Pathogenesis of spinal Degeneration Flashcards
1
Q
Intervertebral disc consists of three components what are these?–
A
- an inner gelatinous nucleus pulposus
- outer annulus fibrosis
- cartilage end plates located superiorly and inferiorly
2
Q
Describe the structure of the annulus fibrosis
A
- circular layer of type 1 collagen fibres that are resistant to tensile strength because the collagen fibres run oblique between the lamellae of the annulus in alternating directions
3
Q
Describe the structure of the nucleus pulposus
A
- nucleus pulposus consists of proteoglycans and water gel held together loosely by irregular networks of fine type 2 collagen and elastin fibres
- the proteoglycan of the nucleus pulposus provides the osmotic properties need
4
Q
Degenerative process of a disc
A
- during degeneration the disc undergo a reductionn in height mainly as a result of a loss of water volume, due to a decrease in the synthesis poteoglycans
5
Q
Nucleus pulposus vascular or avascular?
A
- avascular, disc gets its nutrition from the endplate through a process of osmosis
6
Q
What are the 3 phases in the degenerative process?
A
- dysfunction
- instability
- stabilisation
7
Q
Dysfunction: Phase 1
A
- normal function of a 3 joint complex interrupted by injury
- muscles in hypertonicity (rotatorius or multifidus)
- normal movement restricted
- changes affecting facet joint also affect disc and vise versa
- in dysfunction facets are primarily affected
- generally younger patients
- usually torsional twists with flexion or extension
- may develop into phase 2
- may develop straight into phase 3
8
Q
MECHANISM OF DYSFUNCTION DIAGRAM
A
LEARN THIS FOR EXAM PAGE 5
9
Q
Dysfunction phase: 1 symptoms
A
- acute, subacute, or chronic low back pain
- often localised to one area and to one side
- may refer pain to groin, greater trochanter and posterior thigh asfar as the knee, rarely below knee
- pain is relieved by rest , worse by movement, usually one particular movement may cause a catch
10
Q
Dysfunction phase: 2 signs
A
- multiple
- tenderness on palpation usually on one side and one level over the sacrospinalis and multifidus muscle
- able to lateral bend more to one side than the other
- muscle activity is abnormal
- all movements are restricted especially extension
- some degree of functional scoliosis especially seen on flexion
11
Q
Describe the structure of the intervertebral disc
A
- Tension resisting annulus fibrosis and a compression resisting nucleus pulposus composed largely of proteoglycans and water
12
Q
Instability phase: 2
A
- tendency for the problem to reoccur and each occasion the instability becomes more marked
- usually older patient
- history of spinal pain
- patient stuck on flexion
13
Q
Instability: phase 2- symptoms
A
- back feels weak
- feels as if it might give way
- may produce a catch in back on certain movements
14
Q
Instability: Phase 2 - signs
A
- increased abnormal movement between two vertebrae on motion palpation
- possible to palpate the spinous process with excess movement on bending and straightening
- positive MINORS SIGN and catching on movement from flexion to extension
15
Q
Stabilisation: Phase 3
A
- segment regains stability through fibrosis and osteophytes forming around the posterior joints and within and around the disc
- sometimes phase 1 passes directly into those of phase 3 without the changes seen in phase 2
