BACKGROUND: It remains unknown how timing of preoperative intra-articular knee hyaluronic acid (HA) injections impacts risk for developing postoperative periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). METHODS: The PearlDiver Mariner database was utilized to identified patients undergoing primary TKA between 2015 and 2022 who received an HA injection without a corticosteroid injection within 12 months prior to surgery. The HA cohort was matched 1:1 to a control cohort undergoing no preoperative injections (corticosteroid or HA). Multivariable logistic regression analysis was utilized to determine the risk of preoperative HA injections on PJI at 1, 3, 6, 12, and 24 months postoperative. The following pre-operative intervals between injection and TKA were evaluated: 0-1 month, 1-2 months, 2-3 months, 4-6 months, and 7-12 months. RESULTS: 38,546 patients (HA: n = 19,273
Control: n = 19,273) were analyzed. HA injections within 1 month prior to surgery demonstrated significant increase in rates of PJI at 3-months (OR: 3.00, 95% CI: 1.29 - 6.47
p = 0.005), 6-months (OR: 2.66, 95% CI: 1.30 - 5.46
p = 0.007), 12-months (OR: 2.37, 95% CI: 1.20 - 4.67
p = 0.013), and 24-months (OR: 2.65, 95% CI: 1.50 - 4.68
p <
0.001) postoperatively. HA injections between 1-2 months prior to surgery showed increased rates of PJI at 12-months (OR: 1.60, 95% CI: 1.06-2.41
p = 0.011) postoperatively. No difference in infection risk was demonstrated between patients receiving injections >
2 months prior to surgery relative to matched controls. CONCLUSIONS: Intra-articular hyaluronic acid injections administered within 2 months of TKA appear to increase the risk of PJI.