Osteomyelitis

Question 1

Haematogenous osteomyelitis

Answer 1

Pathogen is carried through blood and seeded in the bone

Usually monomicrobial

Most common form in children

Vertebral is most common form in adults

Question 2

Risk factors for haematogenous osteomyelitis

Answer 2

Sickle cell anaemia

IVDU

Immunosuppression (due to meds or HIV)

Infective endocarditis

Question 3

Non-haematogenous osteomyelitis

Answer 3

From contigious spread of infection from adjacent soft tissues to the bone or from direct injury/ trauma to bone

Often polymicrobial

Most common form in adults

Question 4

Non-haematogenous osteomyelitis risk factors

Answer 4

Diabetic foot ulcers/ pressure sores

Diabetes mellitus

Peripheral arterial disease

Question 5

Microbiology

Answer 5

Staph aureus is most common cause

Salmonella most common in patients with sickle cell anaemia

Question 6

Presentation

Answer 6

Fever

Pain and tenderness

Erythema

Swelling

Question 7

Investigations

Answer 7

Xrays don’t show signs in early disease

Later may show
- periosteal reaction (change to surface of the bone)
- localised osteopenia (thinning of the bone)
- destruction of areas of the bone

MRI best for establishing diagnosis

Bloods show raised inflammatory markers

Blood cultures

Bone cultures to establish causative organism and antibiotic sensitivities

Question 8

Management

Answer 8

Surgical debridement of infected bone and tissues

6 weeks flucloxacillin

If allergic clindamycin

If MRSA vancomycin or teicoplanin