1306. Lower Treatment Failure Rates in Patients with Non-Staphylococcal Prosthetic Joint Infections (PJI) Treated with Debridement and Implant Retention (DAIR) Receiving Chronic Antibiotic Suppression (CAS)

Abstract Background PJI occurs in 0.5-2% of Joint Arthroplasty. Patients with acute non-Staphylococcal PJI who undergo DAIR are treated with 6 weeks of antimicrobials after which CAS may be considered. We aimed to compare the incidence of treatment failure between people who received CAS and those who did not. Methods This is a retrospective cohort study of patients admitted to Veterans Affairs (VA) hospitals from 2003-2017 with a non-Staphylococcal PJI, underwent DAIR and received 6 weeks of antimicrobial treatment (Table 1). CAS was defined as at least 30 days of oral antibiotics after 6 weeks of antimicrobial treatment. Duration of CAS was categorized as short (1-3 months), moderate (3-6 months) and long ( >6 months) (Fig 1). Patients were followed for 5 years. Treatment failure was defined as microbiologically confirmed recurrent PJI, additional debridement or re-operation at the same site. Cause-specific Kaplan-Meier curves were used to compare treatment failure rates between those who did and did not receive CAS, censoring on death. Results Among 468 patients with non-staphylococcal PJI who underwent DAIR, 208 (44.4%) received CAS. Patients with Enterococcus PJI were statistically more likely to receive CAS. K-M curves showed patients on CAS had a higher estimated failure free survival probability at 5 years when compared to those who did not get CAS (66% vs. 55%, p< 0.01) (Fig 2). When antibiotic use was considered as a time-dependent covariate, CAS was associated with a decreased hazard of treatment failure (hazard ratio (HR): .47 (95% confidence interval [CI]: 0.29, 0.76). After statistically adjusting for surgical site, severity of illness, and alcohol abuse, a short duration of CAS was significantly associated with decreased treatment failure (HR=0.24; 95% CI: 0.11, 0.52). There was no significant association between moderate or long duration of CAS and treatment failure (Table 2) Table 2 Conclusion A short duration of CAS may be beneficial among patients with non-Staphylococcal PJI who underwent DAIR. However, there was not a statistically significant association between longer duration of CAS use and treatment failure. Thus, the risks and benefits of long-term antibiotics should be weighed when aiming to prevent recurrence of PJI. Disclosures Mireia Puig-Asensio, MD, GILEAD: Honoraria Andrew Pugely, MD, MBA, Globus Medical: Advisor/Consultant|Globus Medical: Grant/Research Support|Globus Medical: IP royalties|Medtronic: Advisor/Consultant|Medt