spine Flashcards
biceps reflex nerve root
C5
brachioradialis tendon reflex nerve root
C6
tricpes tendon reflex nerve root
C7
wrist extension nerve root
C6
wrist flexion nerve root
C7
finger flexion nerve root
C8
achilles tendon reflex nerve root
S1
tib ant nerve root
L4
EDL nerve root
L5
what ADI indicates mechanical instability in RA?
> 9-10 mm
what PADI/SAC indicates mechanical instability in RA and is an indication for surgery?
< 14 mm
most common location for degen spondy
L4-L5
most common location for isthmic spondy
L5-S1
amount of correction with Smith-Pete osteotomy
5-10 degrees sagittal plane
amount of correction with pedicle subtraction osteotomy
30 degrees sagittal plane
amount of correction with vertebral column resection
30-40 degrees sagittal plane
in adult deformity what is the most reliable predictor of clinical symptoms post op
sagittal balance
GAG and collagen content in the annulus fibrosus?
low GAG, high collagen
GAG and collagen content in the nucleus pulposus?
high GAG, low collagen
what happens to the aging disc?
decreased water content, GAG, proteoglycans, chondroitin sulfate. increased collagen diameter, keratin sulfate
most sensitive imaging for isthmic spondy
SPECT
what symptoms is a/w worse prognosis in myelopathy?
LE weakness (corticospinal tracts)
what amount of AADI motion on flexion and extension indicates instability in RA atlantoaxial subluxation?
> 3.5 mm
safe zone for anterior halo pin placement
above eyebrow, middle to lateral third to avoid supraorbital nerve
anterior cord syndrome
spinothalamic tract - loss of motor, pain, and temperature. preserved proprioception and deep pressure
brown-sequard syndrome
ipsilateral loss of motor and proprioception, contralateral loss of pain and temperature
posterior cord syndrome
loss of proprioception, vibration, deep pressure
symptoms of autonomic dysreflexia
HTN, headache, flushing, sweating, blurred vision, nasal congestion
which spinal cord injury syndrome has the worst prognosis?
anterior cord syndrome
which spinal cord injury syndrome has the best prognosis?
brown-sequard
powers ratio
basion to posterior arch of atlas divided by opisthion to anterior arch of atlas
what radiographic measurement indicates transverse ligament rupture?
combined lateral mass displacement greater than 6.9 mm
what does ADI > 3.5 mm indicate
transverse ligament damaged
what does ADI > 5 mm indicate
transverse and alar ligaments damaged
risk factors for nonunion in type 2 dens fracture
displacement > 5mm, posterior displacement, age > 40, delayed treatment, angulation > 10 degrees
best posterior fixation construct for C1-2
harms C1 lateral mass-C2 pedicle screw. modified Gallie is worst (autograft iliac crest over C2 spinous process + 1 sublaminar wire)
what determines stability of a Jefferson fracture?
integrity of transverse ligament
what is a jefferson fracture and what causes it
traumatic spondylolisthesis of axis due to C2 fracture, hyperextension and secondary flexion
different in jefferson fracture type 2 and 2a morphology and treatment
2 - vertical fracture line, treat with traction. 2a horizontal fracture line, treat with compression halo (traction makes it worse)
threshold that indicates pedicle breach
<8
significant changes on neuromonitoring
50% decrease in amplitude, 10% increase in latency
when is combined anterior-posterior cervical decompression and fusion indicated for myelopathy?
cervical kyphosis > 12 degrees and > 2 levels of compression
what type of neuromonitoring is most sensitive early indicator of intra-op spinal cord injury?
MEPs
activity modifications for Down syndrome patient with ADI 4.5-10 mm, >10 MM
4.5-10 = represents hypermobility, may participate in most activities but avoid high risk sports. >10 = instability, need surgery
what technical factor increases the risk of adjacent segment ossification in ACDF
placing the plate within 5 mm of the proximal disk
at what level are the lumber nerve roots most at risk during an MIS approach
L4-L5
order of closure of neurocentral synchondrosis
develops between centrum and posterior neural arches. closes in cervical first, then lumbar, then thoracic last