MSK emergencies

Question 1

Definition of cauda equina syndrome

Answer 1

Damage to the cauda equina causing acute loss of function to the nerve roots below the conus medullaris

Question 2

Causes of cauda equina syndrome

Answer 2

Acute disc herniation
Spinal stenosis
Trauma (e.g. burst #)
Metastatic or primary spine tumours
Spinal infections (e.g. abscess)
AV malformation
Haemorrhage (subarachnoid, subdural, epidural)
Ankylosing Spondylitis
Iatrogenic
Continuous spinal anaesthesia
Post-surgical

Question 3

Red flag symptoms of cauda equina syndrome

Answer 3

Saddle anaesthesia
Bladder and/or bowel dysfunction
Sensory or motor weakness in either one or both lower limbs
Sexual dysfunction (erectile, ejaculatory, penile sensation, urinary incontinence during intercourse)

Question 4

Signs of cauda equina syndrome

Answer 4

Saddle anaesthesia
Loss on anal tone and wink
\+/ve straight-leg riase test
Red. or absent bulbocavernosus reflex
Bladder distention

Question 5

Immediate investigations if suspect cauda equina syndrome

Answer 5

MRI spine

Residual urine measurement (catheterise prior to imaging if obvious bladder distention)

Question 6

Management of cauda equina syndrome

Answer 6

Disc herniation: immediate (48h) surg
Spinal tumour: surgical resection, RTx
Trauma: immobilisation, steroids
Abscess: surg decompression, antibiotics (usually vanc + cephalosporin until MCS returns)

Question 7

Definition of compartment syndrome

Answer 7

A surgical emergency when elevated pressure within a limited space compromises the circulation with increased risk of irreversible damage to its contents and their function

Question 8

Causes of compartment syndrome

Answer 8

Usually major trauma
- long bone fractures (75% of cases)
- Crush injury
- thermal burns
- penetrating trauma
- injury to vascular structures
Minor trauma
- prolonged compression (e.g. unconscious)
- minor ankle inversion injury
Non-traumatic:
- ischaemia-reperfusion injury
- thrombosis
- bleeding disorders
- vascular disease
- nephrotic syndrome

Question 9

How long can muscles tolerate ischaemia (e.g. compartment syndrome) before onset of necrosis

Answer 9

3 hours

Question 10

Clinical features of compartment syndrome

Answer 10

Pain out of proportion to apparent injury
Persistent deep ache or burning pain
Paraesthesia
Pain with passive stretch of affected compartment
Tense to palpate (wood-like)
Muscle weakness
Pallor (uncommon)
Paralysis (v. late finding)

Question 11

Management of compartment syndrome

Answer 11

DO NOT ELEVATE
Immediate relief of all external pressure (dressings, splint, casts etc.)
Immediate ortho referral
Analgesics
O2
IV isotonic saline if hypotensive
fasciotomy

Question 12

Management of all open fractures

Answer 12

Immobilisation
Antibiotics
Tetanus prophylaxis
Analgesia
Prompt surgical irrigation and debridement

Question 13

Risk of infection in open fractures

Answer 13

Class A (no comorbid factors) 4%
Class B (1-2 comorbid factors) 15%
Class C (3 or more comorbid factors) 31%

Comorbid factors:

• age over 80
• nictoine use
• diabetes
• active malignancy
• pulmonary insufficiency
• Immunocompromised status

Question 14

Work up of open fracture

Answer 14

Like any other fracture

• x ray
• BGL