L3.1 Spinal Mechanism & Spinal disorders

Question 1

What are the 2 types of back pain?

Answer 1

• 1) Mechanical → muscle strains, disc prolapse
• 2) Compressive → Compressive of nerve roots

Question 2

Which are the danger areas for spinal injury?

Answer 2

Cervical (greatest movement) & lumbosacral (weight bearing)

Question 3

What is the movement of spine limited by?

Answer 3

• 1) Thickness of disc – enhances movements
  
  • Relative largest to body – cervical
  • Absolute largest – Lumbar
• 2) Orientation = Limits movement to certain direction

Question 4

How does the movement of flexion and extension affect the facet surfaces?

Answer 4

• During flexion (enhanced by lumbar lordosis) → nucleus projects pos. (Opes facet surfaces)
  
  • Hyperflexion stretches sciatic nerve & may cause nerve root pain
• During extension → minimal movement (Closes facet surfaces)
  
  • Minimal movement
  • Vertebral foramen narrowed

Question 5

What is pain felt follow back injury?

Answer 5

• Pos rami innervate: Facet joints, deep back muscles, and overlying skin
• Facet joint injured → Nerve also supplies muscle
  
  • ∴ goes into a protective reflex muscle spasms
  • Overlying skin also sensitive (feels pain)

Question 6

What does pressure built up in discs cause?

Answer 6

• 1) disc prolapse
• 2) Bulge
• 3) Herniation
• 4) Extrusion (exits nucleus → commonly lodge in vertebral canal)

Question 7

What is compressive type pain?

Answer 7

• nerve roots irritated/pinched
• Causes: herniation or stenosis (narrowing of gap between vertebrae)
• Most common for L4/S5 & L5/S1

Question 8

What happens during a L5/S1 disc prolaspe?

Answer 8

• L5/S1 disc prolapse → affects S1
• Pain: over hip, postero-lateral thigh, leg & heel. Parietal sensory loss in S1
• Movement: restricted & painful, weakened plantar flexion
• Signs: Limited straight leg raise, calf muscle wasting, absent ankle reflex(plantar flex)

Question 9

How does an injury to the cervical spine happen?

Answer 9

• Usually due to trauma
  
  • Whiplash injury – acceleration of head in antero/posterior direction
• During hyperextension of head – more susceptible injury of facet capsule, articular surfaces and supporting ligament

Question 10

What happens during spondylosis (disc degeneration)?

Answer 10

• Water content in disc is lost (spondylosis) with age
• Bone may be irritated
• Osteophytes may develop
  
  • May converge on vertebral canal → stenosis compress nerve root (osteoarthritis)

Question 11

What happens to degeneration in the spine?

Answer 11

• Uncinate process come into contact (cervical)
  
  • Irritate nerve roots & arteries
• May often be associated with osteoporosis (spine fractures)
• Ankylosing spondylitis: Fusion of axial skeleton (ankyloses)

Question 12

What causes and what happens during a cauda equina compression?

Answer 12

• Caused by midline IV disc prolapse
• Loss of reflexes for pelvic viscera, sensory losses involving sacral nerves

Question 13

How can non-mechanical back pain occur?

Answer 13

• May be due to systemic causes (e.g aortic aneurism (enlargement), metastasis (spread) of cancer cells to back)
  
  • Possible patient: Elderly man with urinary problems

Question 14

What is a hangman’s fracture?

Answer 14

• Hangman’s fracture: Both pedicles are fractures
  
  • Seen in driver → crash with no seat belt
  • Hyperextension of neck

Question 15

What is a Jefferson’s fracture?

Answer 15

• Bilateral fracture of the anterior arch + pedicle
• By falling onto vortex of skull (Diving in shallow water)