A 68-year-old man presents 2 years after total knee replacement with acute onset of severe pain, swelling, warmth, and sinus formation. Aspiration yields turbid fluid; synovial WBC is 78,000 cells/µL with 90% neutrophils. Culture grows Staphylococcus aureus. The most appropriate two-stage revision strategy involves:

• A Washout and polyethylene liner exchange only with 2 weeks of intravenous antibiotics
• B Chronic suppressive oral antibiotics without revision surgery
• C Arthroscopic debridement and retention of components
• D Implant removal, articulating antibiotic-laden cement spacer placement, 6 weeks IV antibiotics, then reimplantation ✓

Explanation

Chronic periprosthetic joint infection (>4 weeks from onset, established biofilm) requires two-stage revision: complete implant and cement removal, debridement, placement of an antibiotic-laden cement spacer (maintaining joint space and delivering high local antibiotic concentrations), followed by 6 weeks of pathogen-directed antibiotics, and reimplantation once infection markers normalise. DAIR (debridement, antibiotics, implant retention) is reserved for acute infections within 4 weeks with a well-fixed prosthesis.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.