ABOS Spine Flashcards
Where are sympathetic ganglia in cervical spine
C6 where middle cervical ganglia is, medial boarder of longus colli muscles
How is hypogastric plexus injuried
Anterior approach, retrograde ejaculation
Where do afferent nerve fibers arise
Medial branch nerves originating from next two cephalad levels; L3-4 facet joint innervated by L2 and L3 medial branches
Where does Artery of Adamkiewicz arise
left side b/w T8 and L1
What does neural tube become
from primative streak, becomes spinal cord (failure to closue anencephaly and spina bifida)
What does neural crest become
forms dorsal to neural tube
peripheral NS, pia mater, spinal ganglia, sympathetic trunk
What does notocord become
ventral to neural tube
vertebral bodies and intervertebral discs
NP from notocord, annulus from sclerotomal cells (resegmentation)
Smallest and largest pedicles
T4 smallest, L1 smallest in lumbar spine
T12 largest
What is concerning change in signals for SEPS and MEP
50% amplitude or 10% increase in latency
What is EMG concerning for breached pedicles
<8mA
What nerve can be injured with anterior cervical exposure up to C2
hypoglossal
Landmarks for anterior approach
Angle of mandible C1-C2
Hyoid bone C3-4
Thyroid cartilage C4-5
Cartoid tubercle C6
Anterolateral approach to thoracic spine
2 levels caudal for vertebral body exposed
Segmental arteries at risk midbody b/w intervertebral disks
Diaphragm can be taken down, medial risk of phrenic nerve
Lumbar plexus runs through posterior 2/3rd
Where is superior hypogastric plexus
on L5 body - retrograde ejaculation
A diagram of the back of a human body
Anterior approach to spine
transperitoneal, retroperitoneal
ureters, round ligament, iliac vessels, hypogastric plexus
sympathetic trunk medial to border of psoas, lateral to psoas is ilioinguinal nerve and farther lateral is GFN
Anterior cord syndrome findings
lower extremities more affected than upper, loss of motor and p&T
Flexion/compression injuries
Worst prognosis of all incomplete SCI
Brown-Sequard syndrome
hemitransection, excellent prognosis, 99% ambulatory at final follow up
Central cord syndrome
hyperextension injury in elderly
upper extremity and hands
Good prognosis if <50
Lower extremity recovers first, then bowel/bladder, upper then hands
typically regain ability to walk, hand may remain spastic
surgical decompression only if persistent cord compression
When to decompress for incomplete spinal cord injury
decompress when hit neurologic plateau or worsen, may recover 1-2 levels
Function level depending on cord injry level
C4- puffer, C5 hand controls, C6 manual wheel chair, C7 manual wheel chair with independent transfers
Causes of occipitocervical instability
Traumatic
Acquired: Downs, bony dysplasia, soft-tissue laxity, RA, Mucco
Requires instability of alar, tectorial membrane and alanto-occipital joint capsules
How to diagnosis occipitocervical instability
CT scan occipital condyle-C1 interval <1.5mm
Occipital condyle fracture
cervical orthosis, sugery only if neuro deficits
Powers ratio
Basion to posterior arch/anterior arch to opisthion
1 normal; >1 or <1 concern for anterior or posterior dislocation
Types of C1 fractures
Posterior arch, Jefferson (posterior and anterior arches)
lateral mass
Ligamentous disruptions
How to decide if C1 fracture or ligamentous injury needs surgery
Sum of lateral masses >8.1mm
ADI >3mm
Nonsurgial management of C1 fractures or ligaments injuries
If stable: cervical collar or halo
Surgical options of unstable c1
C1-2 trans-articular screw (vertebral artery caudal), C1 lateral mass and C2 pedicle screws, Occiput- C2 more severe injuries
Atlantoaxial instability causes
Adult: Downs, RA, Os Odontoideum
traumatic: type I odontoid, Atlas fracture, transverse ligament injury
Peds: JRA, Morquio’s sydrome, trauma/infection
How to determine AA instability
flexion/extension xrays
unstable if ADI >3-5mm, >10mm in RA
SAD or PADI: <14mm indication for surgery
Open mouth: sum of lateral mass > 8.1mm
Odontoid ossifications centers
Basilar around 6yo, fuses to dens around age 12
how are odontoid fracture type I and III typically treated
hard cervical collar
Risk factors of odontoid nonunion
posterior displacement >2mm (strongest), >5mm displacement, >4 day delay in treatment, >10 degrees of angulation, smoker
Indication of anterior odontoid screw
minimally displaced, anterior oblique fracture
preserves motion
Indication of posterior C1-C2 fusion
> 40 and type II and risk factors for nonunion, os odontedieum with neuro deficits and poor bone quality
What is a Hangman’s fracture
traumatic spondylolithesis of Axis (bilateral pars fracture of C2)
CT and flex/ext xrays
Treatment for hangmans fractures
Classification of hangmans fracture
Type I: (axial load and hyperextension) <3mm displacement
Type II: axial load and hyperextension with rebouund hyperflexion
Type IIA: flexion distraction
TypeIII: flexion distraction followed by hyperextension, associated facet dislocation
Treatment of Hangmans fractures
Type I rigid collar 4-6weeks
Type II: < 5mm reduction with traction the halo; >5mm surgery
Type IIA: Avoid traction, axial load and hyperextension - halo
Type III: surgical reduction and stabilization
Anterior C-3 interbody fusion, posterior C1-3 fusion, bilateral C2 pars screws
Axis body fractures
typically stable and managed with hard collar
Halo immobilization indications
Upper C spine (does not control facet fractures or dislocations wells
occipital condyle fracture, occipitocervicla dislocation, stable Atlas, type II odontoid <40, Type II and IIA hangmans
Adults 4 pins 80lbs (infected abs, if loose then replace)
Kids; 6-8 2-4lbs, before age 2 Minerva cast
CNVI most commonly injured
Cervical facet dislocation spectrum
Facet fracture (typically superior facet)
Unilateral dislocation ~25% subluxation of xray
Bilateral facet dislocation (80% spinal cord involvement)
Workup for facet dislocation
Flexion/extension xrays
Awake and alert - closed reduction
MRI first: AMS, failed reduction, neurologic deterioration, patient going to OR (need to know if disc)
How to reduce facet dislocation
reduction with tongs: >100lbs ok to use 70% bW
Treatment of stable facet fracture
Halo vs hard orthosis
need to confirm stable on flex/ext xrays
unilateral facet fracture w/o instability <40% lateral mass involvement or absolute height <1cm
Bilateral facet dislocation or unstable facet fracture
single level fusion
Treatment for cervical lateral mass fracture with facet seperation
Posterior decompression and 2 level fusion
Subaxial cervical vertebral body fracture types
Compression, burst, flexion teardrop, extension tear drop
How to assess subaxial cervical vertebral body fracture
MRI to assess PLC
Which features have high risk of SCI with subaxial cervical vertebral body fractures
tear drop, disruption of posterior cortex, PLC injury
Nonoperative treatment of subaxial cervical vertebral body fractures
Hard collar, mild compression but stable (PLC intact), anterior tear drop
Surgical treatment of subaxial cervical vertebral body fractures
Anterior surgery - best within 24 hours
Compression fx with 11 degrees of angulation or 25% height loss
Unstable burst with cord compression
Unstable flexion tear drop with cord compression
Minimal injury to posterior elements
Posterior surgery if significant injury to posterior elements
extension tear drop fracture of cervical spine
avulsion of anteroinferior corner of vertebral body from forced hyperextension
hard collar
Cervical spinous process fracture
Clay-Shoveler fracture
Avulsion of spinous process fracture
Nonop
Closed cervical traction
pin placement: 1cm above pinna, in line with external auditory meatus below equator of skull
Too anterior: extension and superficial temporal artery at risk
Too posterior: flexion
TLICS Scoring
4 indeterminate, 5 surgery
compression 1, burst +1, translation/rotational 3, distraction 4
Nerve: intact 0, nerve root 2, Complete cord/CM 2, incomplete cord 3, CE 3
PLC: intact 0, suspected interminate 2, injured 3
Thoracolumbar burst fracture treatmetn
if PLC intact and neuro intact - nonop TLSO controversial
posterior stablization w/o decompression: PLC, progressive kyphosis
W/ decompression and fusion: neurodeficits, TLCs >5
translational always 3 column
Flexion-distraction thoracic trauma
Chance fracture; high rate of GI injuries
MRI PLC stability
TLSO: stabile PLC, bony chance, neuro intact
Decompression stabilization possible corpectemy: neuro deficits, PLC damage
Thoracolumbar fracture dislocation
typically at the junction, posterior facet dislocation
MRI pLC stability
Posterior open reduction and fusion
Osteoporotic vertebral compression fracture
hx of 2+ VCf greatest risk factor for more
Observation and bracing even in >30 degrees kyphosis or > 50% height loss
<5d: calcitonin for pain or bisphosponates
Kyphoplasty 6 weeks of refractory pain
hold long do fusion constructs need to be in thoracic spine
short segment pedicle screw rod constructs for most thoracolumbar fractures
Most common site of cervcal disc herniation
C5-C6, posterior lateral
ACDF if failed 3 months with radic sypmptoms
Indication of poor prognosis on imaging with myelopathy
Myelomalacia on T2 (bright)
What compression ratio (Torgs) is indicative of poor prognosis with myelopathy
<0.4
Basilar invagination measurements
Ranawat <13mm
>5mm migration with McGregor’s or Chamberlains
MRI cervicomedullary angle <135
Causes of subaxial subluxation in RA
more common with steroids, males, seropositive RA and nodules
Pannus formation at facet and Luschka
Subaxial subluxation in RA measurements
Subluxation of >4mm or 20% indicates cord compression
cervicle height index (body height/width) <2.0 is 100% sensitive for predicting neurologic compromise
Ranawat classificaiton
I: pain, neuro intact
II: dysesthesias, UNM signs, normal strength
IIIA: objective weakness
IIIB: nonambulatory (do not operate)
Surgical indications in RA
Ranawat IIIA, II, IIIB, myelopathy
meet indication for AA, BI or SS
Elective surgery precaution in patient with RA
instability if >4mm motion
Treatment for OPLL
Asians, decompression if myelopathic symptoms
Adjacent segment disease risk after ACDF
25% at 10 years
c5-6 high risk
Smoking strongest patient factor
Outcomes of cervicle disk replacement
equivalent to fusion for neurologic improvement and patient reported outcomes for 1 and 2 level disease
superior reoperation rates
Indication for fusion with laminectomy
complete facet removal
pars fracture
degenerative spondy or scoliosis
Persistent pain after disketomy
Perineural fibrosis
Most common level of thoracic disc herniation
T9-12, even if radiculopathy dont knee to operate
Posterior approach highest rate of neurologic injury
Wiltse Newman Classification
I: dysplastic congenital pars defect
II-A: isthmic pars fatigue fracture
IIB: isthmic pars elongation
IIC: isthmic pars acute fracture
III: degenerative facet instability without a pars fracture
IV: traumatic acute posterior arch fx other than pars
V: neoplastic
How to test for spondylolithesis instability
flex/ext xrays
4mm translation or 10 degrees of angulation
Initial treatment degenerative spondylolithesis
nonop
PLIF or TLIF failure 3-6mo
ALIF reserved for pseudoarthorosis
What is associated with highest risk for in hospital complication with patient undergoing fusion for degen spondyl
Age
Typical level of isthmic spondylolithesis
L5 on S1, can cause radicular symptoms of L5
Indications for surgery in adult isthmic spondylolithesis
slip greater than 50% in growing children
greater than 75% in mature adolescents
Progression more than 30%
functional impairment, pain, neurosymptoms
Decompression with TLIF/PLIF if pain with 6 mo nonop treatment or indications above
Insitu if low grade
When to do pars repair
no slippage, no disc disease
L1-L4 isthmic that fails nonop
risk factors for isthmic spondy
repetitive hyperextension, higher sacral table index, higher pelvic incidence and sacral slope
Risk factor for slip progression
higher grade slip, Myerding 2 >50% risk of progression
clinical tests for spondy
hamstring tightness, back pain aggravated with extension
pain with standing single limb lumbar extension
Indications for TLSO treatment with isthmic spondy
acute pars stress reaction, isthmic failure or low grade failure to improve with PT ~6 weeks
6-12 wks, brace immobilization superior to activity restriction alone for acute stress reaction
What meets criteria for adult spine deformity
> 10 degree curve or >5cm sagittal imbalance on C7 plumb line
idiopathic thoracic spine
degenerative lumbar spine
Risk of progression with adult spine deformity
thoracic curve 1 degree/yr, lumbar 0.5 degrees per year, thoracolumbar 0.25 degrees per year
Surgical indications for adult spine deformity
Coronal curve >50 degrees, Sagittal imbalance >5cm, curve progression, severe pain unresponsive to nonsurgical management
What degrees of curve affect pulmonary function and mortality in ASD
60 for pulmonary compromise, 90 for mortality
Goals of surgery with ASD
Restore sagital balance SVA <5cm (most reliable predictor for resolution of clinical symptoms postop
LL within 9 degrees of PI
Pelvic tilt < 20 degrees
Solid fusion
Cement augmentation better in every way w/o complications
How to choose fusion levels in ASD
Proximally to neutral horizontal vertebrae
Extend to L5 if no L5-S1 pathology
Extend to S1 if pathology: increased stability, higher rate of pseudoarthrosis
Extend to pelvis: >3 fusion level, increases stability and fusion success
When to do an anterior procedure with ASD
Large rigid curves >70 degrees
Most common reason for reoperation in ASD
Hardware failure due to pseudoarthrosis
Risk factors for pseudoarthrosis in ASD
age, kyphosis >20 degrees, >5cm positive sagittal imbalance, smoking
What affect does smoking have with surgical treatment of ASD
infection, pseudoarthrosis, reoperation, lower functional outcome scores
Osteotomies in spine surgery and degree of correction
SPO: 10 degree/level
PSO: for sagittal imbalance >12cm, 30-35 degrees in lumbar, 25 degrees in thoracic (good if anterior fusion unlike SPO)
Vertebral column resection: sagittal imbalance requiring correction up to 45 degrees, good for rigid thoracic spine kyphosis, severe rigid scoliosis, congenital kyphosis
Treatment of sacral insufficiency fractures
WBAT walker, pain control
Sacroplasty failed nonop with Denis zone I
otherwise SI screws
Risk factors for DISh
Gout, Diabetes, hyperlipidemia
bisphosphates then surgery
most common right side of thoracic spine
Types of extra dural spine tumors
Mets: rad and chemo, resection if isolated lesion
Lymphoma: MTX
Intradural intramedullary spine tumors
radicular pain, motor and sensory deficits
Ependymoma: resection
Astrocytoma: benign in children, resection
Intradural extramedullary tumors of spine
Central cord compression and radicular symptoms
Schwannoma S100+, Antoni A/B, surgical resection, post op chemo
Meningoma: meningothelia whorls, surgical resection
Diastematomyelia
congenital spine condition with fibrous, cartilaginous or osseous bar creating and longitudinal cleft in spinal cord
observation if asymptomatic, resect if sxs
Syrinx and synringomyelia
fluid filled cavity in spinal cord, lesion for obstruction CSF flow
Scoliosis, Charcot’s, Klippel feil deformity
Need MRI
Decompression if symptomsO
Osteoblastoma and osteoid osteoma treatment
en bloc resection
Plasmocytoma
radiation, stabilization if neeed
Markers of maturity in AIS
Risser 4, <1cm change in height over 2 visits 6 months apart, 2 years postmenarchal
Klippel Feil
congenital cervical fusion SGM1 chrom 8
Short neck, low hairline, stiff neck, renal and cardiac problems, Sprengles deformity, Scoliosis, deafness
Other tests for congenital scoliosis
renal U/s, ECHO
VACTERAL, Chiari, tether, syrinx, Klippel feil
Risk of progression in infantile scoliosis
RVAD >20, Cobb>20
Scheuermann’s Kyphosis
AD
Anterior wedging >5 degrees across 3 consecutive vertebrae
Bracing: 60-80 degrees if growth remaining
Fusion kyphosis >75, neuro deficits
Atlantoaxial rotatory instability
C1-C2 subluxation or facet dislocation
Torticollis, Downs, RA, Trauma, infection
CT scan diagnosis
<1 week subluxation: soft collar
>1 week: halter traction and hard collar
>3m, neuro deficits, failed halo traction, C1-C2 fusion
Congenital muscular torticollis
recommend U/S, MRI brain and cervical spine
Passive stretching 1 year (>90% resolution), flat facial features contralateral side
Bipolar relase or Z lengthening
Assocations: DDH, adductus, CV foot (packing disorders)
Pediatric intervertebral disc calcificaitons
unknown, pain and stiffness
Observation
Treatment of spinal TB
CT guided bx
Bracing AntiTB drugs
Surgery if neuro deficits or progressive kyphosis (anterior decompression/corpectomy with posterior stabilization)
7 risk factors of antibiotic failure with epidural abscess
IV abx only if no neuro deficits
Neuro deficits, diabetes, CRP>155, WBC >12, Age>65, MRSA, +blood cultures
