Conditions Of The Lumbar Spine

Question 1

How common is Mechanical back pain?1️⃣

Answer 1

• Extremely common
• 50% UK population report lumbar back pain for at least 24hrs in any one yr, half of those last >4wks
• 80% UK population experience lumbar back pain lasting >24hrs in their lifetimes

Question 2

How is mechanical back pain characterised?1️⃣

Answer 2

• Characterised by pain when spine is loaded that worsens with exercise and is relieved by rest
• Tends to be intermittent
• Often triggered by innocuous activity

Question 3

What are the risk factors for mechanical back pain?1️⃣

Answer 3

• obesity
• poor posture
• sedentary lifestyle w/ deconditioning of the paraspinal (core) muscles
• poorly designed seating
• incorrect manual handling

Question 4

State 2 changes involved in the degenerative changes in the vertebral column2️⃣

Answer 4

• disc degenerating

- marginal osteophytosis

Question 5

Why do osteophytes [syndesmophytes] develop adjacent to the end plates of the intervertebral discs?2️⃣

marginal osteophytosis

Answer 5

• Nucleus pulposus dehydrates with age

- leads to decrease in disc height, disc bulging and alteration of load stresses on the joints

Question 6

How are the facet joints affected?2️⃣

Answer 6

• increased stress placed in facet joints
• facet joints develop osteoarthritic changes

-facet joints innervated by meningeal branch of spinal nerve so arthritis perceived as painful

Question 7

Why is radicular or nerve pain perceived?2️⃣

Answer 7

• decreased disc height and arthritis in facet joints and vertebral bodies
• intervertebral foramina decreases in size
• leads to compression of spinal nerves which is perceived as radicular or nerve pain

Question 8

Why does pain occur during herniation of a intervertebral disc (‘slipped disc’)?3️⃣

Answer 8

-due to herniated disc material pressing on a spinal nerve

Question 9

What is the common age group to have a herniated disc?3️⃣

Answer 9

30-50yrs

Question 10

Describe the 4 stages of disc herniation 3️⃣

Answer 10

1- Disc degeneration: chemical changes associated with ageing cause disc to dehydrate and bulge
2- Prolapse: protrusion of NP occurs with slight impingement into the spinal canal. NP contained within rim of AF
3- Extrusion: NP breaks through AF but still contained within disc space
4- Sequestration: NP separates from main body of disc and enters spinal canal

Question 11

State the most common sites for a slipped disc 3️⃣

Answer 11

-L4/5
-L5/S1
Due to the mechanical loading at these joints

Question 12

What 2 sites are the nerve roots most vulnerable at? 3️⃣

Answer 12

1) where they cross the intervertebral disc (‘paracentrally’)
2) where they exit the spinal canal in the intervertebral foramen (‘far laterally’)

Question 13

Where does the NP most commonly and least commonly herniate? 3️⃣

Answer 13

• Most commonly herniates posterolaterally (lateral to the posterior longitudinal l.), causing compression of a spinal nerve within the intervertebral foramen. PARACENTRAL PROLAPSE 96% cases
• herniation is FAR LATERAL 2% cases
• herniation is CENTRAL 2% cases (directly towards spinal cord)

Question 14

Describe the 2 types of nerve roots 3️⃣

Answer 14

1) Exiting nerve root: nerve root that emerges from spinal canal at same level as the intervertebral disc
2) Traversing nerve root: nerve root that emerges at the level below

Question 15

Which nerve roots are affected in the different types of herniation? 3️⃣

Answer 15

• exiting nerve root at risk in far lateral disc herniation

- traversing nerve root at risk in paracentral herniation

Question 16

What is radicular leg pain (“sciatica”)? 4️⃣

Answer 16

Pain caused by irritation or compression of one or more of the nerve roots that contribute to the sciatic nerve (L4 - S3)

Question 17

What are the causes of sciatica? 4️⃣

Answer 17

• marginal osteophytosis

- herniated disc

Question 18

Where is sciatica typically experienced? 4️⃣

Answer 18

Pain experienced in back and buttocks and radiates to the dermatome supplied by the affected nerve root

• hence the pain follows a path ‘from the back to the dermatome’
• if nerve compression also causes paraesthesia, it will only be experienced in the affected dermatome rather than the full path from the lumbar spine to dermatome

Question 19

Describe the typical distribution of pain in sciatica 4️⃣

Answer 19

L4 sciatica: a.thigh, a.knee, medial leg
L5 sciatica: l.thigh, l.leg, dorsum of foot
S1 sciatica: p.thigh, p.leg, heel, sole

Question 20

What are the causes of Cauda equina syndrome? 5️⃣

Answer 20

• disc prolapse when there is a ‘canal filling disc’ that compresses lumbar and sacral nerve roots within the spinal canal
• tumours affecting vertebral column or meninges
• spinal infection/abscess
• spinal stenosis secondary to arthritis
• vertebral fracture
• spinal haemorrhage
• late stage ankylosing spondylitis

Question 21

What are the red flag symptoms of cauda equina syndrome? 5️⃣

Answer 21

• bilateral sciatica
• perianal numbness
• painless retention of urine
• urinary/ faecal incontinence
• erectile dysfunction

Question 22

How is cauda equina syndrome treated? 5️⃣

Answer 22

Surgical decompression within 48hrs of the onset of sphincter symptoms

Otherwise poor prognosis

Question 23

What are the serious and life changing complication of missing a cauda equina syndrome diagnosis? 5️⃣

Answer 23

• chronic neuropathic pain
• impotence
• having to perform self catheterisation to pass urine
• faecal incontinence or impaction requiring manual evacuation of faeces
• loss if sensation and lower limb weakness requiring wheelchair

Question 24

What is spinal canal stenosis? 6️⃣

Answer 24

An abnormal narrowing of the spinal canal that compresses the spinal cord or the nerve roots

Question 25

What are the causes of spinal canal stenosis? 6️⃣

Answer 25

Tends to affect the elderly due to combination of:

• disc bulging
• facet joint osteoarthritis
• ligamentum flavum hypertrophy

Other causes:

• compression fracture of vertebral bodies
• spondylolisthesis
• trauma

Question 26

Describe the symptoms of spinal canal stenosis 6️⃣

Answer 26

Symptoms depend upon the region of the cord or nerve roots that are affected. Lumbar stenosis is most common, followed by cervical stenosis

• discomfort whilst standing
• discomfort or pain in shoulder, arm or hand (C) or in the lower limb (L)
• bilateral symptoms
• numbness at or below the level of stenosis
• weakness at or below the level of stenosis
• neurogenic claudication

Question 27

What is Neurogenic claudication (pseudoclaudication) ? 7️⃣

Answer 27

Symptom rather than a diagnosis

Patient reports pain &/or pins and needles in legs on prolonged standing and on walking, radiating in a sciatica distribution

Question 28

What does neurogenic claudication mean? 7️⃣

Answer 28

• neurogenic: problem originated in nerve
• claudication: derived from Latin for limp (Claudigo) as patient feels cramping pain or weakness in legs and therefore tends to limp

Question 29

What does neurogenic claudication result from? 7️⃣

Answer 29

• Results from compression of spinal nerves as they emerge from the lumbosacral spinal cord
• leads to venous engorgement of nerve roots during exercise
• leads to reduced arterial inflow and transient arterial ischaemia
• ischaemia of the affected nerve(s) results in pain &/or paraesthesia

Question 30

How else does neurogenic claudication present? 7️⃣

Answer 30

• in one or both legs
• classically relieved by rest, a change in position and by flexion of the spine

-movements involving waist flexion are well tolerated such as cycling, pushing a trolley and climbing stairs

Question 31

What is Spondylolisthesis? 8️⃣

Answer 31

The anterior displacement of vertebra above, relative to the vertebra below

Question 32

What are some of the classifications of spondylolisthesis based on the underlying cause? 8️⃣

Answer 32

• congenital or dysplastic: congenital instability of the facet joints
• isthmic: a defect in the pars interarticularis
• degenerative: results from facet joint arthritis and joint remodelling
• traumatic: acute fractures in the neural arch other than the pars interarticularis
• pathological: infection or malignancy
• iatrogenic: caused by surgical intervention

Question 33

What is the par interarticularis? 8️⃣

Answer 33

Part of the vertebra between the superior and inferior articular processes

Question 34

Spondylolysis vs spondylolisthesis? 8️⃣

Answer 34

Spondylolysis: complete fracture in the pars interarticularis without displacement

Spondylolisthesis is once anterior displacement of the upper vertebra occurs. May or may not be associated with instability of the vertebral column

Question 35

What are the symptoms of Spondylolisthesis? 8️⃣

Answer 35

Some individuals remain Asymptomatic 
But most complain of some discomfort ranging from:
-occasional lower back pain
-incapacitating mechanical pain
-sciatica from nerve root compression 
-neurogenic claudication

Question 36

How is Spondylolisthesis treated? 8️⃣

Answer 36

Surgically using screws and rods to stabilise the spine

Question 37

How to spot Spondylolisthesis (& spondylolysis) from radiological images? 8️⃣

Answer 37

• trace outline of a ‘Scottie dog’ in oblique views of the spine. If dog has a ‘collar’ then it is spondylolysis. If dog’s head detached then Spondylolisthesis.
• can also trace line of the anterior and posterior longitudinal ligaments and detect a ‘step’ at the site of displacement

Question 38

What is a lumbar puncture?

Answer 38

It is the withdrawal of cerebrospinal fluid from the subarachnoid space of the lumbar cistern.
Important for variety of CNS disorder such as meningitis and multiple sclerosis etc

Question 39

How is a lumbar puncture performed?

Answer 39

• patient lies on side in knee-chest position as flexion of vertebral column facilitates insertion of the needle by spreading apart the vertebral lamina and spinous processes, stretching the ligamentum flavum
• anaesthetise skin and insert lumbar puncture needle in midline between spinous processes of L3&4 (or L4&5)
• after passing 4-6cm in adults, needle ‘pops’ through ligamentum flavum, then punctures the dura and arachnoid, and enters lumbar cistern
• remove stylet and CSF escapes