Osteomyelitis

Question 1

Definition

Answer 1

• Infection of the bone leading to inflammation, necrosis and new bone formation. Can be acute, subacute or chronic.

• Causative organisms:
o Staphylococcus aureus
o Group A Streptococcus

Question 2

Aetiology

Answer 2

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

Question 3

Risk factors

Answer 3

o Diabetes
o Immunosuppression
o IV drug use
o Prostheses
o Sickle-cell anaemia

Question 4

Epidemiology

Answer 4

• Mostly in YOUNG CHILDREN

* < 20% of cases are in adults

Question 5

Presenting symptoms

Answer 5

• Pain in the affected area
• Fever
• Malaise
• Rigors
• History of preceding skin lesion, sore throat, trauma or operation

• NOTE: infants may not show localising signs

Question 6

Signs on physical examination

Answer 6

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

Question 7

Investigations

Answer 7

• Bloods
o FBC
o Blood culture
o ESR
o CRP

• Swabs of wound or
discharge

• Radiographs
• Radioisotope bone scan - shows areas of increased activity