Factors That Increase the Risk of Prosthetic Joint Infection Within 90 Days After THA and TKA: A Nationwide Population-based Study

Background Prosthetic joint infection (PJI) after THA and TKA is a serious complication. Although previous studies have identified risk factors for overall and late-onset PJI, limited research has focused specifically on infections occurring within the immediate 90-day postoperative period, a time frame critical for assessing surgical quality and early recovery outcomes. Questions/purposes What patient and clinical factors are associated with the development of PJI within 90 days after primary THA or TKA? Methods This was a retrospective, controlled study drawn from a longitudinally maintained, large, national database (the Taiwan National Health Insurance Research Database [NHIRD]). The NHIRD, covering > 99% of the population, provides comprehensive data for reliably identifying and tracking postoperative complications such as PJIs. Patients who underwent THA or TKA between January 2016 and December 2017 were identified. Only patients with complete follow-up data for at least 90 days after surgery, based on insurance records, were eligible for inclusion. The primary outcome was PJI within 90 days, defined as the presence of an ICD-10-Clinical Modification (CM) diagnosis code for PJI recorded in claims within 90 days of the index THA or TKA procedure. A total of 13,442 patients who underwent THA and 40,245 patients who underwent TKA were included. The PJI rate within 90 days was 0.61% (82 of 13,442) for THA and 0.58% (232 of 40,245) for TKA. Cox regression analyses were used to estimate associations between potential demographic and clinical factors and the risk of PJI within 90 days. Results After adjusting for age, sex, diabetes, and other clinically relevant factors, we found that the adjusted HR (aHR) for PJI within 90 days after THA was higher among patients who were male (aHR 2.49 [95% confidence interval (CI) 1.38 to 4.48]; p < 0.01), had a longer length of stay (aHR 1.06 [95% CI 1.04 to 1.09]; p < 0.01), had osteoarthritis (aHR 0.48 [95% CI 0.27 to 0.87]; p = 0.01) or avascular necrosis of the femoral head (aHR 0.43 [95% CI 0.22 to 0.84]; p = 0.01), had diabetes mellitus (aHR 3.72 [95% CI 2.21 to 6.26]; p < 0.01), had hepatitis B infection (aHR 2.44 [95% CI 1.11 to 5.36]; p = 0.03), and had hepatitis C infection (aHR 2.76 [95% CI 1.14 to 6.66]; p = 0.02). The aHR for PJI within 90 days after TKA was higher for patients who were younger than 65 years (aHR 1.57 [95% CI 1.18 to 2.08]; p < 0.01), male (aHR 2.05 [95% CI 1.55 to 2.71]; p < 0.01), had a longer length of stay (aHR 1.09 [95% CI 1.08 to 1.11]; p < 0.01), had osteoporosis (aHR 1.44 [95% CI 1.08 to 1.92]; p = 0.01), and had chronic kidney disease (aHR 1.50 [95% CI 1.06 to 2.11]; p = 0.02). The aHR was lower for patients who had bilateral TKA (aHR 0.31 [95% CI 0.12 to 0.84]; p = 0.02) compared with those who had unilateral TKA only. Conclusion Male sex, diabetes, hepatitis C, osteoporosis, chronic kidney disease, and younger age after TKA were associated with a higher risk of PJI within 90 days. The findings indicate that surgeons may enhance perioperative infection prevention efforts in these high-risk patients by optimizing glycemic control, improving perioperative medical management, minimizing surgical time and blood loss when possible, and ensuring rigorous postoperative wound surveillance. Future large-scale observational studies are needed to refine individualized risk prediction and assess the effectiveness of targeted preventive strategies in real-world clinical practice. Level of Evidence Level III, therapeutic study.