Osteomyelitis

Question 1

What is osteomyelitis?

Answer 1

Inflammation in a bone and bone marrow, usually caused by bacterial infection.

Question 2

What is the most common bacterial cause of osteomyelitis?

Answer 2

Staph aureus

Can be transport of pathogen through the blood and seeding in the bone (haematogenous spread) or from direct contamination e.g. due to fracture or orthopaedic surgery

Question 3

Risk factors for osteomyelitis

Answer 3

Open fractures
Orthopaedic operations, particularly with prosthetic joints

Diabetes, particularly with diabetic foot ulcers

Peripheral arterial disease

IV drug use

Immunosuppression

Question 4

Presentation of osteomyelitis

Answer 4

Can be quite non-specific

Fever
Pain and tenderness
Erythema
Swelling
Lethargy, muscle aches

Question 5

Investigations

Answer 5

MRI scans are best diagnostic imaging

Bloods - raised WCC, CRP and ESR

Blood cultures

Bone cultures - can be performed to establish the causative organism and the antibiotic sensitivities.

X-rays

• Often show no changes (particularly in early disease)
• May see:
• –Periosteal reaction (changes to the surface of the bone)
• Localised osteopenia (thinning of the bone)
• Destruction of areas of the bone

Question 6

Management of osteomyelitis

Answer 6

Surgical debridement of infected tissue/bone

Antibiotic therapy

If associated with prosthetic joints - may need complete revision surgery to replace prosthesis

Question 7

Antibiotic choice and duration for acute and chronic osteomyelitis

Answer 7

Acute:

• 6w Flucloxacillin
• Possibly with rifampicin or fusidic acid added for the first 2 weeks
• Alternatives to flucloxacillin are clindamycin (pen allergy), Vancomycin or teicoplanin when treating MRSA

Chronic:
- 3 months or more antibiotic treatment