Infected total knee arthroplasty: could cotrimoxazole be the answer?

Area of Science:

• Orthopedic Surgery
• Infectious Diseases
• Microbiology

Background:

• Prosthetic joint infection (PJI) is a significant complication following total knee arthroplasty (TKA).
• Understanding the microbiological landscape and antibiotic susceptibility is crucial for effective management.
• Differentiating between acute and chronic PJI is essential for treatment strategies.

Purpose of the Study:

• To delineate the microbiological profile of acute and chronic PJI post-TKA.
• To assess antibiotic susceptibility patterns for common PJI pathogens.
• To inform the selection of appropriate empirical antibiotic therapies.

Main Methods:

• Retrospective review of institutional data from 2021-2024.
• Inclusion of patients undergoing reoperation for PJI after primary TKA.
• Analysis of demographic data, microbiological results, and antimicrobial susceptibility testing.

Main Results:

• Forty patients were included, with chronic PJI (> 6 weeks) being most prevalent (75%).
• Gram-positive organisms predominated, with Staphylococcus aureus (24.2%), S. epidermidis (16.7%), and S. lugdunensis (13.6%) as leading pathogens.
• Vancomycin demonstrated 100% susceptibility in all PJI cases. Cotrimoxazole showed 97% susceptibility against main pathogens in chronic infections.

Conclusions:

• Empirical antibiotic choice for PJI should consider infection timing (acute vs. chronic).
• Vancomycin is recommended as first-line empirical treatment for acute PJI.
• Cotrimoxazole presents a viable alternative for chronic PJI due to low resistance rates, with de-escalation to targeted therapy advised post-culture.