Spine Flashcards
Cervical levels based on regional landmark anatomy?
C2-3: angle of mandible
C3-4: hyoid bone
C4-5: thyroid cartilage
C5-6: cricoid cartilage
The majority of lumbar lordosis is located at these levels?
L4-S1
MEP monitoring threshold in OR?
>75% decrease in MEP amplitude that is sustained
SSEP monitoring threshold in OR?
>10% signal latency
>50% decrease in amplitude
Congenital cervical stenosis definition
<10 mm space available for spinal cord and meet surgical indication for decompression.
<8 mm is absolute, and requires operative decompression in more urgent basis
How to best evaluate OPLL?
CT scan
Myelomalacia vs cord edema on MRI?
Myelomalacia there is cord signal on both T1 and T2.
Cord edema only T2.
Cutoff for the Japanese orthopedic association (JOA) prognostic predictor?
>14 monitor
Below 14 means high risk, patient should be indicated for surgery.
JOA 4 or less means wheelchair bound
What to do if patient has lumbar spinal stenosis with myelopathic features?
Order cervical MRI
Indicators of poor outcome for cervical myelopathy?
***JOA <14
Snake eyes myelomalacia
Older age
Smoking
Space available for cord
Transverse area >70 mm = better
<13 mm mid Sagittal diameter = worse
Surgical algorithm for cervical myelopathy
For cervical myelopathy caused by OPLL, the preferred this approach?
Posterior because high risk of dural tear if going anterior. Only anterior if >10 deg kyphosis
Cord concussion / transient quadriplegia return to play guidelines?
- full resolution of symptoms
- normal strength and sensation
- normal MRI
*must rule out congenital cervical stenosis
Cervical pathology in RA?
1. Basilar invagination
2. Atlantoaxial subluxation
3. Subaxial subluxation (spondylolisthesis at multiple levels, “stair step deformity”)
Why do RA patients have antlantoaxial subluxation?
The pannus between the dens and C1 causes destruction of the transverse ligament
Measure ADI and PADI for surgical decision making (PADI more important)
Atlantoaxial subluxation in RA patient, what are surgical indications?
ADI >10
PADI <14
Treatment is C1-C2 fusion
Collagen in annulus fibrosis?
Type 1
Collagen in nucleus pulposis?
Type 2
Common palsy after cervical spine surgery?
C5
Observation is treatment
Hypoglossal nerve injury can occur with this approach?
High cervical anterior approach (c2-3, c3-4)
Tongue deviates toward side of injury
Forces head/neck extension results in this cord syndrome? Generally in elderly.
Central cord syndrome
Greater motor deficits in upper extremities than lower extremities
Treatment:
- nonop: symptoms improving, no pre-existing myelopathy
-operate: existing severe stenosis, worsening symptoms, pre-existing symptomatic myelopathy
Anterior spinal cord injury/ anterior cord syndrome?
Usually after vascular procedure where the vasculature to the anterior spinal artery is disrupted.
Worse lower extremity function than upper. Loss of pain and temp.
Put in ICU and push MAPs, no surgical intervention indicated
Brown-sequard syndrome
Loss of ipsilateral motor and proprioception.
Loss contralateral pain and temp.
High rate of recovery
In addition to surgically stabilizing the spine in DISH and ankylosing spondylitis trauma what else needs to be done and why?
Decompression due to high rates of compressive epidural bleeds.
