Acute septic Arthritis

Question 1

What is acute septic arthritis?

Symptoms?

Answer 1

Septic arthritis (infectious arthritis): bacterial joint infection, which rapidly destroys the joint

Symptoms:

• Monoarthritis: hot, red, swollen and painful joint (+/- mobility)

Question 2

What are 3 routes of infection of acute septic arthritis?

Answer 2

• Haematogenous
• Eruption of bone abscess
• Direct invasion

Question 3

What are common causative organisms for acute septic arthritis?

Answer 3

• Staphylococus aureus
• Haemophilus influenzae
• Streptococcus pyogenes
• E. coli

Question 4

What is the 3 steps of pathogenesis for acute septic arthritis?

Answer 4

• Acute synovitis with purulent joint effusion
• Articular cartilage attacked by bacterial toxin and cellular enzyme
• Complete destruction of articular cartilage

Question 5

What is the prognosis for acute septic arthritis?

Answer 5

• Complete recovery
• Partial loss of the articular cartilage and subsequent OA
• Fibrous or bony ankylosis

Question 6

How would a neonate present with septicaemia due to acute septic arthritis?

Answer 6

• Irrability
• Resistent to movement

Question 7

How would a child/adult present with acute septic arthritis?

Answer 7

• Reluctant to move the joint
• Increased temperature and pulse
• Increase tenderness

Question 8

What investigations would we carry out for suspected acute septic arthritis?

Answer 8

• FBC, WBC, ESR, CRP, blood cultures
• X ray
• ultrasound
• aspiration

Question 9

What is the most common cause of acute septic arthritis in adults?

Answer 9

• Infected joint replacement
• Death can occur due to this but it is v rare (1%)
• Staph aureus still causative organism

Question 10

DDx for acute septic arthritis?

Answer 10

• Acute osteomyelitis
• Trauma
• Irritable joint
• haemophilia
• Rheumatic fever
• Gout

Question 11

Tx for acute septic arthritis?

Answer 11

• General supportive measures
• Antibiotics (3-4 wks)
  
  • Staph. aureus (Flucloxacillin)
  • MRSA (Vancomycin)
• Surgical drainage and lavage - emergency
• Infected joint replacements