Question

A 26-year-old man presents with a painful, swollen right knee 2 weeks after a sore throat. He has a temperature of 38.2°C. The knee is hot and tender with an effusion. What is the most important immediate investigation?

Accepted Answer

Joint aspiration for Gram stain and culture

Answer

Plain X-ray of the knee

Answer

MRI of the knee

Answer

Autoantibody screen

Answer

No investigations; start NSAIDs only

Practice question

A 26-year-old man presents with a painful, swollen right knee 2 weeks after a sore throat. He has a temperature of 38.2°C. The knee is hot and tender with an effusion. What is the most important immediate investigation?