Orthopaedics

Question 1

What is septic arthritis?

Answer 1

Infection inside a joint

Emergency - infection can quickly begin to destroy the joint and cause systemic illness

Question 2

What age is most commonly affected in septic arthritis?

Answer 2

Occurs at any age but most common in children <4 years

Question 3

What is the mortality in septic arthritis?

Answer 3

10% mortality

Question 4

What is septic arthritis a common complication of?

Answer 4

Joint replacement

Occurs in 1% of straight forward hip and knee replacements (higher in revision surgery)

Question 5

How does septic arthritis present?

Answer 5

• usually single joint affected (often hip or knee)
• hot, red, swollen, painful joint
• refusal to weight bear
• stiffness, reduced ROM
• systemic symptoms (fever, sepsis, lethargy)

Can be SUBTLE in children

Question 6

What is the most common causative organism in septic arthritis?

Answer 6

• S. Aureus

Question 7

What other causative organisms are there for septic arthritis?

Answer 7

• Neisseria gonorrhoea (sexually active teenagers)
• Group A streptococcus (S. pyogenes)
• H. influenza
• E.coli

Question 8

What are differential diagnoses for septic arthritis?

Answer 8

• transient synovitis
• Perthes disease
• SUFE (slipped upper femoral epiphysis)
• juvenile idiopathic arthritis

Question 9

What is the management for septic arthritis?

Answer 9

• admit to hospital
• involve orthopaedic team
• joint aspiration (gram staining, crystal microscopy, culture, antibiotic sensitivities)
• empirical IV antibiotics (until microbial sensitivities known)
• continue abx for 3-6 weeks

Question 10

What management may be required in severe cases of septic arthritis?

Answer 10

Surgical drainage and washout of the joint to clear infection