VIVA: Anatomy - Back

Question 1

Name the structures your needle would pass through when performing a lumbar puncture using a midline approach

Answer 1

2/3 ligaments to pass:
- Skin
- Subcutaneous tissue
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Epidural space and veins
- Dura and attached arachnoid
- Subarachnoid space to reach CSF

Question 2

What level would you do a LP in an adult and why?

Answer 2

Transcristal plane ~L4
Avoids damage to the conus medullaris which ends at L1

Question 3

Describe some of the characteristics of the ligaments passed when doing a lumbar puncture

Answer 3

Supraspinous: continues down the spine, strong and white, lax in extension and taught in flexion
Interspinous: weak ligament
Flavum*: most important ligament, extends between lamina of adjacent vertebrae

*must know these characteristics to pass

Question 4

What are the surface anatomical landmarks when performing a lumbar puncture

Answer 4

Line between the highest point of the iliac crests corresponds with L4
Palpate one vertebra above for L3 and one below for L5
Insertion site at L3/4 or L4/5

Question 5

What type of vertebral body is this? Outline its unique features

Answer 5

Lumbar*:
- Large kidney-shaped body
- Long, slender transverse processes
- Triangular vertebral foramen (larger than thoracic, smaller than cervical)
- Short, thick, hatchet-shaped spinous process
- Articular processes/facets extend vertically

*need to pass + 2 features

Question 6

What levels should a lumbar puncture be performed at, and what landmarks are used?

Answer 6

L3/4, L4/5 or L5/S1*
Spinal cord ends at L2
Space above or below the top of iliac crests at L4 spinous process* avoids the spinal cord

*need to pass

Question 7

Identify this bone, and demonstrate its bony features

Answer 7

7/9 to pass:
- Body
- Pedicle
- Transverse processes
- Superior and inferior articular facets
- Spinous process
- Lamina
- Vertebral foramen
- Intervertebral foramina

Question 8

What movements occur in the lumbar spine?

Answer 8

Flexion and extension
Lateral flexion
Very limited rotation

Question 9

What are some of the unique features of this bone?

Answer 9

4 needed to pass:
- Smaller body
- Longer, thinner and downward sloping spinous processes
- Facet joints more horizontal to allow a greater range of movement
- Foramen transversarium
- Larger canal
- Uncinate process
- Anterior and posterior transverse processes
- No accessory tubercles

Question 10

List the ligaments responsible for the stability of the spine

Answer 10

3 to pass:
- Anterior longitudinal
- Posterior longitudinal
- Supraspinous
- Ligamentum flavum

Question 11

What movements occur at the thoracic vertebra?

Answer 11

Rotation*
Some lateral flexion
Very limited flexion and extension

*needed to pass