Osteomyelitis (1)

Question 1

What occurs here?

What is the most common mode of infection?
→ How else can it be acquired?

What is the most common causative organism?

What are the risk factors?

Answer 1

➊ Inflammation in bone and bone marrow, usually due to bacterial infection

➋ Haematogenous
→ Direct contamination of the bone e.g. during surgery or trauma

➌ Staph aureus

➍ • Open fractures
• Orthopaedic surgery, particularly with prosthetic joint
• DM, particularly with diabetic foot ulcers
• Peripheral arterial disease
• IVDU
• Immunosuppression

Question 2

How does it present?

Which investigations need to be done?

How is it managed?

Answer 2

➊ • Fever
• Pain and tenderness
• Erythema
• Swelling

➋ • Bloods – WCC, CRP, ESR
• Blood cultures
• Bone biopsy and culture
• MRI

➌ • Surgical debridement of infected bone and tissues
• Abx – Flucloxacillin + Fusidic acid/Rifampicin

N.B. Staph aureus is the most common cause of acute osteomyelitis, which is why Flucloxacillin is a good choice of empirical treatment.