A once-daily dose of rivaroxaban 10 mg, an oral, direct Factor Xa inhibitor, was compared with enoxaparin 40 mg subcutaneously once daily for prevention of venous thromboembolism in three studies of patients undergoing elective hip and knee replacement (RECORD programme). A pooled analysis of data from these studies (n = 9581) showed that rivaroxaban was more effective than enoxaparin in reducing the incidence of the composite of symptomatic venous thromboembolism and all-cause mortality at two weeks (0.4% vs 0.8%, respectively, odds ratio 0.44; 95% confidence interval 0.23 to 0.79; p = 0.005), and at the end of the planned medication period (0.5% vs 1.3%, respectively; odds ratio 0.38; 95% confidence interval 0.22 to 0.62; p < 0.001). The rate of major bleeding was similar at two weeks (0.2% for both) and at the end of the planned medication period (0.3% vs 0.2%). Rivaroxaban started six to eight hours after surgery was more effective than enoxaparin started the previous evening in preventing symptomatic venous thromboembolism and all-cause mortality, without increasing major bleeding

Aims. The aim of this study was to evaluate the healthcare costs and benefits of enoxaparin compared to aspirin in the prevention of symptomatic venous thromboembolism (VTE) after total hip arthroplasty (THA) or total knee arthroplasty (TKA) using data from the CRISTAL trial. Methods. This trial-based economic analysis reports value for money as incremental cost per quality-adjusted life-year (QALY) gained in 2022 Australian dollars, compared to a single threshold value of AUD$70,000 per QALY. Event costs were estimated based on occurrence of VTEs and bleeds, and on published guidelines for treatment. Unit costs were taken from Australian sources. QALYs were estimated using CRISTAL six-month follow-up data. Sensitivity analyses are presented that vary the cost of VTE treatment, and extend the analyses to two years. Results. The CRISTAL trial found that enoxaparin was more effective than aspirin in preventing symptomatic VTE within 90 days of THA or TKA (risk difference 1.97% (95% confidence interval (CI) 0.54% to 3.41%; p = 0.007)). The additional cost after a THA or TKA was AUD$83 (95% CI 68 to 97) for enoxaparin, and enoxaparin resulted in an additional 0.002 QALYs (95% CI -0.002 to 0.005). Incremental cost per QALY gained was AUD$50,567 (95% CI 15,513, dominated) for enoxaparin. We can be 60% confident that the incremental cost per QALY does not exceed the willingness-to-pay threshold of AUD$70,000. Increasing the cost of VTE treatment and extension of costs and consequences to two years suggested greater confidence that enoxaparin is good value for money (70% and 63% confidence, respectively). Conclusion. This analysis provides strong evidence that enoxaparin thromboprophylaxis following THA or TKA reduced VTEs, but weak evidence of net economic benefits over aspirin. If the value of avoiding VTEs is high, and there is a strong likelihood of VTE-related health impairments, we can be more confident that enoxaparin is cost-effective compared to aspirin. Cite this article: Bone Joint J 2024;106-B(6):589–595

Aims

We investigated the efficacy and safety profile of commonly used venous thromboembolism (VTE) prophylaxis agents following hip and knee arthroplasty.

Since the introduction of the National Institute for Health and Care Excellence (NICE) guidelines on thromboprophylaxis and the use of extended thromboprophylaxis with new oral agents, there have been reports of complications arising as a result of their use. We have looked at the incidence of wound complications after the introduction of dabigatran for thromboprophylaxis in our unit.

We investigated the rate of venous thromboembolism and wound leakage in 1728 patients undergoing primary joint replacement, both before and after the introduction of dabigatran, and following its subsequent withdrawal from our unit.

We found that the use of dabigatran led to a significant increase in post-operative wound leakage (20% with dabigatran, 5% with a multimodal regimen; p < 0.001), which also resulted in an increased duration of hospital stay. The rate of thromboembolism in patients receiving dabigatran was higher (1.3%) than in those receiving the multimodal thromboprophylaxis regimen, including low molecular weight heparin as an inpatient and the extended use of aspirin (0.3%, p = 0.047). We have ceased the use of dabigatran for thromboprophylaxis in these patients.

Cite this article: Bone Joint J 2014;96-B:122–6.

Aims

There is uncertainty regarding the optimal means of thromboprophylaxis following total hip and knee arthroplasty (THA, TKA). This systematic review presents the evidence for acetylsalicylic acid (aspirin) as a thromboprophylactic agent in THA and TKA and compares it with other chemoprophylactic agents.

We examined the risk of thrombotic and major bleeding events in patients undergoing total hip and knee replacement (THR and TKR) treated with thromboprophylaxis, using nationwide population-based databases. We identified 83 756 primary procedures performed between 1997 and 2011. The outcomes were symptomatic venous thromboembolism (VTE), myocardial infarction (MI), stroke, death and major bleeding requiring hospitalisation within 90 days of surgery.

A total of 1114 (1.3%) and 483 (0.6%) patients experienced VTE and bleeding, respectively. The annual risk of VTE varied between 0.9% and 1.6%, and of bleeding between 0.4% and 0.8%. The risk of VTE and bleeding was unchanged over a 15-year period. A total of 0.7% of patients died within 90 days, with a decrease from 1% in 1997 to 0.6% in 2011 (p < 0.001). A high level of comorbidity and general anaesthesia were strong risk factors for both VTE and bleeding, with no difference between THR and TKR patients. The risk of both MI and stroke was 0.5%, which remained unchanged during the study period.

In this cohort study of patients undergoing THR and TKR patients in routine clinical practice, approximately 3% experienced VTE, MI, stroke or bleeding. These risks did not decline during the 15-year study period, but the risk of dying fell substantially.

Cite this article: Bone Joint J 2014;96-B:479–85.

Prophylaxis against venous thromboembolism after elective total hip replacement is routinely recommended. Our preference has been to use mechanical prophylaxis without anticoagulant drugs. A randomised controlled trial was performed to evaluate whether the incidence of post-operative venous thromboembolism was reduced by using pharmacological anticoagulation with either fondaparinux or enoxaparin in addition to our prophylactic mechanical regimen. A total of 255 Japanese patients who underwent primary unilateral cementless total hip replacement were randomly assigned to one of three postoperative regimens, namely injection of placebo (saline), fondaparinux or enoxaparin. There were 85 patients in each group. All also received the same mechanical prophylaxis during and after the operation, regardless of their assigned group. The primary measurement of efficacy was the presence of a venous thromboembolic event by day 11, defined as deep-vein thrombosis detected by ultrasonography, documented symptomatic deep-vein thrombosis or documented symptomatic pulmonary embolism. The duration of follow-up was 12 weeks.

The rate of venous thromboembolism was 7.2% with the placebo, 7.1% with fondaparinux and 6.0% with enoxaparin (p = 0.95 for the comparison of all three groups). Our study confirmed the effectiveness and safety of mechanical thromboprophylaxis without the use of anticoagulant drugs after total hip replacement in Japanese patients.

Aims

The aim of this study was to present data on 11 459 patients who underwent total hip (THA), total knee (TKA) or unicompartmental knee arthroplasty (UKA) between November 2002 and April 2014 with aspirin as the primary agent for pharmacological thromboprophylaxis.

Post-operative complications after total hip or knee replacement can delay recovery, prolong hospitalisation, increase rates of re-admission and, in the most severe cases, lead to long-term disability or even death. In this analysis of pooled data from four large, randomised, phase III clinical trials that compared the oral, direct Factor Xa inhibitor rivaroxaban with subcutaneous enoxaparin for the prevention of venous thromboembolism after total hip or knee replacement (n = 12 729), the incidence of complications, including bleeding and adverse events related to surgery (such as wound infection, wound dehiscence and haemarthrosis) are reported. Interventions and procedures relating to surgery are also compared between the groups. Bleeding events, including excessive wound haematoma and surgical-site bleeding, occurred at similar rates in the rivaroxaban and enoxaparin groups. Over the total study duration, adverse surgical events occurred at a similar rate in the rivaroxaban group compared with the enoxaparin group after total knee replacement (2.26% vs 2.69%, respectively) and total hip replacement (1.48% vs 1.65%, respectively). Blood loss, wound drainage and transfusion requirements were also similar between the two groups.

This analysis shows that the incidence of adverse surgical events with rivaroxaban was similar to enoxaparin.