Knee effusion

A knee effusion is a fluid accumulation in the intra-articular space of the knee

• May be serous, bloody, or purulent
• Etiology
  • Osteoarthritis
  • Trauma
  • Crystal arthritis (gout)
  • Rheumatoid arthritis
  • Septic arthritis (infection)
  • Ligament injuries
  • Meniscus injuries
• Clinical features
  • Swelling around and above patella
  • Decreased ROM
  • Patellar ballottement
• Diagnosis
  • Swift diagnosis of septic arthritis is important to reduce complication
  • X-ray
    • Check for OA or fracture
  • Joint aspiration
    • Detect bacteria, crystals, blood
  • MRI
    • Check for ligament injuries
• Treatment
  • RICE
  • NSAIDs
  • Depends on underlying cause
  • Septic arthritis -> IV antibiotics