Peri-Prosthetic Joint Infection in Patients Prescribed Suppressive Antibiotic Therapy Undergoing Primary Total Joint Arthroplasty: A 1:4 Case Control Matched Study.

Background: Oral suppressive antibiotic therapy (SAT) has emerged as a potential means to increase rates of infection-free survival in many complex peri-prosthetic joint infection (PJI) cases after total joint arthroplasty (TJA). The purpose of the present study is to evaluate the risk of PJI of a new primary TJA in patients on oral SAT. Patients and Methods: A retrospective matched cohort study from five hospitals in a 20-year period within a large hospital network was performed. Inclusion criteria consisted of patients over age 18 undergoing primary TJA, with any order for oral long-term (>6 months duration) SAT, and minimum of one-year clinical follow-up. Patients were matched 1:4 on age, gender, body mass index (BMI), hip or knee surgery, diabetes mellitus, smoking status, and indication for primary TJA. Student t-test, Fisher exact, and χ2 tests were utilized for group comparisons. Our study was powered to detect a 10.5% increase in PJI incidence compared with a 1% baseline rate of PJI. Results: We identified 45 TJA in 33 patients receiving SAT, which were matched to 180 control cases. There was no difference in the rate of development of PJI at any time point within follow-up between the SAT cohort and control group (2.22% vs. 1.11%; p = 0.561). Conclusions: We found a 2.22% rate of PJI in a cohort of patients receiving SAT identified over a 20-year period. As the clinical scenario of primary TJA while on SAT is rare but likely to become more prevalent, future large-scale studies can be performed to better clarify rates and risk of PJI in this population.