Bone Infection Flashcards
When is antibiotic prophylaxis used in orthopaedic surgery?
When metal work is involved
What are the commonest causes of acute osteomyelitis in children and adults?
Children:
Haematogenous spread
Adults: Trauma or operation(rare) Immunocompromised - Diabetes - Steroids IVDU
What are the most common causative organisms in acute haematogenous osteomyelitis?
- Staphylococcus aureus
- Streptococci
- Coliforms
How does acute haematogenous osteomyelitis typically present?
- Pain
- Tenderness
- Localised inflammation
- Fever
- Preceding history of
- Superficial cut
- Infected sore throat
What investigations are indicated for acute haematogenous osteomyelitis?
- X-rays:
- Normal at first
- Later: hazy edge to bone (periosteal reaction + new bone formation) - Bone scan:
- Show increased activity while X-rays still normal - Bloods:
- Culture
- WCC / ESR / CRP all raised
How is acute haematogenous osteomyelitis treated?
- IV antibiotics
- Oral after a few days
- Up to 6 weeks - Analgesia
- Rest
How is postoperative osteomyelitis with metalwork in situ treated?
- IV antibiotics
- Remove metalwork
- Replace with external fixator
- If # not healed
What is a sequestrum?
An area of pus that is walled off by new bone, often discharging through a sinus.
What is chronic osteomyelitis?
Infection can remain for many years if a sequestrum forms - recurrent acute flare-ups. Surgical removal may be indicated.
What are common sites for acute septic arthritis?
Hip in children
Knee in adults
How does acute septic arthritis typically present?
- Systemically unwell: malaise, fever, rigors
2. Joint: painful, inflamed, swollen, restricted movement
How is acute septic arthritis diagnosed?
Dx based on clinical presentation
Confirmed by aspiration and analysis of aspirate (MC&S)
What investigations are indicated for acute septic arthritis?
- X-rays - normal initially
- US - joint effusion
- Aspiration
- Blood tests: FBC, ESR, CRP, cultures (TB)
True or false: TB can cause acute septic arthritis
True
How is acute septic arthritis treated?
- Joint washout under GA
- IV antibiotics
- Remove any metalwork
A patient presents with a hot swollen knee. The aspirate shows many white cells but no organisms. What is your differential diagnosis?
- Septic arthritis
- Acute monoarthritis (RA)
- Gout
- Pseudogout
A patient presents with a hot swollen knee. The aspirate shows many white cells but no organisms. What else would you like to know?
- Does the patient feel generally well or unwell?
- Are they diabetic
- Are they on steroids? (Immunosupressed, AVN)
- Have they had any previous episodes?
A patient presents with a hot swollen knee. The aspirate shows many white cells but no organisms. The blood markers are normal and the patient is apyrexial and looks well. How do you proceed?
Septic arthritis is unlikely Rx: 1. Splintage 2. Rest 3. NSAIDs
Admit for observation if in doubt
