Extended Antibiotic Use in Total Knee Arthroplasty Is Not Associated with Decreased Periprosthetic Joint Infection Rates.

Abstract

Prophylactic antibiotics are essential in preventing periprosthetic joint infection (PJI) in total knee arthroplasty (TKA), but the optimal duration of administration remains controversial. Existing studies lack long-term follow-up, suffer from small sample sizes, and are limited by cohort heterogeneity. This study aimed to determine whether the duration of prophylactic antibiotics affects PJI rates in TKA. Registry data of 17,223 TKAs performed between 2000 and 2018 were reviewed. Patients were grouped by receiving standard (≤ 24 hours) or extended (> 24 hours) antibiotics. The prevalence of PJI requiring reoperation was recorded for both groups, with clinical assessment at preoperative, 6-month, and 2-year follow-up using the Oxford Knee Score, Short Form-36, and postoperative satisfaction. Of the 17,223 patients, 15,160 (88.0%) received standard-course antibiotics, and 2,063 (12.0%) received extended-course antibiotics. A total of 68 (0.39%) PJI cases were identified: 61 in the standard group (0.40%) and seven in the extended group (0.34%, P = 0.67). High-risk patients (e.g., Charlson Comorbidity Index > 2, diabetes, chronic kidney disease, obesity) on extended-course antibiotics did not show a reduced PJI rate. No differences in outcome measures or satisfaction scores were noted at two years. Extended antibiotic prophylaxis in TKA was not associated with reduced PJI rates in both normal and high-risk patients at two years. The routine use of extended-course antibiotics in TKA should be discouraged. Certain high-risk patient groups may still benefit from extended-course antibiotics, and future studies should focus on identifying them.