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Flashcards in Spine Deck (154):
1

What factor results in degenerative spondylolisthesis?

Sagittal arrangement of the facets

2

What is the coupling phenomenon?

This is a 3d movement of the spine such that rotation and translation occurs together

3

What is Euler's theory?

Look it up

4

When is intradiscal pressure highest?

When standing from a seated position

5

What is the Youngs Modulus?

Stress vs strain of a material

6

What is the elastic and plastic region?

Elastic is when stress changes with strain; Plastic is when strain changes but stress doesn't; After this there is a brittle fracture;

7

Which rods material is very stiff?

Cobolt chrome

8

What are the indications for surgery for radiculopathy?

Uncontrolled pain, persistent pain, progressive neurological deficit and correlation between clinical and radiographic presentation

9

Why is myelopathy not painful?

As the pain receptor inputs are at the dorsal root ganglion

10

What causes a radiular pain with some claudicant features?

Lateral recess stenosis

11

Do you need a plate for a single level ACDF?

NO - acceptable fusion rate without plate. (Need reference for this!)

12

What is the SLIP study (Ghogawala et al)

Prospective RCT for Single level degenerative spondylolisthesis - no better functional outcome with fusion BUT 37.5% failure rate in the non-fusion group requiring further surgery. Better outcome in functional outcome with fusion.

13

What are the cervical complications of rheumatoid arthritis?

Basilar invagination, C1/2 instability and subaxial spine disease

14

What is the rate of adjacent segment disease following a single level fusion?

0.5% per year

15

What is the most common neurological complication following lateral approach to the spine?

Sensory abnormalities (II, IH, GF etc injury)

16

What is the differential diagnosis of an extradural spinal tumour?

Benign nerve sheath tumour (schwannoma, neurofibroma), meningioma, sarcoma, lymphoma, metastasis and infection (TB)

17

What is the most common location for metastases?

The spine (most likely lower thoracic)

18

What is the most common primary spinal tumour?

Haemangioma

19

Which tumours metastases to the brain?

LB&MRC

20

Which tumours met to the spine?

BAL&PCR

21

What is the ECOG performance status?

Look it up

22

Which landmark paper advocates spinal surgery for metastases?

Patchell et al 2005 - Surgical arm was superior in ability to walk, incontinence, weakness, functional status, less steroid and analgesics and survival

23

What classifiication systems are there for spinal tumours?

1) Cell of origin
Primary - Benign vs Malignant
Secondary
2) Anatomical location
Intradural intramedullary
Intradural extramedullary
Extradural
3) Stability
Tomita (2001) vs Tokuhashi (2005) vs Fourney (2011)

24

What is the difference between osteoid osteoma vs osteoid blastoma?

Size >1.5cm

25

What is the SINS (Spine instability Neoplastic Score)?

0-6 (stable); 7-12 (potentially unstable) and >12 (unstable):

Location (0-3)
Pain (0-3)
Bone lesion (0-2)
Radiographic spinal alignment (0-4)
Vertebral body collapse (0-3)
Posterior lateral involvement (0-3)

26

What factors should be considered in patients with metastatic spinal cord compression?

LMNOP:
Location / Life expectancy
Mechanical instability / General medical condition
Neurology
Oncological disease status / Oncology treatments previously (RT)
Performance status

27

What are the indications for MSCC surgery?

Diagnosis
Neurological deterioration / prognosis
Stability
Radioresistant tumours / no further radiotherapy possible

28

What are the contraindications to surgery for MSCC?

Medically unfit, radiosensitive, poor prognosis, multi-level disease, established / longstanding neurological deficit

29

What is the strongest ligament in the human spine?

ALL in the lumbar spine

30

What is the most sensitive way to diagnose craniocervical junction (C0/1) dissociation?

Condylar gap (cup and saucer between occipital condyl and C1 lateral mass

31

What is the most unstable morphology for cervical fractures?

Rotation

32

Where does most axial rotation of the cervical spine occur?

C1/2 (45 degress)

33

Where does most flexion extension occur within the cervical spine?

C0/1 is the most, then the rest is distributed throughout the cervical spine

34

What is Spence's rule?

Overlap of the C1 lateral mass over C2 by >7mm suggests rupture of the transverse atlantal ligament

35

What is the mechanism of injury for craniocervical dissociation?

High velocity distraction / deceleration injury

36

How do you classify C0-C2 fractures / dissociation?

Bony vs ligamentous injury
Bony = C0 (occipital condyle), C1 (Jefferson), C2 (peg, hangmans and lateral mass)
Ligamentous = Craniocervical dissocation, rotatory subluxation and

37

What is a normal atlantodental interval?

38

What is the classification of the subaxial spine?

Anatomical: bony / ligamentous
Stability: SLICs

39

What is the SLICs?

Injury morphology (0-4) - compression =1; burst = 2, distraction = 3 and rotation = 4
Discoligamentous complex (0-2)
Neurological status (0-3) +1 for continuous spinal cord compression; Root injury 1 and SCI 3

SLICs 4 = discussion and >4 = surgery

40

What is the TLICs?

Injury morphology (Compression -1 Burst - 2 Translation / rotation -3 and distraction -4)
Integrity of the PLC
Neurological status

4 = discussion; >5 needs surgery

41

What is the AO spinal fracture classification system?

A = compression / burst
B = Posterior colum injury
C = Both columns injured with rotation

Each is subtype 1-3
C types have highest risk of neurological injury

42

Which publication is in favour of bracing and conservative management of burst fractures?

Cantor et al 1993
(Baily et al 2013 showed no need for bracing with stable burst fractures)

43

What are the indications for surgery on a burst fracture?

Neurological deficit, PLC inolvement, Greater than 30 deg of kyphosis, (Greater than 50% canal compromise and >50% VB collapse)

44

What are the important physiological factors to maintain with SCI?

ABCD:
Arterial oxygenation
BP maintenance / blood flow to the spinal cord
Complication avoidance - bowels / pressure sores / DVT prophylaxis
Decompression surgery
Extras

45

What are the medical managements of spinal cord injury?

See guidelines:

46

What are the factors which result in secondary spinal cord injury?

Excitotoxicity, Apoptosis & Inflammation

47

Why does the FVC drop to 30% following SCI?

Due to loss of function of the intercostal muscles; Accessory muscles are used to augment this and then the patient fatigues resulting in hypoxaemia.

48

Why does respiratory function improve 3 months following SCI?

As muscle tone in the chest wall increases resulting in reduced paradoxical chest movement

49

What is the blood flow in the spinal cord?

Blood flows to the grey matter first then the white matter; Grey matter has the highest requirement (50ml/100g/min) whilst white matter is 10ml/100g/min

50

What level do the cardiac sympathetics arise?

T1-4 - injury above this level results in bradycardia!

51

What BP guidelines are required for SCI?

MAP 85-90mmHg for 7 days

52

What is the leading cause of mortality in SCI?

Pneumonia

53

What is required to diagnose a pneumonia?

Temp >38 or

54

What is the level 1 evidence for VTE prophylaxis in SCI?

TEDs and compression stockings

55

What are the complications of steroids in SCI?

Wound infection
Hyperglycaemia
GI bleed
Pneumonia / Sepsis
Death

56

Why is vertebroplasty in prostate ca less efficacious?

As the metastases are sclerotic so there is higher risk of extravasastion

57

What is the complication rate for kyphoplasty?

2-5%

58

How often does cement extrusion occur with vertebroplasty?

Most cases but is symptomatic

59

What are the complications of vertebroplasty?

Extravasation, SCI, root compression, PE, infection, adjacent level fractures

60

What are the advantages of minimally invasive spinal surgery?

Smaller incision, less pain, same day surgery, reduced infection rate and reduced rate of pseudomeningocoele follwoing CSF leak.

61

Define Load Sharing

This is the ability to convert distraction forces to compression forces to aid fusion

62

How does rod diameter affect fusion?

A smaller rod posteriorly puts more compression on the anterior column so the anterior column will fuse better

63

What is the role of the facet joints?

Guide motion
Load bearing
Resist shear

64

What is the difference between rod stiffness and strength?

A strong rod will not break, a stiff rod will pull the screws out!

65

How does rod diameter affect fusion?

A smaller rod posteriorly puts more compression on the anterior column so the anterior column will fuse better

66

What is the role of the facet joints?

Guide motion
Load bearing
Resist shear

67

What is the difference between rod stiffness and strenght?

A strong rod will not break, a stiff rod will pull the screws out!

68

What is the SPORT trial?

Surgical vs non-operative treatment for lumbar disc herniation (lots of cross over to surgery)

69

What is the differential diagnosis of a far lateral disc herniation?

Neuroma

70

Does myleography show a far lateral disc?

NO

71

How would you manage a patient with cervical stenosis causing myelopathy?

History and examination
MRI
Flexion/ext xray to determine if stabilisation is required
Neurophysiology

72

What is the evidence for operative technique for myelopathy?

Systematic review showed treatment of myelopathy is comparable with anterior and posterior and fusion operations

73

What is SVA?

Sagittal vertical axis - amount of shift of the spinal alignment relative to the plumb line

74

What is the spinal plumb line?

A line from the anterior tip of C7 should pass through the anterior half of the body of S1

75

Which nerve is most commonly injured following a lateral approach to the lumbar spine?

Genitofemoral nerve is most common causing numbness in the groin

76

Where is the femoral nerve during a lateral approach to the spine?

Within the psoas muscle. It moves anterior the lower the level in the spine

77

Where is the femoral nerve during a lateral approach to the spine?

Within the psoas muscle. It moves anterior with lower levels in the spine

78

What is the benefit of using a plate for ACDF?

Earlier return to work (Level 1 evidence)

79

What is the differential diagnosis of an extraspinal mass with some epidural extension?

Tumour: primary - lymphoma / sarcoma; secondary - mets
Infection: TB

80

Where is the most common site for metastatic spinal cord compression?

Lower thoracic

81

Which tumours metastasise to the lung?

BAL&PCR:
Breast
Lung
Lymphoma
Prostate
Colon
Renal

82

What are the malignant tumours that affect the spine?

Chordoma
Chondrosarcoma
Ewings sarcoma
Myeloma
Osteosarcoma

83

What is the difference between osteoid osteoma and osteoblastoma?

Osteoblastoma >1.5 cm

84

What is the differential of an intradural intramedullary tumour?

Ependymoma
Astrocytoma
Haemangioblastoma

85

What is the differential of an intradural extramedullary tumour?

Schwannoma
Neurofibroma
Meningioma
AVM / AVDF

86

What is the differential of an extradural tumor

Bone tumours 1 or 2

87

What is SINS?

Spine instability neoplastic score: 0-6 = stable, 7-12 = indeterminate and >13 = unstable

88

What are the components of the SINS score?

Location (0-3)
Pain (0-3)
Bone lesion lytic / sclerotic (0-2)
Radiological alignment (0-4)
Body collapse (0-3)
Posterior element involvement (0-3)

89

Algorithm for systemic approach to MSCC

L - location
M - mechanical instability
N - neurology
O - Oncology
P - Patient fitness

90

Which spinal mets are radioresistant?

Renal
Sarcoma
Colon
Large cell lung ca

91

Which spinal mets require preop embolisation?

Renal
Thyroid
Hepatic
Angiosarcoma

92

What is the difference between a schwannoma and neurofibroma on PET?

Schwannomas have high uptake on PET-CT

93

How do you interpret a PET scan?

Standard uptake values (look up how to interpret this!)

94

What is the difference in presentation between neurofibroma and malignant peripheral nerve sheath tumour?

Neurofibromas are painless whilst malignant peripheral nerve sheath tumour are painful!

95

What is the lifetime risk of MPNST with NF1?

10%

96

What are the diagnostic criteria for NF-1?

Diagnosis if >2 of 7:
>5 cafe au lait lesions
Axillary freckling
>1 neurofibromas
Optic nerve glioma
Lisch nodule
Sphenoid dysplasia
First degree relative with diagnosis

97

What syndrome has macrocephaly and neurofibromas (no NF-1 associated tumours)?

Legius syndrome

98

What is the ASIA scale?

A - complete
B - Sensory intact
C - Motor intact <3/5
D - Motor intact >3/5
E - Normal

99

What is the distinction between a complete and incomplete spinal cord lesion?

Sacral sparing of sensory or motor function

100

What is spinal shock?

Hyporeflexia / hypotonia immediately post-spinal cord injury

101

What is neurogenic shock?

Cardiovascular changes after spinal cord injury due to loss of sympathetics (above mid thoracic)

102

What causes central cord syndrome?

Hyperextension resulting in ligamentous in-buckling

103

What is the evidence for maintaining BP after SCI?

Know about sICP, sMAP, sCPP and sPRx

104

What proportion of ASIA will improve?

20%

105

What is STASCIS trial?

Surgical timing in acute spinal cord injury

106

What were the results of the STASCIS?

Non-randomised prospective trial of decompression <24h compared to >24 h. Decompression <24h led to better functional outcome!

107

How would you manage a patient with a spinal cord injury?

Acute
Long term

108

What is the Traynelis classification for AOD?

1 - anterior
2 - superior
3 - posterior

109

What is the occipital condyle fracture classification?

1 - linear extension of occipital fracture
2 -
3 -

110

Which transverse ligament injuries will heal with a Halo?

Avulsions from the lateral mass will heal but mid-portion transverse ligament rupture will not heal so offer surgery!

111

What is Spence's rule?

If the overhang of C1 on both sides >7mm then suggests transverse ligament rupture

112

What is the classification for Hangman's fractures?

Effendi classification:
1 - 3mm slip
2 - 4mm slip and angulation
3 - Disc disruption (need surgery!)

113

What is the SLICs?

Morphology
Discoligamentous
Neurological status

114

How do you manage bilateral facet dislocation?

External reduction
Anterior first then posterior fixation

115

What is the Denis 3 column model?

Ant - ant half of body
Middle - post half of body to PLL
Posterior - pedicle backwards

116

What is a seat-belt injury?

Hyperflexion with compression of the body and distraction of the middle and posterior elements i.e. chance fracture

117

What is TLICS?

Thoracolumbar injury classification and severity score

118

What is the AO classification system?

A - Anterior column (compression / burst)
B - Posterior column
C - Rotational element and failure of both elements

119

Do small burst fractures need surgery or bracing?

No difference in outcome if stable thoracolumbar burst fracture i.e. no neurology and intact posterior column

120

Which burst fractures need surgery?

Neurological deficit
Posterior column involvement
>30 deg kyphosis
>50% collapse

121

When should an anterior or lateral approach to a burst fracture NOT be performed?

Posterior ligamentous injury
Coronal / sagittal deformity requiring reduction

122

What is internal bracing?

Percutaneous pedicle screw fixation as there is no operative attempt at fusion. Perc screws hold the fracture to allow it to heal!

123

What are the important things to consider when operating on a spinal haemangioblastoma?

Pre-op angio (embolisation unlikely)
Spinal cord monitoring
Preoperative steriods (evidence?)
TIVA anaesthetic
Dissection within the gliotic plane
Indocyanine green on table angio after to ensure full resection

124

Where can you get haemangioblastomas in VHL?

Within the central nervous system (cranial and spinal) and the eye. Therefore do whole neuroaxis imaging.

125

What tumour is associated with VHL?

Phaeochromocytoma
Renal cell carcinoma
Pancreatic and renal cysts
Pancreatic neuroendocrine tumours
Endolymphatic sac tumour

126

What proportion of patients with VHL have bilateral endolymphatic sac tumours?

10%

127

Work up for VHL?

MRI neuroaxis
Abdominal CT
Genetic mutation

128

How can you diagnose VHL?

More than one haemangioblastoma or single with a visceral lesion
Positive FHx and a single clinical feature
Genetic mutation

129

What is the genetic inheritance of VHL?

Autosomal dominant
Ch3p25

130

What is the incidence of VHL?

1 in 30,000

131

What is the prognosis for VHL?

Most don't survive to 50 years due to RCCs

132

What is the mean age of diagnosis of VHL?

20 years

133

What proportion of renal cysts in VHL transform to RCC?

40-50%

134

What tests would you do for VHL?

Urinary catecholamines and blood metanephrines (VMA)

135

How long do you follow up VHL patients?

Lifelong for surveillance of tumours

136

9 yo boy with myelopathy, snoring, vit D deficiency and basilar impression. What does the snoring suggest?

Syringobulbia or ventral brainstem compression

137

What is the ADI in a child?

<6mm

138

What is it called when the clivus is flat?

Platybasia (check this)

139

What is the normal clival angle?

Look up

140

What is the complication of splitting the palate with a transoral approach?

Velopalatal insufficiency

141

What is the diagnosis if a chalky material is found within the spine?

= Gouty tofus: Gout / Pseudogout
Uric acid crystals are seen with negative birefringence on microscopy

142

What are the features of sclerotic mets on MRI?

Low on T1 and T2

143

What is the most common cause of sclerotic mets diffusely within the cord?

prostate mets

144

DD of long segment signal change?

NMO
MS (shorter segements)
ADEM
Transverse myelitis
Inflammatory causes
B12 def
DAVF

145

What features are suggestive of an ependymoma over astrocytoma of the spinal cord?

Haemosiderin cap (due to haemorrhage) so low on T2 at the edges
Homogeneous
More central

146

What is it called when nuclei within a tumour surround vessels?

Pseudo-rosettes

147

Spinal tumour with strong GFAP and rosettes. What is the diagnosis?

Ependymoma

148

What is the histology of a pilocytic astrocytoma?

Long hair like cells

149

What is the WHO grading of ependymomas?

Grade 2

150

What is the radiological feature of a ventral cord hernation?

Scalpel sign

151

What is the DD of a spinal arachnoid cyst?

Dorsal arachnoid web
Epidermoid
Ventral cord herniation

152

What is a long-term side effect of syringomyelia?

Neuropathic pain

153

Why do patients developed a delayed C5 palsy after cervical decompression?

Decompression results in stretching of the C5 nerve root (due to it being shortest and 90 degree angle)

154

What are the features of a delayed C5 palsy?

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