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Published on: December 3, 2017
Prosthetic joint infection risk after TKA in the Medicare population
Steven M Kurtz1, Kevin L Ong, Edward Lau
1Exponent, Inc, 3401 Market Street, Suite 300, Philadelphia, PA 19104, USA.
Unlabelled:
The current risk of infection in contemporary total knee arthroplasty (TKA) as well as the relative importance of risk factors remains under debate as a result of the rarity of the complication and temporal changes in the treatment and prevention of infection. We therefore determined infection incidence and risk factors after TKA in the Medicare population. The Medicare 5% national sample administrative data set was used to identify and longitudinally follow patients undergoing TKA for deep infections and revision surgery between 1997 and 2006. Cox regression was used to evaluate patient and hospital characteristics. In 69,663 patients undergoing elective TKA, 1400 TKA infections were identified. Infection incidence within 2 years was 1.55%. The incidence between 2 and up to 10 years was 0.46%. Women had a lower risk of infection than men. Comorbidities also increased TKA infection risk. Patients receiving public assistance for Medicare premiums were at increased risk for periprosthetic joint infection (PJI). Hospital factors did not predict an increased risk of infection. PJI occurs at a relatively high rate in Medicare patients with the greatest risk of PJI within the first 2 years after surgery; however, approximately one-fourth of all PJIs occur after 2 years.
Level Of Evidence:
Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
Insights
The risk of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is 1.55% within 2 years and 0.46% thereafter. Women and patients with comorbidities face higher risks, while hospital factors do not significantly increase PJI rates.
Area of Science:
- Orthopedic Surgery
- Infection Control
- Health Services Research
Background:
- Infection risk and contributing factors after total knee arthroplasty (TKA) require ongoing investigation due to evolving treatments.
- Understanding these factors is crucial for improving patient outcomes and preventing complications.
Purpose of the Study:
- To determine the incidence of deep infections following TKA in the Medicare population.
- To identify patient-specific and hospital-related risk factors for periprosthetic joint infection (PJI) after TKA.
Main Methods:
- Analysis of the Medicare 5% national sample administrative data from 1997-2006.
- Longitudinal follow-up of patients undergoing TKA to identify deep infections and revision surgeries.
- Cox regression analysis to assess patient and hospital characteristics as risk factors for PJI.
Main Results:
- An overall infection incidence of 1.55% within 2 years and 0.46% between 2 and 10 years post-TKA was observed in 69,663 patients.
- Female sex was associated with a lower risk of infection, while comorbidities increased the risk.
- Patients receiving public assistance for Medicare premiums had a higher risk of PJI; hospital factors were not significant predictors.
Conclusions:
- Periprosthetic joint infection (PJI) occurs at a significant rate in Medicare patients undergoing TKA, with the highest incidence in the first two years.
- While most PJIs occur within two years, a substantial proportion (approximately 25%) manifest later.
- Identifying at-risk patient populations, such as those with comorbidities or on public assistance, is vital for targeted prevention strategies.
