Comparison of Infection Risk with Corticosteroid or Hyaluronic Acid Injection Prior to Total Knee Arthroplasty

Background: Recent studies have shown that intra-articular injections <= 3 months before total knee arthroplasty increase the risk of periprosthetic joint infection. We are aware of no previous study that has differentiated the risk of periprosthetic joint infection on the basis of the type of medication injected. In addition, we are aware of no prior study that has evaluated whether hyaluronic acid injections increase the risk of infection after total knee arthroplasty. In this study, we utilized pharmaceutical data to compare patients who received preoperative corticosteroid or hyaluronic acid injections and to determine whether a specific injection type increased the risk of periprosthetic joint infection. Methods: Patients undergoing unilateral primary total knee arthroplasty were selected from a nationwide private insurer database. Ipsilateral preoperative injections were identified and were grouped by medication codes for corticosteroid or hyaluronic acid. Patients who had received both types of injections <= 1 year before total knee arthroplasty were excluded. The outcome of interest was periprosthetic joint infection that occurred <= 6 months following the total knee arthroplasty. The risk of periprosthetic joint infection was compared between groups (no injection, corticosteroid, hyaluronic acid) and between patients who received single or multiple injections. Statistical comparisons were performed using logistic regression controlling for age, sex, and comorbidities. Results: A total of 58,337 patients underwent total knee arthroplasty during the study period; 3,249 patients (5.6%) received hyaluronic acid and 16,656 patients (28.6%) received corticosteroid <= 1 year before total knee arthroplasty. The overall infection rate was 2.74% in the no-injection group. Multivariable logistic regression showed independent periprosthetic joint infection risk for both corticosteroid (odds ratio [OR], 1.21; p = 0.014) and hyaluronic acid (OR, 1.55; p = 0.029) given <= 3 months before total knee arthroplasty. There was no increased risk with injections >3 months prior to total knee arthroplasty. Direct comparison of corticosteroid and hyaluronic acid showed no significant difference (p > 0.05) between medications or between single and multiple injections. Conclusions: Preoperative corticosteroid or hyaluronic acid injection <= 3 months before total knee arthroplasty increased the risk of periprosthetic joint infection. There was no difference in infection risk between medications or between multiple and single injections. On the basis of these data, we recommend avoiding both injection types in the 3 months prior to total knee arthroplasty.