Spine Flashcards
In infantile scoliosis, a Cobb angle of what is associated with progression?
> 20 DEGREES
What two types of infantile scoliosis are there?
Resolving type and progressing type
What advanced imaging needs to be obtained in infantile scoliosis and why?
MRI; rule out syrinx, tethered cord, cyst or tumor
What genetics are associated with infantile scoliosis?
Autosomal dominant with variable penetrance
What is thoracic insufficiency syndrome?
Characterized by decreased thoracic growth and lung volume
In infantile scoliosis, pulmonary function impairment is associated with curves above what degree?
> 60 degrees
In infantile scoliosis, cardiopulmonary issues are associated with curves above what degree?
90 degrees
In infantile scoliosis, what foot deformity can be seen on exam?
cavovarus
Abnormal abdominal reflexes is associated with what in the setting of infantile scoliosis?
Presence of a syrinx
A Cobb angle greater than what degree is associated with progression of a curve in infantile scoliosis?
> 20 degrees
A rib vertebral angle difference (RVAD) greater than what degree is associated with curve progression in infantile scoliosis?
> 20 degrees is linked to a high rate of progression; <20 degrees is associated with spontaneous recovery
What are the indications for nonoperative management of infantile scoliosis?
Cobb angle <30 degrees; RVAD <20 degrees; 90% will resolve spontaneously
What are the indications for serial Mehta casting in infantile scoliosis?
Cobb >30 deg, flexible curve, RVAD >20 deg, phase 2 rib-vertebrae relationship (rib-vertebral overlap)
What are the indications for growing rod constructs in infantile scoliosis?
Cobb >50 deg to 60 deg
Spinal fusion before what age results in pulmonary compromise?
Fusion before age 10
What pulmonary function tests are improved with growing rod constructs?
FVC
Herniated discs are associated with a sudden increase in what factors?
Osteoprotegrin, interleukin-1 beta, RANKL, and PTH
What are the risk factors for nonunions in patients with type II odontoid fractures?
Fracture gap >1 mm; delay in treatment >4 days; posterior displacement >5 mm; posterior displacement after application of halo vest of >2 mm
How many pins are used for adult halo pin placement?
4 pins
How many pins are used for pediatric halo pin placement?
6-8
What is the torque for adult halo pins?
8in-pounds of torque
What is the torque for pediatric halo pins?
lower than adults - 2-4in pounds of torque (finger tight)
What is the most common nerve injured in halo orthoses?
Abducens (CN VI); loss of lateral gaze on affected side
BMP-2 is FDA approved for which spine procedure?
Single-level ALIF
What is the annulus fibrosis composed of?
type I collagen (oriented obliquely), water, and proteoglycans
What is the proteoglycan to collagen ratio for the annulus fibrosis?
high collagen / low proteoglycan ratio
What is the nucleus pulposus composed of?
composed of type II collagen, water, and proteoglycans (~88% water)
What is the collagen to proteoglycan ratio of the nucleus pulposus?
low collagen / high proteoglycan ratio
What is the innervation of the vertebral disc?
the dorsal root ganglion gives rise to the sinuvertebral nerve, which innervates the superficial fibers of annulus
Herniated disks are associated with a spontaneous increase in the production of what?
Osteoprotegrin, IL-1beta, RANKL, PTH
Disc aging leads to a loss of what?
Overall water content, a decrease in water, proteoglycans, nutritional transport, viable cells, pH
Disc aging leads to an increase of what?
lactate, keratin sulfate to chondroitin sulfate ratio, degradative enzyme activity, density of fibroblast-like cells
What is considered a significant change in SEPs intraop?
50% decrease in amplitude, or 10% prolongation in latency
What is considered a significant change in MEPs intraop?
> 100 V increase in threshold, >50% decrease in MEP amplitude
What is pathognomonic of intervertebral disk (IVD) degeneration?
degradation of large proteoglycan molecules in the nucleus pulposus
Disc aging leads to an overall loss of water content and conversion to what?
fibrocartilage
What type of collagen is found in the nucleus pulposus?
Type II
What type of collagen is found in the annulus fibrosus?
Type I
Annular tears and fissures occur most frequently in what location?
Annular tears and fissures occur most frequently in the posterolateral location of the annulus fibrosis
What is the most abundant proteoglycan in the intervertebral disc?
Aggrecan
Within the intervertebral disk, aggrecan is primarily responsible for:
Aggrecan’s primary function in the intervertebral disc is to maintain water content
What are the 5 components of the disc that decrease with aging?
water, proteoglycans, nutritional transport, absolute number of viable cells, pH
What are the 4 components of the disc that increase with aging?
- keratin sulfate to chondroitin sulfate ratio
- lactate
- degradative enzyme activity
- density of fibroblast-like cells (fibroblast-like cells reside in the annulus fibrosus only)
What is the innervation to the disc?
the dorsal root ganglion gives rise to the sinuvertebral nerve, which innervates the superficial fibers of annulus
What two cervical spine injuries are risk factors for vertebral artery injury?
atlas fracture, facet dislocations
How is neurogenic shock characterized?
characterized by hypotension and relative bradycardia
How is neurogenic shock treated?
Swan-Ganz catheter and pressers
What are the characteristics of spinal shock?
Areflexia (flaccid paralysis), absent bulbocavernosus reflex, bradycardia and hypotension (lack of sympathetic response)
When does spinal shock usually resolve?
Within 48 hours of injury
At what level is intubation usually required in a spinal cord injury?
SCI above C5 likely to require intubation
Seat belt sign should raise suspicion for what type of spinal cord injury?
seat belt sign (abdominal ecchymoses) should raise suspicion for flexion distraction injuries of thoracolumbar spine
How does autonomic dysreflexia present?
Headache, agitation, hypertension (usually due to visceral stimulation)
What is the embryology of the atlas? (Number of ossification centers & their names)
Three ossification centers; two neural arches and one body
What is a relatively common anatomic variation of the atlas?
Incomplete posterior arch
What ligament is the primary stabilizer of atlantoaxial junction?
The transverse ligament; prevents posterior migration of the odontoid into the spinal canal
What is the function of the atlantoaxial transverse ligament?
prevents posterior migration of the odontoid into the spinal canal
What is the function of the paired alar ligaments?
connect the odontoid to the occipital condyles; contributes to occipitocervical stability
What joint articulation provides ~50% of cervical spine flexion and extension?
Occiput-C1; the atlanto-occipital joint
What radiographic findings are indicative of a transverse ligament rupture?
ADI > 3 mm; LMD >6.9 (Spence) or >8.1 (Heller)
What is a normal ADI (atlantodental interval)?
<3 mm in adult; <5 mm in child
What is a normal value for space available for the cord (SAC)?
Greater than or equal to 13
What is the blood supply to the apex of the dens?
Branches of the internal carotid artery
What is the blood supply to the base of the dens?
Branches from the vertebral artery
What is the trajectory for a C1 lateral mass screw?
10°medial, 22°cephalad
What structure is at risk with perforation of the anterior cortex when placing a C1 lateral mass screw?
Internal carotid artery
What are 3 criteria for acute closed reduction with traction of a c-spine injury?
- awake & alert
- neurologic deficit
- compression due to fracture/dislocation
What are 3 reasons to abort attempted acute closed reduction with axial traction?
- worsening neurologic exam
- failure to reduce
- overdistraction
What demographic group is most commonly affected by central cord syndrome?
elderly with minor extension injury
What are other associated injuries with atlas fratures and transverse ligament fractures?
50% with spine fractures; closed head injuries; neurologic injury (low due to space for spinal cord
What percentage of patients with spinal cord injuries suffer from MDD?
~11%
What is the most common cause of incomplete tetraplegia?
Central cord syndrome
How should patients with a potential spinal cord injury be immobilized initially?
rigid C collar, firm spine board with lateral supports
What 3 sensory inputs travel through the lateral spinothalamic tract (LST)?
pain, temperature, gross sensation
What 3 sensory inputs travel through the dorsal columns?
proprioception, vibration, fine touch
What clinical exam finding does a unilateral C5/6 facet dislocation have?
C6 radiculopathy; Numbness radiating down to the thumb, weakness in wrist extension
What clinical exam finding does a unilateral C6/7 facet dislocation have?
C7 radiculopathy; Numbness radiating to the index and long finger, weakness in wrist flexion, triceps
What radiographic findings are associated with instability in a cervical lateral mass seperation?
> 3.5 mm of displacement, >10 deg kyphosis, >10 deg of rotational difference compared to adjacent vertebra
Thoracolumbar burst fractures typically occur at what level(s)?
T10-L2
The posterior ligamentous complex of the spine consists of what structures?
supraspinous ligament, interspinous ligament, ligamentum flavum, and facet capsule
The thoracolumbar Injury Severity Score (TLISS) is based on what three injury axes?
- Injury mechnism/morphology
- Neurologic status
- Integrity of PLC
A score greater than what number indicates surgical management in TLICS/TLISS?
> 4 (ie 5 of greater suggests operative management)
A hyperactive bulbocavernosus reflex is suggestive of what?
Disinhibition and a complete SCI
In patients with symptoms of cervical myelopathy, what variable is associated with improved outcomes with nonoperative management?
Transverse area of the spinal cord >70mm2
Is a cervical laminoplasty a motion-preserving technique?
yes
What are the contraindications to cervical laminoplasty?
- kyphosis >13 deg (does not adequately decompress; bowstringing of spinal cord)
- severe axial neck pain
Fixed kyphosis of >13 deg is a contraindication to what cervical spine surgeries?
posterior only procedures
Anterior cervical fusion combined with what posterior procedure has the theoretical benefit of decreased muscular atrophy and preserved muscle attachments?
Laminoplasty
What are the indications to combined anterior and posterior cervical spine surgery?
- multilevel stenosis in the rigid kyphotic spine
- multi-level anterior cervical corpectomies
- postlaminectomy kyphosis
Why is a cervical laminectomy alone almost never indicated?
progressive kyphosis - 11 to 47% incidence if laminectomy performed alone without fusion
Is there a higher rate of surgical site infection in posterior or anterior cervical spine surgery?
Posterior
Bilateral keyhole foraminotomies at the C4/5 level may help reduce the incidence of what complication?
C5 nerve palsy (reported to occur in ~ 4.6% of patients after surgery for cervical compression myelopathy)
What nerve root palsy is seen in patients after surgery for cervical compression myelopathy?
C5 nerve palsy
Prolonged recovery in a C5 nerve palsy is assoiated with what findings?
- multilevel paresis
- motor grade ≤2
- sensory involvement with intractable pain
Prolonged retractor placement in an ACDF can result in injury to what nerve?
Recurrent Laryngeal Nerve
What is the most likely neurologic complication following cervical laminoplasty?
C5 nerve root palsy
What are the indications for surgery for a thoracolumbar burst fracture?
neurologic deficts with active compression of the neural elemenents and spinal instability in the sagittal plane
**
The TLICS fracture scoring system is based on what?
Fracture morphology, neurologic status, PLC integrity
A TLICS score above what number is indication for surgery?
> 4
How tight should halo pins be in adults?
tighten to 8 inch-pounds (in-lb) of torque
What are the indications for treating thoracolumbar burst fractures nonoperatively?
- patients that are neurologically intact and mechanically stable
- posterior ligament complex preserved
- no focal kyphosis on flexion and extension lateral radiographs
- kyphosis < 30° (controversial)
- vertebral body has lost < 50% of body height (controversial)
- TLICS score = 3 or lower
What MRI findings correlate with a poorer prognosis following decompression for cervical myelopathy?
signal changes on T1-weighted images correlate with a poorer prognosis following surgical decompression
In thoracolumbar burst fractures, what are two injury characteristics associated with a traumatic durotomy?
- splint spinous process
- lamina fracture
What are five instances an anterior decompression and stabilization is preferred for burst fractures?
- neurologic deficits caused by anterior compression (bony retropulsion) , especially above the conus medullaris (above L2)
- allow for thorough decompression of the thecal sac
- substantial vertebral body comminution in order to reconstitute the anterior column
- kyphotic deformity >30°
- chronic injuries (greater than 4-5 days from the injury)
What spinal cord circumference is associated with improved outcomes with nonoperative management in cervical myelopathy?
improved nonoperative outcomes associated with patients with larger transverse area of the spinal cord (>70mm2)
What four structures constitute the posterior ligamentous complex?
- supraspinous ligament
- interspinous ligament
- facet capsules
- ligamentum flavum
What is the origin of pathophysiology in spinal epidural abscesses?
50% hematogenous; 33% spread from diskitis
What is the most common caustative organism is spinal epidural abscesses?
Staph aureus (50-60%); followed by E coli (18); pseudomonas seen in IV drug users
What percentage of patients with a spinal epidural abscess will have neurologic deficit?
33%
What is the imaging modality of choice for diagnosis of spinal epidural abscess?
MRI with gad
A CRP and/or WBC above what level is a risk factor for failure of treating a spinal epidural abscess alone?
> 115 and >12k, respectively
What physical exam finding is a risk factor for failure of treating a spinal epidural abscess alone?
neurologic deficits (strongest predictor of medical treatment failure)
An age great than what is a risk factor for failure of treating a spinal epidural abscess alone?
> 65
Infection with what organism is a risk factor for failure of treating a spinal epidural abscess alone?
MRSA; also a risk factor to have + blood cultures
What is the diagnostic criteria for ankylosising spondylitis?
- +HLA-B27
- uveitis
- bilateral sacroilitis
What is the definition spondylolysis?
defined as complete fracture of the pars interarticularis
What percentage of individuals with a pars interarticularis lesion will have progression to spondylolisthesis?
approximately 15% of individuals with a pars interarticularis lesion have progression to spondylolisthesis
What are 3 indications to obtain an MRI in pediatric spondy?
- acute presentation
- high suspicion but neg radiographs
- neurologic deficit
What slip angle is associated with greater slip progression in pediatric spondylolisthesis?
angle >45-50 degrees associated with greater slip progression, instability, and development of post-op pseudo
What slip angle is associated with development of post-op pseudo in pediatric spondylolisthesis?
> 45-50
How is pelvic incidence measured?
pelvic tilt + sacral slope
What is an indication for L4-S1 posterolateral fusion in spondylolytic spondlylisthesis?
High grade slips (Meyerding grade III, IV, V); remember reduction of slip is controversial (high rate of neurologic impairments)
What is the most sensitive imaging modality to detect fractures in ankylosing spondylitis patients?
CT; entire spinal axis should be imaged in patients presenting with trivial trauma
What is the characteristic finding on MRI studies with gadolinium in an epidural abscess?
a ring enhancing lesion is pathognomonic for abscess
What is the most common nerve root injury in pediatric isthmic sponylolisthesis?
L5 nerve root
How do outcomes of pars interarticularis repair compare to fusion procedures in pediatric spondy?
superior to fusion procedures, preserves motion
What are 2 indications for an L5-S1 posterolateral fusion, +/- ALIF, +/- sacroiliac fusion in pediatric isthmic spondy?
- L5 spondylolysis that has failed nonoperative treatment
- low grade spondylolisthesis (Myerding Grade I and II) that has:
*failed nonoperative treatment
*is progressive has neurologic deficits
*is dysplastic due to high propensity for progression
What is a contraindication to performing a par interarticularis repair in pediatric spondy?
disc degeneration (obtain MRI for surgical planning)
In ankylosing spondylitis, what is the most common site of spine fractures?
C-spine is the most common site of fracture in AS and is most susceptible to hyperextension injuries
What is the definition of diffuse idiopathic skeletal hyperostosis (DISH)?
flowing ossification of the anterior longitudinal ligament for four consecutive levels
What is the definition/lines measured for pelvic incidence?
Pelvic incidence is defined as the angle between the line perpendicular to the sacral plate at its midpoint and the line connecting this point to the femoral heads axis; PI = pelvic tilt + sacral slope
What is the predominant symptom in cervical intraforaminal disc herniations?
predominantly radicular pain
What is the predominant symptom in cervical posterolateral disc herniations?
predominantly motor symptoms
What is the most common location of cervical disc herniations?
Posterolateral
What best view to identify foraminal stenosis caused by osteophytes in the cervical spine?
Oblique radiographs
What percentage of patients over the age of 40 years will have a degenerated discs on cervical MRIs?
greater than 50%
What percentage of patients with cervical radiculopathy improve with nonoperative management?
75%
Return to play can be expedited by admistration of what in cervical radiculopathy?
Medrol dose pack
What remains the gold standard surgical treatment for cervical radiculopathy?
anterior diskectomy and fusion
Is a single level ACDF a contraindication to return to play for athletes?
no
What structure is at increased risk with a left sided anterior approach to C7-T1?
thoracic duct
Theoretically, the recurrent laryngeal nerve is less at risk with a left or right sided approach?
left sided
The recurrent laryngeal nerve passes between the trachea and what structure?
esophagus
What is the gold standard autograft for cervical spine fusion?
Iliac crest bone graft
In cervical arthrodesis, use of allograft has higher rates what complication(s)?
pseudoarthrosis and subsidence
Adjacent segment ossification is more likely to occur in ACDF when the anterior plate is placed within mm of the supra-adjacent disc space?
5 mm
What approach is used for anterior cervical foraminotomy?
anterolateral; the longus colli is split longitudinally
What muscle lies just medial to the anterior tubercle of the transverse process?
longus colli; use of the anterior tubercle is helpful to identify longus colli
What structures are at risk during anterolateral approach to the cervical spine?
sympathetic chain and vertebral artery
The risk of dysphagia in ACDF can be reduced with the use of what implant?
zero-profile anchored cages
Horner’s syndrome is caused by injury to what?
sympathetic chain
The sympathetic chain lies on the lateral border of what muscle at C6?
longus colli
In anterior cervical spine approaches, surgery duration greater than ** what time** is a risk factor for airway complications?
> 5 hours
Exposure above what level increases the risk for airway complications in anterior cervical spine approach?
C4
What is the annual cost of low back pain in the US?
$100 billion
What is the most common cause of low back pain?
Muscle strain
What system/signs are used to evaluate for non-organic low back pain?
Wadell Signs
What are the indications to obtain lumbar spine radiographs in the setting of low back pain?
- pain greater than one month and not responding to nonoperative treatment
- red flag signs are present
Is lumbar disc herniation more common in men or women?
Men; 3:1 ratio
What is the most common level of the spine for lumbar disc herniations?
L5/S1
[…] leads to tears of the outer annulus which leads to herniation of nucleus pulposis
recurrent torsial strain
{…} of posterior longitudinal ligament weakest region
lateral edge
What nerves provide pain innervation to the posterior annulus?
sinuvertebral nerves provide pain innervation to the posterior annulus
Cellular senescence of what cells leads to loss of proteoglycan production leading to disc height loss?
fibrochondrocytes
annular tears compromise […] stresses that act against the deforming forces of the nucleus pulposus
hoop
What factors are implicated in nerve irritation leading to radiculopathy?
MMP, PE2, TNF-alpha, NO, IL-6
[…] matrix is responsible for height of the intervertebral disc
hydrophilic
Intervertebral discs are attached to vertebral bodies by what type of cartilage?
Hyaline
[…] disc herniation affects the traversing/descending/lower nerve root
posterolateral (paracentral)
[…] disc herniations affect exiting/upper nerve root
foraminal (far lateral, extraforaminal)
Foraminal herniated disc material can compress the […] and lead to more severe pain
dorsal root ganglion
Chronic lumber disc herniations are present for longer than how many months?
Over 6 months
Radiculopathy in what nerve root would result in weak hip adduction?
L3
Radiculopathy in what nerve root would result in weak knee extension?
L3
Dermatomal pain in the anteromedial thigh can result from radiculopathy of what nerve root?
L3
Radiculopathy in what nerve root would result in weak ankle dorsiflexion?
L4>L5
Radiculopathy in what nerve root would result in weak patellar tendon reflex?
L4
Radiculopathy in what nerve root would result in dermatomal pain in the lateral thigh and medial foot?
L4
Radiculopathy in what nerve root would result in weak EHL?
L5
Radiculopathy in what nerve root would result in weak ankle inversion?
L5
Radiculopathy in what nerve root would result in weak hip abduction?
L5
Radiculopathy in what nerve root would result in dermatomal pain in the anterolateral thigh and dorsum of the foot?
L5
Radiculopathy in what nerve root would result in weak ankle plantarflexion?
S1
Radiculopathy in what nerve root would result in diminished achilles tendon reflex?
S1
Radiculopathy in what nerve root would result in dermatomal pain in the posterior calf and lateral foot?
S1
At what degree of hip flexion does the SLR test reproduce pain?
30-70 degrees
What is the most important and predictive physical exam finding for identifying who is a good candidate for surgery for a herniated lumbar disc?
SLR
SLR tests for what nerve roots?
L4, L5, S1
What is Lasegue’s sign?
SLR
What is Wasserman sign?
Femoral nerve stretch
Femeral nerve stretch (Wasserman sign) tests what nerve roots?
L2, L3
Trendelenberg gait is weakness in what muscle? This muscle is innervated by what nerve root?
Gluteus medius; L5
What percentage of patients with lumbar disc herniations improve without surgery?
90%
What patient factor is a positive predictor of a good outcome with nonoperative treatment for lumbar disc herniations?
Higher level of education
A higher level of education in a patient with a lumbar disc herniation is a positive predictor for a good outcome with what type of treatment?
Non-operative treatment
What is the indication for seletive nerve root corticosteroid injection in lumbar disc herniations?
No improvement with therapy & medications after 6 weeks
A […] corticosteroid injection approach is best for far lateral disc herniations
transformational (as opposed to interlaminar)
Selective nerve root corticosteroid injections results in long-lasting improvement in what percentage of patients?
50% (as opposed to 90% with surgery)
Selective nerve root corticosteroid injections outcome results are best in patients with […] as opposed to contained discs.
extruded discs
Better surgical outcomes with a laminotomy and discectomy for lumbar disc herniations are observed if addressed within […] months
2 months
Patients may return to medium to high-intensity activity at […] weeks following a laminotomy and discectomy for lumbar disc herniations.
4 to 6 weeks
Improvement in […] are greater with operative compared to nonoperative treatment in patients with lumbar disc herniations
pain and fuction
Improvement in pain and function greater with or without surgery for patients with lumbar disc herniations?
improvement in pain and function is greater with surgery
Improvement in pain and function is […] with surgery for patients with lumbar disc herniations.
greater
Early and sustained pain relief out to […] years is seen in patients who undergo operative as opposed to nonoperative treatment for lumbar disc herniation.
2
[…] likelihood of receiving disability at 5 years in patients who undergo operative versus non-operative treatment for lumbar disc herniations
Equal
A positive predictors for good outcome with surgery in patients with lumbar disc herniations is […] pain as the chief complaint
leg
A […] SLR is a predictor for good outcome with surgery in patients with lumbar disc herniations
positive
Weakness that correlates with nerve root impingement seen on MRI is a […] predictor for a good outcome with surgery in patients with lumbar disc hernitions
positive
Marital status is a […] predictor for a good outcome with surgery in patients with lumbar disc hernitions
Positive
Progressively worsening symptoms prior to surgery are a […] predictor for a good outcome with surgery in patients with lumbar disc hernitions
Positive
In professional athletes with disc lumbar herniations, which two factors portend to good surgical outcomes?
Younger age at injury and greater number of games played
[… and …] herniations are associated with worse surgical outcomes as opposed to [… and …] herniations in lumbar disc herniations.
[central and extraforaminal] herniations are associated with worse surgical outcomes as opposed to [paracentral and foraminal] herniations in lumbar disc herniations.
What are four patient factors that are negative predictors for good outcome with surgery in lumbar disc herniations?
- Worker’s comp
- Chronic headaches
- Smoking
- Depression
Treatment of lumbar disc herniations with a steroid taper has demonstrated significant improvement in […] but no signifiant improvement in […].
signifiant improvement in function, but no significant improvement in pain
Physical therapy with […] exercises is extremely beneficial in the treatment of lumbar disc herniations.
extension
Fragment excision vs extended disc space curettage (subtotal discectomy)in treatment of lumbar disc herniations results in […] long term back pain with fragment excision
lower
Is lower long term back pain seen in fragment excision or subtotal discectomy in the surgical treatment of lumbar disc herniations?
lower long term back pain is seen with fragment excision
[…] reherniation rates are seen with fragment excision at 2-years follow-up for lumbar disc herniation
higher
Higher reherniation rates are seen with fragment excision at […]-years follow-up for lumbar disc herniation
2-years
What approach is used for far lateral lumbar microdiskectomies?
utilizes a paraspinal approach of Wiltse
What is the intermuscular plane for the approach of Wiltse?
Multifidus and longissimus
What structure is palpated for localizing the approach of Wiltse?
transverse process
What structure is at risk with the approach of Wiltse (paraspinal approach)?
dorsal root ganglion (have to dissect above and below the transverse process)
Recurrent herniation of the nucleus pulposus is defined as what?
recurrent sciatica at the same operated level with a pain-free interval of 6 months prior to recurrence of symptoms
What is the rate of recurrence for a herniated nucleus pulposus?
5-15%
Revision rate at 8-year follow-up is […] according to the SPORT trial for recurrent herniated nucleus pulposus
15%
Revision rate at […]-year follow-up is 15% according to the SPORT trial for recurrent herniation of nucleus pulposus
8
Which risk factors are protective against recurrent lumbar disc herniations?
- discrete herniations
- small annular defects (<6 mm)
Annular defects less than what size are protective against rehernition of a lumbar disc?
annular defects less than 6 mm
Outcomes for revision lumbar discectomy have been shown to be […] compared to primary discectomy
as good as/equivalent
Dural tears at the time of surgery for lumbar disc herniations has been shown to effect long-term outcomes how?
has not been shown to adversely affect long term outcomes
Epidural fibrosis is associated with […] outcomes following revision surgery
poor
Patients with epidural fibrosis are […] times more likely to suffer from recurrent radiculopathy
3.2
Patients with epidrual fibrosis are 3.2 times more likely to suffer from […]
recurrent radiculopathy
What changes on MRI imaging are associated with post-operative back pain in the setting of lumbar disc herniations?
Modic changes (vertebral bone marrow signal intensity)
What percentage of patients with lumbar disc herniations will have improvement of symptoms within 3 months without substantial medical treatment?
90%
90% of patients with lumbar disc herniations will have improvement of symptoms within […] months without substantial medical treatment
3
Patients with lumbar disc herniations are less likely to improve if still symptomatic after […] weeks
6
BMI greater than what is a predictor of poor outcome with non-operative treatment of lumbar disc herniation
30
[…] lumbar disc herniations show the greatest degree of spontaneous reabsorption
sequestered
What is the mechanism of lumbar disc resorption in the setting of lumbar disc herniation?
macrophage phagocytosis and enzymatic degradation
In the setting of lumbar disc herniations, surgical treatment is […] to nonsurgical treatment in the long term
equivalent; note - surgery provides faster pain relief
[…] is the reproduction of pain with tilting head to the affected side and rotating head to the ipsilateral side
Spurling’s sign
Spurling’s sign is the reproduction of pain with tilting head to the […] side and rotating head to the […] side
affected; ipsilateral
In the cervical spine the nerve roots exit […] the pedicle of the numbered level.
above (for example, the C7 nerve root exits above the C7 pedicle at the C6-7 level)
An L4-5 posterolateral disk herniation would affect the […] nerve root.
L5
Tibialis posterior is innervated by the […] nerve root
L5
The [… ] nerve supplies the cricothyroid muscle and modulates voice pitch and explosive sounds.
superior laryngeal
Psoas major is innervated by […]
lumbar plexus branches from L1-L3
the […] nerve root would be affected by a disc herniation at the C5/6 level
C6
The recurrent laryngel nerve originates from the […].
vagus nerve (cranial nerve X)
superior laryngeal nerve runs along with the […] artery
superior thyroid
Cauda equina most commonly occurs at what lumbar level?
L4/5
A […] is the most common cause of cauda equina syndrome
disc herniation
Antiplatelet medications can be safely resumed approximately […] hours post-op from spinal procedures
48-72
In cauda equina, long term […] dysfunction is common
urinary
What are three prognostic variable that are associated with a poor outcome with cauda equina syndrome?
- saddle anesthesia
- bladder dysfunction
- delay in treatment >48 hours
The conus medullaris tapers/ends at what spinal level?
T12 or L1 vertebral body
The cauda equina is a collection […] peripheral nerves within the lumbar canal
L1-S5
Why are nerve roots considered to be more susceptible to compression; esp at the cauda equina level?
they are only covered by endoneurium
What parasympathetic nerves promote urination by contraction of the detrusor urinae muscles and relaxation of the internal sphincter?
pelvic splanchnic nerves and the inferior hypogastric plexus
What sympathetic nerves promote urinary retention by relaxation of the detrusor urinae muscles and contraction of the internal sphincter?
hypogastric plexus
The external sphincter of the bladder is controlled by the […] nerve
pudendal nerve; voluntary control
What are the two most common presenting symptoms of cauda equina syndrome?
- back pain (most common)
- bilateral or unilateral leg pain (2nd most common)
Normal post-void residual volume is less than […]
50 to 100 mL
PVR values […] ml with a 97% negative predictive value for cauda equina syndrome
< 200 mL
In cauda equina, motor recovery may continue up to […] post-op
1 year
In cauda equina, bladder function may continue to improve up to […] post-op
16 months
In cauda equina syndrome, what is an indication to perform a laminectomy (bilateral laminectomy and medial facetectomy) as opposed to microdiskectomy?
older patient with degenerative changes included hypertrophic ligamentum flavum, lateral recesss stenosis
[…] is the most common reason for lumbar spine surgery in patients > 65 years old
Lumbar spinal stenosis
Lumbar spinal stenosis most commonly occurs at the […] level.
L4-5; (91%)
In the lumbar spine, facets become more […] as you move inferior
coronal
The spinal facet joints are what type of joint?
zygapophyseal joint
Central lumbar spinal stenosis is defined as a cross sectional area […] on axial CT.
<100mm2; or or <10mm A-P diameter
Lateral recess stenosis (subarticular recess) affects the descending or traversing nerve root?
Descending
Overgrowth of the […] articular facet is usually the primary culprit in lateral recess stenosis (subarticular recess)
superior
In the treatment of lumbar spinal stenosis, preoperative opioid use is associated wiht what?
prolonged hospital stays and increased post-operative pain
Removal of greater than […] of the facet joint results in instability
50%
In lumbar spinal stenosis, patients treated with surgery are at risk of adjacent segment degeneration >30% at […] years
10
In a wide pedicle to pedicle decompression for lumbar spinal stensosis, improvement is seen in what three outcomes with surgical treatment?
- pain
- function
- satisfaction
[…] are strongest predictor of clinical outcomes after decompression for lumbar spinal stenosis
comorbid conditions
After decompression for lumbar spinal stenosis, what is the most common cause for failed surgery?
recurrence of disease above or below decompressed level
What is the most common MAJOR complication following surgery for lumbar spinal stenosis?
Infection; seen in 10%
[…] nerve deficits common following a transpsoas approach at higher lumbar levels
genitofemoral
Genitofemoral nerve deficits common following a […] approach at higher lumbar levels
transpsoas
Genitofemoral nerve deficits common following a transpsoas approach at […] lumbar levels
higher
[…] nerve at risk with prolonged or excessive retraction during a transpsoas approach to the L4/L5 disc space
femoral and/or obturator
Femoral and/or obturator nerve at risk with prolonged or excessive retraction during a transpsoas approach to the […] disc space
L4/L5
A UTI is seen in what percentage of patients following surgery for lumbar spinal stenosis?
34%
Transient neurologic changes are seen in what percentage of patients following surgery for lumbar spinal stenosis?
36% (genitofemoral n - higher lumbar levels; femoral or obturator L4/5)
Degenerative spondylolisthesis is […] times more common in women than men
~8
Degenerative spondylolisthesis is […]-fold more common at L4/5 than other levels
5
degenerative spondylolisthesis is 5-fold more common at […] level than other levels
L4/5
[…]-oriented facets increase the risk for degenerative spondylolisthesis
Sagittally
What is the most common presenting symptom of degenerative spondylolisthesis?
mechanical low back pain
On flexion-extension radiographs, instability is defined as […] mm of translation or […] of angulation of motion compared to adjacent motion segment
spondylolisthesis
4 mm; 10 degrees
Lumbar decompression and fusion is indicated in degernative spondylolisthesis after how many months of failed non-operative treatment and steroid injection?
After 6 months
What is the indication for ALIF in the setting of degenerative spondylolisthesis?
revision cases with pseudarthrosis
Injury to […] nerve plexus can cause retrograde ejaculation
superior hypogastric
Injury to superior hypogastric plexus can cause […]
retrograde ejaculation
In degenerative spondylolisthesis, adding an interbody cage increases […] without increasing […] rates
hospital costs; fusion rates
Do cortical bone trajectory scores have increased, equivocal, or decreased pain scores at 1-week post-op compared to pedical screws when used in degenerative spondylolisthesis?
Decreased
In degenerative spondylolisthesis, the risk of adjacent segment degeneration requiring surgery is about […] at 10 years
20-29%
Surgical complication rates for degenerative spondylolisthesis increase with what four factors?
- increased age
- Increased operative time
- Increased intra-operative blood loss
- number of levels fused
Isthmic spondylolisthesis rarely progress past a Myerding grade […]
II
Decompression and fusion of adult isthmic spondylolisthesis is indicated after […] months of failed non-operative treatment.
6
In isthmic spondylolisthesis, slip progression more common in what gender?
females
In isthmic spondylolisthesis, […] is the most predictive factor of slip progression and overall outcome
Slip angle
Coronal plane imbalance is defined as lateral deviation of the normal vertical line of the spine greater than […] degrees
10
Sagittal plane imbalance is defined as radiographic sagittal imbalance of […]
greater than 5 cm
What is the most common presenting symptom of adult spinal deformity?
low back pain
In adult spinal deformity, a […] is most useful for assessing stenosis and bony anatomy as rotation makes interpretation of MRI difficult
CT myelogram
In adult spinal deformity, a […] allows for better appreciation of bony anatomy and rotational deformity than MR
CT myelogram
In adult spinal deformity, a coronal curves less than […] degrees rarely progress
30
In adult spinal deformity, […] help with sleep disturbance
tricyclic antidepressants
In adult spinal deformity, thoracic curves great than […] degrees affect pulmonary function tests
60
In adult spinal deformity, thoracic curves greater than […] degrees affect mortality
90
In adult spinal defomrity, […] plane balance is the most reliable predictor of clinical symptoms postoperatively
sagittal
In adult spinal deformity, correction of lumbar lordosis to normal anatomic range can be obtained utilizing the equation pelvic incidence = lumbar lordosis +/- […] degrees
9 degrees
Correction of […] to normal anatomic range most predictive of sagittal plane correction maintenance
lumbar lordosis
What patient factors are associated with worse surgical outcomes in adult spinal deformity?
- baseline depression
- obesity
In Smith-Peterson osteotomies, correction is at the level of the […]
disc
In Smith-Peterson osteotomies, one can expected […] degrees of correction with each level of osteotomy
10
A pedicle-subtraction osteotomy is indicated with severe sagittal imbalance greater than […] cm
12
Pedicle-subtraction osteotomies are used when requiring […] degrees of correction in the lumbar spine
30-35
Pedicle-subtraction osteotomies are used when requiring […] degrees of correction in the thoracic
25
In pedicle subtraction osteotomies, correction is at the level of the […] and not at the disc
vertebral body
Vertebral column resections are utilized for corrections requiring correction of up to […] degrees
45
In adult spinal deformity, curves larger than […] degrees is an indication for an anterior approach.
70
There is a […] complication rate seen with anterior approaches to the spine in adult spinal deformtiy.
higher
What post operative complication is most likely to result in poor clinical outcome following adult spinal deformity surgery?
venous thromboembolism
What is the overall complication rate in adult spinal deformity surgery?
~13.5%
The most common surgical technique resulting in pseudoarthrosis status post adult spinal deformity correction is […] fusion
posterior only
The most common levels for pseudoarthrosis to occur following adult spinal deformity correction surgery is:
- L5-S1
- Thoracolumbar junction
Age greater than […] is a risk factor for pseudoarthrosis following surgery for adult spinal deformity
55
Kyphosis greater than […] degrees is a risk factor for pseudoarthrosis following surgery for adult spinal deformity
20
Positive sagittal balance greater than […] cm is a risk factor for pseudoarthrosis following surgery for adult spinal deformity
5
The […] approach is a risk factor for pseudoarthrosis following surgery for adult spinal deformity
thoracoabdominal
In surgery for adult spinal deformity, a lower rate of mechanical complications is seen with GAP scores less than […]
3
In adult spinal deformity, curves greater than […] deg commonly progress
50
In adult pyogenic vertebral osteomyelitis, 50-60 percent of cases occur in […] spine
lumbar
What is the most common pathogen for adult pyogenic osteomyelitis?
Staph aureus
What is the second most common pathogen in adult pyogenic vertebral osteomyelitis?
Staph epidermis
What pathogen is seen adult pyogenic vertebral osteomyelitis in patients with IV drug use?
Pseudomonas
What is the most common cause of inoculation in adult pyogenic vertebral osteomyelitis?
hematogenous seeding
Adult pyogenic vertebral osteomyelitis caused by contiguous spread from local infection is most commonly associated with […] abscesses
retropharyngeal and retroperitoneal
An epidural abscess is present in […] percent of patients with spondylodiskitis
about 18
In adult pyogenic vertebral osteomyelitis, fever is only present in […] percentage of patients
33% or 1/3
Is spinal disc destruction typical or atypical of a neoplasm?
atypical
In adult pyogenic vertebral osteomyelitis, WBC is elevated in what percentage of patients?
only ~50%
In patients with suspected adult pyogenic vertebral osteomyelitis, a CT guided biopsy is indicated when patients who do not have indications for immediate open surgery and […]
blood cultures are negative
In AIS, a curve greater than […] degrees before skeletal maturity will continue to progress
25
In AIS, after skeletal maturity, thoracic curves greater than […] degrees will progress 1-2° / year
50 degrees
In AIS, after skeletal maturity, lumbar curves greater than […] degrees will progress 1-2° / year
40 degrees
Risser stage […] correlates with the greatest velocity of skeletal linear growth
zero
In AIS, what is the greatest predictor of curve progression?
curve magnitude and peak growth velocity
Peak growth velocity is seen at Risser stage […]
0; just before stage 1
7° curve on scoliometer during Adams forward bending test correlates to a […] degree coronal plane curve
In AIS a Cobb angle less than […] degrees is an indication for observation alone
25
In AIS, a Cobb angle from […] to […] is an indication for bracing
25 to 45; (note:curves must be flexible and patient must be skeletally immature)
In AIS, the goal of bracing is to […], not correct the deformity.
stop the progression
In AIS, there is a 50% reduction in need for surgery with compliant brace wear of at least […] hours a day
13
When bracing for AIS, the number needed to treat (NNT) is […] in highly compliant patients
four
In AIS, posterior spinal fusion is indicated for curves great that what degree?
45
In AIS, curves with an apex above […] need a CTLSO brace
T7
When bracing for AIS, bracing success is defined as […] degree curve progression
less than 5 degree
In AIS, bracing failure is defined as: […] degree or more curve progression, or absolute progression beyond […] degrees
6; 45
Skeletal maturity is defined as Risser stage […]
4
Skeletal maturity is defined as […]cm change in height over 2 visits 6 months apart
less than 1
Skeletal maturity is defined as […] year(s) postmenarchal.
2
resistance to screw pullout increases by undertapping by […]
1 mm
In AIS, ASF with instrumentation increases the risk of pseudarthrosis when thoracic […] is present
hyperkyphosis
In AIS surgery, […] most common organism for delayed infection
Propionibacterium acnes
In AIS, curves […] degrees are associated with cardiopulmonary dysfunction, early death, pain, and decreased self image
greater than 90 degrees
Congenital Scoliosis is a congenital spinal deformity that occurs due to the failure of normal vertebral development during […] week of gestation.
4th to 6th
Congenital scoliosis is caused by a developmental defect in the formation of the […]
mesenchymal anlage
What associated systemic anomalies are seen in congenital scoliosis?
cardiac defects, genitourinary defects, spinal cord malformations
Goldenhar/OculoAuricular Vertebral Syndrome is characterized by what?
hemifacial microsomia and epibulbar dermoids
[…] is not indicated in primary treatment of congenital scoliosis (no effectiveness shown)
bracing
In congenital scoliosis, osteotomies between ribs is indicated when greater than […] ribs are fused and there is the potential for thoracic insufficiency syndrome.
Progression of congenital scoliosis is most rapid in the […] years of life
first three years
in congenital scoliosis, […] failure of formation is rapidly progressive and often results in paralysis
Anterior
In congenital scoliosis, anterior failure of […] is rapidly progressive and often results in paralysis
formation
In congenital scoliosis, anterior failure of […] can be rapidly progressive but rarely results in paralysis
segmentation
In congenital scoliosis, […] failure of segmentation can be rapidly progressive but rarely results in paralysis
anterior
In congenital scoliosis, most rapid progression is seen in what morphology of vertebrae?
unilateral unsegmented bar with contralateral hemivertebra
In congenital scoliosis, unilateral unsegmented bar with contralateral hemivertebra have the greatest potential for rapid progression with progression of […] degrees/year
5 to 10
In congenital scoliosis, which vertebrae morphology is least likely to progress?
Block vertebrae
Brace wear for the treatment of AIS, must be worn for an average of at least […] hours per day to achieve 90-93% success rate
12.9
In skeletally immature patient AIS and a curve between 25-45 degrees, rigid bracing of at least 12.9 hours/day decreases the need for surgery by […] percent
50
