Adult spinal deformity Flashcards
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?
Symptoms
- 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
Signs
- 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?
Idiopathic
- 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
- 0.5<span>o</span> 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?
xrays
- 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
MRI
- 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
- NSAIDS
- 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
Advantages
- 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
Disadvantage
- 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
advantage
- increased stability of long fusion construct
- increases success of lumbosacral fusion
disadvantage
- 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


