INTRAWOUND ANTISEPTICS DO NOT DECREASE THE RISK OF PERIPROSTHETIC JOINT INFECTION FOLLOWING PRIMARY ARTHROPLASTY FOR FEMORAL NECK FRACTURE

Aim The purpose of the present study was to (1) identify patients at high risk for periprosthetic joint infection (PJI) following arthroplasty for femoral beck fracture (FNF) and (2) determine if intrawound antisepsis is beneficial for PJI prevention generally or in either high-risk or low-risk groups compared to normal saline irrigation. Methods A retrospective review of patients undergoing total hip arthroplasty (THA) or hemiarthroplasty (HA) for FNF was conducted at 11 institutions for the years 2010-2022. The final cohort included 1,674 patients meeting inclusion criteria with minimum 1-year follow-up (n=756 THAs and n=918 HAs), of which 74 (4%) were diagnosed with PJI at 90-days postoperatively by 2013 MSIS criteria. Preoperative and intraoperative variables were compared between those with and without PJI, followed by multivariable regression to identify PJI risk-associated variables which allowed subsequent stratification into high-risk and low-risk groups. Risks of PJI at 90-days and 1-year were compared by intrawound antiseptic type (povidone iodine [PI], antibiotic powder [AP], or normal saline [NS]) overall and in each stratified group. Patients receiving other antiseptics were excluded from secondary analyses. Results Risk factors independently associated with PJI included BMI (OR 1.07, 95% CI 1.03-1.10, p<0.001), liver disease (OR 2.22, 95% CI >0.99-4.91, p<0.05), assisted ambulation (OR 1.74, 95% CI 1.05-2.88, p=0.03) or nonambulatory status (OR 3.02, 95% CI 0.84-10.83, p=0.09) pre-injury, and intraoperative blood transfusion (OR 2.69, 95% CI 1.37-5.27, p=0.004). Overall, rates of PJI at 90-days (NS, 2.97%; PI, 3.24%; AP, 2.97%; p=0.27) and 1-year (NS, 3.61%; PI, 3.24%; AP, 2.97%; p=0.64) were compared – multivariable models confirmed the no-difference findings. After stratification into high-risk (n=351) and low-risk (n=1051) groups, there was no difference in 90-day or 1-year PJI between intrawound antiseptic type in either group by multivariable analysis. Specifically, high-risk 90-day PJI: AP vs NS (5% vs 9%, OR 0.61, 95% CI 0.18-2.10, p=0.43) or PI versus NS (19% vs 10%, OR 2.50, 95% CI 0.99-6.36, p=0.05). While low-risk 90-day PJI: (4% AP, 3% NS, 1% PI; p=0.64). Conclusion Increased BMI, liver disease, non-independent baseline ambulatory status, and intraoperative blood transfusion are associated with increased risk of 90-day PJI following THA or HA for FNF. However, use of intrawound antiseptics compared to NS irrigation alone does not confer benefit in preventing PJI generally or in either high-risk or low-risk patients. That said, large, prospective randomized studies are needed to make definitive conclusions but should follow this model of risk stratification.