Spine

Question 1

SPORT trial outcome for degenerative spondylolisthesis

Answer 1

For degenerative spondylolisthesis:
Decompression WITH fusion - 80% satisfactory outcomes
Decompression WITH fusion - Standard of care
Instrumentation - Better fusion rates, but no better outcomes and higher re-operation rates
Decompression WITHOUT fusion - 70% satisfactory outcomes

Question 2

What is the most common level for Degenerative Spondylolisthesis vs. Isthmic Spondylolisthesis

Answer 2

Degenerative = L4/5
Isthmic = L5/S1

Question 3

How to draw Pelvic Incidence

Answer 3

Line 1: Center of S1 endplate to center of femoral heads
Line 2: Line perpendicular to the center of the S1 endplate

Pelvic incidence = Pelvic tilt + Sacral slope
Pelvic incidence is independant of the position of the pelvis

Question 4

How to draw Sacral slope

Answer 4

Line 1: Parallel to S1 endplate

Lene 2: Horizontal line

Question 5

How to draw Pelvic tilt

Answer 5

Line 1: Center of the S1 endplate to the center of the femoral heads
Line 2: Vertical line through the femoral heads

Question 6

Yearly rate of curve progression in Adult Idiopathic Scoliosis (Thoracic / Thoracolumbar / Lumbar)

Answer 6

Thoracic = 1 degree per year for curves > 50 degrees
Thoracolumbar = 0.5 degrees per year
Lumbar = 0.25 degrees per year

Note: Degenerative scoliosis more likely to progress than Idiopathic Adult

Question 7

Wiltse Classification of Spondylolisthesis

Answer 7

1 = Dysplastic
2 = Isthmic
3 = Degenerative
4 = Traumatic (post-traumatic)
5 = Pathologic
6 = Surgical (post-surgical)

Question 8

Radiographic parameters to aim for in correction of Adult Scoliosis

Answer 8

Saggital vertical axis within 50mm of the L5/S1 disc

Pelvic tilt less than 25 degrees

Question 9

Diagnostic criteria for Scheuermann’s Kyphosis

Answer 9

1. Kyphosis >45 degrees (norm = 40)
2. > 5 degrees wedging at 3 or more adjacent vertebra
3. > 30 degrees Thiraco-Lumbar kyphosis (norm = 0)
   (from Sorensen 1964)

Other features:
Schmorl's nodes
Irregular and flat vertebral endplates
Increased AP diameter of Apical vertebra
Narrow disc spaces
Spondylosis in adults

More than 80, operatey

Question 10

Central cord syndrome - What tract is affected, what is clinically weak?

Answer 10

Lateral Corticospinal tract
Upper limb weakness > Lower limb weakness
Distal weakness > Proximal weakness (Fingers > Shoulder)

Question 11

Differential diagnoses for Myelopathy

Answer 11

Stroke
Ageing
Amyotrophic Lateral Sclerosis
Multiple Sclerosis
Movement disorder
Vitamin B12 deficiency

Question 12

Simple argorithm for Cervical decompression

Answer 12

1 to 2 levels = Anterior alone ok
3+ levels + >10 degrees Kyphosis = A and P
3+ levels + <10 degrees Kyphosis = Posterior alone ok

Question 13

Definition of spinal shock

Answer 13

Temporary physiological stage of the acutely traumatized spinal cord, manifested by the transient absence of reflexive function caudal to the spinal cord injury.

Question 14

In what clinical situation is an MRI not necessary with bifacet / unifacet C-spine dislocation / listhesis prior to attempt at reduction

Answer 14

Complete spinal cord injury - nothing to lose, just go ahead and reduce it.

Question 15

Ankylosing spondylitis Non-Orthopaedic manifestations

Answer 15

Anterior Uveitis (20-40%)
Aortitis
Aortic regurgitation
Aortic calcification
Pulmonary fibrosis

Aortic calcification is a relative contraindication to thoracic kyphosis correction

Question 16

Ankylosing spondylitis skeletal manifestations

Answer 16

Setonegative (RF -ve) spondyloarthropathy

Enthesitis
Sacroiliitis
Klebsiella pneumoniae synovitis
Spinal kyphosis
Arthritis
Spinal ankylosis
Costovertebral joint ankylosis (loss of chest expansion)
Hip FFD

Question 17

Indications for surgery in spine infection

Answer 17

NBACK

Neurology
Biopsy
Abscess
Continued symptoms despite ABs
Kyphosis

Question 18

Numbers to know in atlantoaxial subluxation

Answer 18

Related to Rheumatoid neck mostly.

ADI >3mm = abnormal
ADI >7mm = severe
ADI >10mm = high risk or paralysis

PADI / SAD <14mm = neural compression

Question 19

What is the CervicoMedullary angle

Answer 19

Angle between anterior line of brainstem and anterior line of spinal cord at the Ocipito-Cervical junction

Less than 135 degrees = high rate / risk if myeolopathy

Usually relevant in Rheumatoid c-spine

Question 20

What is the slip angle in spondylolisthesis?

Answer 20

Line 1: along posterior sacrum
Line 2: perpendicular to Line 1
Line 3: along inferior border or slipped vertebra

Slip angle between Line 2 and Line 3

> 30 degrees = high risk of progression

Question 21

Risk factors for non-union of Type 2 dens fractures

Answer 21

Displacement > 5 mm
Distraction > 2 mm
Posterior displacement
Angulation >11 degrees
Comminution
Reverse oblique pattern
Age >40
Delayed presentation

Question 22

What are the components of the Posterior Ligamentous Complex of the spine?

Answer 22

SUPRAspinous ligaments
INTERspinous ligaments
Ligamentum flavum
Facet joint capsules

Question 23

Posterior cord syndrome. What’s gone, what’s left, what’s the cause?

Answer 23

Gone: vibration and proprioception
Intact: motor (can have bladder issues)
Cause: Tabes dorsalis, friedreich ataxia, AIDS, multiple sclerosis, cervical myelopathy

Question 24

Anterior cord syndrome. What’s gone, what’s left, what’s the cause?

Answer 24

Gone: motor, pain, temperature (urinary retention)
Intact: proprioception
Cause: anterior spinal artery infarct, disc herniation, radiation

Question 25

Central cord syndrome. What’s gone, what’s left, what’s the cause?

Answer 25

Gone: motor weakness (arms > legs) Intact: sensation Cause: syrinx, tumor, cervical spondylosis

Question 26

How are pelvic incidence and lumbar lordosis related?

Answer 26

Lumbar lordosis should be Pelvic Incidence +/- 9 degrees This is relevant for planning deformity correction

Question 27

Non-Structural causes of scoliosis?

Answer 27

CHIPS ``` Compensatory (LLD) Hysterical Irritative (Tumor, infection) Postural Sciatic (Nerve root) ```

Question 28

Structural causes of scoliosis?

Answer 28

NIC NAOMI Neuromuscular Idiopathic Congenital ``` Neurofibromatosis Achondroplasia Osteogenesis Imperfecta Marfan's Irradiation ```

Question 29

Neuromuscular causes of scoliosis

Answer 29

Myopathic (Muscular dystrophy, Polio, SMA) Neuropathic (CP, Syrinx, Spina bifida) Mixed (NSMNs)

Question 30

3 types of idiopathic scoliosis

Answer 30

Infantile (5%) ( < 4 yo ) Juvenile (15%) ( 4 to 10 yo ) Adolescent (80%) ( > 10 yo )

Question 31

What is the indication for surgery in congenital scoliosis

Answer 31

Progression > 4-6 degrees per year It is better to operate early to fuse the segment than wait too long and not be able to achieve correction.

Question 32

What is the RVAD angle of Mehta

Answer 32

In Early-Onset (infantile) scoliosis (Not congenital) Angle between inferior endplate of vertebra and its rib, subtract from the same angle of the other rib. If < 20 degree difference, then 90% chance of spontaneous recovery If > 20 degree difference, then likely to need surgery

Question 33

What is a Phase 2 rib?

Answer 33

In Early-Onset (infantile) scoliosis (Not congenital) On an AP X-ray: Phase 1: rib head does not overlap vertebra Phase 2: rib head overlaps vertebra Phase 2 = high chance of needing surgery

Question 34

What is the difference between degenerative and isthmic spondylolisthesis?

Answer 34

``` Degenerative = no pars defect Isthmic = pars defect ``` Degenerative can be due to: Facet degeneration, horizontal orientation, disc degeneration or ligamentous laxity Isthmic is due to microtrauma

Question 35

Indications for spondylolisthesis fusion

Answer 35

Failure of non-op after 6 months Neurologic deficit progression Instability (slip progression) Cauda equina

Question 36

In adult spinal deformity, what are the indications to extend fusion to S1 (not stop at L5)?

Answer 36

``` C7 plumb line not restored Sacral slope not restored Any disease of L5/S1 - disc - spondy - facet arthropathy Prior L5/S1 laminectomy ```