Which combination of findings is most consistent with a periprosthetic joint infection and guides diagnostic workup?

• A. Wound drainage and fever with elevated ESR/CRP; joint aspiration with culture and imaging; may require irrigation/debridement and revision
• B. Only fever with normal inflammatory markers
• C. Imaging alone without lab tests
• D. Synovial fluid analysis is not helpful

Answer: (C)

Diagnosing a periprosthetic joint infection requires bringing together several types of information, not relying on a single test. The presence of wound drainage or fever flags infection, and elevated ESR/CRP supports an inflammatory process consistent with infection. To confirm and guide treatment, sampling the joint with aspirated synovial fluid for culture (and analysis) provides microbiologic evidence of infection and helps identify the organism. Imaging then plays an important supporting role by showing prosthesis status, peri-implant lucency, fluid collections, or abscesses, which helps plan management but cannot establish infection on its own. Synovial fluid analysis is indeed useful in this context. Taken together, the combination of clinical signs, inflammatory markers, joint aspiration with culture, and imaging best guides the diagnostic workup and subsequent management, which may include irrigation/debridement and revision if needed.