clinical anatomy of the vertebral column

Question 1

What does the vertebral column consist of

Answer 1

33 vertebrae in total, 23 cartilaginous disks between them.

Question 2

What are the functions of the vertebral column?

Answer 2

Upright position, assists with balance, shock absorbent and facilitates movement e.g. flexion and extension. Protects vertebral canal housing spinal cord.

Question 3

How are the curves of the vertebral column seen?

Answer 3

sagittal plane

Question 4

What type of joint is an intervertebral disc?

Answer 4

Fibrocartilaginous joint

Question 5

What is the structure of the intervertebral disc?

Answer 5

Consists of an outer annulus fibrosus and inner nucleus pulposus

Question 6

What keeps the intervertebral discs in place?

Answer 6

Anterior and posterior longitudinal ligaments form boundaries and provide stability. Anterior stronger. Anterior prevents hyperextension, posterior prevents hyperflexion.

Question 7

Why do we “shrink” in height we get old?

Answer 7

Joint space narrowing, loss of muscle mass and tone, reduced volume of intravertebral disc

Question 8

Why do the intervertebral discs not heal properly after injury?

Answer 8

Avascular and low cell density

Question 9

what are the articulation points?
what are articular surfaces covered in?

Answer 9

Superior articular facets articulate with vertebrae above. Inferior with vertebrae below. Indirectly articulate via intervertebral discs.
Articular surfaces covered in hyaline cartilage.

Question 10

important ligaments and what are they between?

Answer 10

: Ligamentum flavum – between lamina. Interspinous and supraspinous – spinous processes.

Question 11

how to insert a lumbar puncture?
what are the layers the needle goes through?

Answer 11

Question 12

causes of back pain

sinrim

Answer 12

Question 13

why is back pain important?

Answer 13

Estimated that between 60 – 80% of the population have back pain at some point in their lives.

Very common presentation in both GP and ED.

Some presentations are chronic, some are medical emergencies.

Question 14

• What changes in the intervertebral disc increase the risk of nucleus pulposus herniation?
• What factors or activities contribute to the development of annular tears or intervertebral disc herniation?
• Which regions of the spine are most commonly affected by intervertebral disc herniation, and why?
• What are the key symptoms of sciatica, and how is it related to intervertebral disc herniation?
• How is the straight leg raise test used to diagnose sciatica and nerve root irritation?

Answer 14

Intervertebral Disc Pathology: Annular Tears and Herniation

Pathophysiology
- Annular Tears:
- Water content in the annulus fibrosus (AF) decreases with age.
- Reduced water content lowers AF tension, leading to fissures or tears.
- Nucleus Pulposus (NP):
- The gelatinous NP can be replaced by fibrous tissue, reducing compressive force resistance.
- Weight transfer to the weakened AF causes progressive fissures.
- Once these fissures reach the peripheral AF, there is a risk of NP herniation.

Common Causes
1. Age-Related Changes:
- Decline in disc hydration and elasticity.
2. Mechanical Stressors:
- Repetitive Flexion: Bending the spine.
- Heavy Lifting: Occupations requiring strenuous activity.
- Contact Sports: Injuries due to high-impact activities.
- Trauma: Direct injury to the vertebral column.

Common Sites
- Lumbar Region:
- Most commonly at L4-L5 or L5-S1 levels.
- These regions bear significant mechanical loads.

Clinical Features
1. Local Symptoms:
- Lower Back Pain:
- Dull ache, exacerbated by spinal flexion.
- Postero-Lateral Herniation:
- Impinges on spinal nerve roots, particularly L5 or S1.

2. Sciatica:
   
   • Nerve Root Involvement: L5 or S1 part of the sciatic nerve.
   • Symptoms:
     
     • Pain or paraesthesia in the dermatomal distribution (L4-S3).
     • Weakness in corresponding myotomes.
   • May present as a sharp, radiating pain down the leg.

Diagnosis
- Straight Leg Raise Test:
- Useful for detecting nerve root irritation, specifically sciatica.

Summary
- Annular tears and IV disc herniation commonly occur due to age-related degeneration or mechanical stresses.
- Most herniations are in the lumbar spine (L4-L5, L5-S1) and lead to lower back pain and sciatica.
- Diagnostic tools like the straight leg raise test help identify nerve involvement.

Question 15

what type of herniation is often an emergency and why

Answer 15

Posterior herniation of IV disc is often an emergency: cauda equine syndrome or spinal cord compression (if above L1/L2

Question 16

how to diagnose for herniated intervertebral disk and how to treat

Answer 16

Diagnosis (Dx)?
Clinical findings
MRI
Treatment (Tx)?
Analgesia, nonsteroidal anti-inflammatory drug
Keep active rather than bed rest
Avoid activities which aggregate symptoms (e.g. lifting)
Physiotherapy
Steroid injection may help
Surgery is the last resort

Question 17

what is kyphosis
causes/ consequences
what scan shows osteoporosis

Answer 17

Excessive Convex Curvature of the Spine: Kyphosis and Osteoporosis

Pathophysiology
- Kyphosis:
- An excessive convex curvature of the spine, often affecting the thoracic region.
- Osteoporosis:
- A condition where decreased bone mineral density (BMD) leads to weak, porous bones prone to fractures.
- Bones act as a reservoir for calcium; calcium deficiency contributes to reduced bone strength and structural integrity.

Diagnostic Tool
- DEXA Scan (Bone Densitometry):
- Measures bone mineral density (BMD).
- Assesses bone strength and identifies osteoporosis.
- Lower BMD values indicate increased risk of fractures.

Causes
- Age-Related Factors:
1. Degenerative Disc Disease: Loss of intervertebral disc height exacerbates spinal curvature.
2. Muscle Loss: Weak spinal support contributes to kyphosis.
3. Wedge/Compression Fractures: Collapsed vertebrae increase spinal curvature and deformity.

Consequences
1. Mobility:
- Reduced mobility due to pain and structural deformity.
2. Risk of Falls:
- Kyphosis alters balance, increasing the likelihood of falls.
3. Fractures:
- Weak, brittle bones are more prone to fractures, perpetuating a cycle of immobility and additional fractures.

Summary
- Kyphosis is commonly associated with osteoporosis, where weakened bones result in excessive spinal curvature and vertebral fractures.
- Diagnostic confirmation is done via DEXA scan, measuring bone mineral density.
- Prevention and management focus on maintaining bone health and preventing fractures to reduce complications.

Question 18

what to look for on scans => AP view and lateral view

Answer 18

Look for The owl’s two eyes (pedicles) and beak (spinous process); shape and contours
On AP = anteroposterior film: A winking owl (single or bilateral pedicle disruption) suggests possible fracture.
On a lateral X-ray, a compression fracture appears as a wedge-shaped vertebral body, commonly seen in osteoporosis.

Question 19

Other causes of winking owl sign

Answer 19

Bone metastasis
TB
Neurofibromatosis
Congenital hypoplasia of pedicle

Question 20

vertebral fractures
what does the range look like
when to suspect
what type of treatment

Answer 20

Spinal fractures can vary in severity depending on the patient’s age and the type of trauma:

Compression Fracture: Common in older adults with brittle bones (like in osteoporosis). The vertebra partially collapses, usually in the front, creating a wedge shape.
Burst Fracture: Seen in younger patients after severe trauma, where the vertebra breaks into pieces and may push fragments into surrounding tissues or the spinal canal.

When to Suspect a Spinal Fracture
Trauma: A history of significant trauma (falls, accidents), even mild trauma in older adults with weak bones.
Pain: Sudden, severe central back pain that improves when lying down.
Deformity: Visible abnormal curvature or changes in spinal shape.
Tenderness: Pain when pressing over the affected part of the spine.

Treatment depends on the type of fracture and its stability

Question 21

SPONDYLOSIS & FACET JOINT SYNDROME
what is it?
what region is it in?
what can it be associated with?
when is pain worse?

Answer 21

Osteoarthritis (Degeneration) of the spine / facet joint
Common in cervical and lumbar regions.
May be associated with bony spurs (osteophyte)
Pain is worse on rotation or lateral flexion.

Question 22

what is SPONDYLOLYSIS
what can it progress to?

Answer 22

Stress fracture through the pars interarticularis of the lumbar vertebrae
Can progress to spondylolisthesis

Question 23

what is spondylolisthesis?
what region?
what could occur?
what might it compress?

Answer 23

Anterior slip of a vertebra on the lower segment due to weakness of ligamentum flavum or fracture of pedicle.
Usually slips towards one side
Commonly L4/L5 or L5/S1
There may be impingement of the spinal nerve as it exits through the intervertebral foramen
May compress on the spinal cord or cauda equina

Question 24

what is spina bifida?
what is the cause?
what are the risk factors?

Answer 24

Spina Bifida: Cause and Development (Simplified)

Spina bifida is a neural tube defect that happens during early development in pregnancy. Here’s what this means:

1. What Goes Wrong?
   
   • During development, a part of the spine called the sclerotome (which forms the vertebrae) does not develop or fuse properly.
   • This leaves a gap or defect in the spine where it fails to close completely.
2. Why Does It Happen?
   
   • Exact Cause: Not fully understood.
   • Risk Factors:
     
     • Folate (Folic Acid) Deficiency: Low levels of folic acid during early pregnancy increase the risk.
     • Medications: Some drugs, like valproic acid (used for epilepsy or mood disorders), can interfere with neural tube closure.

In Summary:
Spina bifida occurs because the spine doesn’t close properly during development, often linked to folate deficiency or medication use, but the exact cause isn’t always clear.

Question 25

ABNORMAL NUMBER of VERTEBRAE

Answer 25

Sacralisation of L5
Lumbarisation of S1

Question 26

what is ANKYLOSING SPONDYLITIS
what does it eventually cause?

Answer 26

An inflammatory disease of the joints and ligaments of the spine
Eventually causes ankylosis of vertebral and sacroiliac joints (Bamboo spine).

Question 27

Patient is admitted with severe lower back pain, which came on all of a sudden. The pain is radiating down both legs and she is having difficulty walking.

How will you assess this patient systematically?

History BROUP B vs neurological exam SMART SD

which imaging technique?

Answer 27

History

PQRST: Pain at rest.

Low back pain, dull in nature.
Radiates down both buttocks, thighs and lower legs (radicular pain).

Acute onset (hours-days)

Urinary incontinence (S2-4)? Are you aware when your bladder feels full (urinary retention)?

Bowel incontinence (S2-4)?

Numbness around perianal region + buttocks? (saddle anaesthesia - S2-4)

Neurological Examination

Local tenderness? (lumbar spine)

Loss of sensation? (touch, pain, temperature) in dermatomes supplied by lumbar + sacral nerve roots.

Lower limb muscle weakness? (unilateral or paraplegia)

Loss of knee and ankle reflex (L3-4 and S1)

Saddle anaesthesia? (loss of sensation)

Loss of anal sphincter tone? (on PR exam) – S2-4

which imaging technique?

Question 28

what is CAUDA EQUINA SYNDROME?
causes:
-degenrative
-traumatic
-infective
-malignant
symptoms
SPINE

Answer 28

Summary of Cauda Equina Syndrome (CES)

Definition:
Cauda Equina Syndrome is caused by severe compression of the lumbar and sacral nerve roots in the lumbar cistern, leading to serious neurological symptoms.

Key Risks:
- Permanent incontinence
- Sexual dysfunction
- Paraplegia

Importance:
Prompt diagnosis and surgical decompression are crucial to prevent lasting damage.

Causes (Aetiology):
1. Degenerative:
- Lumbar disc herniation (most common)
- Spondylolisthesis
2. Traumatic:
- Vertebral fracture or dislocation
- Epidural hematoma (trauma or post-surgery)
3. Infective:
- Epidural abscess
- Tuberculosis
4. Malignant:
- Metastases
- Primary CNS malignancies

Question 29

cancers of spine
what is more common than primary cancer?
what are Common cancers that metastasis to spine?

Answer 29

Metastasis to spine is much more common than primary cancer
Common cancers that metastasis to spine:
Prostate
Breast
Lung
Renal

Question 30

what is Osteomyelitis
types of infections

How do they spread?

Answer 30

Osteomyelitis is an infection of the bone and bone marrow. When it affects the spine, it can lead to severe complications and is often referred to as vertebral osteomyelitis. This infection can occur in people of all ages and may be caused by various bacteria, depending on the circumstances.

Common Causes of Vertebral Osteomyelitis:
Staphylococcus aureus:

Most common cause of bone infections in people of all age groups.
This bacterium is typically found on the skin and can enter the body through cuts, wounds, or other breaches in the skin.
Salmonella species (in sickle cell disease):

In individuals with sickle cell disease, Salmonella bacteria are more likely to cause vertebral infections.
This is because people with sickle cell disease are at higher risk for infections involving Salmonella, especially when the spleen is damaged or absent.
Pott’s Disease (Tuberculosis of the Spine):

A form of spinal tuberculosis, Pott’s disease occurs when pulmonary tuberculosis (TB) spreads to the vertebrae.
It’s uncommon in many places but can still be a significant issue, especially in regions with high rates of tuberculosis.
How Infection Reaches the Spine:
Hematogenous Spread (via the bloodstream):

The spine’s blood supply makes it possible for infections in other parts of the body to reach the vertebrae.
Blood vessels in the spine are more prone to infections since they have a more complex network of venous flow that lacks valves, making it easier for bacteria to travel and colonize the bones.
Direct Spread:

Infections in nearby tissues, like cellulitis (skin infection), can spread directly to the spine.
The lack of valves in the veins in the spinal region makes it easier for bacteria from nearby tissues to travel to the spine and cause infection.
Post-Surgical or Post-Procedure Infections:

Infections can also occur after surgery or procedures on the spine.
The most common bacteria involved in post-surgical infections are streptococcus species, which are normally present on the skin (skin commensals). These bacteria can enter the body during surgical procedures, leading to infection.

Question 31

What is Discitis?
aetiology and pathophysiology ?
when to have a high suspicion?

Answer 31

infection of the intervertebral disc
Similar aetiology and pathophysiology to osteomyelitis of the vertebra.

Have a high suspicion of discitis in intravenous drug users with subacute back pain (days-weeks)

Question 32

how to detect infection of the spine

Answer 32

MRI

Question 33

what is this?
cause

Answer 33

ODONTOID PEG FRACTURE (C2).
Odontoid (peg) view plain film.
Lateral CT.
Caused by sudden severe flexion.

Question 34

what is this?
cause

Answer 34

JEFFERSON FRACTURE (C1).
Caused by axial loading i.e. falling on head.

Atlas compressed between occiput and C2 with fracture of the lamina and pedicles.

Question 35

what is this and what is it associated with?

Answer 35

FACET JOINT DISLOCATION (Example C4-C5)

These are rotational injuries, rarely occurring in isolation.

Associated with significant ligament injury, therefore unstable.

Question 36

what is this?
what was it historically caused by/ how about now?

Answer 36

HANGMANS FRACTURE (C2)

Hyperextension leading to pedicle fracture.

Historically caused by hanging. In modern times seen in patient’s who have struck their head on the steering wheel during an RTC.

Question 37

whiplash injury - what does it tear?

Answer 37

Question 38

What are the risks and considerations of C-Spine immobilization in the Emergency Department?

Answer 38

Here’s a clearer explanation of cervical spine (C-spine) injury and the risks of immobilization:

True C-Spine Injury Is Rare:
- Cervical spine injuries (damage to the neck area of the spine) are uncommon.
- Precaution: Despite the rarity, many patients with potential neck injuries are immobilized (secured in place) as a safety measure until it’s confirmed whether there’s an injury or not.

Risks of Immobilization:
1. Raised Intracranial Pressure (ICP):
- Cause: Tight collars or restraints can limit the flow of blood out of the head.
- Effect: This can increase pressure inside the skull, leading to potential brain problems.

2. Pain:
   
   • Cause: Being immobilized for long periods can cause discomfort.
   • Effect: Pain or distress from staying in one position can increase the patient’s discomfort.
3. Tissue Ischaemia/Pressure Sores:
   
   • Cause: Prolonged pressure from collars or immobilization devices on the skin.
   • Effect: This can restrict blood flow to certain areas, causing tissue damage or pressure sores (ulcers).
4. Impaired Ventilation:
   
   • Cause: Immobilization can limit neck and chest movement.
   • Effect: This can make breathing more difficult and affect lung function.

Summary:
- While cervical spine injuries are rare, patients are often immobilized as a precaution.
- However, immobilization carries risks like increased pressure in the brain, pain, tissue damage, and difficulty breathing. These risks need to be managed carefully.