic if between C7 and T1, thoracic if between T2 and T11, thoracolumbar if between T12 and L1, lumbar if between L2 and L4, or lumbosacral if at L5 or below. While there should not be any curve in the coronal place normally, the sagittal Cobb angle can be used to measure normal cervical lordosis, thoracic kyphosis and lumbar lordosis (40-60°) using a lateral radiograph.
Which one of the following statements
regarding development of scoliosis in patients with neuromuscular disorders is most accurate?
a. Neuromuscular curves tend to be longer and involve more vertebrae than idiopathic scoliosis curves
b. Neuromuscular curves form due to the
Heuter-Volkmann principle
c. Neuromuscular scoliosis tends to develop later than most cases of idiopathic scoliosis
d. Neuromuscular spinal deformities are
less likely to progress in severity
e. Neuromuscular curves are rarely associated with pelvic obliquity
a. Neuromuscular curves tend to be longer and involve more vertebrae than idiopathic scoliosis curves
The Heuter-Volkmann principle states that
decreased loading across an epiphyseal growth
plate inhibits growth and increased pressure tends
to accelerate growth, hence imbalance of forces
across vertebral end plates due to neuromuscular
disease results in scoliosis. A wide spectrum of spinal deformities may develop including scoliosis
(most common), hyperkyphosis, hyperlordosis,
and complex multiplanar deformities. Neuromuscular curves are typically long, sweeping C-shaped curves that extend to the pelvic region. The curve apex is usually in the thoracolumbar or lumbar region. When secondary curves develop, they are usually unable to restore coronal balance. Significant sagittal plane deformity often accompanies coronal plane deformity. Pelvic obliquity is common and poses a major problem because it creates an uneven sitting base. Neuromuscular scoliosis develops at an earlier age than most cases of idiopathic scoliosis, often before age 10 and are more likely to progress
in severity due to the early age of onset of neuromuscular disease.Neuromuscular causes of scoliosismay be myopathic or neuropathic. Myopathic causes include muscular dystrophies (Duchenne, limbgirdle, and fascioscapulohumeral),myotonic dystrophy and congenital hypotonia. Neuropathic causes
may be upper motor neuron (cerebral palsy, Friderich’s ataxia, syringomyelia, quadriplegia), lower motor neuron (spinalmuscular atrophy, poliomyelitis, dysautonomia) or mixed. The prevalence of spinal deformities in different neuromuscular diseases is variable: cerebral palsy (25%), myelodysplasia (60%), spinal muscular atrophy (67%), Friedreich’s ataxia (80%), Duchenne’s muscular dystrophy (90%), and spinal cord injury before 10 years of age (100%).
Which one of the following statements
regarding management of neuromuscular scoliosis is LEAST accurate?
a. Neuromuscular curves do not respond
well to orthotic treatment, and spinal surgery is frequently required
b. Observation is reasonable for patients with small curves (30°)
c. Surgery is not recommended before the age of 5
d. Earlier surgical treatment is advised for
patients with Duchenne’s muscular
dystrophy (when curves reach 20°)
e. Curves up to 90° are most commonly
treated with posterior spinal instrumentation and fusion
c. Surgery is not recommended before the age of 5
Evaluation of neuromuscular scoliosis requires
assessment of the spinal deformity as well as multidisciplinary evaluation of underlying neuromuscular disease (e.g. developmental, seizures,
musculoskeletal, infections). Observation is
reasonable for curves <30°, large curves without
functional loss in severe developmental disability, and those not fit for major spinal reconstructive surgery. In most cases of neuromuscular
scoliosis, a spinal orthosis will not prevent curve
progression but serves to (i) help nonambulatory
patients to sit and (ii) slows progression of spinal
deformities until the onset of puberty (permits
growth of the spine prior to definitive treatment
with spinal instrumentation and fusion).
Orthotic management is challenging in neuromuscular disorders because of poor muscle control, impaired sensation, pulmonary
compromise, impaired gastrointestinal function,
obesity, and difficulty with cooperating with
brace wear. In general, operative treatment is
considered when progressive curves exceed 40°
or when patients develop trunk decompensation,
and there is no absolute minimum age to consider surgery. Earlier surgical treatment is
advised for patients with Duchenne’s muscular
dystrophy (when curves reach 20°) due to predictable pulmonary deterioration associated with further curve progression. It is not necessary to delay surgery until skeletal maturity. Curves up
to 90° are most commonly treated with posterior
spinal instrumentation and fusion. Curves
exceeding 90° or curves with severe stiffness
are considered for more complex procedures.
Combined anterior (i.e. ATDF - anterior thoracic discectomy and fusion) and posterior
approaches may help deformity correction,
enhance fusion and avoid the crankshaft phenomenon (by destroying anterior growth plates
in skeletally immature patients).
Which one of the following statements aboutvinfantile idiopathic scoliosis is LEAST accurate?
a. Idiopathic adolescent curves are commonly right thoracic, whereas infantile scoliosis curves are left sided
b. Genetic testing for scoliosis curve
progression is currently not available
c. Infantile scoliosis commonly affects girls, whereas adolescent idiopathic scoliosis predominantly affects boys
d. Infantile scoliosis is associated with
plagiocephaly
e. A rib vertebral angle (RVA) of >20°
is associated with curve progression
c. Infantile scoliosis commonly affects girls, whereas adolescent idiopathic scoliosis predominantly affects boys
The criterion for diagnosis of scoliosis is a coronal
plane spinal curvature of 10° or more as measured
by the Cobb method. Curves less than 10° are
referred to as spinal asymmetry. MRI spine including craniocervical junction is required to exclude
CNS causes (e.g. syrinx, Chiari malformation,
tethered cord). Idiopathic scoliosis is defined as a
spinal deformity characterized by lateral bending
and fixed rotation of the spine in the absence of
any known cause. Idiopathic scoliosis is classified
according to age at onset into infantile (birth-3
years), juvenile (3-10 years), and adolescent (after
10 years) subtypes. An alternative classification
distinguishes early-onset scoliosis (0-5 years) from
late-onset scoliosis (after 5 years) due to increased
cardiopulmonary risk associated with early-onset
scoliosis due to rapid curve progression. In general, the younger the age at diagnosis, the more
likely the deformity will progress and require
treatment. Infantile idiopathic scoliosis is common in Europe but rare in the USA, and is characterized by male predominance, commonly a left
thoracic curve, and is associated with plagiocephaly, developmental delay, congenital heart disease, and developmental hip dysplasia; it is divided into resolving (85%) and progressive
(15%) types, with progression likely in those with
a rib-vertebral angle difference >20° and increasing rib phase (overlap of rib head and apical vertebral body). Resolving curves are observed with
advice to sleep in the prone position. Progressive
curves are treated with serial derotational (plaster)
casting followed by orthotic treatment with a Milwaukee brace. Curves that continue to progress
despite orthotic treatment require surgery.
Growth preserving options (permit delay of definitive fusion until the child has achieved additional growth) include posterior spinal instrumentation without fusion or the vertically expandable prosthetic titanium rib. Posterior spinal instrumented The criterion for diagnosis of scoliosis is a coronal plane spinal curvature of 10° or more as measured by the Cobb method. Curves less than 10° are referred to as spinal asymmetry. MRI spine including craniocervical junction is required to exclude CNS causes (e.g. syrinx, Chiari malformation, tethered cord). Idiopathic scoliosis is defined as a spinal deformity characterized by lateral bending and fixed rotation of the spine in the absence of any known cause. Idiopathic scoliosis is classified according to age at onset into infantile (birth-3 years), juvenile (3-10 years), and adolescent (after 10 years) subtypes. An alternative classification distinguishes early-onset scoliosis (0-5 years) from late-onset scoliosis (after 5 years) due to increased cardiopulmonary risk associated with early-onset scoliosis due to rapid curve progression. In general, the younger the age at diagnosis, the more
likely the deformity will progress and require
treatment. Infantile idiopathic scoliosis is common in Europe but rare in the USA, and is characterized by male predominance, commonly a left
thoracic curve, and is associated with plagiocephaly, developmental delay, congenital heart disease, and developmental hip dysplasia; it is divided into resolving (85%) and progressive
(15%) types, with progression likely in those with
a rib-vertebral angle difference >20° and increasing rib phase (overlap of rib head and apical vertebral body). Resolving curves are observed with
advice to sleep in the prone position. Progressive
curves are treated with serial derotational (plaster)
casting followed by orthotic treatment with a Milwaukee brace. Curves that continue to progress
despite orthotic treatment require surgery.
Growth preserving options (permit delay of definitive fusion until the child has achieved additional growth) include posterior spinal instrumentation without fusion or the vertically expandable prosthetic titanium rib. Posterior spinal instrumented
Which one of the following statements
regarding juvenile idiopathic scoliosis is
LEAST accurate?
a. It shows increasing female predominance with older ages
b. Refers to scoliosis presenting at age
4-10 years
c. The majority of curves require treatment
d. Surgical treatment is usually considered when curves reach 50-60°
e. Single-staged posterior fusion procedures are the preferred surgical treatment
e. Single-staged posterior fusion procedures are the preferred surgical treatment
Juvenile idiopathic scoliosis represents a gradual
transition from the characteristics of infantile idiopathic scoliosis to those of adolescent idiopathic scoliosis. It is less common than adolescent idiopathic scoliosis, increasing female predominance is noted with increasing age from 4- to 10-yearolds, and right thoracic and double major curve types are commonest. Approximately 70% of curves progress and require some forms of treatment (bracing or surgery). Orthotic treatment is initiated for curves in the 25-50° range. Surgical
treatment is considered when curve magnitude
exceeds 50-60°. Surgical decision making is complex in view of the wide age range of patients presenting in this group. Major concerns include the effect of treatment on remaining growth and
potential for development of crankshaft phenomenon if a single-stage posterior fusion procedure is performed. Dual growing rod instrumentation is considered for early juvenile scoliosis patients.
Combined anterior and posterior fusion with
posterior instrumentation is an option for older
patients.
Which one of the following statements
regarding adolescent idiopathic scoliosis is most accurate?
a. Lumbar and thoracolumbar curves are
more likely to progress than thoracic
curves because they lack the inherent stability provided by the rib cage
b. It is commoner in females and tends to
have a right thoracic curve
c. Female sex is not a risk factor for curve
progression
d. Genetic risk stratification is not an option
e. Curves measuring 50-75° at maturity
progress steadily at a rate of approximately 5° per year
b. It is commoner in females and tends to have a right thoracic curve
Adolescent idiopathic scoliosis is the most common type of scoliosis in children (prevalence is 3% in the
general population), but few adolescent patients
(0.3%) develop curves requiring treatment. Commonly patients are female (especially larger curves), have a right thoracic curve and do not have severe pain. Risk factors for curve progression in skeletally immature patients are future growth potential (e.g. age at onset, Risser stage, Tanner stage, menarche, peak height velocity, triradiate physeal closure, skeletal age as determined by hand radiographs), curve
magnitude, curve pattern, female sex and genetic
risk score. Curves measuring less than 30° at maturity are least likely to progress. Curves measuring 30-50° are likely to progress an average of 10-15° over the course of a normal lifetime. Curves measuring 50-75° at maturity progress steadily at a rate of approximately 1° per year. Lumbar and thoracolumbar curves are more likely to progress than thoracic curves because they lack the inherent stability provided by the rib cage.
Which one of the following statements
regarding the management of adolescent idiopathic scoliosis is LEAST accurate?
a. Untreated adult patients with a history of adolescent idiopathic scoliosis do not have increased mortality
b. In the absence of hypokyphosis, cardiorespiratory complications occur with curves of 90° or more
c. Bracing is contraindicated in the presence of skeletal maturity
d. Observation is appropriate for curves less than 20°
e. Skeletally mature adolescents with curves of >30° should undergo posterior instrumented fusion
e. Skeletally mature adolescents with curves of >30° should undergo posterior instrumented fusion
The mortality rate of untreated adult patients
with adolescent idiopathic scoliosis is comparable
with that of the general population, unlike those
with early-onset scoliosis (before age 5) who
develop severe curves (90°) with cor pulmonale
and right ventricular failure, resulting in premature death. Common reasons for presentation
are back pain and cosmesis. The treatment
options for adolescent idiopathic scoliosis include
observation, orthoses, and operation. The
purpose of observation for adolescent idiopathic
scoliosis is to identify and document curve progression and thereby facilitate timely intervention. Bracing aims to prevent progression, and the general types of orthoses used for adolescent idiopathic scoliosis are CTLSO (Milwaukee brace, most efficacious for curve apex above T8), TLSO (e.g. Boston brace; curves with an
apex at T8 or below; better tolerated), bending
brace and flexible brace. Contraindications to
brace treatment include skeletal maturity, curves
>40°, thoracic lordosis (worsens cardiopulmonary restriction), not tolerating. Surgical decision
making is based on the coronal Cobb angle, sagittal plane alignment, rotational deformity, the
natural history of the patient’s curve, and the
patient’s skeletal maturity
Which one of the following statements
regarding the Lenke classification of scoliosis curves is LEAST accurate?
a. There are six types based on the number of structural and non-structural curves present
b. It does not take into account thoracic kyphosis
c. Curve types are subclassified by the relationship of the center sacral vertical line to the lumbar spine
d. Curve classification takes the form of
curve type, lumbar modifier and thoracic
sagittal modifier
e. Cervical curves are not included in the
classification
b. It does not take into account thoracic kyphosis
The Lenke classification is based on assessment
of PA, lateral, and side-bending radiographs
(the latter aim to distinguish structural from
non-structural curves) and measuring the Cobb
angle of all curves present; the curve with the
largest Cobb angle is the major curve, which is
always structural, while other minor curves can
be classified as structural or non-structural on
the basis of Cobb angle >25° on side bending
films and degree of kyphosis. Various combinations at proximal thoracic, main thoracic and thoracolumbar/lumbar levels result in 6 curve
types: (1) main thoracic, (2) double thoracic,
(3) double major, (4) triple major, (5) thoracolumbar/lumbar, and (6) thoracolumbar/lumbar-main thoracic. Next, a lumbar spine modifier is applied
depending on the relationship of the center
sacral vertebral line to the lumbar spine: (A)
between pedicles, (B) touches apical body, and
(C) completely medial. Finally, a thoracic sagittal
modifier describes degree of T5-T12 kyphosis:—
(hypo) if <10°, N (normal) if 10-40°, and +
(hyper) if >40°. The classification takes the form
of (1-6) + (A, B or C) + (, N, +), e.g. 1BN.
A 12-year-old girl with scoliosis was found to have a fluid-filled cavity within the spinal cord on a routine preoperative MRI scan. Which one of the following statements is LEAST accurate?
a. There is an increased risk of neurological deficit with spinal distraction and instrumentation in this patient
b. A left-sided thoracic curve is more likely in this patient
c. Scoliosis is reported in 25-85% of
syringomyelia cases.
d. She may have abnormal abdominal reflexes
e. Decompression of the syrinx causes improvement of the scoliosis in most cases
e. Decompression of the syrinx causes improvement of the scoliosis in most cases
Syringomyelia, a fluid-filled cavity within the spinal cord, may lead to scoliosis that can be mistakenly attributed to idiopathic scoliosis. Associated
spinal curvature has been reported in 25-85%.
Syrinx related curves are rapidly progressive,
atypical and usually left sided, and associated with
abnormal abdominal reflexes. Other musculoskeletal features include pes cavus, wasting of intrinsic hand muscles and Charcot joints. A symptomatic syrinx requires surgical treatment, which may improve neurologic deficits and prevent curve progression. Surgical treatment (spinal distraction and instrumentation) of scoliosis without recognition of syringomyelia can result in
increased neurological complications.
Which one of the following statements
regarding adult scoliosis is most accurate?
a. Type 1 adult scoliosis is associated with degenerative disease of the spine
b. Curves 30-50° at skeletal maturity progress on average 3° per year
c. Curves between 50° and 75° progress at an average of 5° per year.
d. Leg length discrepancy is a cause of Type 2 adult scoliosis
e. Adult idiopathic scoliosis generally does not progress if curves are less than 50°
a. Type 1 adult scoliosis is associated with degenerative disease of the spine
Adult scoliosis can be divided into type 1 adult
scoliosis, which is degenerative; type 2 idiopathic
adolescent scoliosis, which progresses into adulthood; and type 3 secondary adult scoliosis, which may be due to a leg length discrepancy, hip
pathology, or may be secondary to a metabolic
bone disease such as osteoporosis combined with
asymmetric arthritic disease. Adult idiopathic
scoliosis: curves <30° generally do not progress,
curves 30-50° progress 10-15° during life, and
curves 50-75° progress at 1° per year. Degenerative scoliosis usually develops after the age of 50 and is typically associated with disk degeneration, facet arthritis, thickening/hypertrophy of the
ligamentum flava, loss of lumbar lordosis, and lateral listhesis. Degenerative scoliosis can lead to
neurogenic claudication, radicular pain, and
back pain.
Which one of the following statements
regarding congenital scoliosis is LEAST
accurate?
a. The defect arises between weeks 4 and 6 of embryogenesis.
b. Fully segmented hemivertebrae results in rate of progression of 5° per year
c. Block vertebrae are defects of segmentation
d. Wedge vertebrae are defects of formation
e. Incarcerated hemivertebrae produce little or no spinal deformity
b. Fully segmented hemivertebrae results in rate of progression of 5° per year
Congenital scoliosis is due to vertebral anomalies
that produce a frontal plane growth asymmetry.
The anomalies are present at birth, but the curvature may take years to become clinically evident.
During weeks 4-6 of the embryonic period.
Defects of segmentation include block vertebra
(bilateral failure of segmentation), unilateral bar
alone, or unilateral bar with contralateral hemivertebra. Defects of formation include hemivertebra (unilateral complete failure of formation) or wedge vertebra (unilateral partial failure of formation). Most rapidly progressive deformities are unilateral unsegmented barhemivertebra at 5-6° per year. Fully segmented hemivertebra progresses at 1-2° per year. Semi-segmented, incarcerated, and non-segmented hemivertebrae produce little or no deformity.
Which one of the following is NOT included in the VACTERLS association?
a. Eye abnormalities
b. Tracheo-esophageal fistula
c. Cardiac abnormalities
d. Single umbilical artery
e. Anorectal abnormalities
a. Eye abnormalities
VACTERL association is usually defined by the presence of 3 of: vertebral, anorectal, cardiac, tracheo-esophageal fistula, renal abnormalities and limb dysplasia. Extensions of the association include lung abnormalities and single umbilical artery, amongst others.
A 15-year-old presents with back pain and kyphotic deformity in the thoracic spine with a Cobb angle of 60° between T5 and T12. He is unable to correct the deformity by active extension. Sagittal CT spine is shown. Which one of the following statements regarding
this condition is LEAST accurate?
a. The condition is often accompanied by a lumbar hyperlordosis
b. This is the most common cause of
thoracic back pain in adolescents
c. MRI spine should be performed
preoperatively
d. Extension bracing is not appropriate even in skeletally immature patients
e. Ligamentum flavum excision should be
performed at the apex of the curve during surgery
d. Extension bracing is not appropriate even in skeletally immature patients
Scheuermann’s kyphosis is a kyphotic deformity
of >45° in the thoracic spine with >5° of anterior wedging across three consecutive vertebrae, and
is the commonest cause of thoracic back pain in
children and adolescents. The exact cause is
unknown but may involve avascular necrosis of
the vertebral body ring apophysis. Type I
Scheuermann’s kyphosis is a rigid, angular
thoracic kyphosis and has a hereditary component while type II is thoracolumbar, more painful, and affects predominantly athletes and
laborers. A male or female approaching the
end of skeletal growth presents with back deformity and/or pain. The increased thoracic kyphosis is accentuated with forward-bending, but not corrected by active extension (unlike in postural kyphosis). The condition is often associated with a lumbar hyperlordosis. Other radiological features include vertebral endplate irregularities, Schmorl’s nodes, and decreased disk space height are additional radiographic findings that may be present. An MRI scan is indicated to look for disk herniation, cord abnormalities and spinal stenosis. Extension bracing is appropriate
for curves between 45° and 74° with 2 years of
growth remaining and greater than 5° wedging.
An apex at T9 or above is traditionally treated
with a Milwaukee type brace. A thoracolumbar
orthosis (TLSO) is considered if the apex is
below T9. Braces should be updated every 4-6
months to maximize deformity correction and
weaned with skeletal maturity. Indications for
surgery include (1) skeletally immature adolescent patients with painful kyphosis >75° with
local wedging >10° not responsive to 6 months
of bracing, (2) skeletally mature patients with
painful deformity resistant to bracing, (3) curves
>80° in skeletally mature patients. Surgery
entails a posterior spinal fusion with dual-rod
instrumentation/anterior release and interbody
fusion. The fusion level should stop distally at
the vertebra which is parallel to the floor (usually
the L3 level). A ligamentum flavum excision
should be performed at the apex to prevent
buckling of the ligament and therefore decrease
the risk of neurological deficit.
