M1-2 Class Notes

Question 1

What happens to the posterior annulus if the flexed position is maintained for many years?

Answer 1

• distention
• weak
• cracked
• decreased strength

Question 2

What are the risks with a weakened posterior annulus?

Answer 2

• Herniated disc
• Decrease in tensile strength over years
• Adaptive lengthening of noncontractile tissue

Question 3

What changes happen to the anterior annulus with years in a flexed position?

Answer 3

Becomes compressed - NP pushed posteriorly

Question 4

How might long term flexed position change one’s posture after many years?

Answer 4

• Reduced lordotic curve
• Adaptive lengthening of posterior musculature and ligaments
• Adaptive shortening of anterior musculature and ligaments
• Structural change in posture

*Can’t be fixed in one session of tx

Question 5

Because only the fibers oriented in the direction of rotation become taut, what does this mean for the layers resisting rotation?

Answer 5

• Only HALF of the layers are resisting rotation

- Every other layer will be taut or slackened in the same direction

Question 6

What happens to the annulus during rotation and why?

Answer 6

• Annulus layers tighten down like a screw and approximate the vertebral bodies
• Because the layers are not elastic in nature

Question 7

Which layers of the annulus tighten down during rotation?

Answer 7

The layers oriented in the direction of rotation

Question 8

Which layers of the annulus are put on slack during rotation?

Answer 8

Annular layers oriented in the opposite direction

Question 9

Which is the only ligament that is taut during extension?

Answer 9

ALL

Question 10

Why is the ALL crucial to prevention of anterior slippage?

Answer 10

• resists body weight that is mostly distributed in the anterior L-spine
• Downhill slide of L5 of S1 caused by lumbar lordosis

Question 11

What would happen if the ligamentum flavum buckled as opposed to having some elastic rebound?

Answer 11

Would protrude into the spinal canal and apply pressure to the SC

Question 12

Ligamentum flavum: How is it positioned when the spine is in neutral?

Answer 12

LF is under a bit of tension

Question 13

Why is the LF under tension in neutral spine?

Answer 13

• If you were to go into more extension, it could retract some
• Allows you to move into extension without relying solely on muscles

Question 14

What would happen to the LF over time if you sit slumped?

Answer 14

• LF adaptively lengthens
• Lose passive support for extension
• Muscles have to work harder

Question 15

Which part of bone has an easier time with nutrient absorption and why?

Answer 15

• trabecular

- easier for stuff to move in and out of webbing

Question 16

Where is the pars located?

Answer 16

Where the lamina and pedicle meet

Question 17

Why is the pars under constant pressure?

Answer 17

BW pushed through facets to prevent anterior translation

Question 18

Why don’t you get anterior slippage with spondylolysis?

Answer 18

Rest of the vertebra holds it in place

• facets
• bony structures
• connective tissues

Question 19

Rather than anterior slippage, what problems does a spondylolysis cause with respect to the contralateral side?

Answer 19

• Creates more load on the other side

- Increased likelihood of the same problem on the other side » spondylolisthesis

Question 20

What radiographic view is used to dx a spondylolysis/spondylolisthesis?

Answer 20

Oblique

Question 21

Which grade of spondylolisthesis is the worst? How is it determined?

Answer 21

• Grade 4

- determined by degree of slippage

Question 22

What happens to the vertebral body/facets with bilateral spondylolisthesis?

Answer 22

• Inferior facet locked in place

- BW pushes vertebral body forward

Question 23

Difference between “spondylitic” and “degenerative” spondylolisthesis?

Answer 23

• Spondylitic = pars fx

- Degenerative = articular surfaces eroded/thin » allows for anterior slippage and excessive lengthening of the pars

Question 24

Increased disc height = increased ______

Answer 24

Movement

Question 25

How does the annulus restrict movement?

Answer 25

Annulus acts as a ligament to prevent movement

Question 26

Outer annulus fibers are more (horizontal/vertical/oblique)

Answer 26

Vertical

Question 27

Inner layers of the annulus are more (vertical/horizontal/oblique)

Answer 27

Oblique

Question 28

What is the benefit to different orientations of fibers?

Answer 28

Give some resistance in every possible motion you could do

Question 29

What enables the NP to attract water and nutrients?

Answer 29

Hydrophilic nature of proteoglycans

Question 30

Aging diminishes the ability of the NP to ________

Answer 30

Imbibe water