This study will provide us with clear information about the postoperative concentration of antibiotic reached in synovial fluid, thereby helping surgeons to determine if concentration could potentially prevent the growth and regrowth of common infecting microorganisms (based on their MIC and MBEC). There is a need to define the actual benefit of antibiotic-loaded bone cement, because the addition of antibiotic can reduce its mechanical strength. Moreover, if sub-therapeutic antibiotic levels are achieved, this could facilitate the emergence of resistant bacterial strains. Amidst the transition towards value-based care, our research will enable surgeons to decide whether antibiotic-loaded cement is truly cost-effective in the prevention of PJI.

Inclusion Criteria:

• All participants undergoing cemented primary total knee arthroplasty (TKA) who are 18 years or older.

Exclusion Criteria:

• Withdrawal of informed consent,
• allergy to any of the study medications or to bone cement,
• use of antibiotics within 4 weeks before collecting the samples (not including perioperative antimicrobial prophylaxis),
• high risk of infection,
• history of peri-articular injections for multimodal pain management.