Vertebral Column Flashcards Preview

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Flashcards in Vertebral Column Deck (59):
1

Development of sacral and thoracic hyphoses

Before birth

2

Development of cervical lordosis

As weight o baby's head held straight

3

Development of lumbar lordosis

Through walking and holding body upright

4

Percentage of weight on body of vertebrae

75

5

Percentage of weight on arch of vertebrae

25

6

Structure of solid (cortical) bone

Crystalline

7

Suitability of solid bone

Static load - would break bonds between crystals in dynamic load

8

Factors impacting quality o bone

Genetics - densest in polynesians and africans
Physical aspect - exercise

9

Strongest part of vertebra

Pedicle

10

Weakest part of vertebra

Middle part of anterior portion of body - still needs 600kg to crush (800kg to crush whole body)

11

Peak bone density age

20s

12

Which type of bone declines quickest?

Trabecular (quicker than cortical) - alters loading properties

13

Types of fracture due to trabecular bone decline

Anterior wedge
Biconcave fracture
Crush

14

Differences (2) between vertebral column and other synovial joints

1. Forces generated go through body of V and not synovial joint itself (except two joints of skull)
2. Ligaments not intimate with vertebral articular joints

15

Stability of cervical spine?

Decreased: Horizontal articular surfaces - increased likelihood of dislocation

16

Stability of thoracic spine?

Vertical zygohypophysial joints - stable

17

Stability of lumbar spine?

locked with no rotation - stable

18

Inclination of lumbosacral joint + stability?

50% + 16% wedge-shaped vertebrae + no movement = ensure stability

19

Features of annulus fibrosus

□ Collagen lamellae are laid out in different directions, usually 6 degrees difference between them, causing for the annulus to be resistant to pressure and stress

□ Fluid can leave, but negative charge of GAG disallows complete emptying

Shock absorber

20

Weak link of intervertebral disc

Vertebral end plates

21

Vertebral end plate function

Nutrition by diffusion of nutrients - - Respiration at very slow rate and amount of fluid flowing is very small

- Fluid will leave into bone during day, when forces are taken away negative pressure draws fluid back into the intervertebral disc - takes nutrients with it

22

Features of nucleus pulposus

□ Pressure on intervertebral will cause force vectors to initiate bulging out to form hernias
□ 70-90% water,
□ proteoglycans attached to hyaluronic acid
- 25% of disc volume in cervical region, 50% in lumbar region

23

Ligamentum flavum

Between lamina
Plenty of elastic fibres

24

Intertransverse ligaments

Between transverse processes - most effective in lumbar region

25

Anterior Longitudinal lig.

In front of bodies
Stretched in extension

26

Posterior Longitudinal lig.

Posterior surface of bodies
Stretched in forward flexion

27

Range of movement in vertebral column

Restricted by limited range of deformation of intervertebral disc and the shape of the synovial articulation and their associated ligaments

28

Flexion and extension in VC

Highest in cervical and lumbar regions
Lowest in the thoracic region

29

Lateral flexion in VC

Most in cervical and lumbar regions
Little in thoracic

30

Rotation in VC

Greatest in C1/2 - almost 35 degrees

31

Erector spinae muscles

Ileocostalis
Longissimus
Spinalis

32

Posterior muscles function in VC stability

Tension of thoracolumbar fascia

33

Function of erector spinae

Contraction increases interdiscal pressure

When holding load in front of you - ES will increase in contraction
-The further away the load, the more activity from ES
- COG more forward

Size and weight of load in same position does not alter activity of ES
- Doesn’t alter COG

34

Quadratus lumborum function in VC

Stabilises diaphragm

Lateral flexion of trunk

35

Psoas major function in VC

- Ipsilateral flexion and contralateral rotation
- Increases interdiscal pressure
- Vertebral column flexes relative to the pelvis - accentuates lumbar lordosis

36

Abdominal muscle function in VC

Transversus abdominis
§ Also contributes to tightening the thoracolumbar fascia
§ Acts like a corset - muscular tone of the abdominal wall
§ Separates the ribs from the iliac crest

Allows for good diaphragm movement

37

Proportion of vertebrae fractures occurring in body

70%
(30% of that in anterior aspect)

38

Fractures of vertebral arch

rare

39

Facet Joint damage

Pars interarticularis - failure may occur there during sports
§ rapid extension movements but also with repeated loading (ceiling painting)

40

Intervertebral disc failure primary site of pathology

Endplate fractures and lesions

41

Causes of intervertebral disc internal failure

- Asymmetry of facet joints - leads to change in joint axes and hence intervertebral disc
- Lateral bending
□ Stretches the annulus more than forward bending
- Lack of glycosaminoglycans
□ They take in more fluid to relieve stress
- Dehydration of int. discs
□ Vertebrae come close together tightening the intervertebral foramen and impinging on spinal nerve
□ Osteophytes develop, loss of range of movement

42

Consequences of Inter. Disc internal failure

- Degeneration of body = more pressure on arch (rise from 8% to 40%)
□ Intervertebral cannot take the load

- Spondylolysis, Spondylolisthesis
□ Fracture of pars interarticularis

43

Spondylolysis: what is an isthmus fracture called?

Scottie Dog fracture

44

Movement in Atlanto-Occipital joint

○ Flexion and Extension
§ Posteriorly limited by bony element
○ Lateral flexion - very slight
§ No lat flex between C1 and C2

45

Movement in Atlanto-Axial joint

○ Flexion, extension and rotation

46

Groups of AA joint ligaments

Deep
Intermediate
Superficial

47

Deep AA joint ligaments

□ Transverso-occipital
□ Apical and Alar ligaments of dens
□ Transverse ligament
□ Transverso-axial ligament

48

Intermediate AA joint ligaments

Cruciate ligament

49

Superficial AA joint ligaments

Median Occipito-axial ligament

Posterior Longitudinal Ligament

50

Range of movements in neck

• Flexion and Extension
- most in C0/1, but a lot throughout cervical region

• Rotation - majority in C1/2
○ No lateral flexion

51

Fracture of atlas

Weight of head is placed on articular condyles of the atlas

Vertical force can cause a compression injury (fracture of atlas)

Opening of atlas ring and sliding of lateral parts laterally - sliding

Possible damage to vertebral artery if dislocation occurs

52

Displacement of AA joint

Trauma or rheumatoid arthritis

Increase in laxity -> dislocation by stretching of transverse ligament

Fractures of the dens
□ If stable and no dislocation - safe
□ Loosening of transverse ligament - v. dangerous

53

Compression of vertebral body

Trabeculae alignment causes a weak anterior portion of the body = Wedging

Posterior ligaments usually intact and fracture stable - unlikely damage to spinal cord

Burst fracture - should be ok if fragments don’t get to spinal cord and damage it

54

Flexion subluxation and dislocation

Vertebra coming on front of the one below

No damage to vertebrae

Likely to damage posterior ligaments
□ Poor blood supply to ligs. - slow recovery

Spinal fusion - recommended if no damage to spinal cord but damage to ligaments

55

Extension subluxation

Damage to anterior ligament

Moving apart of vertebrae

Collar used to stabilise
□ Unstable position of spinal cord

Possible damage to vertebral arteries

56

Osteoporosis

Loss of horizontal and vertical trabeculae

Bone remodelling process
§ Bone resorption exceeds bone formation

57

Sites of osteoporotic fracture

Wrist
Cervical spine
Hip joint

58

Changes in vertebral body with increasing age

Trabeculae decrease and thin

With age, more cortical bone by proportion

59

How to repair damaged vertebral bodies (hollow inside)

Kyphoplasty and Vertebroplasty