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Flashcards in Adult spinal deformity Deck (27):

Define adult spinal deformity?

  • Adult spinal deformity= a lateral spinal curve >10o in a skeletally mature individual


What is the epidemiology of adult spinal deformity?

  • Males = females
  • Mean age is 60 years
  • up to 90% have symptoms related to stenosis


What is the pathoanatomy of adult spinal deformity?

  • Degenerative sciolosis results from Asymmetric disc degneration and or facet degeneration
  • may occur in sagittal ( kyphosis/lordosis) or coronal plane ( scoilosis)
  • risk factors for sagittal plane deformity
    • osteoporosis
    • preexisitng sciolosis
    • degenerative disc disease
    • itraogenic scoliosis


What are the signs and symptoms of adult spinal deformity?


  • back and leg pain - 61%
  • neurogenic claudication- pain LL and buttocks
    • no relief with sitting/forward flexion 
    • caused by spinal stenosis on concave side
  • ​Radicular leg pain and weakness
    • foraminal and lateral recess stenosis


  • Muscle weakness
  • prominence thorac when bending forwards
  • Neuro exam to exclude any nerve compression


Name the types of adult spinal deformity?

  • Idiopathic ASD
    • residual 
    • the untreated adolescent idiopathic sciolosis post skeletal maturity
  • De novo ASD- progressive degenerative changes in spine
    • degenerative
    • Iatrogenic
    • Paralytic
    • Post traumatic


what are the differences between idopathic ASD and De novo ADS?


  • larger more predictable curves
  • mutliple levels
  • normally thoracic spine

De novo

  • smaller less predcitable curves
  • fewer vertebral segements
  • normally lumbar spine


What is the progression of the curve?


  • 1.0o per pa for thoracic curve >50o
  • 0.5o for thoracolumbar 
  • 0.24o for lumbar curves
  • Curves <30o rarely progress
  • Curves >50o commonly progess

progession all due to location

  • thoracic curve progress more rapid than lumbar, thoracolumbar adn double major curves
  • loss of normal sagittal balance ( thoracic kyphosis, lumbar lordosis) common 
  • risks- osteoporosis, preexisiting scoliosis, itatrogenic instability, degenerative disc disease



What iinvestigations are useful in adult spinal deformity?


  • ap and lateral 
  • measure cobb angle - magnitue of curve
  • C7 plumb line
  • (C7 ) centre sacral vertical line- coronal malignment
  • bending views- curve flexibility & possibility of correctio with surgical intervention


  • identify- Central canal stenosis, facet hypertrophy, pedicular enlargement, formainal encroachment & disc degeneration

CT myeolgraphy

  • useful as MRI because rotational deformity and bony anatomy better on CT


What are the tx for adult spinal deformity?

Non operative

  • mainstay of tx in whom surgery CI
  • Coronal curves <30o rarely progress
  • Core strengthening programs- low impact walking, swimming, cycling and selected weight lifting
  • Tricyclic antidepressants - with sleep distrubance
  • corticosteriod injections or selective nerve root blocks
    • diagnostic- to validate foraminal compression
    • therapeutic
  • bracing coupled with continuous exercise


What are the indications for surgical tx?

  • Coronal angle >50o

  • sagittal imbalance 

  • curve progression

  • intractable back pain or radicular pain that has failed nonsurgical efforts

  • cosmesis (controversial)

  • cardiopulmonary decline

    • thoracic curves >60deg affect pulmonary function tests 

    • thoracic curves >90deg affect mortality





what is the surgical tx of  ASD?

  • Posterior curve correction and instrumented fusion
    • thoracic curves >50o
    • Most double curves >50 o
  • Combined anterior and posterior fusion
    • isolated thoraolumbar curves
    • islocated lumbar curves
    • extreme rigifity requiring anterior release


What are the surgical tx for adult spinal deformity?

  • Correction often requires combined ant/post surgeries either staged or preformed same day
  • Longer surgeries, higher complication risks, more medial stress pt.careful pt selection and preop planning

Thoracic curves- arthrodesis

  • limited thoracic curves approached posteriorly
  • exceptions are extremely rigid- may need release from anterior first
  • only thoracic deformity tx-> compromise lumbar spine
  • start arthrodesis high T2/T3

Isolated thoracolumbar/lumbar curves

  • decompression, instrumentation & arthrodesis of deformity, correction of curve
  • Posterior or combined ant/post approach

2 or more structural curves

  • multiple curvex can be corrected posteriorly
  • proximal extend to neutral/horzontal curve


What are the goals of surgery?

  • Achievement of spinal balance
    • correct Sagittal vertical axis to within 5cm of neutral
    • ensure pelvic tilt is <20 degrees
    • ensure lumbar lordosis is within 9 degrees of pelvic incidence
  • relief of pain
  • solid arthrodesis


What are the features with extending arthrodesis to S1?

  • Contraversial
  • Key consideration is any instability of L5-S1 segement to include spondylolisthesis or previous laminectomy
  • only indicated if no pathology at L5-S1- otherwise need to extend to S1


  • L5-S1 fusion extends stability of long fusion construct
  • Anterior column support becomes more important  and is more efficiently gained thru an anterior approach, allowing for ant release and better deformity correction
  • stopping at L5 may -> painful disc pathology below fusion in future years
  • Pts with normal sacral inclination and normal C7 plumb line have the lowest incidence of L5-S1 disc degeneration


  • Increase peudoarthrosis rate
  • increase surgical time
  • increase reoperation rates
  • Increase rate of sacral insufficiency fractures
  • alters gait post op


When is sacrum fusion required?


  • If any pathology at L5-S1
    • Spondolythesis, spondylolysis
    • same advantage & disadvanatges as L5/S1 fusion


when is sacropelvic fusions required?

  • If sacrum involved in fusion with more than 3 vertebra
  • uses iliac bolts


  • increased stability of long fusion construct

  • increases success of lumbosacral fusion


  • prominent hardware





When are osteotomies required?

  • To regain sagittal balance in severly angulated deformities
  • 30o or more can be gained thru different types of osteotomies
    • pedicle subraction
    • Smith- peterson techique​ - see pic
    • more correction in lumbar than thoracic spine
  • Larger ooperations with higher complication rates, more blood loss, grater technical fitnesses


Describe how you would meaure the cobb angle?

  • locate superior vertebra-superior surface tilts towards side of concavity
  • locate inferior vertebra- inferior suface tilts towards concavity
  • erect perpendicular 900 line from superior edge of superior vertebra and inferior edge of inferior vertebra
  • where cross = cobbs angle
  • normal 10-20 o
  • 20-40 brace
  • 40o > surgery


What is sagittal balance?

  • Due to normal cervical lordosis, thoracic kyphosis and lumbar lordosis
  • normal alignment
    • vertical axis runs from centre C2 to ant border of T7 to middle of T12/L1 disc, posterior to L3 and crosses post superior corner of sacrum
    • radiographic plump line dropped form C7 to superior-postrior corner of S1
  • most reliable radiographic predictor of clinical health status in adults with spinal deformity


What is negative sagittal balance?

What is positive sagittal balance?

  • Axis is posterior to sacrum
  • occurs in pt with lumbar hyperlordosis


  • Axis is anterior to sacrum 
  • occurs in pts with hp flexion contracture or flat-back syndrome


what is the prognoiss of adult spinal deformity?

  • Worse prognosis 
    • symptoms progress to side of curve convexity
    • sagittal plane imbalance


What are the indications for a vertebral column resection- vertebrectomy?

  • Severe sagittal imbalance (provides more correction than PSO) requiring correction of up to 45deg

  •  rigid angular thoracic spine kyphosis, such as associated with tumor, fracture or infection

  • severe rigid scoliosis

  • congenital kyphosis

  • hemivertebrae resection in thoracic/lumbar spines



When would a anterior approach be required?

  • Large curves >70o
  • rigid curves
  • isolated lumbar/thoracolumbar
  • anterior interbody fusion at L5/S1 when fusing to sacrum
  • Anterior release and fusion usually combined with posterior instrumentation and fusion at smae day or staged
    • longer surgery
    • higher complications rate
    • more medically stressful
    • adv- helps restore sagittal and coronal balance
    • more stability L5-S1 with long fusion construct



what are the complications?

  • 10% irreversible major complications- neurological, DVT?PE, cardiac effecting overal outcome
  • venous thromboelmbolism-> poor outcome
  • Pseudoarthrosis
    • most common in post spinal fusion-15%
    • common L5-S1
    • risks; age >55, smoking, positive sagittal balance, hip arthritis,kyphosis >20o,thoracoabdominal approach
  • ​Infection
    • ​UTI
  • ​Neurological compromise
    • ​0.5-5%
  • ​PE
    • ​1-20%
  • ​Instrumental problems


How do you masure pelvic tilt?

  • draw aline along sacrum
  • perpendicular line to this
  • vertical line from obtruator foramen
  • intersection of line = angle


How do you measure the sacral angle?

  • line along sacral body
  • horizontal line parallel to L5 which transects this
  • angle formed is sacral angle/slope


How do you measure the pelvic inclination?

  •  Pelvic incidence defined as the angle between the perpendicular to the sacral plate at its midpoint and the line connecting this point to the femoral heads axis.
  • “Pelvic Incidence = Pelvic Tilt + Sacral Slope.