Spine Flashcards
Name the 3 spinal columns and their contents
Anterior Column: anterior 2/3 of vertebral body + ALL
Middle Column: posterior 1/3 of vertebral body + PLL
Posterior Column: pedicles, lamina, ligaments
When do you have a high likelihood of spinal instability after trauma?
When there is injury to 2 or more columns (and especially if there is injury to the posterior ligaments)
Clues of spinal instability after trauma
Chance fracture (posterior stability lost)
Widened interspinous distance/facet diastasis
Widened interpedicular distance on AP
Retropulsion/loss of posterior vertebral height on lateral
Progressive kyphosis with non-op management
What is a Chance fracture (Lumbar)
- Involves all 3 columns, “seat belt injury”
- Flexion-distraction injury (mechanism) where the anterior column fractures under compression and the middle and posterior columns fail under tension (often see a transverse fracture through the posterior vertebral body and fx through posterior column or injury to posterior ligaments).
- Commonly have GI injuries
What is Neurogenic shock?
Systemic hypotension from diffuse vasodilation after SCI (does not refer to motor/sensory/reflexes)
What is Spinal shock?
Temporary neurologic response after SCI with absence of motor, sensation, reflexes (does not refer to circulatory collapse).
*Determine status of spinal shock by bulbocavernosus reflex (this is one of the first reflexes to return after spinal shock. Lack of motor and sensory function after the reflex has returned indicates complete SCI)
What is the ASIA classification?
-Grading scale for spinal cord injury, A->D
-Must not be in spinal shock (check bulbocavernosus reflex)
“E is for everyone” - totally normal
A = Complete, no motor, complete deficit sensory B = Incomplete, no motor, incomplete deficit sensory C = Incomplete, more than half of muscles below the level of injury have grade LESS THAN 3, incomplete deficit sensory D = Incomplete, more than half of muscles below the level of the injury have grade GREATER THAN 3, incomplete deficit sensory E = Normal, nl motor, nl sensory
*Level named is the last FULLY INTACT level, ex: C5 ASIA B means that deltoid is working but biceps is not
Central Cord Syndrome
Elderly person with neck hyperextension mechanism.
Symptoms: More profound motor weakness of the upper extremities and less severe weakness of the lower extremities. A varying degree of sensory loss below the level of the lesion and bladder symptoms (urinary retention) may also occur.
Most common incomplete spinal cord injury.
Affects lateral corticospinal tract.
Burst Fracture (Lumbar)
Fracture involving the anterior and middle columns.
Occurs from axial loading + flexion
Can cause retropulsion into canal which can cause neuro deficits (these fragments will resorb over time and it is rare to see progression of neuro deficits)
*Should get MRI to confirm no posterior ligament injury, if present this is not a burst fx
-Non-op = neuro intact and posterior column intact, WBAT
-Operative = if neuro deficit and imaging shows compression, if posterior column is not intact, treat with decompression (ie. laminectomy) + fusion
Compression fractures involve this column only
Anterior
Flexion teardrop fracture (cervical)
Equivalent of chance fracture in the cervical spine.
- Failure of posterior column in tension
- Usually have SCI present
- Unstable and needs surgery
Extension teardrop fracture (cervical)
Avulsion from neck hyperextension
- No posterior injury present
- Usually non-op w/ C-collar
How many columns do each of these injuries involve..
Burst
Chance
Burst = 2 columns (anterior and middle, although PLL should be intact) Chance = 3 columns
Chance fracture mechanism?
Flexion distraction injury (“seat belt injury”) that disrupts all 3 columns. The anterior column fails in compression, the middle and posterior columns fail in tension.
Seat belt injury, thus commonly have GI injuries.
Posterior column can fail through ligaments or through bone.
Chance fracture treatment
Operative in most cases via surgical decompression and stabilization
-indications: neurologic deficit, patients with injury to the posterior ligaments
Nonoperative
-indications: bony chance fracture in posterior column which lends to stability and no neurologic deficits
Compression fracture involves what column
anterior
Compression fracture treatment
Nonoperative:
- Almost everyone
- Calcitonin x4 weeks for pain improvement
- Consider starting bisphosphonates for osteoporosis management
- Bracing not necessary but can help pain
Operative:
- Kyphoplasty can be considered if at 6 weeks still having pain
-DO NOT DO VERTEBROPLASTY (AAOS Guideline)
Facet dislocations occur via this mechanism
flexion + distraction
Facet dislocation treatment
Awake patient…
- Closed reduction, then MRI, then fusion
- Monitoring neuro status during reduction
- If change in neuro status during reduction this triggers MRI and then more immediate operative fusion (MRI can demonstarte disc herniation, myelomalacia, whether posterior ligaments intact)
Obtunded patient…
- MRI first, then open reduction + fusion
(Need to know if you have a disk fragment pushing on the cord to plan anterior vs posterior surgery)
Dens fracture location and classification
Type 1: Tip -> C-collar
Type 2: Base of dens (watershed) -> Operative (Halo possible if patient is young to preserve ROM)
Type 3: Extends into C2 body -> C-collar
Lumbar disc herniation location types and nerve roots affected…
Considering L4-5 disc herniation as an example…
- Central Prolapse: associated with back pain and cauda equina
- Paracentral (aka posterolateral): most common (weak area of PLL), affects the traversing/descending nerve root (L5) as it travels inferior around the inferior lumbar pedicle.
- Foraminal (far lateral): affects exiting or upper nerve root (L4)
Ankylosing spondylitis
Seronegative autoimmune arthropathy (ie negative rheumatoid factor)
+HLA B-27
4:1 male to female, begins in 20s
May be associated with uveitis
-Inflammation of enthesis -> bony erosion -> tissue ossification
- Affects SI joints, spinal joints, pubic symphysis, disc annulus
Exam findings in ankylosing spondylitis
<2 cm chest wall expansion
Painful SI joint exams (+FABER)
Ankylosing spondylitis commonly has advanced arthritis of hips and shoulders. If patients have hip dislocations after THA, they are at a much higher risk of dislocating _____
anteriorly
This is true because of the fixed spinal deformity where they often compensate by hyperextending through their hips
