Spine Flashcards

1
Q

unilateral facet dislocation X-ray finding and presentation

A

leads to ~25% subluxation on xray

associated with monoradiculopathy that improves with traction

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2
Q

bilateral facet dislocation X-ray?

A

leads to ~50% subluxation on xray

often associated with significant spinal cord injury

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3
Q

Mechanism and location of cervical facet fracture and dislocation

A

flexion and distraction forces +/- an element of rotation

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4
Q

What levels do cervical facet fractures occur at most often?

A

~75% of all facet dislocations occurred within the subaxial spine (C3 to C7)
17% of all injuries were fractures of C7 or dislocation at the C7-T1 junction
reinforces need to radiographically visualize the cervicothoracic junction

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5
Q

Flexion distraction injuries of the c-spine according to Allen-ferguson have four stages, what are they?

Bonus: what ligament is intact in unilateral dislocations but not bilateral? What ligament is intact in both?

A

Stage 1: facet subluxation
Stage 2: unilateral facet dislocation
Stage 3: bilateral facet dislocation with 50% displacement
Stage 4: complete dislocation

PLL/ALL

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6
Q

Role of MRI in cervical facet dislocations after successful closed reduction, how do they guide treatment?

A

Surgical stabilization following successful closed reduction
PSF or ACDF can be performed in the absence of significant disc herniation
ACDF performed if significant disc herniation present

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7
Q

What improves cervical radiculopathy?

A

Shoulder abduction

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8
Q

Treatment of odontoid fractures in elderly.

Taken from JAAOS Hsu et al 2010

A

Type 1 and 3: collar
Type 2 stable: collar
Type 2 unstable: Posterior C1-2 fusion

Posterior C1-2 fusion high rate of morbidity and mortality in this age group (approx 20%) but still lower than use of a halo-vest (approx 40%).

A nonunion of type 2 is acceptable in this age group provided no s/s of myelopathy. Hence OK to treat stable 2s in a collar alone.

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9
Q

Treatment of odontoid fractures in non-elderly.

Taken from JAAOS Hsu et al 2010

A
Type 1 and 3: Collar
Type 2b (Grauer modification with fracture line anterosuperior to posteroinferior): Good pattern for anterior odontoid screw.

Type 2: Low risk: Use halo-vest (or collar, but collar associated with higher nonunion rate (50% vs 30% with halo vest)

High risk: Surgical. Dealers choice of anterior screw, vs posterior C12 fixation, etc.

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10
Q

Risk factors for odontoid nonunion

A
Age >40
Posterior displacement >5mm
Angulation >11 degrees
Neurologic deficits
Comminution of fracture

Ekong et al (from the Hsu JAAOS article 2010)

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11
Q

Describe harris lines and rule of 12

A

BAI: basion-posterior axial interval
BDI: basion-dens interval

Each should be 12 or less

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12
Q

List 7 ligamentous constraints of the upper C spine

A

Tectorial membrane (PLL)
Cruciate ligament (which includes transverse ligament)
Alar ligments (dens to condyles)
Apical ligment (dens to basion)
Nuchal ligament (external occipital protuberance to the posterior atlas and spinous processes)
Superior continuation of ALL
Superior continuation of ligamentum flavum

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13
Q

Outline treatment for occipital condyle fractures for types 1-3

A

Type 1. (comminuted condyle from compression/impaction mechanism). Stable and treat in collar

Type 2. basal skull # extending into condyle. Stable and treat in collar

Type 3. Associated with avulsion off condyle. If stable can be treating with collar. If unstable should to O-C2 fusion. Stability can be sorted out with dynamic manual traction under fluoro, or halo traction with lateral imaging. Any distraction >2mm means it’s unstable (either fracture distraction or O-C distraction.

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14
Q

Indications for Rigid Collar or Halo in atlas fracture

A

Isolated anterior or posterior ring fracture (with intact transverse ligament)

Stable burst (jefferson) ie. with combined lateral mass displacement of less than 7mm

Stable unilateral lateral mass fracture (may need MRI to sort out when transverse ligament intact to confer stability)

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15
Q

Indications for surgery in atlas fractures

A
  1. Plough fracture (dens driven through anterior arch of C1)
  2. Unstable burst (jefferson) with combined lateral mass displacement of >7mm
  3. Unstable unilateral lateral mass fracture (ie. transverse ligament ruptured).

If reducible in supine traction but displaces when you attach halo, can just leave them for 6 weeks in traction.

Usually Occ to C2 fusion, option to Atlas ORIF but not easy.

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16
Q

Levine and Edwards classification of Hangman’s #

A
  1. Bilat pars fracture minimally displaced. HALO.
    1A. Unilat pars with contralateral body fracture. (side bend mechanism). HALO.
  2. Bilateral pars # with >3mm translation
    Reduce with traction/extension and use Halo vest 12 weeks. Mechanism is rebound flexion after hyperextension and axial load. Stable to apply traction. Can operate if residual displacement after reduction. C1-3 posterior or C23 ACDF.

2A. Bilateral pars # with more oblique pattern. Usually angulated moreso than translated. Associated with C23 disc and PLL disruption because mech is flexion/distraction. Interspinous ligs gone too. Very unstable (ALL is only thing intact). Reduce in extension. Do not apply traction!
Tx: HALO if reduces, if still displaced do C23 ACDF or posterior C1-3 fixation.

  1. Bilateral pars # with C23 facet dislocations.
    Mech is hyperflexion then hyperextension. Mandatory to do posterior open reduction (won’t be able to reduce with traction). Options are C1-C3 fusion. Or preserve atlantoaxial motion by placing interfrag screws in C2 across fracture and fuse to C3.
    Must use halo postop.
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17
Q

SLIC classification

A
Morphology:
Compression 1
Burst 2
Distraction 3
Translation 4

Discoligamentous:
Intact 0
? 1
Disrupted 2

Neuro:
Intact 0
Root involvement 1
Complete 2
Incomplete 3
Add +1 for continuous cord compression

NONOP 3 or less

4: consider for surgery
5: operative

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18
Q

C - spine stability (White and Panjabi)

A

Unstable if >5points

2 points each:
Anterior element injury, posterior element injury, translation >3.5mm, kyphosis >11deg, positive stretch test >1.7mm, SC injury

1 point each:
Root injury, abnormal disc space narrowing, dangerous anticipated loads

Orthobullets adds: >25% vertebral body height loss

19
Q

List factors that may preclude use of C1-2 transarticular fixation

A

Medial VA trajectory
Hypoplastic C2 pars
Irreducible C1 C2 position
Large thoracic kyphosis blocking low trajectory.

20
Q

2 risks with anterior penetration during C12 transarticular screws

A

Internal carotid artery

Superior hypoglossal nerve

21
Q
Preop predictors for clinical outcome in LSS surgery?
HINT:
Radiologic
Comorbidities
Depression
Symptoms

Aalto et al Spine 2006
“Preoperative Predictors for Postoperative Clinical Outcome in Lumbar Spinal Stenosis”

A

Radiologic:

  • AP stenosis diameter = 6mm on myelogram predicted less pain postop
  • Stenosis cross-sectional area on MRI = 70mm2 had better postop Oswestry score than CSA >70mm2.
  • Preop scoliosis predicted worse postop pain.

Comorbidities:

  • Better preop walking capacity predicted better postop walking capacity.
  • Preop cardiovascular comorbidity predicted worse outcomes.

Depression:
-Depression and unrealistic expectations did worse.

Symptoms:

  • Shorter symptom duration associated with less postop pain (in lateral stenosis only).
  • Preop back-dominant pain had worse satisfaction.
22
Q

Straight leg raise tests which roots?

Femoral nerve stretch tests which roots?

A

SLR: L4-S3
FN:L2-L4

23
Q

Does duration of symptoms matter in lumbar spinal stenosis WRT outcomes?

Radcliff et al 2011 SPINE
(subgroup analysis of SPORT trial)

A

Patients with duration of symptoms 12 mos.

For patients with degenerative spondy, there was not difference in outcomes with respect to duration in symptoms.

24
Q

What are the anatomic borders of the lateral recess

A

Posterior: superior articular facet
Anterior: Disk and vertebral body
Medial: Thecal sac
Lateral: Pedicle

25
Q

4 radiographic signs of instability in lumbar degenerative spinal stenosis.

A

Spondylolisthesis on lateral xray
Lateral listhesis on AP xray
Widened facets on T1 MRI
Fluid-filled facets on T2 MRI

26
Q

Complications with laminectomy (isolated) for LSS

2012 JAAOS Issack et al

A

Dural tear 10% (does not affect outcome)
Infection 2%
Postlaminectomy Instability 3.7%
Epidural hematoma (rare)

27
Q

Adult isthmic spondy - which level at higher risk of slip progression? L45 or L5S1?

A

L45 higher risk of slip progression

JAAOS Jones et al 2009, pg 610

28
Q

Compare and constrast DISH vs AS

A
DISH:
non-marginal syndesmophyes (candle wax) @ min. 3 consecutive levels
No SI involvement
HLA B27 negative
Tends to be older age
Disk space preserved
No osteopenia
RF: gout, DM, hyperlipidemia.
Can have hoarseness, dysphagia
AS:
Marginal syndesmophytes (bamboo spine)
SI joints involved first (spine later, +/- uveitis)
HLA B27 usually positive
RF usually negative
Younger patient (20s-30s at onset)
Disk space ossifies
Yes osteopenia
Other probs include cardiac conduction, aortitis, pulm fibrosis, renal amyloidosis
Have
29
Q

In spine mets, surgery then rads? OR rads then surgery?

A

Surgery first, rads second is better.
Patchell: patients who had rads first then crossed over to surgical arm did worse.

JAAOS 2011

30
Q

Factors influencing choice of Ant vs Post c spine approach in myelopathy.

A
Sagittal alignment
Number of levels (disease extent)
Location of compressive pathology (ant or post)
Premorbid neck pain
Any prior operations
31
Q

Anterior approach to lumbar spine. Nerve on psoas? Two nerves lateral to psoas?

A

On psoas: genitofemoral

Lateral to psoas: Ilioinguinal & Iliohypogastric

32
Q

Outline ECOG stages for determination of performance status in spinal mets patients

A

ECOG
0 Fully active: able to carry on all predisease activities without restriction
1 Restricted in strenuous activity; ambulatory; able to perform light work
2 Ambulatory; able to perform self care; unable to work; bedridden ≤50% of the time
3 Limited self care; bedridden ≥50% of the time
4 Completely disabled; incapable of self care; bedridden

33
Q

Mechanism (4) of steroid treatment in metastatic spine lesions.

Dose of steroids?

A

Reduce vasogenic edema
Reduce inflammation
Stabilize liposomal membranes
Some tumourlytic effect in MM/Lymphoma

100mg IV Decadron, then 24mg IV q6h

34
Q

Common treatment algorithm for spine rads to metastatic spine disease.

A

30 Gy in 10 fractions

35
Q

In spine mets, surgery then rads? OR rads then surgery?

A

Surgery first, rads second is better.
Patchell: patients who had rads first then crossed over to surgical arm did worse.
Also, surgery then rads much better than rads alone.

JAAOS 2011

36
Q

Spinal Instability Neoplastic Score (SINS)

A
Location in spine
Pain relief with recumbancy
Type of lesion (lytic, blastic, etc)
Malalignment
Vertebral collapse
Posterior element involvement
37
Q

Outcomes of PSF alone vs circumferential fusion for low-grade adult isthmic spondy.

JAAOS 2009 Jones

A

Better clinical outcomes reported with PSF combined with ALIF/PLIF vs PSF alone.

38
Q

Take home message from SPORT trial

JAAOS 2012 Asghar

A

HNP: randomized cohort - surgery better but not stat significant. OBS cohort - as treated analysis, surgery statistically better. Magnitude of treatment effect not as high with HNP.

DS and LSS: high level of crossover. As treated analysis of OBS cohorts show very significant benefit to surgery.

Overall: 2-3 % infection, 10% dural tear (3% in HNP), 10-15% reoperation rate. No paralysis, and nerve root injury EXTREMELY rare.

39
Q

Which gets more adjacent level degeneration/disease in the cervical spine? ACDF or non-fusion procedure?

Cho JAAOS 2013

A

Similar rates of adjacent level degen/disease regardless of fusion or non-fusion procedure.

No evidence that a fusion procedure leads to adjacent level degen.

40
Q

Based on Hildebrand study, 1999, who gets more adjacent level disease in the C-spine - single level fusion or multilevel fusion?

Cho JAAOS 2013

A

Statistically lower rates of adjacent disease in the multilevel fusion (12%) vs 18% for single level fusion

RFs for developing adjacent level disease?

  • Preexisting spondylotic change
  • Procedures next to C5-6 and C6-7
41
Q

Risk factors for wrong site spinal surgery.

A
Emergent surgery
Obese patient
Hx of prior surgery (altered anatomy)
Unfamiliar equipment
2 surgeons involved
Multiple procedures during one surgery
Misinterpret intraop xray
42
Q

Indications to operate on discitis

A

Failure to respond to antibiotics
Progressive neuro deficit
Progressive deformity

43
Q

Surface landmarks for anterior spine approach

A
C3 - hyoid bone
C4/5 - thyroid cartilage
C5 - cricoid cartilage
C7 - most prominent
L2 Renal artery
L4 Aortic bifurcation
S1 Iliac bifurcation
44
Q

Pearls for thoracoabdominal approach

A

For access to T12 and L1, diaphraghm has to be cut.
Above T12 - principles of thoracotomy
Below L1 - principles of lumbotomy

For T12-L1
Gain access to thoracic cavity posteriorly (cut parietal pleura)
Gain access to retroperitoneum anteriorly (cut three layers of abdominal musculature)
To connect the retroperitoneum to the thoracic cavity, the diaphragm must be cut. Leave 1cm peripheral flap for later repair.