JOA - 2026-07-15 - Journal Article
Low-dose Aspirin Once Daily is Noninferior for Venous Thromboembolic Prophylaxis After Primary Total Joint Arthroplasty: An Analysis of 8,073 Cases Over 10 Years.
Guo EW, Honey NE, Wang Z, Kaarto P, Hallstrom BR, Kheir MM
Topics
Key Takeaway
Aspirin 81 mg once daily yielded an overall VTE rate of 1.1% at 90 days after primary TJA, statistically noninferior to twice-daily aspirin or potent anticoagulants across 8,073 cases.
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Summary
This single-institution retrospective study compared VTE rates among primary THA and TKA patients receiving aspirin 81 mg once daily, higher-dose/twice-daily aspirin, or potent anticoagulation over a 10-year period. Overall VTE incidence was 1.1%, with TKA carrying a higher rate than THA (1.4% vs. 0.9%, P=0.02). Logistic regression found no significant difference in VTE rate by anticoagulation regimen (P=0.61); only higher Elixhauser Comorbidity Index independently predicted VTE (OR 1.09, 95% CI 1.04–1.15).
Key Limitation
Non-randomized anticoagulant assignment means patients receiving potent anticoagulants likely had higher baseline thrombotic risk, confounding the between-group VTE rate comparison despite logistic regression adjustment.
Original Abstract
BACKGROUND
Venous thromboembolism (VTE) is a well-known complication after primary total joint arthroplasty (TJA). Aspirin is increasingly used for VTE prophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) given its efficacy and favorable side effect profile, although optimal dosing and frequency remain uncertain. Given the long-term effect of aspirin on platelet function, the conventional twice-daily frequency (or higher dosing) of aspirin may be unnecessary. The purpose of this study was to investigate the VTE incidence in patients receiving 81 mg aspirin once daily for prophylaxis after primary TJA, which has been our institution's protocol for the past decade.
METHODS
This was a retrospective study of 8,073 patients who underwent primary total hip and knee arthroplasties from a single institution between 2014 and 2023. Patients who experienced a VTE event within 90 days of surgery were identified using our statewide registry. The VTE rates were compared between patients receiving aspirin 81 mg once daily, a higher dose/frequency of aspirin, or more potent anticoagulation. Univariate and logistic regression analyses were performed.
RESULTS
The overall VTE rate was 1.1% (90 of 8,073), with a lower incidence after THA compared to TKA (0.9 versus 1.4%, respectively, P = 0.02). In our logistic regression analyses, there was no difference in VTE rate between all anticoagulation methods (P = 0.61). The only variable that was predictive of VTE was a higher Elixhauser Comorbidity Index (odds ratio [OR] 1.09, 95% confidence interval [CI] 1.04 to 1.15, P < 0.01).
CONCLUSION
Our institutional protocol of using 81 mg aspirin once daily has an acceptable incidence rate of VTE after TJA. It is noninferior to the conventional twice-daily 81 mg aspirin or higher dosing, as well as potent anticoagulants.