Periprosthetic Joint Infection Following Total Knee Arthroplasty Is Associated With a Significantly Elevated Risk of Mortality: A Population-Level Database Study

Prosthetic joint infection (PJI) following hip or knee replacement surgery is a devastating complication, with grave consequences for the patient, the healthcare system, and society at large. The purpose of this study was to compare the long-term mortality rates between patients who develop PJI after a total knee arthroplasty (TKA) and those who do not develop PJI. This study was a retrospective population-level database study using the ICES database. All eligible participants interacting with a single-payer public healthcare system. The primary outcome was 10-year mortality in patients who developed a PJI within one year of index TKA compared to those who did not develop PJI within one year of index TKA. Mortality rates were calculated for the full cohort and by group (PJI vs. no PJI within one year) at 5 and 10 years post-operatively. Mortality rates were plotted using Kaplan-Meier Survival Curves, and compared using Log Rank Testing with the proportional hazards assumption. A total of 263,204 patients who underwent primary TKA in the study period (mean age: 67.9 years SD: 9.3, 1,228 of whom subsequently developed a PJI within one year (0.5%). Across the entire sample, compared to patients who did not develop an infection within one year, those who did had significantly higher rates of congestive heart failure, chronic obstructive pulmonary disease, and diabetes. A total of 1,200 patients who developed PJI within one year of index TKA were matched to 1,200 patients who did not, with standardized differences less than 10% for all covariates, indicating a robust match. After matching, TKA recipients that had a PJI in the first year had a significantly higher ten-year mortality rate (86 7.1% vs 19 1.6%; absolute RD 5.45% 95% CI 3.82%–7.09%; HR 4.66 95% CI 2.84–7.65). Patients who develop PJI within one year following TKA are at significantly higher risk of mortality at 10 years post-TKA compared to those who do not develop PJI. The mortality rates are similar to some adult cancers. The etiologic factors leading to this increased risk remain unclear, and warrant further investigation, in addition to ongoing efforts to further the prevention, diagnosis, and management of PJI.