Osteomyelitis

Question 1

What is osteomyelitis?

Answer 1

infection of bone leading to inflammation, necrosis + new bone formation. Can be acute, subacute or chronic.

Question 2

Name 3 causative organisms of osteomyelitis

Answer 2

Staphylococcus aureus
Group A Streptococcus
Mycobacterium tuberculosis

Question 3

Describe the pathogenesis of osteomyelitis

Answer 3

Bacterial infection from indirect inoculation from skin (e.g. trauma, operative, chronic skin ulcers, haematogenous spread)

Question 4

List 6 risk factors for osteomyelitis

Answer 4

Diabetes  
Immunosuppression  
Trauma
IVDU
Prostheses  
Sickle-cell anaemia

Question 5

Describe the epidemiology of osteomyelitis

Answer 5

Mostly in YOUNG CHILDREN

< 20% of cases are in adults

Question 6

4 symptoms of osteomyelitis

Answer 6

Pain in affected area
Fever + Rigors
Malaise
Hx of preceding skin lesion, sore throat, trauma or operation

Question 7

How may presentation of osteomyelitis differ in infants?

Answer 7

may not show localising signs

Question 8

List 6 signs of osteomyelitis

Answer 8

Localised erythema
Tenderness
Swelling
Warmth
Painful/limited movement of affected limb
Seropurulent discharge from wound or ulcer

Question 9

What investigations are performed in osteomyelitis?

Answer 9

FBC: high WCC, ESR, CRP
Blood culture/ swabs of wound or discharge
X-ray: Cortical thickening + osteopenia
MRI bone scan: confirms dx + identifies abscess
Bone biopsy

Question 10

Tx for acute osteomyelitis

Answer 10

Flucloxacillin IV
Clindamycin IV (if penicillin allergy) 
Vancomycin IV (if Staph Aureus suspected)
All for 6/52 
All +/- fusidic acid or rifampicin 2/52

Question 11

Tx for chronic osteomyelitis

Answer 11

Surgical debridement

Parenteral abx