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zAnatomy (duplicate) > Anatomy - spine > Flashcards

Anatomy - spine Flashcards

1
Q

Is the inferior articular process of the facet joint anterior or posterior in the cervical spine?

A

Posterior

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2
Q

What is the orientation of the zygopophyseal joints of the cervical, thoracic and lumbar spine?

A

see image

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3
Q

What does a high riding vertebral artery refer to?

A

An abnormal course in C2

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4
Q

From what levels do the vertebral artery normally run?

A

C1-C6

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5
Q

In what percent of the population does the vertebral artery run in C7?

A

7.5%Normally runs from C1-C6

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6
Q

What is spinal shock?

A

All phenomena surrounding transaction of the spinal cord that results in temporary loss of all or most spinal reflex activity below the level of injury.Characterized by loss of bulbocavernosus reflex

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7
Q

What is neurogenic shock?

A

Hypotension and bradycardia following SCI

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8
Q

Which vertebrae have bifid spinous processes?

A

C2-C6

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9
Q

In what percent of people does the vertebral artery run in C7?

A

7.5%Remember - mostly it’s C1-C6

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10
Q

Describe the safe zone for 8mm occipital screws. What are the dangers?

A

+/-2cm at Nuchal line+/-1cm, 1cm below the nuchal line+/-0.5cm, 2cm below the nuchal lineThe dangers are:Dural venous sinuses that are immediately behind these regions

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11
Q

Describe the insertion point for thoracic pedicle screws:

A

Intersection point of 2 lines:A: Vertically along:Midpoint of facet joint and/or insertion of TP into the lamina (the Valley)B: Horizontally along:Superior ridge of TP and/or inferior base of facet joint

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12
Q

Describe the insertion point for lumbar pedicle screws

A

Intersection of 2 lines:A: Vertically along the superior facetB: Horizontally along the mid-point of the TP

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13
Q

What level has the smallest pedicle? The largest?

A

Smallest overall: T4Smallest in L-spine: L1Largest in T-spine: T1

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14
Q

Define the motor level

A

Most caudal level with 3/5 power with 5/5 power above

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15
Q

What is the grading system in the ASIA scale?

A

E: “Excellent.” No neurological compromiseD: Incomplete: >50% muscles below level >/= 3/5C: Incomplete: /= 3/5B: Incomplete: only sensory preserved. Motor dysfunction includes sacral segments S4-5A: “Awful”. Complete. No motor or sensory function is preserved, including sacral segments S4,5

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16
Q

Define the sensory level

A

Most caudal level with normal pinprick and light touch

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17
Q

What is the most common incomplete cord injury?

A

Central cord

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18
Q

With respect to central cord syndrome, what is the presentation, pathophysiology and prognosis?

A

Presentation: Motor deficit UE>LE, hands>armsPathophysiology: Corticospinal tract, with part controlling hands centrally, are more affectedPrognosis: Good. Full function rare but omst ambulatory

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19
Q

With respect to anterior cord syndrome, what is the presentation, pathophysiology and prognosis?

A

Presentation: Motor dysfunction LE>UE & dissociated sensory deficit below SCI with STT lost and dorsal columsn preserved

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20
Q

With respect to Brown-Sequard syndrome, what is the presentation, pathophysiology, prognosis?

A

Presentation: ipsilateral loss of motor function, proprioception and vibration with contralateral loss of pain and temperaturePathophysiology: Ipsilateral: Motor: LCST, Sensory: DCContralateral: Sensory: LSTTPrognosis: Excellent 99% ambulatory

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21
Q

What is posterior cord syndrome?

A

Loss of proprioception only. Very rare

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22
Q

What tract is the main descending motor pathway in the cervical spinal cord?

A

Lateral corticospinal tract

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23
Q

The occiput is the thickest in what location?

A

5cm lateral to the external occipital protuberance

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24
Q

In the setting of bilateral C5-6 facet dislocation, which of the following structures is usually preserved?A: Facet joint capsules2: Ligamentum flavum3: Poseterior annulus4: Anterior longitudinal ligament5: Interspinous ligament

A

4: Anterior longitudinal ligament

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25
Q

Which of the following pedicles has the smallest transverse diameter in most people?A: T1B: T12C: L1D: L3E: S1

A

3: L1Remember, T4 is the smallest overall, with L1 being the second smallest, but T4 is not listed in this question

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26
Q

Which area of the spinal cord has the worst collateral blood supply? The best?

A

Worst: T4-T9Best: Cervical and lumbar - they have redundant supply

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27
Q

Describe the main blood supply to the spine? What is the name of the collateral blood supply?

A

Main: 1x median longitudinal anterior spinal artery2x (right & left) longitudinal posterior spinal arteriesThese are supplied by various radicular arteriesCollateral:Vaso Corona: anastomosis between the longitudinal vessels forming a fine pial plexusGives limited blood supply

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28
Q

What artery provides the largest blood supply to the lumbar area? Where does it arise?

A

Artery of Adamkeiwicz. Arises most commonly from left T8-10

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29
Q

What is the Artery of Adamkeiwicz?

A

Major radicular artery supplying the longitudinal arteries in the T/L spine Usually arises from left T8-10 Can arise on right or left, anywhere from T7-L4Usually Left T10

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30
Q

What are the signs of sacral dysmorphism? Why is it important and what should you do instead?

A

Signs:Sacralization of L5Lumbarization of S1Presence of mammillary processesOval or oblong foramenTongue in Groove sign of SI jointImportant to recognize to avoid iatrogenic injury to L5 during SI screw insertion. If dysmorphic, plan for S2 screw instead (of S1)

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31
Q

What is the highest motor level that the patient can have and initially still be ventilator independent? Why?

A

C5 C3,4,5 make up the phrenic nerve, which supplies the motor function of the diaphragm (C3,4,5 keep the diaphragm alive)People with C3-C4 levels can progress to be ventilator independent

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32
Q

What are Harris’ measurements of the spine? What do they measure?

A

They measure atlanto-occipital dissociation There are 2 measurements: Basion to the tip of the dens (BDI) & Basion to the posterior axial line Neither one should be >12mm (Rule of 12’s)

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33
Q

What is the rule of 12’s in the spine?

A

Harris’s Rule of 12’s:Measures occipito-atlantal dissociation.On the Harris measurements, neither the BDI or BAI should be >12mm. If it is, it’s a sign of occipito-atlantal dissociation

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34
Q

What is a Jefferson’s fracture? mechanism?

A

Fracture of the lateral mass of C1 - essentially a “burst fracture” of c1 from axial loading - usually diving into a pool or similar mechanism

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35
Q

In a Jefferson’s fracture, how much lateral overhang on open mouth x-ray indicates disruption of the transverse ligament?

A

A total overhand (both sides added up) of >8mm indicates disruption of the transverse ligament (>6.9mm on CT, though there is some controversy)

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36
Q

What are the risk factors for non-union of odontoid fractures?

A

Displacement >6mmAngulation >10

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37
Q

What is a Hangman’s fracture? mechanism?

A

bilateral c2 pars fracture. hyperextension and distraction. traumatic spondylolisthesis of c2 on c3

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38
Q

What are the contents of the carotid sheath?

A

Common carotid artery +/- internal carotid arteryInternal jugular vein Vagus nerveDeep cervical lymph nodesArtery is medial to vein, with nerve in between

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39
Q

Name the surface landmarks for the following spinal levels:C2-3C3C4-5C6C7T4T7T8L2L4L4-5S1

A

C2-3: MandibleC3: HyoidC4-5: Thyroid cartilageC6: Cricoid cartilageC7: Cervical vertebral prominenceT4: NipplesT7: Distal scapular angleT8: Belly buttonL2: Renal arteriesL4: Bifurcation of aortaL4-5: Iliac crestS1: Iliac bifurcation

40
Q

What are the ligamentous attachments to the dens?

A

Transverse atlantal ligamentsAlar ligaments x2Apical odontoid ligamentAnterior atlantoaxial ligament

41
Q

What is a PLIF? TLIF?

A

PLIF: Posterior lumbar interbody fusionTLIF: Transforaminal lumbar interbody fusion

42
Q

What is autonomic dysreflexia?

A

Autonomic dysreflexia is a potentially dangerous clinical syndrome that develops in individuals with spinal cord injury at or above the level of T6, resulting in acute, uncontrolled hypertension.

43
Q

Which of the following most accurately describes the medial-lateral (transverse) pedicle diameters in the T/L spine?1. Diameters are smaller in the lower T-spine than mid-T spine2. Diameters are smaller in the mid-T spine than high T-spine3. Diameters are smaller in the high T-spine than the mid-T-spine4. Diameters are larger in the upper L-spine than the lower T-spine5. Diameters are larger in the high T-spine than the lower L-spine

A

2.Diameters are smaller in the mid-T spine (T5-7) than the high T-spine (T2-T4)

44
Q

A misplaced screw is recognized after lumbar surgery. The screw has grossly violated the inferior cortex of the left L4 pedicle. What is the most likely neurologic sequelae?

A

L4 weakness (ankle dorsiflexion)

45
Q

Post-ACDF, a patient comes complaining of hoarseness. Which side did the patient likely have their surgery on and what structure was damaged?

A

Right sideDamage to recurrent laryngeal nerve- Nerve is more variable on the right side so it’s easier to damage- So operate on the left if possible

46
Q

A patient comes in post-cervical spine ACDF complaining of a drooping eyelid. On examination, you see that she has constricted pupils, no sweating on one side of the face (ptosis, miosis, anhidrosis). What structure was damaged. Where is this structure located?

A

Sympathetic ganglia in the C-spine was damaged- This caused a Horner’s syndromeThe sympathetic ganglia are located on the longus colli muscles

47
Q

What signs characterize UMN disorder?

A

Spasticity and exaggerated DTR

48
Q

What levels do the vertebral artery run?

A

C1-C6

49
Q

`What does a high-riding vertebral artery refer to?

A

The abnormal course in C2

50
Q

In what percent of people does the vertebral artery run in C7?

A

7.5%- Remember it normally runs only from C1-C6

51
Q

The occiput is thickest in what location?

A

5cm lateral to the external occipital protuberance

52
Q

In the setting of bilateral C5-6 facet dislocation, which anatomical structure is usually preserved?

A

Anterior longitudinal ligament

53
Q

Which area of the spinal cord has the worst collateral blood supply? The best?

A

Worst: T4-T9Best: Cervical and lumbar- They have redundant blood supply

54
Q

Describe the main blood supply to the spine? What is the name of the collateral blood supply

A

Main supply: 1 median longitudinal anterior spinal artery2 (right & left) longitudinal posterior spinal arteriesThese are supplied by various radicular arteriesCollateral:Vaso corona: anastomosis between the longitudinal vessels forming a fine pial plexusGives limited blood supply

55
Q

What is the artery of Adamkeiwicz?

A

Major radicular artery supplying the longitudinal arteries in the T/L spineUsually arises from left T10 - Arises Left 75% and right 25%Can arise on right or left anywhere from T7-4

56
Q

What are the signs of sacral dysmorphism?

A

Sacralization of L5Lumbarization of S1Presence of mammillary processesOval or oblong foramen Sacral intervertebral discs”Tongue in Groove” sign of SI jointImportant to recognize to avoid iatrogenic injury to L5 during screw insertion - If dysmorphic, plan for S2 screw instead of S1

57
Q

Why is it important to recognize sacral dysmorphism?

A

Important to recognize to avoid iatrogenic injury to L5 during screw insertion

58
Q

What nerve is at risk with SI screw placement in a patient with sacral dysmorphism?

A

L5

59
Q

What is the highest motor level that the patient can have and still be ventilator INDEPENDENT? Why?

A

C5C3,4,5 make up the phrenic never, which supplies the motor function of the diaphragm- C3,4,5 keep the diaphragm alive

60
Q

What are Harris’s measurements of the spine? What do they measure?

A

Measure occitio-atlanto dissociation2 measurements:- Basion to the tip of the dens (BDI) and basion to the posterior axial line (BAI)- Neither one of these should be >12mm- This is the rule of 12’s

61
Q

What is the rule of 12’s in the spine?

A

Measurements of occipito-atlantal dissociation - Neither one of the Harris measurements (BDI, BAI) should be greater than 12mm

62
Q

What is a Jefferson’s fracture?

A

Fracture of the lateral mass of C1

63
Q

In a Jefferson fracture, how much lateral overhang on open-mouth x-ray indicates disruption of the transverse ligament?

A

A total overhang (both sides added up) >8mm indicates disruption of the transverse ligament- >6.9mm on CT - there is some controversy

64
Q

What are the risk factors for non-union of odontoid fractures?

A

Displacement >6mmAngulation >10deg

65
Q

What is a teardrop fracture?

A

Fracture of the anterior inferior endplate- Must differentiate between flexion and extension types- Flexion is unstable and associated with SCI. Extension is stable

66
Q

What are the contents of the carotid sheath?

A

4 things:Common carotid artery +/- internal carotid arteryInternal jugular veinVagus nerveDeep cervical lymph nodes- Artery is medial to the vein, with nerve in between

67
Q

Neurogenic shock is best characterized by:

A

Systemic hypotension & bradycardia following SCI- Remember: neurogenic shock not equal to spinal shock

68
Q

What is the expected functional outcome of a patient with a C5 neurologic level following complete SCI?

A

Mobility in an electric wheelchair- Cannot use UE

69
Q

What is spinal shock?

A

Physiologic or anatomci transection of the cord, resulting in temporary loss or depression of all or most spinal reflex activity below the level of the injury- Characterized by loss of bulbocavernosus reflex- Important b/c exam is not reliable during period of spinal shock

70
Q

How do you perform a bulbocavernosus reflex?

A

Normal: - Anal sphincter contraction (anal wink) after squeezing the glans penis or tugging on the foley - In women, squeeze the clitoris or tug on the foley

71
Q

Is the inferior articular process of the facet joint anterior/posterior vs. superior/inferior in the C-spine?

A

Inferior articular process is anterior

72
Q

Name the intrinsic craniocervical ligaments

A

They all reside within the spinal canal. From dorsal to ventral:Tectorial membrane: connects posterior body of axis to anterior foramen magnum. Is the cephalad continuation of the PLLCruciate ligaments: lies anterior to tectorial membrane, behind the odontoid processOdontoid ligaments (alar and apical)

73
Q

What is the tectorial membrane a continuation of?

A

Posterior longitudinal ligament

74
Q

Name the extrinsic ligaments of the craniocervical spine

A

Ligamentum nuchae: extends from external occipital protuberance to the posterior aspect of the atlas and cervical spinous processesFibroelastic membranes: Replace the anterior longitudinal ligament, intervertebral disks, and ligamentum flavum between the occiput and atlas and between the atlas and axisAtlanto-occipital joint capsuleAtlanto-axial joint capsule

75
Q

What is the amount of lateral mass displacement necessary to indicate disruption of the transverse ligament on on imaging?

A

6.9mm vs. 8.1mm6.9mm: Spence: critical amount of total displacement (on CT)8.1mm: Heller. However this measurement may be obviated using calibrated axial and sagittal CT

76
Q

What is Swischuk’s Line?

A

Connects the anterior aspect of the spinous processes of C1 and C3.If the anterior aspect of the spinous process of C2 misses this line by ⩾2 mm true subluxation of hangman’s fracture must be considered.This line is only applicable to those demonstrating subluxation.The distance is frequently 2 mm or more if no subluxation is apparent.Figure: (A) No subluxation. Therefore, PCL cannot be applied. Anterior aspect of spinous process of C2 commonly misses PCL by 2 mm. (B) Subluxation is present. The anterior aspect of spinous process of C2 misses the PCL >2 mm. Finding is suggestive of a hangman’s fracture of the neural arches of C2. (C) Pseudosubluxation is present. The anterior aspect of spinous process of C2 touches or lies within 2 mm of PCL. (Adapted from figure from Fesmire FM and Luten RC.16)

77
Q

Describe the cervicomedullary angle and its significance:

A

The cervicomedullary angle can be measured on MRI by drawing a line along the anterior aspect of the cervical spinal cord and the medulla.This angle is normally between 135° and 175°With progressive craniocervical disease, the brainstem angulates ventrally over the displaced odontoid process, leading to increased obliquity of the cervicomedullary angle.

78
Q

What are the synovial joints of the spine?

A

Facet jointsAtlanto-occipital jointLateral Atlanto-axial jointCentral atlanto-axial joint

79
Q

Figures 8a and 8b show the radiograph and MRI scan of a 31-year-old man with severe back pain and intermittent leg pain. Which of the following anatomic measurements has been best correlated with this patient’s condition?1.Pelvic tilt2.Pelvic Incidence3.Lumbar Lordosis4.Thoracic Kyphosis5.C7 Sagittal plumb line

A

2.Pelvic Incidence

80
Q

Which of the following is most predictive of disability in adult patients with scoliosis?1. Coronal plane cobb angle2. Retrolisthesis at L3/43. Osteoporosis4. Sagittal plane decompensation5. Severity and number of levels of disk degeneration

A
  1. Sagittal plane decompensation
81
Q

On a standing lateral radiograph of the spine in which the edge of the film represents a true vertical, a normal C7 plumb line should intersect which of the following anatomic landmarks?1.Center of the C7 vertebral body and posterior-superior corner S12.Center of C7 body and anterior-superior corner of S13.Anterior border of C7 vertebral body and anterior-superior corner of S14.Anterior border of C7 body and posterior-superior corner of S15.Posterior border of C7 vertebral body and posterior-superior corner of S1

A

1.Center of the C7 vertebral body and posterior-superior corner S1

82
Q

Figure 169a is the lateral radiograph of a 19-year-old female gymnast with low back and leg pain. Examination reveals exacerbation of back pain with extension. She has a normal motor examination but diminished light touch sensation in an L5 distribution. What measurement shown in Figure 169b has been correlated with this disease?1.Slip Angle2.Sacral Slope3.Pelvic Tilt4.Pelvic Incidence5.Spinopelvic Angle

A
  1. Pelvic incidence
83
Q

Figure 255 shows the axial CT scan of a 33-year-old man with severe neck pain after a motor vehicle collision. Which structure is most important in guiding treatment?1.VA2.Alar Lig3.Apical Lig4.Transverse Lig5.Post Lig Complex

A
  1. Transverse ligament
84
Q

What osseous structure is seen by the * in Figure 237?1- Inferior articular facet of C42- Inferior articular facet of C53- Superior articular facet of C54- Pedicle of C55- Pars interarticularis of C5

A
  1. Inferior articular process of C4
85
Q

Figures 89a and 89b are the parasagittal and axial CT scans of a 42-year-old patient seen after a motor vehicle collison. What anatomic structure is identified by the asterisk in Figure 89b?1.C6 facet2.C7 facet3.C6 pars4.C6 pedicle5.C7 pedicle

A
  1. C6 Facet
86
Q

What is the nerve injury shown?

A

CN VINo lateral gaze

87
Q

A 27-year-old male is an unrestrained passenger in a motor vehicle accident. He was medically stabilized in the emergency room. His initial injury CT scans are seen in Figures A and B. He is neurologically intact and placed in a halo fixator prior to surgical treatment. What is the most common neurologic complication with halo traction?1. Weakness in biting and chewing strength2.Deficit in medial and downward eye movement3.Deficit in lateral eye movement4.Inability to close eyes against resistance5.Tongue deviation toward the affected side

A
  1. Deficit in lateral eye movement (CN VI injury)
88
Q

After application of a halo device, a patient has pain and numbness over the medial one third of the eyebrow. This is most likely the result of injury to which of the following structures?1.Second dorsal rami2.Facial nerve3.Auriculo temporal nerve4.Lesser occipital nerve5.Supraorbital nerve

A
  1. supraorbital nerve injury
89
Q

The halo vest is least effective at controlling which of the following spinal motions?1- Lateral bend2- Flexion3- Extension4- Axial rotation5- Axial distraction

A
  1. Axial distraction
90
Q

What vertebra does the vertebral artery run in?

A

C1-C6Although all the cervical vertebra have a vertebral foramen

91
Q

Which vertebra has the smallest diameter pedicle in the lumbar spine? Smallest overall?

A

L1 is smallest in lumbar spineT4 is smallest overall

92
Q

Which vertebra has the largest pedicle in the upper spine? Overall?

A

T1 largest in upper spineL5 largest overall (unless you count S1, then it’s S1)

93
Q

The occiput is thickest in what location?1.At the external occipital protuberance2.1cm lateral to the foramen magnum3.2cm superior to the foramen magnum4.2cm cranial to the occipital condyles5.5cm lateral to the external occipital protuberance

A
  1. 5cm lateral to the external occipital protuberane
94
Q

A misplaced pedicle screw is recognized after lumbar surgery. The screw has grossly violated the inferior cortex of the left L4 pedicle. What is the most likely neurologic sequelae?1. Weakness of plantar flexion, numbness along the lateral foot3. Weakness of hip flexion, numbness along the inguinal crease4. Weakness of foot dorsiflexion, numbness along the medial ankle5. Weakness of toe dorsiflexion, numbness of the first web space

A

4: Weakness in foot dorsiflexion, numbness along medial ankleKnocked out L4

95
Q

Which of the following most accurately describes the medial-lateral (transverse) pedicle diameters in the thoracic and lumbar spine?1. Diameters are smaller in the lower thoracic spine (T10-T12) than the mid-thoracic spine (T5-T7)2. Diameters are smaller in the mid-thoracic spine (T5-T7) than the high thoracic spine (T2-T4)3. Diameters are smaller in the high thoracic spine (T2-4) than the mid-thoracic spine (T5-T7)4. Diameters are larger in the upper lumbar spine (L1-2) than the lower thoracic spine (T10-12)5.Diameters are larger in the high thoracic spine (T2-T4) than the lower lumbar spine (L3-S1)

A
  1. Diameters are smaller in the mid-thoracic spine (T5-T7) than the high thoracic spine (T2-T4)
96
Q

A 76-year-old woman has neck pain after falling down a flight of stairs. Figures 65a and 65b show a lateral radiograph and sagittal CT scan of her cervical spine. Which factor is an absolute contraindication for the placement of C1-C2 transarticular screws?-Osteoporosis-Aberrant Vertebral Artery-Previous C2 laminectomy-C1 fracture-Disruption transverse lig

A
  1. Aberrant vertebral artery ??
97
Q

What is autonomic dysreflexia?

A

In a high-level spinal cord injury, intact lower motor neurons sense the painful stimuli below the level of injury and transmit the message up the spinal cord (see diagram).At the level of the spinal cord injury, the pain signal is interrupted and prevented from being transmitted to the cerebral cortex. The site of the spinal cord injury also interrupts the two branches of the autonomic nervous system and disconnects the feedback loop, causing the two branches to function independently.The ascending information reaches the major splanchnic sympathetic outflow (T5-T6) and stimulates a sympathetic response. The sympathetic response causes vasoconstriction, resulting in:hypertensionpounding headachevisual changesanxietypallorgoose bumps below the level of injuryThis hypertension stimulates the baroreceptors in the carotid sinuses and aortic arch. The PSNS is unable to counteract these effects through the injured spinal cord, however. Instead, the PSNS attempts to maintain homeostasis by slowing down the heart rate. The brainstem stimulates the heart, through the vagus nerve, causing bradycardia and vasodilation above the level of injury. The PSNS impulses are unable to descend past the lesion, and therefore no changes occur below the level of injury.

zAnatomy (duplicate) (13 decks)

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