Comparison of clinical outcomes of enoxaparin and aspirin for postoperative venous thromboembolism prophylaxis in hip fractures

Objective: The risk of symptomatic venous thromboembolism (VTE) following hip fracture surgery is estimated at 1%-6%, necessitating effective prophylactic measures. While aspirin has been widely used in total hip and knee arthroplasty due to its comparable efficacy, reduced bleeding risk, and cost-effectiveness, its role in trauma patients remains under researched. This study aims to evaluate the efficacy and safety of aspirin and enoxaparin for VTE prophylaxis in hip fracture patients.

Methods: This two-center, retrospective study analyzed 306 adult patients who underwent hip fracture surgery between 2019 and 2023. Patients were divided into 2 groups: the aspirin group (81 mg twice daily) and the enoxaparin group (40 mg subcutaneous once daily), both receiving prophylaxis for 4 weeks postoperatively. Demographics, comorbidities, surgical details, and clinical outcomes—including major bleeding events, symptomatic VTE (deep vein thrombosis and pulmonary embolism), periprosthetic joint infection (PJI), blood transfusion requirements, and 90-day mortality—were recorded. Statistical analyses were performed using Pearson chi-square and independent t-tests, with significance set at P < .05.

Results: The aspirin group (n = 136) and enoxaparin group (n = 170) had mean ages of 67.66 Å} 19.67 and 63.42 Å} 19.71 years, respectively. Hemoglobin decrease was significantly lower in the aspirin group (1.75 Å} 1.07 g/dL vs. 2.73 Å} 1.56 g/dL, P = .001). In addition, the amount of postoperative blood transfusion was statistically significantly lower in the aspirin group compared to in the enoxaparin group (0.89 vs. 1.31 units, respectively, P = .034). There was no significant difference in mean hospital stay (6.84 vs. 6.65 days, P = .751). The incidence of major bleeding was higher in the enoxaparin group (3.7% (n = 5) vs. 5.3% (n = 9)), though not statistically significant (P = .789). Symptomatic VTE occurred in 3.7% (n = 5) of the aspirin group and 5.3% (n = 9) of the enoxaparin group (P = .453). Periprosthetic joint infection was observed in 2 patients in the enoxaparin group but none in the aspirin group (P = .447). Mortality within 90 days was lower in the aspirin group (8.8% (n = 12) vs. 15.9% (n = 27)), but the difference was not statistically significant (P = .066).

Conclusion: This study suggests that aspirin appears to be a reasonable alternative to enoxaparin for VTE prophylaxis in hip fracture patients, demonstrating comparable efficacy with a lower blood transfusion requirement and similar rates of major bleeding and symptomatic VTE. Given its affordability, ease of administration, and favorable safety profile, aspirin appears to be a reasonable and costeffective alternative for high-risk trauma patients.

Cite this article as: Korkmaz O, Hakyemez ÖS, Çakır N, et al. Comparison of clinical outcomes of enoxaparin and aspirin for postoperative venous thromboembolism prophylaxis in hip fractures. Acta Orthop Traumatol Turc. 2026; 60(2), 0305, doi: 10.5152/j.aott.2026.25305.