Clinical Anatomy of the Spine

Question 1

What are some features of the osteology of the spine?

Answer 1

33 vertebrae = 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), 4 coccygeal (fused)
4 curves of the spine = help maintain posture

Question 2

What are the atypical vertebrae of the spine?

Answer 2

C1 and C2 (axis and atlas) = allow head movement

C7 (vertebral prominence) = no formena transverse process

Question 3

What kind of joint are the intervertebral discs?

Answer 3

Intervertebral fibrocartilaginous joints

Question 4

What kind of joints are zygapophysial joints?

Answer 4

Facet joints (synovial joints)

Question 5

What movements do the facet joints and intervertebral discs allow?

Answer 5

Flexion, extension and lateral flexion = cumulative effect

Question 6

Why is there less flexion and extension in the thoracic spine?

Answer 6

Ribs cause constraint

Question 7

Why is lumbar rotation less than thoracic rotation?

Answer 7

Due to more vertically orientated facet joints

Question 8

Why does the cervical spine allow the greatest movement?

Answer 8

Due to more horizontal facet joints

Question 9

What happens to intervertebral discs with aging?

Answer 9

Lose water content = overload of facet joints and second degree osteoarthritis

Question 10

What makes the pain of osteoarthritis and spondylosis worse?

Answer 10

Worse with extension of spine = facet joint injections with fluoroscopy can help

Question 11

How can osteoarthritis in one or two motion segments be treated?

Answer 11

Localised fusion

Question 12

What are some changes that can occur in intervertebral discs?

Answer 12

Outer annulus fibrosis and inner gelatinous nucleus pulposus

Question 13

Where does degeneration of the intervertebral discs most commonly occur?

Answer 13

l4/5 and L5/S1 = also most common sites of slipped disc

Question 14

What occurs in acute disc prolapse?

Answer 14

Lifting heavy object causes annulus tear, rich innervation to outer annulus, pain on coughing, most settle by three months

Question 15

What do 60% of asymptomatic people over >45 show on an MRI?

Answer 15

Bulging disc = 10% have disc extrusion, 5% have asymptomatic nerve root compression

Question 16

Where do motor nerves originate?

Answer 16

Anteriorly = bodies in anterior grey horn, (sensory neurons originate dorsally)

Question 17

Where does the spinal cord run through?

Answer 17

Spinal canal = formed by vertebral column

Question 18

What is formed from the anterior and posterior roots?

Answer 18

Mixed spinal nerve = exits via intervertebral column

Question 19

How are sensory and motor nerve roots arranged in the lumbar spine?

Answer 19

Run together with two pairs at each level (susceptible to compression)

Question 20

Where does the spinal cord end?

Answer 20

L1

Question 21

What are some features of cauda equina syndrome?

Answer 21

Junctional upper motor neuron = weakness, spasticity, increased tone, hyperreflexia
Lower motor neuron = weakness, flaccidity, loss of reflexes

Question 22

Where does the exiting nerve root outside the thecal sac pass?

Answer 22

Under pedicle of corresponding vertebra

Question 23

Where are the transversing nerve roots located?

Answer 23

Pair whilst remaining in the thecal sac positioned anteriorly (in the lateral recess) in preparation to penetrate

Question 24

What nerve is commonly compressed in disc prolapse?

Answer 24

Transversing nerve root commonly

Question 25

What is compressed in a far lateral disc prolapse?

Answer 25

Exiting nerve root

Question 26

What does nerve root compression cause?

Answer 26

Radiculopathy resulting in pain down sensory distribution of nerve root (dermatome) = called sciatica when in lower leg Also weakness in any muscle supplied (myotome) and reduced/absent reflexes

Question 27

What nerve roots contribute to the sciatic nerve?

Answer 27

L4, L5 and S1 | Also S2 and S3

Question 28

What is sciatica?

Answer 28

Radiation of nerve pain along sensory distribution of sciatic nerve

Question 29

What can spinal stenosis cause?

Answer 29

Compression of nerve roots = usually by osteophytes and hypertrophied ligaments in osteoarthritis

Question 30

What is the pain of spinal stenosis like?

Answer 30

Radiculopathy or burning leg on walking = neurogenic claudication Some cases benefit from surgical decompression

Question 31

What are some features of myelopathy?

Answer 31

Spinal cord compression (e.g tumour, disc prolapse) | Upper motor neuron signs

Question 32

What causes cauda equina syndrome?

Answer 32

Caused by pressure (usually prolapsed disc) on all lumbosacral nerve roots at level of lesion (including sacral nerve roots for bladder/bowel control)

Question 33

What are some symptoms of cauda equina syndrome?

Answer 33

Bilateral lower motor neuron signs, bladder and bowel dysfunction, saddle anaesthesia and loss of anal tone

Question 34

What are the erector spinae muscles?

Answer 34

Iliocostalis, longissimus thoracis, spinalis thoracis = source of sprains and strains

Question 35

What do the ligaments of the spine contribute to?

Answer 35

Stability

Question 36

What is a chance fracture?

Answer 36

Very unstable = fractured vertebral body with disruption to posterior ligaments with/without fracture of posterior elements

Question 37

How can a chance fracture be treated?

Answer 37

Surgical stabilisation

Question 38

What are the landmarks for lumbar puncture and spinal anaesthesia?

Answer 38

Posterior iliac crest (L4), PSIS (S2)

Question 39

What are some bone and joint causes of back pain?

Answer 39

``` Bone = fracture, tumour, infection Joint = spondylosis, osteoarthritis, spinal stenosis ```

Question 40

What are some muscular and disc causes of back pain?

Answer 40

Muscles and ligaments = sprains and strains | Disc = degenerative back pain, sciatica, cauda equina syndrome

Question 41

What does mechanical back pain relate to?

Answer 41

Joints, ligaments, and muscles = no red flag features

Question 42

What are some features of mechanical back pain?

Answer 42

Worse with activity, relieved by rest, tends to be long course relapsing and remitting

Question 43

What are some risk factors for mechanical back pain?

Answer 43

Obesity, poor posture, poor lifting technique

Question 44

How can mechanical back pain be treated?

Answer 44

Nothing can be done surgically = analgesia, physio, pain clinic, chiropractor

Question 45

What are some surgical treatments for back pain and what are they good for?

Answer 45

Discectomy/decompression, good for sciatica/leg pain which doesn't settle with 3 months conservative management

Question 46

How are some negatives of doing an MRI of the spine?

Answer 46

False positives, middle aged (about age 45) asymptomatic patients will have signs so not specific, less specific in ageing patients