Question

A 70-year-old man with known osteoarthritis of both knees presents with sudden worsening pain, swelling and warmth in the right knee over 24 hours. He is febrile at 38.6 °C. What is the most appropriate immediate investigation?

Accepted Answer

Arthrocentesis with synovial fluid analysis and culture

Answer

Plain X-ray only

Answer

Serum uric acid level only

Answer

MRI of the knee

Answer

No investigation; treat as flare of osteoarthritis

Practice question

A 70-year-old man with known osteoarthritis of both knees presents with sudden worsening pain, swelling and warmth in the right knee over 24 hours. He is febrile at 38.6 °C. What is the most appropriate immediate investigation?