Spine Flashcards
Safe zone for occipital screw placement
Triangular region created by connecting 2 dots 2cm lateral to the external occipital protuberance, and a point 2 cm inferior to it
Point B on the pictures
Slip angle greater than what degree is associated with greater risk of progression?
>50 degrees
6 things to do if a neuro alert during scoliosis surgery
- check equipment
- check blood pressure >90mmHg
- check Hgb
- reverse or lessen correction
- wake up test
- remove implants if spine stable
Risks of postoperative spinal infection
Longer OR time
Immunocompromised state
Increased blood loss (decreases circulating Abx)
Poor nutritional status
Obesity (BMI >35kg/m^2)
Use of instrumentation or OR microscope
Prior spinal surgery or local radiation
Longer constructs or more extensive procedures
Tobacco or alcohol use
Multiple trauma
Anklylosing spondylitis trauma
What must you do?
CT scan of spine
Often skip fractures
Fieldig Classification of AARD
Type I:
Unilateral facet subluxation with intact transverse ligament
Type II:
Unilateral facet subluxation with 3-5mm of anterior displacement (injured TL)
Type III:
Bilateral anterior facet displacement of >5mm
High risk of neuro compromise
Type IV:
Posterior displacement of Atlas (C1)
Safe zone for halo application (anterior pins)?
Lateral 1/3 of eyebrow, below the equator (site D in figure)
Avoids supraorbital and supratrochlear nerves
In facet dislocation, what must you do after successful reduction and why?
MRI - to look for disc herniation
What age does the secondary ossification center of the dens fuse with the rest of C2?
~12 years
Normal range of kyphosis in mid-thorcic spine (T5-12)
20-50 degrees
Power’s Ratio
Basion to posterior arch/Opisthion to anterior arch
Normal is 1
Abnormal: occipito-atlantal instability
Three types of Diastematomyelia?
- boney
- fibrous
- cartilaginous
Why do you have to use a paediatric spinal board for paediatrics? What age do you have to use it until?
To compensate for large head
Paediatric boards have an occipital cutout to compensate for this
Use until 8 years
Name 6 surgical options for degenerative spondy:
Laminoplasty
Laminectomy no fusion
Laminectomy UNinstrumented fusion
Laminectomy + instrumented fusion
(all of the above ± PLIF/ALIF/TLIF)
Dynamic stabilization (see pic)
Lumbar interspinous spacers (prevents extension)
Treatment algorithm for AARD
Acute
- Soft collar, anti-inflammatories, exercise program
Acute >1 week
- Head halter traction and bracing
Subluxation > 1month
- halo traction and bracing
Subluation > 3 months, late diagnosis or neuro deficits
- Posterior C1-2 fusion
If a patient presents with a cervical rotational deformity what injury should you think of?
Unilateral facet dislocation
Disc herniations at the following levels with affect which nerve root?
- C2-C3
- C7-T1
- T4-T5
- L2-L3
- L5-S1
1 - C3
2 - C8
3 - T4
4 - L3
5 - S1
Interpret:
a) ADI < 3 mm
b) ADI between 3 and 5 mm
c) ADI > 5 mm
a) Normal
b) Transverse Ligament Rupture
c) Transverse Ligament and Alar Ligaments Ruptured
Most common locations for pseudoarthrosis in adult spinal deformity?
L5-S1
Thoracolumbar junction
(so any junctional area)
Why is discography not so good?
It causes accelerated disc degeneration and loss of height.
What are the components of TLICS and what score means surgery?
- Morphology
- Neurologic injury
- Status of PLC
5 or more get OR
What type of vertebral malformation is most likely to cause a progressive congenital scoliosis?
Unsegmented bar with a contralateral hemivertebrae
Tx. is PSIF with resection of vertebrea
Components of PLC?
Supraspinous ligament
Interspinous ligament
Facet capsule
Ligamentum flavum
Complications of vertebroplasty/kyphoplasty
Cement extravasation
Cement Embolism
new fracture
neurologic compromise
How to improve outcomes (arthrodesis) in fusion for spondy?
Pedicle screws
Interbody fusion
Non-smokers (major risk for pseudoarthrosis)
Rate of tandem stenosis for patients with lumbar or cervical stenosis?
20%, so image other area if symptoms aren’t clear
5 conditions resulting in Atlanto Axial Instability?
- Downs
- RA
- Dens Fracture
- Atlas Fracture
- Transverse Ligament Rupture
Outcomes of SPORT trial with respect to degenerative scoli
Surgical intervention > non surgical at 2 years and 4 years
No difference in surgical method used
Patients with predominantly leg pain did the best
Pelvic incidence
Pelvic tilt
Sacral slope
Which are position dependent?
Pelvic tilt and sacral slope are position dependent
pelvic incidence does not change after skeletal maturity
What is abnormal structure in congenital muscular torticullis?
Tight SCM
Most common nerve injury with myelopathy decompression?
C5 palst
Treatment is observation
With OPLL and myelopathy, what guides your choice of appraoch?
1) If kyphotic = Have to go ANTERIOR and do corpectomy/OPLL resection
**** Risk of dural tear
2) If lordotic = Can go posterior and do laminoplasty or laminectomy/fusion without OPLL resection
Risk factors for pseudoarthrosis of anterior single rod technique
Smoking
Weight >70kg
Thoracic hyperkyphosis >40 degrees
Risks of Low back pain
Obesity
Smoker
Male
Lifting
Vibration
Prolonged Sitting
Job dissatisfaction
Two surgical options for a curve > 50 in a Juvenile patient?
- Growing rods, VEPTR
- Anterior and Posterior fusion (have to do both sides to avoid crankshaft phenomenon)
Physical exam findings of diastematomyelia:
a) 4 local findings
b) 5 associated conditions
- hairy patch
- skin dimple
- Subcutaneous mass
- teratoma
- scoliosis
- tethered cord
- cavus foot
- claw toes
- clubfoot
Describe Chamberlains line
Line from dorsal margin of hard palate->posterior edge of the foramen magnum
abnormal if tip of dens > 5 mm proximal Chamberlain’s line
normal distance from tip of dens to basion of occiput is 4-5 mm
this line is often hard to visualize on standard radiographs
What is the success rate of nerve root injections for lumbar herniations?
50%
Describe peltic tilt:
Angle formed between
- Line parallel to side of radiograph
- Line from center of femoral head to the center of the S1 endplate
Isthmic spondy (and spondy in general) is associated with what change in pelvic incidence?
Increased
THINK: higher incidence allows it to slip easier
indications for hemivertebrectomy
- Hemivertebrae (failure of formation) with progressive curve causing truncal imbalance and oblique takeoff
- Patients less than 4-5 years
- Curve less than 40 degrees
Main finding of:
Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurological deficit. A prospective, randomized study. - Wood 2003
Operative treatment of patients with a stable thoracolumbar burst fracture and normal findings on the neurological examination provided no major long-term advantage compared with nonoperative treatment.
Which of the following shows increased production when adisc herniates?
- osteoprotegrin (OPG)
- interleukin-1 beta
- receptor activator of nuclear factor-kB ligand (RANKL)
- parathyroid hormone (PTH)
All of them.
5 spinal conditions that can result in Juvenile Scoliosis?
- syringomyelia
- arnold-chiari
- tethered cord
- spinal dysraphism
- tumor
What percentage of Juvenile Scoliosis patients have an abnormal MRI?
18-25%
Define Sacral slope
Angle formed between:
- horizontal line parallel to the bottom of radiograph
- Line parallel to the S1 endplate
Name 6 syndromes/diseases assocated with basilar invagination
Klippel-Feil
Osteogenesis imperfecta
Morquio syndrome
achondroplasia
spondyloepiphyseal dysplasia
occipitocervical synostosis
Describe cervicomedullary angle
Angle formed between:
line along ventral surface of medulla
line along upper cervical cord
less than 135 suggests impending neurologic compromise
What is the relationship between:
- sacral slope
- pelvic incidence
- pelvic tilt
pelvic incidence = pelvic tilt + sacral slope
Outcomes of SPORT trial regarding herniated nucleus pulposus?
Surgical intervnetion > nonoperative,
although both groups did well
Define instability on flexion-extension x-rays as it pertains to lumbar spine spondy
4mm of translation or 10 degrees of angulation of motion compared with adjacent motion segment
When do the basilar synchondrosis and secondary ossification centers fuse?
Basilar synchondrosis: age 6
Secondary ossification center: appears at 3, fuses at age 12
2 deformities associated with Klippel Feil?
- Scoliosis
- Sprengels
6 presenting symptoms in patients with DISH
Dysphagis and stridor
Hoarseness
Sleep apnea
Difficulty with intubation
Cervical myelopathy
Spinal Fracture
What is defined as instability on flex-ex radiographs?
Instability: >3.5mm of motion between flexion and extension views
Two common complications following Postero Decompression and instrumented fusion for degenerative spondylolisthesis?
- Pseudoarthrosis (5-30%)
- Adjacent level disease (2.5% per year)
4 clinical findings associated wiht Scheuermann’s
Hyperlordosis
Spondylolsis
Scoliosis
Pulmonary compromise in curves >100 degrees
For revision anterior cervical approach with previon RLN injury what do you do?
Go from the same side to avoid bilateral injury
Technique for posterior reduction of facet dislocations?
- Can only do after disc is dealt with if present
- Can burr tops of superior facets
- Put lateral mass screws in and then use these to reduce
- Fuse one level above and below
Scheuermann’s kyphosis.
What’s the outcome of non-op curves (by size)
>75 degrees: severe pain that affects ADLs
What percentage of RA patients have atlantoaxial instability?
50-80%
SO CHECK FOR IT - especially in oral exam
Indications & Contraindications for vertebroplasty/kyphoplasty
See pic
New studies show that it may be beneficial, at least in the short term, for vertebral compression fractures
Injury to what nerve structure causes retrograde ejaculation?
Superior hypogastric plexus
(retroperitoneal approach to spine)
What disorder causes a passively correctable chin-on-chest deformity?
Dropped head syndrome
vs. AS (non-correctable chin on chest)
Caused by cervical paraspinal weakness
What is more likely to present with dysphagia: OPLL, DISH or Ank Spon?
DISH
4 dangers of Smith-Robinson Anterior approach to C-spine
Recurrent laryngeal nerve
Sympathetic chain
Carotid sheath
Post-operative hematoma
Best phase on MRI to look for foraminal stenosis and what to look for?
T2
Look for loss of perineural fat
What is the treatment for low grade isthmic spondylolistheis that is painful and fails 6 months of physio?
12 weeks of TLSO
Hypoglossal (CN 12) injury during ACDF - tongues deviates which way?
towards side of injury
Indications for MRI in scoliosis workup (7)
Atypical curve pattern (left thoracic curve, short angular curve, apical kyphosis)
Signs of syndromic or neural axis pathology
- Cavus feet
- Signs of dysraphism
- Asymmetric abdominal reflexes
- neurologic symptoms or pain
- Signs of Marfan’s/Down’s/Lysosomal storage disease
Rapid progression
Excessive kyphosis
Structural abnormalities
Child 20 degrees
All patients with congenital scoliosis
Collagen type in nucleus pulposus
Type II
It’s like articular cartilage
What is a Hangman’s fracture?
Traumatic anterior spondylolisthesis due to bilateral fracture of pars interarticularis
Halo application principles in adults (location, pins, tightness)
4 pins
- 2 anterior pins over lateral 1/3 of eyebrow below equator
- 2 posterior pins opposite of anterior ones
8 inch pounds of torque
Best treatment of this fracture?
Fracture separation of lateral mass
2 level posterior spinal instrumented fusion (PSIF)
If a patient has a hypoglossal nerve injury after anterior approach, what side will their tongue deviate towards?
Towards the affected side
4 complications with lumbar disc herniation surgery
Dural tear
Recurrent HNP
Discitis
Vascular catastrophy
What is the most common neurologic finding after cervical laminoplasty?
C5 palsy
NOT recurrent laryngel nerve palsy: you’re not going anterior for a laminoplasty
What is the treatment for syringomyelia?
- Cevical dempression without fusion initially once it becomes symptomatic
- Instrumented fusion 3-6 months later
In adults, what is the first line of treatment in spondylolysis with no neuro symptoms?
Observe
Difference between Type 2 and Type 2A Levine/Edwards?
Levine/Edwards is Hangman’s fractures
2 = > 3mm displacement, disc is compromised
Treat with traction then Halo vest.
2 A –> Horizontal fracture
NO TRACTION
Reduce with extension then Halo vest.
C-spine myelopathy. Indications for anterior only, posterior only and anterior + posterior decompression ± fusion
Name 1 absolute contraindication to posterior only decompression
Anterior only (ACDF): gold standard for 1-2 level disease
Posterior only: <13 degrees kyphosis
- Some say <10 degrees but definitely <13 degrees
Anterior + Posterior: rigid kyphosis >10 degrees and multilevel disease (>2 levels)
Kyphosis >13 degrees is an absolute contraindication to any posteriorly only decompression
Changes during normal aging of IV discs
Changes are like that of articular cartilage
Decrease in:
- Collagen II (changes to fibrocartilage)
- nutritional support
- water content
- Absolute number of cells
- Proteoglycans
- pH
Increase in:
- Collagen I
- Keratin sulfate : chondroitin sulfate ratio
- Lactate
- Degradative enzyme activity
No change in:
absolute quantity of collagen
Subaxial insatbility is present in what percent of RA patients?
20%
How long do you have to culture acid fast bacili?
Up to 10 weeks
Do osteoblastoma respond to NSAIDs?
No
When do you brace in scoliosis for:
Congenital
Infantile
Juvenile
AIS
Congenital:
May brace supple compensatory curves
Infantile:
Cobb >20 (consider, but many resolve spontaneously)
Cobb >30 for sure
Juvenile:
Cobb >20
Adoelscent:
Cobb >25
Findings associated with Scheuermann’s kyphosis
Anterior wedging across 3 consecutive vertebra
Disc narrowing
Endplate irregularities
Schmorl’s nodes
- Herniation of disc into vertebral endplate
Scoliosis
Compensatory hyperlordosis
Important to look for spondylylysis
What level does the aorta bifurcate?
L4
4 differences between DISH & AS spine
DISH:
right thoracic often in isolation (protective pulsatile aorta)
nonmarginal osteophytes
preservation of disc space
Flowing candle wax (vs. squared off bamboo spine of AS)
Non HLA-B27 association
What shoulde you rule out with muscualr torticullis with no palpable SCM mass?
Klippel feil
AARD (atlanto-axial rotatory deformity)
3 Indications for PLIF in spondylolisthesis
Severe slip
Neurologic compromise
Saggital imbalance
Name 5 mimickers of lumbar radiculopathy
Major technical factor in improving fusion rates in posterior spinal fusion?
pedicle screws
Differential for myelopathy? (5)
- Stroke
- B12 deficiency
- Movement disorder
- ALS
- MS
What type of sub-cervical spinal trauma almost always gets posterior instrumented fusion 2 levels in each direction?
Thoracolumbar Fracture Dislocation
Commonly occurs at junction (T10-L2)
What cobb angles will puts the patient at risk of cardiopulmonary decline and mortality?
Cardiopulmonary decline:
Thoracic curves >60 degrees affect pulmonary function tests
Thoracic curves >90 degrees affect mortality
What are three signs of segemental spinal instability (specifically lumbar)?
- Degenerative scoliosis
- Spondylolisthesis (degenerative or isthmic)
-
Surgical over resection
- > 50% of either facter
- Complete laminectomy
4 risk factors for myelopathy in OPLL
>60% spinal canal stenosis
≤6 mm of space available for the cord
increased cervical range of motion
OPLL that is laterally deviated within the spinal canal
(JAAOS 2014)
Is bullet removal from spinal canal more likely to improve motor outcomes in incomplete injuries in T12-L4 or from T1-T11?
T12-L4
Most common type of spondylolysis/listhesis in adult?
Degenerative
Symptomatic acute osteoporotic spinal compression fracture (within 5 days). name the medical treatment?
Calcitonin x 4 weeks
AAOS 2010 - moderate evidence for
Who gets OPLL?
ASIANS, Men
Radiographic definition of central stenosis:
Cross sectional area less than 100cm2
or
less than 10mm AP diameter on axial CT
Where is the most common site for isthmic spondy and where is the most common location that predisposes to progression?
L5-S1 most common
L4-5 will progress
In Brown-Seqard syndrome what deficit is there in the contralateral limb?
Spinothalamic - pain and temperature
Findings in anterior cord syndrome
lower extremity affected more than upper extremity
loss:
LCT (motor)
LST (pain, temperature)
preserved:
DC (proprioception, vibratory sense)
Worst prognosis
May mimic complete cord
Where does pseudosubluxation happen and how do you verify diagnosis?
1) C2 on C3
2) Swischuks line should be wihting 1.5 mm of C2 sp and the deformity should reduce on extension xray
What is important to look for on physical exam if considering deformity correction or THA on a patient with Ank Spon?
Hip flexion contractures
In C-spine immobilization of a paediatric patient, where do you want to keep the external auditory meatus?
Keep external auditory meatus inline with the shoulders
This puts them in a slight position of extension
True or false: All congential scoliosis from vertebral malformations is progressive
False.
Depends on etiology. Things like a single unsegmented hemi vertebrae is unlikley to progress.
Unsegmented bars almost always progress.
What other organs do you need to image before surgery on congenital scoliosis?
Heart and kidneys
In doing a laminectomy and fusion, what is the biggest risk of adjacent level change?
Laminectomy (no fusion) at the adjacent level
In AARD, which side will the patient’s head be tilted and rotated to?
Ipsilateral rotation and contralateral tilt of the head in relation to the lateral mass of C1
Opposite of Torticollis
Best candidate for radiosurgery for spinal tumours?
Life expectancy > 1 months, b/c effects don’t come on for 3-4 weeks
How does a well repaired dural tear affect outcomes after lumbar decompression?
No effect
What is rate of overall complications with adult spine deformity correction?
10-20%
Most common surgical technique resulting in pseudoarthrosis in adult spinal defomrity correction?
Posterior fusion only
I think they mean no instrumentation??
Cord syndrome prognosis from best to worst
Brown-sequare (best)
Central cord
Posterior cord
Anterior cord (Worst)
What condition is the Wiltse appraoch best used for?
Far lateral lumbar disc herniation
What do you call a bar that crosses the spinal cord and causes a cleft in the spinal cord?
Diastematomyelia
T/F: helmets increase risk of c-spine injury
False
They do not increase risk of c-spine injury
4 conditions that pre-dispose to traumatic cervical spine trauma
- DISH
- Ank Spon
- Previous Fusion
- Connective Tissue Disorders
What is the most imporant radiographic finding that may predict complete neural recovery post decomrpessive surgery for atlantoaxial instability?
PADI/SAC > 13mm
Anterior reduction technique of facet dislocation?
- Can only do for a unilateral facet dislocation
- Caspar pins in proximal and distal bodies
- Rotate upper pin towards the dislocation
2 Treatment options for synovial facet cyst
Laminectomy & decompression
- classically 1st line treatment but high recurrence rates
Facetectomy & instrmented fusion
- Some now consider this first line
Most important factor when deciding treatment of Axis fracture?
Stability of Transverse Ligament
If it is ruptured then do either C1-C2 or Occ - C2 fusion
Harris Rule of 12: Describe
If either of:
Basion-Dens interval (BDI)
or
Basion posterior axia line interval (BAI)
>12mm, its a sign of occipito-atlanto instability/dislocation
What is radiologic definition of Scheurmans?
Anterior wedging of > 5 degrees accross 3 continuous vertebreas
Are results for revision lumbar discectomies worse, better or the same?
Equivalent
How do vertebral compression fractures affect mortality?
Increase it x2 to matched controls
Higher in men
higher with earlier age of fracture
However, improved with cement augmentation (kyphoplasty) by 2-7 years
(JAAOS 2014)
Functional level of the following spinal level injuries
C4
C5
C6
C7
C4 —> Electric wheelchair with head/chin controls
C5 —> electric wheelchair with hand control
C6 —> Manual wheelchair with sliding board
C7 —> Manual Wheelchair with independent transfers
What is the radiographic sign of an unstable degenerative spondylolisthesis?
> 4mm translation on flex/ex
Where do you find free nerve endings in the spinal unit?
PLL, annulus fibrosis, facet joint
NOT in the nucleus pulposus
Risks of pseudoarthrosis in adult spinal deformity correction (7)
Age >55
kyphosis >20 degrees
positive sagittal balance >5cm
hip arthritis
smoking
thoracoabdominal approach
incomplete lumbopelvic fixation
What reflex differentiates between intracranial and intraspinal lesions?
Jaw Jerk
If positive, then it’s an intracranial cause of myelopathic symptoms
Name 2 radiographic indices that indicate poor outcomes in Spondylolisthesis
Increased lymbosacral kyphosis
Positive sagittal balance
(not really the same)
HOw do you avoid junctional kyphosis post-op Scheuermann’s kyphosis?
Make proper selection of levels
Avoid overcorrection
limit to 50% of original curve
General indications for surgery in adult spinal deformity (6)
Curve > 50 degrees
Sagittal imbalance
Curve progression
Intractable back pain or radicular pain that has failed nonop
Cardiopulmonary decline:
Cosmesis (controversial)
What spinal lesion causes an occipital headache worse with valsalva?
Syringomyelia
What part of the spinal cord is least sensitive to radiation (ie for stereotactic radiosurgery)
Thoracic spine
(JAAOS 2014)
Describe TLICS
Max score: 10
>4 operate
4 = dealer’s choice
Radiographic findings of Scheuermann’s kyphosis
anterior wedging across three consecutive vertebrae
disc narrowing
endplate irregularities
Schmorl’s nodes (herniation of disc into vertebral endplate)
scoliosis
compensatory hyperlordosis
important to look for spondylolysis on lumbar films
What are the parameters for a structural minor curve according to lenke?
> 25 degrees and do not bend out to less than 25 degrees with lateral bend
Patient placed in garder wells tongs and reduced with traction for jumped facets. Patient develop nystagmus and other stroke like symptoms.
What is the most likely cause?
Vertebrobasilar insufficiency
Rate of pseudo arthrosis in single elvel ACDF?
5-10%
45-year-old manual laborer presents to the office with acute onset back pain that radiates to his right leg after carrying a heavy object. He also has mild non-progressive weakness with ankle dorsiflexion on that side. What should be his initial treatment
PT and NSAIDs should be first line