Osteomyelitis

Question 1

What is osteomyelitis?

Answer 1

Infection of bone marrow

Can be due to haematological spread or direct invasion from trauma

Can be acute or chronic

Question 2

What is the difference between acute and chronic osteomyelitis?

Answer 2

Acute
-Common target site is metaphyseal plates of long bones in young children or spine of immunosuppressed adults

Chronic

• prolonged inflammation of the bone marrow
• most commonly due to open fractures or surgery

Question 3

What are common causative organisms?

Answer 3

Neonates- E.coli
<4 Hib
All ages= staph aureus, strep pyogenes, strep pneumoniae

Question 4

What is the pathophysiology?

Answer 4

Inflammatory response leading to increased intraosseous pressure and pain

Pus then appears in the main shaft of the long bone and forces its way to the surface forming a subperiosteal abscess which can form a sinus and drain at the surface

The compromised blood flow then leads to necrosis

Osteoblasts stimulate new bone formation and the bone will heal with abx and controlled intraosseous pressure

Question 5

What are symptoms of acute osteomyeltis?

Answer 5

Continuous throbbing pain worse at night

Fever
Tiredness
Localised erythema, warmth and oedema- late sign

Sepsis

Neonates

• FTT
• Drowsy
• Irritable

Children- cannot touch or move adjacent joint

Adult backache

Question 6

What are symptoms of chronic osteomyelitis?

Answer 6

History of osteomyelitis
Recurrent pain, fever, redness and swelling
Excoriation of surrounding skin
Foul and purulent discharge
Thickened overlying tissue

Question 7

What investigations are needed?

Answer 7

Bloods

• WCC, CRP= raised
• U&Es, LFTs= look for abnormalities
• Blood cultures= ?sepsis
• Uric acid if near joint

Septic screen

XR

• normal/soft tissue swelling in 1st 10 days
• by 2 weeks= decreased bone density and new bone formation

MRI= gold standard

Question 8

What are differentials to osteomyelitis?

Answer 8

Cellulitis
Necrotising fasciitis
SA if near joint
Crystal associated arthritis if near joint
Compartment syndrome if recent trauma
Rheumatic fever

Question 9

What is the management of osteomyelitis?

Answer 9

Acute

• urgent orthopaedic referral
• A-E
• Analgesia
• IV fluids
• IV abx for 3 months
• -adults= fluclox, clindamycin
• -Paeds= fluclox, clindamycin, cefotaxime
• Supportive structures e.g. splints

Chronic

• Admit
• IV abx to prevent spread and control flare
• appropriate dressing
• surgery= if significant symptoms or clear evidence of sequestrum

Question 10

What is viral arthropathy?

Answer 10

Arthritis caused by viral infection
Occurs in prodromal phase with associated rash, fever, conjunctivitis and malaise

Symmetrical and non destructive