Lecture 5 - finished

Question 1

IVD degeneration epidemiology

Answer 1

Common in adults, esp those 50+

Most common in the L4-L5 and L5-S1 regions

Question 2

Pathology of IVD degeneration

Answer 2

Biochemical changes:
- With aging, several biochemical changes are observed in the IVD
- The IVD progressively becomes more desiccated, stiff and less able to resist mechanical forces 
= reduced proteoglycan synthesis
= reduction in proteoglycan size
= reduced water content
= increased collagen content
= reduced elastin content

Degeneration:
- Decreased ability to resist shear forces
    = fissures in annulus fibrosis
- Increased forces on endplates
    = Endplate micro-fractures may occur

** as a result of annulus fibrosis and end plate microfractures there is acute inflammation and healing

Fissures:
- Causes hernitations of nucleus pulposus, which can happen either in the
- vertebral end plate = schmorls nodes
OR
- CNS = Spinal nerve impingement or spinal cord impingement

Question 3

What biochemical changes occur in IVD degeneration?`

Answer 3

= reduced proteoglycan synthesis
= reduction in proteoglycan size
= reduced water content
= increased collagen content
= reduced elastin content

Question 4

What does a decrease in water content do to discs? What does this eventually lead to?

Answer 4

Decreased disc hydrostatic pressure
Decreased nucleus pulposus elasticity
Decreased disc height (i.e. flattening)

This eventually leads to altered biomechanical properties

Question 5

What can fissures in the annulus fibrosis lead to?

Answer 5

Herniation of nuclear material into:

• the spinal cord
• the spinal nerves

Herniation into the intervertebral endplates causes:

• Schmorls nodes
• Reactive bone growth

Question 6

When herniations into the intervertebral end plates cause reactive bone growth, how does this manifest?

What do these manifestations result in?

Answer 6

Osteophytes
Lipping

They result in spondylosis (= spinal degeneration)

Question 7

How does disc degeneration result in facet joint spondylosis?

Answer 7

IVD degenerates and flattens
The facet joint becomes misaligned
The facet develops secondary OA
The facet develops spondylosis

Question 8

How does spondyolsis worsen?

Answer 8

Increases osteophyte production
Narrowing of spinal canal
Narrowing of IV foramina
Nucleus pulposus becomes fibrocartilage
Fibrosis of affected structures

Question 9

What is the main manifestation of chronic disc degeneration?

Answer 9

Pain

Question 10

What can cause pain from chronic disc degeneration?

Answer 10

Facet misalignment
Facet joint arthritis
Vertebral instability
Root canal stenosis
Spinal canal stenosis
PLL tension and ossification

Question 11

Is spinal spondylosis associated with back/neck pain?

Answer 11

No

Question 12

Describe a partial herniation:

Answer 12

Fibrocartilagenous material extrudes/bulges posteriorly
The annulus usually bulges to one side of the PLL
The degree of the partial herniation gradually increases with successive injuries

Question 13

Describe a posterolateral rupture:

Answer 13

May press on a nerve root proximal to its point of exit through the IV foramen
- e.g. L4/L5 herniation causes compression of the 5th lumbar root

Question 14

Describe a large central herniation

Answer 14

Herniation of both the capsule (annulus fibrosis) and the nucleus pulposus
- may result in compression of the spinal cord or cauda equina.

Question 15

Describe a complete herniation

Answer 15

Herniation where part of the nucleus may:

• break free and lie free in the spinal canal
• break loose and work its way into the IVF

Question 16

What are some characteristic of cervical IVD herniation?

Answer 16

Neck pain
Neck stiffness
+/- upper limb neuro ssx
Spinal cord compression ssx

Question 17

What are some lumbar symptoms of IVD herniation?

Answer 17

Lumbar pain and tenderness
Lumbar muscle spasm
Lumbar stiffness and reduced ROM
\+/- sciatica
\+/- paraesthesia

Question 18

To what side will someones posture lean if they have a disc prolapse that is protruding medial to the spinal nerve?

Answer 18

They will lean/tilt towards the painful side

Question 19

To what side will someone posture lean if they have a disc prolapse that is protruding lateral to the spinal nerve?

Answer 19

They will lean away from the painful side

Question 20

Signs of posterolateral cervical IVD herniation

Answer 20

• Limitations of certain neck movements (one movement will usually be free)
• Full ROM in upper limb
• Slight muscle wasting in the upper limb
• Slight sensory impairment in the cervical nerve distribution
• Abnormal tendon reflex in the corresponding cervical supply

** any variation and combination of the above might happen