Effective VTE Prophylaxis with Enoxaparin After Elective THR or TKR: a Retrospective Observational Study

Background: Orthopedic patients are at the highest risk for venous thromboembolism (VTE). Nowadays, with VTE prophylaxis as a routine in patients undergoing total hip replacement (THR) and total knee replacement (TKR), fatal pulmonary embolism (PE) is rare and the rates of symptomatic VTE within 3 months dropped to 1.3%-10%, compared with the rates of 50%-70% before VTE prophylaxis implementation. In this study, we aim to evaluate the VTE prophylaxis and incidence in patients who underwent THR and TKR in Centro Hospitalar Universitário de Santo António (CHUdSA).

Methods: We included 483 patients who underwent elective THR or TKR in CHUdSA from March 2019 to February 2020 and who were under enoxaparin as a VTE prophylaxis drug. All data related to prescribed enoxaparin were collected from the nationwide common electronic drug prescription system (PEM).

Results: Of the 483 eligible patients, 192 (39.75%) underwent elective THR and 291 (60.25%) underwent TKR. Enoxaparin was prescribed for 31.86 ± 5.98 and 30.28 ± 5.97 days, on average, for the THR and TKR groups, respectively ( = .005). Patients completed, on average, 29.38 ± 8.12 days and 28.20 ± 7.32 days of VTE prophylaxis with enoxaparin in the THR and TKR groups, respectively ( = .098). The incidence of VTE was approximately 3.13% and 0.69% in the THR and TKR groups, respectively ( = .064).

Conclusion: In CHUdSA, we usually prescribe enoxaparin 40 mg once daily for up to 35 days for VTE prophylaxis after THR or TKR. High therapeutic compliance rates resulted in very few events.