Dilute Povidone-Iodine Irrigation Reduces the Rate of Periprosthetic Joint Infection Following Hip and Knee Arthroplasty: An Analysis of 31,331 Cases

Background: Total joint arthroplasty (TJA) surgeons employ various strategies to reduce the risk of periprosthetic joint infection (PJI). Few studies have examined the efficacy of preclosure dilute povidone-iodine irrigation in a large cohort accounting for recent practice changes in TJA. This study compared the risk of PJI in TJA patients with and without dilute povidone-iodine irrigation. Methods: This is a retrospective study of all consecutive primary TJAs between 2009 and 2019 at a single institution. We included 31,331 cases, of which 8659 were irrigated with dilute povidone-iodine and 22,672 were irrigated with sterile saline prior to closure. The primary endpoint was PJI as defined by 2018 International Consensus Meeting criteria with a minimum follow-up of 1 year. Multivariate logistic regression was used to determine the association between dilute povidone-iodine irrigation and PJI while controlling for demographics, comorbidities, and operative factors. Results: In total, 340 patients (1.09%) developed PJI. Dilute povidone-iodine irrigation was associated with 2.34 times lower rate of PJI (0.6% vs 1.3%). Using multiple regression, dilute povidone-iodine remained significantly associated with a reduction in PJI. The absolute risk reduction was 0.73% and number needed to treat was 137 patients. Female gender, American Society of Anesthesiologists score, operative time, anesthesia type, prophylactic antibiotic type, and tranexamic acid were other significant factors in the regression model. Conclusion: The routine use of dilute povidone-iodine could prevent 1 PJI for every 137 TJA patients, regardless of their preoperative risk. These findings support the use of povidone-iodine irrigation as a safe and cost-effective measure to reduce PJI.