A 66-year-old woman develops fever, raised CRP (148 mg/L), and ESR (88 mm/hr) 4 weeks after total knee replacement. Aspiration of the knee yields 28,000 WBC/µL with 92% neutrophils and positive alpha-defensin. The organism grown is coagulase-negative Staphylococcus sensitive to rifampicin and vancomycin. She is fit for surgery. The optimal surgical management is:

• A IV antibiotics for 6 weeks with retention of implant
• B Two-stage revision: explantation with antibiotic spacer, then reimplantation after 6–8 weeks
• C One-stage revision: explantation and immediate reimplantation with antibiotic cement
• D DAIR (debridement, antibiotics, irrigation, retention of implant) ✓

Explanation

DAIR (debridement, antibiotics, irrigation, and implant retention) is indicated for acute postoperative periprosthetic joint infection (PJI) within 4–6 weeks of primary surgery when the implant is well-fixed, the organism is of low virulence, and the patient is fit for surgery — all conditions met here. The success rate of DAIR in acute PJI is 70–80% when combined with rifampicin-based oral suppression for biofilm-active coverage. Two-stage revision is the gold standard for chronic or late PJI (>4 weeks with biofilm-embedded bacteria), not acute infection. IV antibiotics alone without surgery rarely eradicate PJI.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.