Scoliosis Flashcards
What is Scoliosis?
A complicated deformity, characterised by both lateral curvature and vertebral rotation.
As the disease progresses:
- the vertebrae and spinous processes of the major curve rotate toward the concavity of the curve
- ribs follow the rotation of the vertebrae
Concave side of the curve:
- ribs close together
- the anterior ribs pushed anteriorly.
Convex side:
- ribs widely separated
- the posterior ribs pushed posteriorly, causing the characteristic rib hump seen in thoracic scoliosis.
A significant lateral deviation (more than 10° ) of the spine with vertebral rotation within the curve
Remember: True scoliosis is not only a deformity in the coronal plane, but it is also a rotational deformity.
Scoliosis curves most common in thoracic spine
Diagnosed in childhood or early adolescence with the primary age of onset being 10-15 years old
A Cobb angle of <10°:
- asymptomatic
- does not progress
Treatment:
- smaller curves do not require treatment
- larger curves require a brace or surgery to restore normal posture
What is Dextroscoliosis?
Curve convex to right
What is Levoscoliosis?
Curve convex to left
What is Kyphoscoliosis?
Scoliosiswith component of kyphosis
What is S-Curve Scoliosis?
3 adjacent curves (1 to right, 1 to left and 1 at lumbosacral junction)
What is Primary curve (Aka major curve or structural curve) ?
The most pronounced curve where the main structural abnormality is present
What is Secondary curve (Aka minor curve or non-structural curve)?
Less pronounced compensatory curves that develop above and/or below the primary curve to maintain balance
What is the Apex?
The vertebral body or disc space demonstrating the greatest rotation and/or furthest deviation from the expected centre of the vertebral column. The endplates of the apical vertebra are often horizontal or near horizontal.
What is the end vertebrae?
The vertebrae most tilted towards each other and present on either side of the apex. They form the basis of the Cobb angle.
What is neutral vertebrae?
Present on either side of the apex with no rotation (axial plane). In some cases, they are like end vertebrae but never closer to the apex than the end vertebrae.
What is stable vertebra?
The first vertebra below the lowest curve, roughly bisected by the central sacral vertical line
What type of curve is a primary curve?
first to develop
At the time of diagnosis, it is not always possible to differentiate primary curves from secondary curves.
structural
largest curve
not correctable with ipsilateral bending
vertebral morphologic changes (E.G wedging)
May progress
Usually > 25 degrees
What type of curve is a secondary curve?
develop to balance the head and trunk over the pelvis, in the frontal and the sagittal plane.
At the time of diagnosis, it is not always possible to differentiate primary curves from secondary curves.
compensatory curve
smaller curve
non structural
correctable with ipsilateral bending
doesn’t usually progress
usually <25 degrees
What type of curve is a structural curve?
Do Not correct with side-be
What type of curve is a non-structural curve?
can be secondary curves - postural, secondary to short leg or muscle spasm.
What is cobb angle?
measured between the superior endplate of the proximal end vertebra and the inferior endplate of the distal end vertebra
most consistent despite inter-examiner variability
Two lines are drawn on a PA spinal radiograph
one extending from the top of the most tilted upper vertebra and the other from the bottom of the most tilted lower vertebra.
The angle formed by these lines is the Cobb angle.
What is risser-ferguson method?
First line originating at the centre of the upper end-vertebra
Second line from the centre of the lower end-vertebra
Angle formed by the intersection of two lines at the centre of the apical vertebra gives the DEGREE OF CURVATURE
tell me about cobbs vs risser-ferguson
Risser’s method - only used on congenital curves
Cobb’s method - preferred method
Cobb’s is more consistent inter- and intra-examiner reliability of measurement.
Cobb’s gives higher measurement (5-10° or 25%)
Regardless of which method is used it is essential that the same vertebral levels are used on subsequent examinations for follow-up
Radiograph must be produced with patient in same position as initial study
(So need standardized positioning protocol)
What is pedicle rotation?
After measuring the angle of curvature, estimate the degree of rotation of the vertebra at the apex of the curve by looking at the relation of the pedicles to midline.
GRADE 0: No pedicle rotation.
GRADE 1: Pedicle visible between the lat. edge of the VB & midline.
GRADE 2: Pedicle of the convexity visible just lateral to the center line.
GRADE 3: Pedicle of the convexity overlaps the center line.
GRADE 4: Pedicle is rotated past center line.
What is the Skeletal Maturity: Iliac Apophysis (Risser’s sign)?
Determine the physiological or skeletal maturity of the patient to treat patients effectively as Skeletal maturity and chronological age do not necessarily match.
The iliac crests provide a convenient index of skeletal maturity.
Appears 16 M, 14 F
Grows progressively toward PSS - Lat-med
Grades 1-4 within 1yr (capping)
Grade 5 or fusion takes 2-3yrs after capping
When the iliac crest apophyses meet the sacroiliac junction and firmly seal to the ilium, maturation is nearly complete.
once skeletal maturity has been reached, curvature below 30 degrees do not progress
What is the skeletal maturity - Left Hand & Wrist – Greulisch &Pyle ?
A single AP view of the left hand and wrist to estimate skeletal maturity
Patients under 20 yoa
Important in planning treatment regime
What is the vertebral maturity: Vertebral Ring Apophysis?
Look for evidence of maturation in the VBs at the endplates.
When the plates blend in with the VB to form a solid union, maturation is complete.
What are the different types of scoliosis?
Structural (Non-functional):
- Idiopathic
- Congenital
- Degenerative
- Neuromuscular
- Post-traumatic
2. Non-structural (Functional)
- postural scoliosis
- compensatory scoliosis
- due to muscle spasm (secondary to lumbar or thoracic injuries) or leg length discrepancy(causing a lateral shift in the spine)
3. Transient structural scoliosis
- sciatic scoliosis
- hysterical scoliosis
- inflammatory scoliosis
tell me about Structural Scoliosis : Idiopathic Scoliosis
Unknown cause
most common type of scoliosis
usually diagnosed during puberty
Equal prevalence in boys and girls though curves greater than 30° that require treatment is more prevalent in girls than boys (ratio 1:8)
Does not require surgical intervention
Further divided into:
infantile idiopathic scoliosis – 0 – 3 years of age
juvenile idiopathic scoliosis – 4 – 10 years of age
Adolescent idiopathic scoliosis – >10 years of age
Tell me more about infantile idiopathic scoliosis?
Presents as a left thoracic curve in 90% of cases
The male/female ratio is 3:2
Tell me more about juvenile idiopathic scoliosis?
The male/female ratio is 1:2 to 1:4
Boys are more affected between 3 and 6 years of age (1:1)
Girls are more affected between 6 and 10 years of age (1:8)
The number of right and left curves is equal in the younger group (<6 years at presentation)
Right curves predominate in the older group (80%).
What is adolescent idiopathic scoliosis?
A structural lateral curvature of the spine between 10 and 18 yoa
- m/c a thoracic curve with right-sided convexity, with or without a compensatory lumbar curve with left-sided convexity.
The diagnosis is confirmed when a 10° lateral curvature is present on a frontal upright radiograph.
MR imaging - for the evaluation of an unusual pattern of curvature, associated with neuropathy or a curve with an early onset, unusually rapid progression, and neurologic deterioration at follow-up
Curvatures <50° - same incidence of back pain and mortality as in the general population
Curvatures >50° - greater prevalence of back pain.
Thoracic curvatures >100° - affect lung function and increased mortality rate compared with the general population
Treatment - varied and includes observation, bracing, and surgery.
- Bracing - limited effectiveness
- for curves between 25° and 40° (skeletally immature patients)
- successfully prevent curve progression in 75% population
tell me about congenital scoliosis
Most frequent congenital spinal deformity present at birth which can first be identified on foetal ultrasound
Further divided into:
Incomplete or failure of formation of vertebrae (Hemivertebra)
Failure of separation/segmentation of vertebrae (Block vertebra)
Combination of both above/Mixed congenital syndromes (Klippel-Feil, caudal regression etc)
Treatment based on:
- patient age
- progression of curve
- location & type of anomaly
what is incomplete formation of vertebrae?
Hemivertebra – where part of one (or more) vertebra may not form completely at birth
- produces a sharp angle in the spine
What is a failure of separation of vertebrae?
Where the spine fails to separates into vertebral segments resulting in partial fusion (joining two or more vertebrae together)
What is Combination of Bars and Hemivertebrae?
Combination of 1 and 2 above occurring together causing growth problems and requiring surgery at an early age to stop the increased curvature of the spine
What is Degenerative Scoliosis (AKA Adult Scoliosis)?
Affects adults (>50 years ofage)
M/c in the lumbar spine but other curve patterns may occur
Often associated with hypolordosis and coronal plane decompensation
Asymmetric degenerative change of the discs or facet joints leading to asymmetric biomechanical forces that result in additional asymmetric disc space collapse and eventual lateral listhesis and segmental rotator listhesis between lumbar segments
A common cause of back pain and disability - associated with foraminal, lateral root compression or claudication due to central, foraminal, or subarticular spinal stenosis
Further divided into:
1. Type 1 - primarily degenerative.
- caused most frequently by a disc or facet joint arthritis
2. Type 2 - progression of adolescent scoliosis in adulthood
3. Type 3 - secondary scoliosis mostly caused by osteoporosis
Surgical treatment - primarily neural decompression and correction of truncal balance
What are the 3 types of Degenerative Scoliosis (AKA Adult Scoliosis)?
Type 1 - primarily degenerative.
- caused most frequently by a disc or facet joint arthritis
2. Type 2 - progression of adolescent scoliosis in adulthood
3. Type 3 - secondary scoliosis mostly caused by osteoporosis
What is Neuromuscular Scoliosis?
Secondary to neurological or muscular diseases e.g., cerebral palsy, spinal cord trauma, muscular dystrophy, spinal muscular atrophy and spina bifida.
Generally, progresses more rapidly than idiopathic scoliosis
often requires surgical treatment
Spinal curvature without rotation – other diagnoses apart from idiopathic scoliosis must be considered
What is post-traumatic scoliosis?
Vertebral Fracture
Radiation
Surgical
Micro-trauma (Spondylolisthesis)
Degenerative
Extraspinal contractures (post-burns)
What is Non-Structural Scoliosis?
Generally non-progressive
Milder curves and usually a minor curve
Less rotational component
No structural alterations
Correction on lateral bending
Due to:
Postural
Hysterical
Antalgic – Disc herniations / Nerve root irritation
Inflammatory - Inflammatory bowel disease, appendicitis
LLD (leg-length deficiency) – extraspinal cause
Hip contractures
When diagnosing scoliosis, what is the patient history components to consider?
Age of onset
Evidence of maturation
Presence of back pain
Neurological symptoms, including abnormalities, weakness or sensory changes
Feelings about overall appearance and back shape
Family history
When diagnosing scoliosis, what is the physical examination components to consider?
Height measurement
Gait check
Foot shape
Neurological examination including motor, sensory and reflex testing (including abdomen)
Skin inspection
Assessment of pubertal development
Symmetry of shoulders and iliac crest
Forward bending test
What are signs of scoliosis?
Uneven shoulders
Head not cantered directly above the pelvis
One or both hips raised or unusually high
Rib cages at different heights
Uneven waist
The appearance or texture of the skin overlying the spine changes (dimples, hairy patches, colour abnormalities)
The entire body leaning to one side
What are the symptoms of scoliosis?
Back pain or stiffness
Diminishing pulmonary function (e.g., difficulty breathing)
Pain and numbness in legs
What are the four basic spinal parameters evaluated in scoliosis?
Curvature
rotation
flexibility
skeletal maturation
Allradiographic scoliosis imaging should be reported according to the scoliosis reporting template with all the individual components described . What are the Locally agreed standards?
Indicate number of curves
Identify each apical vertebra and whether right or left side curved
Quantify the Cobb angle for each curve
Comment on rotation
Comment on shoulder asymmetry
Assess skeletal maturity (Risser staging)
Comment on presence of vertebral abnormality
Save key image with Cobb angle(s)
Any recommendations for further imaging
How do you take the cobb angle?
Choose the most tilted vertebrae, toward the concavity, above and below the apex of the curve (i.e., the of the curve)
The angle between intersecting lines drawn perpendicular to the superior endplate of the superior-end vertebra to the inferior endplate of the inferior-end vertebra = the Cobb angle.
When reporting the angle, REMEMBER to mention that the Cobb method is being used and STATE the end vertebrae used for the measurement.
Once chosen, the same levels should be used to measure curvature on follow-up radiographs.
NOTE: If endplates are difficult to visualize, the borders of the pedicles may be used.
What does a cobb angle of 0-10 degrees indicate?
Spinal curve
What does a cobb angle of 10-20 degrees indicate?
Mild scoliosis
What does a cobb angle of 20-40 degrees indicate?
Moderate scoliosis
What does a cobb angle of >40 degrees indicate?
Severe scoliosis
What is the risser-ferguson method?
In this method of scoliotic curvature is determined by the angle formed by the intersection of two lines at the centre of the apical vertebra
The first originating at the centre of the upper end vertebra and the other at the centre of the lower end vertebra
What is the skeletal maturation?
Iliac apophyses appear first at ASIS
Ossification travels medially to the PSIS
Boys – 16 yoa; Girls – 14 yoa
LIMITATION: far less reliable in boys as ossification starts at a later age than girls. THEREFORE, in boys, growth not considered complete until grade 5 ossification is achieved.
The crest is divided into four equal parts:
- Grade 1 – 4 = EXCURSION
- excursion of the ossified apophysis takes approximately 1 year
- Grade 4 = complete excursion of the ossified apophysis of the iliac crest = completion of spinal growth and cessation of curve progression in girls
- Grade 5 = FUSION
- fusion of the ossification centre to the iliac crest takes another 2 years
What is sagittal balance?
Describes the relationship of the head relative to the pelvis in the sagittal plane.
Measured on a standing lateral view by dropping a plumb line from the centre of the C7 vertebral body vertically downward and assessing the distance of this line from the posterior aspect of the S1 vertebral body
Restoration of sagittal balance improves the success rate of scoliosis surgery
RESULTS:
1. Neutral sagittal balance (Healthy patients)
- Plumb line intersects the sacral landmark
2. Positive sagittal balance
- Plumb line >2 cm anterior to the posterior aspect of the S1 vertebral body
- Patients present with back pain (likely to be fatigue pain due to truncal muscles, hips, knees, and thighs under continual strain to keep head in line with the shoulders and hips and over the feet)
- “flat-back” deformity due to loss of normal lumbar lordosis and resultant forward-tilting posture (e.g., flexed hips and knees to maintain an erect posture)
3. Negative sagittal balance
- Plumb line is 2 cm posterior to the sacral landmark
What is coronal balance?
Coronal balance is measured on an upright anteroposterior view.
A plumb line is dropped vertically from the centre of the C7 vertebral body.
This usually intersects with the central sacral vertical line.
Positive and negative coronal balance are present when this plumb is line is greater than 2 cm to the right and left, respectively.
The restoration of coronal balance reduces several cosmetic deformities including having one shoulder higher than the other.
What are the treatment options for scoliosis?
The treatment options for scoliosis:
Conservative:
Curve measuring <20°:
- Observe / Active monitoring
- monitor regularly with imaging to check curve progression
- Information class
Curve measuring <20° - 40°:
- Orthoses e.g., brace
- Physiotherapy
- Surgical:
Curve measuring >40°:
- Surgery + postoperative rehabilitation.
What are the causes of structural scoliosis?
Idiopathic (70%) - infantile, juvenile and adolescent
Congenital (10%) - Failure in vertebral formation, failure in vertebral segmentation or combination of the two
Trauma
Extra spinal contractures
Bone infection
Lung disease: previous h/o empynema, fibrosis or pneumonectomy
Neurofibromatosis
Rheumatoid disease
What are the causes of non-structural scoliosis?
Postural
Nerve root irritation - herniation of nucleus pulposus / tumours
related to leg length discrepancy
related to contractures of the hip
An increase in the Cobb angle by 5° or more per year indicates progression of scoliosis. True or false?
True
What is Hueter-Volkmann law?
scoliosis is initiated by vertebral rotation in the axial plane, producing asymmetric forces of compression and traction on the convex and concave sides of spinal curvature.
The identification of the curve apex, end vertebrae, neutral vertebrae, and stable vertebrae is important when interpreting the radiographic features of scoliosis. True or false?
True
minor curves may begin as non-structural curves and progress to structural curves. True or false
True
What is the most common type of scoliosis?
Idiopathic scoliosis
What are the progressive forms of scoliosis?
Juvenile (4-10)- idiopathic
Congenital
What are the non generally progressive forms of scoliosis?
Infantile (0-3) and adolescent (11-18) - idiopathic
What is the risser index?
Risser index:
- describes skeletal maturity as the extent of excursion of the ossification centre of the iliac crest
- grade 0 (no ossification centre)
- grade 1 (ossification centre at the outer fourth of the iliac crest)
What imaging can be used to detect underlying causes of scoliosis?
Both MR imaging and CT can be recommended for the detection of underlying causes of scoliosis
What is structural scoliosis?
Often accompanied by vertebral axial rotation
Will not completely correct and does not reduce to less than 25° on bending views.
If the structural curve is straightened, the non-structural curve will correct spontaneously.
What is non-structural scoliosis?
Curves maintain truncal balance, e.g., a lumbar levoscoliosis may be present to compensate for the major thoracic dextroscoliosis and keep the head above the pelvis.
a lumbar levoscoliosis will straighten when the patient bends to the left.
Over time, it may become structural because of shortening of ligaments, muscle atrophy, and osseous changes that occur with the spine in a prolonged position.
