Clinical Effectiveness and Safety of Aspirin for Venous Thromboembolism Prophylaxis After Total Hip and Knee Replacement: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Venous Thromboembolism Prophylaxis in Major Orthopedic Surgeries and Factor XIa Inhibitors

Venous thromboembolism (VTE), comprising pulmonary embolism (PE) and deep vein thrombosis (DVT), poses a significant risk during and after hospitalization, particularly for surgical patients. Among various patient groups, those undergoing major orthopedic surgeries are considered to have a higher susceptibility to PE and DVT. Major lower-extremity orthopedic procedures carry a higher risk of symptomatic VTE compared to most other surgeries, with an estimated incidence of ~4%. The greatest risk period occurs within the first 7-14 days following surgery. Major bleeding is also more prevalent in these surgeries compared to others, with rates estimated between 2% and 4%. For patients undergoing major lower-extremity orthopedic surgery who have a low bleeding risk, it is recommended to use pharmacological thromboprophylaxis with or without mechanical devices. The choice of the initial agent depends on the specific surgery and patient comorbidities. First-line options include low-molecular-weight heparins (LMWHs), direct oral anticoagulants, and aspirin. Second-line options consist of unfractionated heparin (UFH), fondaparinux, and warfarin. For most patients undergoing knee or hip arthroplasty, the initial agents recommended for the early perioperative period are LMWHs (enoxaparin or dalteparin) or direct oral anticoagulants (rivaroxaban or apixaban). In the case of hip fracture surgery, LMWH is recommended as the preferred agent for the entire duration of prophylaxis. However, emerging factor XI(a) inhibitors, as revealed by a recent meta-analysis, have shown a substantial decrease in the occurrence of VTE and bleeding events among patients undergoing major orthopedic surgery. This discovery poses a challenge to the existing paradigm of anticoagulant therapy in this specific patient population and indicates that factor XI(a) inhibitors hold great promise as a potential strategy to be taken into serious consideration.

The impact of adopting low-molecular-weight heparin in place of aspirin as routine thromboprophylaxis for patients with hip fracture

PURPOSE OF THE STUDY

In 2010, the National Institute for Health and Care Excellence (NICE) recommended the use of anticoagulants rather than aspirin as pharmacological thromboprophylaxis after hip fracture. We examine the impact of implementing this change in guidance on the clinical incidence of deep vein thrombosis (DVT).

STUDY DESIGN

Demographic, radiographic and clinical data were retrospectively collected for 5039 patients admitted to a single tertiary centre in the UK for hip fracture between 2007 and 2017. We calculated rates of lower-limb DVT and examined the impact of the June 2010 change of departmental policy, from use of aspirin to use of low-molecular-weight heparins (LMWH) in hip fracture patients.

RESULTS

Doppler scans were performed in 400 patients in the 180 days after a hip fracture, and identified 40 ipsilateral and 14 contralateral DVTs (p<0.001). The rate of DVT reduced significantly following the 2010 change in departmental policy from aspirin to LMWH in these patients (1.62% vs 0.83%, p<0.05).

CONCLUSIONS

The rate of clinical DVT halved following the change from aspirin to LMWH for pharmacological thromboprophylaxis, but the number needed to treat was 127. A figure of <1% for the incidence of clinical DVT in a unit that routinely uses LMWH monotherapy following hip fracture provides a context for discussions of alternative strategies, and for power calculations for future research. These figures are important to policy makers and to researchers as they will inform the design of the comparative studies on thromboprophylaxis agents for which NICE has called.

Comparison of the Efficacy and Safety of Aspirin and Low-Molecular-Weight Heparin in Patients With a Fracture: A Meta-Analysis

The aim of this study is to compare the efficacy and safety of aspirin and low-molecular-weight heparin (LMWH) in preventing thromboembolic events in patients with fractures. The present meta-analysis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched EMBASE, PubMed, and EBSCO to find articles comparing aspirin and LMWH in patients with orthopedic trauma from inception to April 15, 2023. Limits were set to studies published in the English language only. Outcomes assessed in this meta-analysis included VTE and all-cause mortality. VTE can manifest as deep venous thrombosis (DVT) and pulmonary embolism. For safety analysis, rates of wound complication, infection, and bleeding complications were compared between the two study groups. A total of three studies were included in this meta-analysis enrolling 12884 patients. The study found no significant difference between the two groups in the risk of DVT and pulmonary embolism, and aspirin was non-inferior to LMWH for the prevention of all-cause mortality in patients. Additionally, no significant safety risk was associated with aspirin thromboprophylaxis. These findings suggest that inexpensive over-the-counter aspirin is as effective as LMWH in terms of safety and efficacy profile, making it a feasible option to consider in clinical practice.

Thirty day low-dose versus regular-dose aspirin for venous thromboembolism prophylaxis in primary total joint arthroplasty

BACKGROUND

The optimal dosing of aspirin (ASA) monotherapy for prophylaxis after total joint arthroplasty is debatable. The objective of this study was to compare two ASA regimens with regards to symptomatic deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding, and infection 90 days after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

We retrospectively identified 625 primary THA and TKA surgeries in 483 patients who received ASA for 4 weeks post-op. 301 patients received 325 mg once daily (QD) and 324 patients received 81 mg twice daily (BID). Patients were excluded if they were minors, had a prior venous thromboembolism (VTE), had ASA allergy, or received other VTE prophylaxis drugs.

RESULTS

There was a significant difference in rate of bleeding and suture reactions between the two groups. Bleeding was 7.6% for 325 mg QD and 2.5% for 81 mg BID (p = .0029 Χ2, p = .004 on multivariate logistic regression analysis). Suture reactions were 3.3% for 325 mg QD and 1.2% for 81 mg BID (p = .010 Χ2, p = .027 on multivariate logistic regression analysis). Rates of VTE, symptomatic DVT, and PE were not significantly different. The incidence of VTE was 2.7% for 325 mg QD and 1.5% for 81 mg BID (p = .4056). Symptomatic DVT rates were 1.6% for 325 mg QD and 0.9% for 81 mg BID (p = .4139). Deep infection was 1.0% for 325 mg QD and 0.31% for 81 mg BID (p = .3564).

CONCLUSION

Low-dose ASA in patients with limited comorbidities undergoing primary THA and TKA is associated with significant lower rates of bleeding and suture reactions than high dose ASA. Low-dose ASA was not inferior to higher dose ASA for the prevention of VTE, wound complications, and infection 90 days postoperatively.

Statistical Fragility of Venous Thromboembolism Prophylaxis Following Total Joint Arthroplasty

Background

Statistical fragility is a quantitative measure of the robustness of the statistical conclusions drawn in a study. Although statistical fragility has been comprehensively evaluated in the arthroplasty literature, the statistical fragility of large-scale randomized trials evaluating venous thromboembolism (VTE) prophylaxis has not been evaluated. The purpose of this study was to determine the utility of applying the fragility index (FI) and the fragility quotient (FQ) analysis to randomized controlled trials (RCTs) evaluating VTE prophylaxis following total joint arthroplasty.

Methods

A systematic review was performed by searching multiple databases to identify RCTs that evaluated VTE prophylaxis following total joint arthroplasty from 2000 to 2020. The FI was determined by manipulating each reported dichotomous outcome event until a reversal of significance was appreciated with 2 × 2 contingency tables. The associated FQ was determined by dividing the FI by the sample size.

Results

Thirty-two RCTs were ultimately included for analysis. The overall FI incorporating all 32 RCTs was only 7 (interquartile range 3-9), suggesting that the reversal of only 7 events is required to change study significance. The associated FQ was determined to be 0.01. Of the RCTs that reported lost-to-follow-up data, the majority of studies had lost-to-follow-up numbers greater than 7.

Conclusions

Our findings suggest that RCTs evaluating VTE prophylaxis following total hip arthroplasty and total knee arthroplasty may lack statistical stability as few outcome events are required to reverse the significance of outcomes. Future randomized trials should consider reporting FI and FQ along with the P value analysis to provide better context to the integrity of statistical stability.

Trends of Venous Thromboembolism After Total Hip Arthroplasty in the United States: Analysis From 2011 to 2019

BACKGROUND

In 2011, the American Academy of Orthopaedic Surgeons released a Clinical Practice Guideline` that recommended routine venous thromboembolism (VTE) prophylaxis after total joint arthroplasty. The purpose of this study was to examine (1) the change in the incidence of 90-day VTE, deep vein thrombosis, and pulmonary embolism, (2) the change in the utilization of antithrombotic agents; and (3) the change in the economic burden associated with VTE after total hip arthroplasty (THA) from 2011 to 2019.

METHODS

National, administrative claims data from 2011 to 2019 were used to identify patients who underwent primary THA for osteoarthritis. Exclusions entailed liver pathology, coagulopathy, malignancy, or those on prior prescribed blood thinners before THA. Multivariable regression was used, controlling for age and Charlson Comorbidity Index for all years, with 2011 as the reference year.

RESULTS

From 2011 to 2019, there was a significant reduction in 90-day VTE rates after THA, with a significant reduction in deep vein thrombosis and pulmonary embolism during this time frame as well. Of the antithrombotic agents prescribed after THA, the utilization of prescribed aspirin significantly increased and that of nonaspirin anticoagulants significantly decreased. Among nonaspirin anticoagulants, the utilization of direct factor Xa inhibitors and direct thrombin inhibitors significantly increased. The added reimbursements associated with VTE after THA significantly decreased during this period.

CONCLUSION

Since 2011, the incidence and economic burden associated with VTE after THA have significantly declined. In addition, there has been an increase in prescription aspirin and direct oral anticoagulants.

LEVEL OF EVIDENCE

Therapeutic, III.

Trends in Venous Thromboembolism After Shoulder Arthroplasty in the United States: Analysis Following the 2009 American Academy of Orthopaedic Surgeons Clinical Practical Guidelines

BACKGROUND

In 2009, the American Academy of Orthopaedic Surgeons released a consensus recommending venous thromboembolism (VTE) prophylaxis after total shoulder arthroplasty (TSA). The purpose of this study was to examine the (1) change in incidence of 90-day VTE, deep vein thrombosis (DVT), and pulmonary embolism; (2) change in utilization of chemoprophylaxis; and (3) change in the economic burden associated with VTE after TSA from 2010 to 2019.

METHODS

Using the PearlDiver database, national data from 2010 to 2019 were used to identify patients who underwent primary TSA for osteoarthritis and/or rotator cuff arthropathy. Exclusions entailed liver pathology, coagulopathy, or those on prior prescribed blood thinners before TSA. Multivariable regression was used controlling for age and Charlson Comorbidity Index for all years with 2010 as the reference year.

RESULTS

From 2010 to 2019, there was a reduction in VTE rates from 0.89% in 2010 to 0.78% in 2019. Regarding implant type, there was no notable change in incidence of VTE, DVT, and pulmonary embolism within 90 days after anatomic TSA. Notable reductions were observed in both VTE and DVT after reverse TSA from 2010 to 2019. Prescribed chemical VTE prophylaxis utilization after TSA markedly increased from 4.41% in 2010 to 11.70% utilization in 2019. The utilization of aspirin markedly increased from 17.27% in 2010 to 65.17% in 2019. Among anticoagulants, the utilization of direct factor Xa inhibitors increased from 0.0% utilization in 2010 to 66.09% utilization in 2019. The added reimbursements associated with VTE after TSA markedly decreased from $14,122 in 2010 to $4,348 in 2019.

CONCLUSION

The incidence and economic burden associated with VTE after TSA have markedly declined following the 2010 American Academy of Orthopaedic Surgeons clinical practice guidelines. This reduction can be attributed to both an increase in VTE prevention through increased utilization of prescribed chemoprophylaxis and improvement in VTE treatment strategies.

LEVEL OF EVIDENCE

Therapeutic, III.

Mussel-inspired alkaline phosphatase-specific coating on orthopedic implants for spatiotemporal modulating local osteoimmune microenvironment to facilitate osseointegration

Inadequate initial osseointegration and consequent prosthesis loosening are the most severe complications after artificial arthroplasty. Proper immune responses are crucial for the successful implantation of artificial prostheses. Macrophages are central in osteoimmunomodulation because they exert distinct functions with highly plasticity. Herein, we developed an alkaline phosphatase (ALP) sensitive mussel-inspired coating on orthopedic implants for promoting osseointegration. First, the resveratrol-alendronate complexes were deposited on titanium implant surface through mussel-inspired interfacial interactions. Upon prosthesis implantation, macrophages first polarized towards M1 type to initiate inflammatory responses and bone regeneration. As osteogenesis progresses, increasing amounts of ALP secreted by osteoblasts was cleaved the resveratrol-alendronate complexes. Then, the released resveratrol further promoted osteogenic differentiation of BMSCs and induced locoregional macrophages M2 polarization. Our results demonstrated that the bioinspired osteoimmunomodulation coating remarkably facilitated the prosthesis-bone integration by spatiotemporally modulating macrophages switching from M1 to M2 polarization in response to a real-time healing signal during osteogenesis. In summary, the mussel-inspired osteoimmunomodulation coating technology may provide a new approach for promoting osseointegration after artificial arthroplasty.

Approaches for optimizing venous thromboembolism prevention in injured patients: Findings from the consensus conference to implement optimal venous thromboembolism prophylaxis in trauma

ABSTRACT

Venous thromboembolism (VTE) is a major issue in trauma patients. Without prophylaxis, the rate of deep venous thrombosis approaches 60% and even with chemoprophylaxis may be nearly 30%. Advances in VTE reduction are imperative to reduce the burden of this issue in the trauma population. Novel approaches in VTE prevention may include new medications, dosing regimens, and extending prophylaxis to the postdischarge phase of care. Standard dosing regimens of low-molecular-weight heparin are insufficient in trauma, shifting our focus toward alternative dosing strategies to improve prophylaxis. Mixed data suggest that anti-Xa-guided dosage, weight-based dosing, and thromboelastography are among these potential strategies. The concern for VTE in trauma does not end upon discharge, however. The risk for VTE in this population extends well beyond hospitalization. Variable extended thromboprophylaxis regimens using aspirin, low-molecular-weight heparin, and direct oral anticoagulants have been suggested to mitigate this prolonged VTE risk, but the ideal approach for outpatient VTE prevention is still unclear. As part of the 2022 Consensus Conference to Implement Optimal Venous Thromboembolism Prophylaxis in Trauma, a multidisciplinary array of participants, including physicians from multiple specialties, pharmacists, nurses, advanced practice providers, and patients met to attack these issues. This paper aims to review the current literature on novel approaches for optimizing VTE prevention in injured patients and identify research gaps that should be investigated to improve VTE rates in trauma.

Incidence of Symptomatic Venous Thromboembolism (VTE) in 8,885 Elective Total Hip Arthroplasty Patients Receiving Post-operative Aspirin VTE Prophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a potentially reducible cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Health and Care Excellence (NICE) published updated guidelines in 2018 which recommend the use of both mechanical and pharmacological methods in patients undergoing elective total hip arthroplasty (THA).

OBJECTIVES

The aim of this study was to present the symptomatic VTE incidence in 8,885 patients who underwent THA between January 1998 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Intermittent calf compression stockings are routinely used from the time of surgery until mobilization (usually the following day) with prophylactic doses of low molecular weight heparin (LMWH) during inpatient stay (from 2005 onwards) and then Aspirin 150mg once daily for six weeks on hospital discharge (or Aspirin only prior to 2005), with use of other therapies occasionally as required.

METHODS

Analysis of prospective data collection from consecutive patients at a single institution undergoing THA was performed with the incidence of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within six months of the index operation as the primary outcome measure. Ninety-day all-cause mortality of this cohort of patients was also analysed.

RESULTS

8,885 patients were reviewed. This included 7230 primary, 224 complex primary and 1431 revision cases. The overall incidence of symptomatic VTE after elective THA was 1.11% (99/8885) - with the incidence of symptomatic DVT of 0.59% (52/8885) and the incidence of symptomatic PE of 0.53% (47/8885). There was no significant difference (χ² test, p=0.239) in the symptomatic VTE incidence between primary (1.20% - 89/7230), complex primary (0.89% - 2/224) and revision cases (0.70% - 10/1431). The 90-day all-cause mortality was 0.88% (78/8885). Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to PE. There was no significant difference (p=0.327) in length of stay (and hence amount of pharmacologic prophylaxis with LMWH received by patients before commencement of Aspirin) with the average length of stay for those patients who did not suffer a VTE of 6.8 days compared with 7.6 days for those who did suffer a VTE.

CONCLUSION

Our results support the use of aspirin as an effective form of prophylaxis against symptomatic VTE following THA in contradiction to NICE and American Academy of Orthopaedic Surgery (AAOS) recommendations. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other advantages of using aspirin for VTE prophylaxis.

Aspirin thromboprophylaxis following primary total knee arthroplasty is associated with a lower rate of early prosthetic joint infection compared with other agents

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) are at increased risk of venous thromboembolism (VTE). Aspirin has been shown to be effective at reducing rates of VTE. In select patients, more potent thromboprophylaxis is indicated, which has been associated with increased rates of bleeding and wound complications. This study aimed to evaluate the effect of thromboprophylaxis choice on rates of early prosthetic joint infection (PJI) following TKA.

METHODS

A review of 11,547 primary TKA patients from 2013 to 2019 at a single academic orthopaedic hospital was conducted. The primary outcome measure was PJI within 90 days of surgery as measured by Musculoskeletal Infection Society criteria. There were 59 (0.5%) patients diagnosed with early PJI. Chi-square and Welch-Two Sample t-tests were used to determine statistically significant relationships between thromboprophylaxis and demographic variables. Significance was set at p<0.05. Multivariate logistic regression adjusted for age, body mass index, sex, and Charlson comorbidity index was performed to identify and control for independent risk factors for early PJI.

RESULTS

There was a statistically significant difference in the rates of early PJI between the aspirin and non-aspirin group (0.3 vs 0.8%, p<0.001). Multivariate logistic regressions revealed that patients given aspirin thromboprophylaxis had significantly lower odds of PJI (odds ratios (OR)=0.51, 95% Confidence Interval (CI) 0.29 to 0.89, p=0.019) compared to non-aspirin patients.

CONCLUSIONS

The use of aspirin thromboprophylaxis following primary TKA is independently associated with a lower rate of early PJIs. Arthroplasty surgeons should consider aspirin as the gold standard thromboprophylaxis in all patients in which it is deemed medically appropriate and should carefully weigh the morbidity of PJI in patients when non-aspirin thromboprophylaxis is considered.

Comparison of 90-Day Adverse Events Associated With Aspirin and Potent Anticoagulation Use for Venous Thromboembolism Prophylaxis: A Cohort Study of 72,288 Total Knee and 35,142 Total Hip Arthroplasty Patients

BACKGROUND

While aspirin is acceptable for venous thromboembolism (VTE) prophylaxis following total joint arthroplasty in most patients, more potent agents are used in patients considered higher risk for VTE. We evaluated the efficacy and safety of aspirin versus potent anticoagulation agents following total knee arthroplasty (TKA) and total hip arthroplasty (THA).

METHODS

A cohort study of 72,288 TKA and 35,142 THA from the Kaiser Permanente Total Joint Replacement Registry was performed (2009 to 2019). Identified medications were aspirin, factor Xa inhibitors, low-molecular-weight heparin (LMWH), and warfarin. A validated VTE risk score was assigned to each patient. Propensity score-weighted logistic regressions were used to evaluate 90-day VTEs. Noninferiority testing was performed with a margin of 1.25 using the upper bound (UB) of the 1-sided 95% CI.

RESULTS

For TKA, aspirin was not inferior to LMWH (odds ratio [OR] = 0.77, UB = 1.09) and warfarin (OR = 0.64, UB = 0.90); there was no evidence to support noninferiority of aspirin compared to factor Xa inhibitors. Findings were consistent for THA (LMWH: OR = 0.59, UB = 0.75; warfarin: OR = 0.69, UB = 0.89). TKA was considered higher risk for VTE, whereas aspirin use demonstrated noninferiority compared to warfarin (OR = 0.54, UB = 0.81), we lacked evidence of noninferiority when compared to LMWH and factor Xa inhibitors. We lacked evidence of noninferiority of aspirin versus any potent anticoagulation in higher-risk THA.

CONCLUSION

Aspirin was found to be effective and safe for VTE prevention in primary total joint arthroplasty, including in patients considered higher risk for VTE.

LEVEL OF EVIDENCE

III.

Effectiveness of different antithrombotic agents in combination with tranexamic acid for venous thromboembolism prophylaxis and blood management after total knee replacement: a prospective randomized study

BACKGROUND

Tranexamic acid (TXA) has been widely applied in total knee arthroplasty (TKA) to significantly reduce perioperative blood loss and improve knee function recovery in patients after surgery. The choice of antithrombotic agents for venous thromboembolism (VTE) prevention after TKA is controversial. Therefore, this study aimed to compare the effects of different antithrombotic agents on patients after primary unilateral TKA in the context of applied TXA.

METHODS

A total of 180 patients undergoing primary unilateral TKA from October 2020 to December 2021 were included in this study. All patients were given an intraoperative drip of 60 mg/kg TXA. Thereafter, patients were divided into three groups (n = 60 each). Baseline data were comparable among the three groups. The average follow-up time was 3.02 ± 0.09 months. Group 1 enrolled patients receiving oral rivaroxaban (RA) at 10 mg, Group 2 included patients who received subcutaneous Dalteparin sodium at 2500 IU, while Group 3 included patients taking oral aspirin (ASA) at 100 mg. Patients in all the three groups received treatment once a day for 30 days at 12 h postoperatively. The primary outcomes in this study were post-treatment drainage volume and thrombotic complication rate. The secondary outcomes included hematologic parameters, transfusion rate, intraoperative blood loss, total blood loss (TBL), and bleeding complication rate.

RESULTS

The average drainage volume after treatment was significantly lower in Group 3 than in Group 1 and Group 2 (205.2 ± 69.0 vs 243.4 ± 72.5 vs 295.4 ± 72.5 ml, P < 0.001), and there was a significant difference between Group 1 and Group 2 (243.4 ± 72.5 mL vs 295.4 ± 72.5 mL, P < 0.001). The blood transfusion rate of Group 2 dramatically increased compared with Group 1 and Group 3 (20.0% vs 6.7% vs 5.0%, P = 0.01). The bleeding complication rate in Group 1 apparently increased relative to Group 2 and Group 3 (26.7% vs 10.0% vs 8.3%, P = 0.008). Besides, there was no significant difference in the thrombotic complication rate among the three groups.

CONCLUSION

Under the background of TXA application, ASA, RA, and Dalteparin sodium were all effective on preventing VTE after TKA. In addition, ASA effectively reduced post-treatment Hemoglobin (Hb) loss, drainage volume, TBL, transfusion rate, and bleeding complications compared with RA and Dalteparin sodium.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2200060169). Date of Registration: 21/05/2022.

Clinical effectiveness and safety of aspirin and other anticoagulants for venous thromboembolism prophylaxis after major orthopedic surgery: a systematic review and meta-analysis of randomized clinical trials

Purpose

Patients undergoing major orthopedic surgeries, such as total hip replacement (THR), total knee replacement (TKR), and trauma surgery, are at an elevated risk of venous thromboembolism (VTE), causing significant morbidity and mortality. Previous studies have investigated aspirin as a thromboprophylactic agent for arthroplasty, besides trauma surgery. Therefore, we sought to analyze the efficacy of aspirin compared to that of other anticoagulants for VTE prophylaxis in patients undergoing major orthopedic surgeries.

Methods

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The study protocol was registered with the PROSPERO register. Randomized controlled trials that investigated the use of aspirin for thromboprophylaxis in major orthopedic lower limb surgeries were included and analyzed. Quality analysis of the literature and level of evidence were assessed. The primary clinical outcome was VTE. Secondary clinical outcomes included mortality, bleeding events, and wound complications.

Results

Eight high-quality studies with level 2 evidence (published within 2006-2021) were included, comprising 6220 patients. The incidence of VTE with aspirin was not found to be more significant than other anticoagulants (risk ratio (RR) = 1.18, 95% CI: 0.89-1.58, P = 0.25). Regarding secondary outcomes, there were no significant differences between aspirin and other anticoagulants (mortality (RR = 1.40, 95% CI: 0.27-7.23, P = 0.69), bleeding events (RR = 0.89, 95% CI: 0.57-1.39, P = 0.61), or wound complications (RR = 0.64, 95% CI: 0.30-1.35, P = 0.24)).

Conclusion

The current meta-analysis did not show any difference between aspirin and other anticoagulants as thromboprophylactic agents in preventing VTE in patients who underwent major orthopedic surgeries.

Low-Dose Aspirin for Venous Thromboembolism Prophylaxis is Associated With Lower Rates of Periprosthetic Joint Infection After Total Joint Arthroplasty

BACKGROUND

Aspirin as a venous thromboembolism (VTE) prophylactic agent has been shown to have antistaphylococcal and antibiofilm roles. Optimal acetylsalicylic acid (ASA) dosage would facilitate antimicrobial effects while avoiding over-aggressive inhibition of platelet antimicrobial function. Our purpose was to determine the periprosthetic joint infection (PJI) rate after total joint arthroplasty in patients receiving low-dose ASA (81 mg twice a day), in comparison to high-dose ASA (325 mg twice a day).

METHODS

We conducted a retrospective cohort study between 2008 and 2020. Eligible patients were older than 18 years, underwent primary total joint arthroplasty, both total knee arthroplasty and total hip arthroplasty, had a minimum 30-day follow-up, and received a full course ASA as VTE prophylaxis. Patients' records were reviewed for PJI, according to Musculoskeletal Infection Society criteria. Patients were excluded if they underwent revision arthroplasty, had a history of coagulopathy, or had an ASA regimen that was not completed. In total 15,825 patients were identified, 8,761 patients received low-dose ASA and 7,064 received high-dose ASA.

RESULTS

The high-dose cohort had a higher PJI rate (0.35 versus 0.10%, P = .001). This relationship was maintained when comparing subgroups comprising total knee arthroplasty (0.32 versus 0.06%, P = .019) or total hip arthroplasty (0.38 versus 0.14%, P = .035) and accounting for potentially confounding demographic and surgical variables (odds ratio = 2.59, 95% CI = 1.15-6.40, P = .028).

CONCLUSION

Comparing low-dose to high-dose ASA as a VTE prophylactic agent, low-dose ASA had a lower PJI rate. This may be attributable to a balance of anti-infective properties of ASA and antiplatelet effects.

Aspirin May Be a Suitable Prophylaxis for Patients with a History of Venous Thromboembolism Undergoing Total Joint Arthroplasty

BACKGROUND

In recent years, aspirin has become a popular agent for venous thromboembolism (VTE) prophylaxis following total joint arthroplasty (TJA). Yet patients with a history of VTE are often given more aggressive prophylactic agents because of their increased baseline risk. The purpose of this study was to assess whether aspirin is an effective prophylactic agent in patients with a history of VTE.

METHODS

This was a single-institution, retrospective cohort study. The electronic clinical records of 36,333 patients undergoing TJA between 2008 and 2020 were reviewed. Data on demographic characteristics, comorbidities, intraoperative factors, and postoperative complications were collected. A propensity score-matched analysis was performed, as well as a multivariate regression analysis to account for confounders.

RESULTS

Of the 36,333 patients undergoing TJA, 1,087 patients (3.0%) had a history of VTE and were not receiving chronic non-aspirin. The risk for subsequent VTE was significantly higher (p = 0.03) in patients with a history of VTE (1.4%) compared with patients without prior VTE (0.9%). However, the incidence of VTE was not significantly lower (p = 0.208) in patients with a history of VTE who received aspirin (0.4%) compared with patients who received other VTE prophylaxis (1.5%). Propensity score matching showed no difference in VTE rates between the 2 groups (2.2% compared with 0.55%; p = 0.372). In a regression analysis accounting for VTE risk, the administration of aspirin was not associated with an increased risk for subsequent VTE (adjusted odds ratio, 0.32 [95% confidence interval, 0.02 to 1.66]; p = 0.274).

CONCLUSIONS

Our findings suggest that, although patients with a history of VTE have an increased baseline risk for subsequent VTE, aspirin may be a suitable VTE prophylaxis in this group of patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Preferências e práticas de ortopedistas brasileiros por técnicas de tromboprofilaxia na artroplastia total do joelho: Levantamento entre membros da Sociedade Brasileira de Cirurgia do Joelho (SBCJ)

Objetivo Descrever as preferências e práticas atuais de uma amostra de cirurgiões de joelho do Brasil quanto à forma de tromboprofilaxia na artroplastia total do joelho (ATJ).

Método Na presente pesquisa realizada pela internet, cirurgiões associados à Sociedade Brasileira de Cirurgia do Joelho (SBCJ) foram convidados a responder voluntariamente a um questionário anônimo incluindo o tempo de experiência cirúrgica pessoal, percepções sobre as melhores opções de tromboprofilaxia e as reais práticas no ambiente onde trabalham.

Resultados Entre dezembro de 2020 e janeiro de 2021, 243 participantes responderam ao questionário completo. Exceto por 3 (1,2%) participantes, todos declararam praticar tromboprofilaxia, a maioria (76%) combinando as formas farmacológica e mecânica. A droga mais prescrita é a enoxaparina (87%), com modificação para rivaroxabana (65%) após a alta. O momento de início da tromboprofilaxia variou conforme o tempo de formação do cirurgião de joelho (p ≤ 0,03) e as preferências e práticas variaram conforme a região do país (p < 0,05) e o sistema de saúde no qual trabalham os cirurgiões (público ou privado; p = 0,024). A opção por tromboprofilaxia mecânica também dependeu do tempo de formação do cirurgião.

Conclusão As preferências e práticas de tromboprofilaxia na ATJ são diversas nas regiões do Brasil e sistemas de saúde (público ou privado). Dada a inexistência de uma diretriz clínica nacional, a maior parte dos ortopedistas segue ou a diretriz de seu próprio hospital ou nenhuma. O método de profilaxia mecânica e a pouca utilização do ácido acetilsalicílico são os pontos que mais destoam das diretrizes e práticas internacionais.

What Are the Drivers of Readmission for Serious Venous Thromboembolic Events after Primary Total Knee Arthroplasty? An Analysis of 862,915 Patients

Venous thromboembolism (VTE) is a relatively common complication among patients undergoing primary total knee arthroplasty (TKA). This complication occurs in a spectrum of severity ranging from an incidental finding to serious readmission-requiring events. To date, the risk factors of serious VTE that require readmission have not been characterized. This study examines the patient and hospital characteristics associated with readmission for serious VTE after TKA. The National Readmission Database (NRD) from the Agency of Healthcare Research and Quality (AHRQ) was queried for patients who underwent primary TKA from January 2016-December 2018. The study population consisted of patients who were readmitted within 90 days following primary TKA with a primary diagnosis of VTE. Multivariable regression models were constructed to evaluate patient characteristics (age, sex, insurance, elective nature of procedure, hospital characteristics, discharge status, income, and comorbidities) associated with higher risk of developing readmission-requiring VTE. Readmission rates for VTE exhibited a higher incidence in patients older than 61 (compared with 40 and under), males (OR:1.08, 95%CI [1.03-1.14]), patients with nonelective procedures (OR:20.21, 95% CI [19.16-21.32]), patients at large hospitals(OR:1.17, 95% CI [1.09-1.25]), patients at private hospitals (OR:1.19, 95% CI [1.09-1.29]), and patients with non-home discharge statuses. Comorbidities of paralysis (OR:1.52, 95% CI [1.19-1.94]), neurological disorders (OR:1.12, 95% CI [1.02-1.23]), metastatic cancer (OR:1.48, 95% CI [1.01-2.17]), obesity (OR:1.11, 95% CI [1.06-1.17]), fluid and electrolyte imbalance (OR:1.28, 95% CI [1.18-1.38]), blood loss anemia (OR:1.29, 95% CI [1.02-1.64]), and iron deficiency anemia (OR:1.24, 95 % CI [1.15-1.33]) increased risk of VTE. Certain comorbidities requiring chronic anticoagulation were associated with lower risk of VTE. Insurance status and patient income did not exhibit any correlation with VTE incidence. Patient characteristics of male sex, age > 61, and baseline comorbidities (paralysis, neurological disorders, metastatic cancer, obesity, fluid and electrolyte imbalance, and blood loss/iron deficiency anemia) were at an increased risk of developing serious VTE. Patients without continued supervision at their discharge environment were at higher risk of developing serious VTE. Extra prophylaxis and special protocols may be warranted in these patients to prevent VTE complications.

Retrospective Cohort Analysis of Aspirin Use and Venous Thromboembolism in Patients with Pancreatic Cancer and an Indwelling Central Venous Catheter

Background Patients with pancreatic cancer are at high risk of developing venous thromboembolism (VTE). It is unknown if aspirin reduces the risk of VTE in this setting.

Objectives We sought to determine whether there is an association between aspirin use and VTE risk in patients with pancreatic cancer receiving chemotherapy with a central venous catheter (CVC).

Patients/Methods We conducted a single-center, retrospective cohort study of adult patients diagnosed with pancreatic cancer and treated with chemotherapy using a CVC. Subjects were excluded if they were on anticoagulation at the time of CVC placement. The probability of VTE was analyzed using a time-to-event analysis framework for the development of VTE using the product-limit method of Kaplan and Meier (univariate) and adjusting for important confounding covariates using Cox proportional hazards regression (cause-specific hazard) and again using Fine and Gray regression (subdistributional hazard) with death prior to VTE considered a competing event.

Results The final analysis included 314 cases (125 with any aspirin use and 189 without). Patients with any aspirin use had fewer VTE events (34.4%) compared with those without aspirin use (42.3%; p = 0.021) by log-rank test and after adjustment for multiple covariates using a Cox proportional hazards model (hazard ratio [HR] = 0.60; 95% confidence interval [CI]: 0.40–0.92; p = 0.019). Using Fine and Gray regression to account for death as a competing event, the effect of aspirin remained in the direction of benefit, but was not statistically significant (HR = 0.70; 95% CI: 0.47–1.05, p = 0.083). Higher body mass index, active smoking, and metastatic stage of cancer were associated with VTE events in the Cox proportional hazards model. Rates of major bleeding or clinically relevant minor bleeding were similar between treatment groups.

Conclusions Aspirin may reduce the risk of VTE in patients with pancreatic cancer with a CVC. We did not observe a significant increase in the rates of major bleeding or clinically relevant nonmajor bleeding.

Incremental net monetary benefit of direct oral anticoagulants for the prevention of venous thromboembolism after total knee or hip replacement: A systematic review and meta-analysis

INTRODUCTION

This meta-analysis was conducted to quantitatively pool the incremental net benefit (INB) of using direct oral anticoagulants (DOACs) for the prevention of venous thromboembolism (VTE) in patients undergoing total knee or hip replacements (TKR or THR).

MATERIALS AND METHODS

We performed a comprehensive search in several databases published before June 2021. Studies were included if they were cost-effectiveness analyses reporting cost per quality-adjusted life-year or life-year of DOACs compared to low molecular-weight heparins (LMWHs) or other anticoagulant agents for the prevention of VTE after TKR or THR. Risk of bias was also assessed using the biases in economic studies (ECOBIAS) checklist. Various monetary units were converted to purchasing power parity, adjusted to 2020 US dollars. The INBs were pooled across studies using a random-effects model, stratified by high-income countries (HICs) and low- and middle-income countries (LMICs). Heterogeneity was assessed using the I² statistic.

RESULTS

A total of 49 comparisons (TKR = 25 and THR = 24) from 16 studies was included. In HICs, DOACs were cost-effective compared to LMWHs from the health care system/payer perspective for the prevention of VTE after both TKR and THR with corresponding INBs (95 % CI; I²) of $231.91 ($178.71, $285.11; 0 %) and $254.99 ($159.20, $350.77; 27.79 %), respectively. In LMICs, DOACs were not cost-effective compared to LMWHs for both TKR and THR with the INBs of $94.13 (-$40.21, $228.47; 97.04 %) and $80.55 (-$157.37, $318.47; 99.78 %), respectively. No evidence of small-study effects was identified in any analyses. The cost-effectiveness of using DOACs for TKR and THR in HICs was robust across a series of sensitivity analyses.

CONCLUSIONS

DOACs were cost-effective as compared to LMWHs for VTE prophylaxis following TKR and THR surgeries in HICs. Further studies from LMICs are warranted.

Thrombin antithrombin complex concentration as an early predictor of deep vein thrombosis after total hip arthroplasty and total knee arthroplasty

Aim

Early predictive markers of venous thromboembolism (VTE) after total hip arthroplasty (THA)/total knee arthroplasty (TKA) remain unclear. Our study identified early predictive markers for VTE after THA/TKA.

Methods

A single-institution retrospective review study was conducted between May 2020 and April 2022 (n = 256). All patients underwent Doppler ultrasounds exam in preoperation and seventh day after surgery. Deep vein thrombosis (DVT) was defined by Doppler ultrasound of the lower extremities, which revealed thrombosis. Thrombin-antithrombin complex (TAT), thrombomodulin (TM), and plasmin-antiplasmin complex (PIC) concentration were tested from each patient’s preoperative and postoperative days 1, 4, 7, 14. These values were then accessed via receiver operating characteristic (ROC) curve analysis and further quantified the level of this risk by concentration.

Results

On postoperative day 1 (pod-1), all patients’ TAT and PIC concentrations were significantly higher than those preoperatively (p < 0.05). The levels of TAT and PIC in patients in the DVT group on pod-1 were significantly higher than those in the non-DVT group (p < 0.05). At pod-1, the TAT concentration for DVT patients was 49.47 ng/mL compared to 20.70 ng/mL for non-DVT patients, PIC was 3.72μg/mL compared to 1.65μg/mL. ROC curve analysis demonstrated that a TAT concentration of 24.3 ng/mL had a sensitivity of 87.9% and a specificity of 69.1%.

Conclusion

TAT levels on pod-1 may predict DVT early after THA/TKA, which makes it possible for early intervention to decrease the incidence of DVT.

Time to Venous Thromboembolism Events Following Total Hip Arthroplasty: A Comparison Between Aspirin and Warfarin

BACKGROUND

The attitude and approach of orthopedic community for minimizing venous thromboembolism (VTE) has evolved over the last decade with the trend toward use of aspirin (and mechanical modalities) in lieu of aggressive anticoagulation. The optimal length of VTE prophylaxis following total hip arthroplasty (THA) still remains unknown. This study aimed to determine the timing of VTE in patients who received aspirin compared to warfarin, and determine if 30 days of prophylaxis remain adequate.

METHODS

This is a retrospective study of 18,003 patients undergoing primary and revision THA at a single institution between January 2008 and August 2020. During this time, our institution underwent a transition from the use of warfarin to aspirin as the main method for VTE prophylaxis. Symptomatic deep vein thrombosis and pulmonary embolism occurring within 90 days of surgery were identified from medical records and phone call logs. Aspirin and warfarin cohorts were matched to account for demographic and comorbidity differences. Timing of pulmonary embolism was determined based on either the date of diagnostic imaging or patient-provider phone calls confirming diagnosis.

RESULTS

The cohorts included 46 patients in the warfarin group and 46 in the aspirin group. Time to VTE was significantly shorter in the warfarin group compared to aspirin (P = .021) with a median time to VTE of 3 days (interquartile range 2-14) and 10 days (interquartile range 4-19) respectively. Over 90% of the events occurred within 32 or 30 days of surgery in the warfarin and aspirin groups respectively.

CONCLUSION

Based on the findings, a 30-day aspirin prophylaxis remains appropriate for patients undergoing THA.

Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty May Experience Higher Rates of Venous Thromboembolism When Prescribed Direct Oral Anticoagulants vs Aspirin

BACKGROUND

Morbidly obese (body mass index [BMI] >40 kg/m²) patients undergoing total joint arthroplasty (TJA) are at high risk for postoperative venous thromboembolism (VTE); however, there is debate surrounding the optimal pharmacologic agent for prevention of VTE after TJA in this patient subset. Current guidelines recommend against direct-acting oral anticoagulants (DOACs) in patients of BMI >40 kg/m² due to low quality evidence justifying their use. We evaluated whether patients of BMI >40 kg/m² undergoing primary unilateral TJA would have increased risk of postoperative VTE if prescribed DOACs compared to non-DOAC agents such as aspirin.

METHODS

This retrospective study analyzed 897 patients of BMI >40 kg/m² undergoing primary unilateral TJA. Demographic and comorbidity-related variables were collected. The association between postoperative VTE and prophylactic pharmacologic agent prescribed was evaluated by multivariate logistic regression.

RESULTS

After controlling for comorbidities, we found that the sole use of DOACs, specifically apixaban, for VTE prophylaxis was associated with an increased risk of developing VTE compared to prophylaxis with aspirin alone in patients of BMI >40 kg/m² (odds ratio 2.962, P = .016). Regardless of VTE prophylactic agent, patients with BMI >40 kg/m² undergoing TKA had at least 4.5-fold increased odds of developing VTE compared to patients undergoing THA (OR 4.830, P = .019).

CONCLUSION

In our retrospective study of a large sample size of patients with BMI >40 kg/m², we found that the use of DOACs, specifically apixaban, for VTE prophylaxis following TJA was associated with increased odds of a VTE complication compared to the use of aspirin alone.

Cost-Effectiveness of Aspirin for Extended Venous Thromboembolism Prophylaxis After Major Surgery for Inflammatory Bowel Disease

BACKGROUND AND PURPOSE

Venous thromboembolism extended prophylaxis after inflammatory bowel disease surgery remains controversial. The purpose of this study was to evaluate if adopting an aspirin-based prophylaxis strategy may address current cost-effectiveness limitations.

METHODS

A decision analysis model was used to compare costs and outcomes of a reference case patient undergoing inflammatory bowel disease-associated colorectal surgery considered for post-discharge thromboembolism prophylaxis. Low-dose aspirin was compared to an enoxaparin regimen as well as no prophylaxis. Source estimates were obtained from aggregated existing literature. Secondary analysis included out-of-pocket costs. A 10,000-simulation Monte Carlo probabilistic sensitivity analysis accounted for uncertainty in model estimates.

RESULTS

An enoxaparin-based regimen compared to aspirin demonstrated an unfavorable incremental cost-effectiveness ratio of $908,268 per quality-adjusted life year. Sensitivity analysis supported this finding in > 75% of simulated cases; scenarios favoring enoxaparin included those with > 4% post-discharge event rates. Aspirin versus no prophylaxis demonstrated a favorable ratio of $106,601 per quality-adjusted life year. Findings were vulnerable to a post-discharge thromboembolism rate < 1%, aspirin-associated bleeding rate > 1%, median hospital costs of bleeding > 3 × , and decreased efficacy of aspirin (RR > 0.75). The average out-of-pocket cost of choosing an aspirin ePpx strategy increased by $54 per patient versus $708 per patient with enoxaparin.

CONCLUSIONS

Low-dose aspirin extended prophylaxis following inflammatory bowel disease surgery has a favorable cost-safety profile and may be an attractive alternative approach.

Global Research Status and Trends in Venous Thromboembolism After Hip or Knee Arthroplasty From 1990 to 2021: A Bibliometric Analysis

Background

Venous thromboembolism (VTE) after hip or knee arthroplasty has attracted increasing attention over the past few decades. However, there is no bibliometric report on the publications in this field. The purpose of this study was to analyze the global research status, hotspots, and trends in VTE after arthroplasty.

Methods

All articles about VTE research after hip or knee arthroplasty from 1990 to 2021 were retrieved from the Web of Science Core Collection database. The information of each article including citation, title, author, journal, country, institution, keywords, and level of evidence was extracted for bibliometric analysis.

Results

A total of 1,245 original articles from 53 countries and 603 institutions were retrieved. The USA contributed most with 457 articles, followed by England and Canada. McMaster University in Canada was the leading institution for publications. The journals with the highest output and citation were the Journal of Arthroplasty and the Thrombosis and Haemostasis, respectively. The median number of citations was significantly different among the levels of evidence (F = 128.957, P < 0.001). The research hotspots switched from VTE diagnosis and heparin to factor Xa inhibitors (fondaparinux, rivaroxaban, apixaban) and direct thrombin inhibitors (dabigatran etexilate, ximelagatran), and finally to aspirin, risk factor studies, which can be observed from the keyword analysis and co-cited reference cluster analysis.

Conclusions

This study observed an increasing trend of research articles on VTE after arthroplasty. Publications with higher levels of evidence gained further popularity among researchers and orthopedic surgeons. Additionally, individualized VTE prevention and the development of new, safe, effective, and inexpensive oral agents would be emerging trends in the future.

Aspirin Is an Effective Prophylaxis for Venous Thromboembolism in Ambulatory Patients with Femoral Neck Fracture Undergoing Hip Arthroplasty

BACKGROUND

Although aspirin has been adopted as an effective and safe prophylaxis against venous thromboembolism (VTE) by the arthroplasty community, the role of aspirin in the prevention of VTE in the setting of arthroplasty for trauma remains insufficiently known. Therefore, the present multicenter study investigated the efficacy of aspirin as VTE prophylaxis for patients with femoral neck fracture undergoing total hip arthroplasty or hemiarthroplasty.

METHODS

We reviewed the medical records of 1,141 patients with femoral neck fracture who underwent total hip arthroplasty or hemiarthroplasty from 2008 to 2018 at 3 different institutions. Data on patient demographic characteristics, body mass index, history of VTE, and comorbidities were obtained from an electronic chart query and were confirmed by reviewing the medical records manually. Patients were allocated to cohorts based on the type of prophylaxis administered: aspirin (n = 454) and other anticoagulants (n = 687). Patients were then propensity score-matched on the basis of the risk score calculated using a previously validated tool and the remaining confounding variables. The primary outcome was the development of symptomatic VTE, namely deep vein thrombosis (DVT) or pulmonary embolism (PE) confirmed by appropriate imaging, within 90 days after the surgical procedure. A bivariable analysis was performed.

RESULTS

The overall VTE rate was 1.98% for patients who received aspirin compared with 6.7% for patients who received other anticoagulants (p < 0.001). After propensity score matching and regression modeling, aspirin was found to be noninferior to more potent anticoagulation in preventing VTE after both total hip arthroplasty and hemiarthroplasty.

CONCLUSIONS

Aspirin is an effective option for VTE prophylaxis in patients with femoral neck fracture who undergo hip arthroplasty. Based on the patient management benefits of aspirin for elective arthroplasty and the present study, we suggest its use in standard-risk ambulatory patients.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Venous Thromboembolism Prophylaxis and Hormonal Contraceptive Management Practice Patterns in the Perioperative Period for Anterior Cruciate Ligament Reconstruction

Purpose

To evaluate the venous thromboembolism (VTE) prophylaxis practices of surgeons performing anterior cruciate ligament reconstruction (ACLR) in female patients using hormonal contraceptives.

Methods

Our research team designed an investigational survey using branching logic that was made available to the AANA membership. The survey was designed to identify clinical decision making regarding VTE prophylaxis after ACLR in patients without risk factors for VTE, the counseling of patients about VTE risk associated with hormonal contraceptives, and the use of VTE prophylaxis after ACLR in patients taking hormonal contraceptives.

Results

Ninety-four respondents completed the survey. Eighty-nine respondents identified their gender (63% male and 37% female respondents). Respondents reported performing the following number of ACLRs annually: more than 50 (40%), 30 to 50 (29%), 15 to 30 (29%), and fewer than 15 (2%). Of the respondents, 62 (67%) reported that VTE developed after ACLR in their patients (male patients only, 32%; female patients only, 24%; and both male and female patients, 34%). Sixty-seven percent used chemoprophylaxis after ACLR. Surgeons who asked about hormonal contraceptive use were more likely to be women (P = .01; odds ratio [OR], 4.2). Surgeons who changed their VTE prophylaxis plan as a result of asking about hormonal contraceptive use were more likely to be women (P = .02; OR, 2.8). Surgeons who asked about hormonal contraceptive use were more likely to have female patients with VTE after ACLR (P = .03; OR, 2.9). Surgeons who changed their VTE prophylaxis plan as a result of asking about hormonal contraceptive use were more likely to have female patients with VTE after ACLR (P = .001; OR, 4.6).

Conclusions

There is no standard of care for VTE prophylaxis after ACLR. A surgeon’s own gender and prior clinical experience with VTE after ACLR may influence his or her likelihood to consider a patient’s hormonal contraceptive use regarding VTE risk after ACLR.

Clinical Relevance

The use of hormonal contraception is a risk factor for VTE in female patients undergoing ACLR. It is important to identify current practice patterns and the need for a standard of care.

Electronic Health Record Risk-Stratification Tool Reduces Venous Thromboembolism Events in Surgical Patients

Background

Venous thromboembolism is a preventable cause of morbidity and mortality after surgery. To ensure that patients receive appropriate venous thromboembolism chemoprophylaxis, a nonmandatory risk-stratification tool based on patient clinical condition was implemented through the electronic health record to stratify patient risk and recommend chemoprophylaxis. We hypothesized that implementing this tool would reduce postoperative venous thromboembolism events in general surgery as well as across all surgical services.

Methods

All adult patients undergoing inpatient surgical operations (January 2012–December 2019) at a single quaternary care center and Level 1 trauma center were abstracted from institutional electronic health record database and stratified into patients admitted before and after venous thromboembolism risk-stratification tool implementation. Bivariable analyses compared venous thromboembolism chemoprophylaxis prescription and venous thromboembolism events with implementation and screening among all surgical patients as well as in general surgery patient subset.

Results

A total of 64,377 adults underwent operations: 27,819 preimplementation and 36,558 postimplementation. A significant reduction in venous thromboembolism events occurred from pre- to post-tool implementation for all cases (0.77% vs 0.47%, P < .001). General surgery patients (n = 15,723) had a significant increase in chemoprophylaxis prescription (81.9% vs 86.0%, P < .001) and a significant reduction in venous thromboembolism events (1.41% vs 0.59%, P < .001). After tool implementation, use of extended postdischarge chemoprophylaxis was greater among general surgery patient subset than the entire patient cohort (46.7% vs 29.6%, P < .001).

Conclusion

The integration of a nonmandatory electronic health record risk-stratification tool was associated with a significant reduction in venous thromboembolism events. Extended chemoprophylaxis was prescribed in nearly half of general surgery patients at very high risk for postdischarge events.

•

Implementing an electronic VTE risk-stratification tool reduced surgical VTE events.

•

Even as a nonmandatory tool, risk stratification led to overall fewer VTE events.

•

Postoperative VTE events were reduced by 39% after the tool was integrated in EHR.

•

With the tool, general surgery had 58% less VTE events and improved prophylaxis use.

Does the publication of NICE guidelines for venous thromboembolism chemical prophylaxis influence the prescribing patterns of UK hip and knee surgeons?

INTRODUCTION

We assessed the practice of surgeons regarding venous thromboembolism (VTE) chemical prophylaxis for total hip replacement (THR) and total knee replacement (TKR), before and after issuing of updated National Institute for Health and Care Excellence (NICE) guidance in 2018.

METHODS

A survey, circulated through the British Hip Society and regional trainee networks/collaboratives, was completed by 306 UK surgeons at 187 units. VTE chemical prophylaxis prescribing patterns for surgeons carrying out primary THR (n=258) and TKR (n=253) in low-risk patients was assessed after publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored.

RESULTS

Following the new guidance, 34% (n=87) used low-molecular-weight heparin (LMWH) alone, 33% (n=85) aspirin (commonly preceded by LMWH) and 31% (n=81) direct oral anticoagulants (DOACs: with/without preceding LMWH) for THR. For TKR, 42% (n=105) used aspirin (usually monotherapy), 31% (n=78) LMWH alone and 27% (n=68) DOAC (with/without preceding LMWH). NICE guidance changed the practice of 34% of hip surgeons and 41% of knee surgeons, with significantly increased use of aspirin preceded by LMWH for THR (before=25% vs after=73%; p<0.001), and aspirin for TKR (before=18% vs after=84%; p<0.001). Significantly more regimens were NICE guidance compliant after the 2018 update for THR (before=85.7% vs after=92.6%; p=0.011) and TKR (before=87.0% vs after=98.8%; p<0.001).

CONCLUSION

Over one-third of surveyed surgeons changed their VTE chemical prophylaxis in response to 2018 NICE recommendations, with more THR and TKR surgeons now compliant with latest NICE guidance. The major change in practice was an increased use of aspirin for VTE chemical prophylaxis.

Perioperative air travel increases the risk of venous thromboembolism following lower limb arthroplasty

Purpose

Venous thromboembolism (VTE) is a significant complication following lower limb arthroplasty (LLA). There is a paucity of evidence with regard to air travel following LLA. Orthopaedic surgeons are often asked by patients regarding air travel following LLA, and there is a need for evidence to guide these patients.

Methods

This was a retrospective cohort study. We identified two cohorts, one travelling to and from the hospital by air and another, by land. All patients received routine preoperative and post-operative care, and thromboprophylaxis, as per our hospital guidelines. We collected baseline demographics, ASA score and incidence of VTE at 90 days using local patient records and a national joint registry. We also recorded data on flight time and overland distance of travel.

Results

Two hundred and forty-three patients travelled by air; mean flight time was 74 min. In total, 5498 patients travelled a mean 25.3 miles over land to the hospital. No differences in baseline demographics or ASA score were observed. Four patients developed a VTE in the flight group, with 32 patients suffering a VTE in the control group. There was a significant difference in the VTE rate between the flight and control groups (p < 0.05); the relative risk of developing a VTE in the flight group was 2.85.

Conclusions

In our cohort, perioperative short haul air travel is associated with an increased risk of VTE at 90 days following LLA. Orthopaedic surgeons must ensure that their patients are cognizant of the risks associated with perioperative air travel and take measures to minimise these risks.

New Oral Anticoagulants for Venous Thromboembolism Prophylaxis in Total Hip and Knee Arthroplasty: A Systematic Review and Network Meta-Analysis

Background: There is controversy over whether use of new oral anticoagulants (NOACs) associates with increased hemorrhage risk compared with non-NOAC. Meanwhile, determining which NOAC to use remains unclear. We aimed to summarize the evidence about NOACs in venous thromboembolism (VTE) prevention for patients with total hip and knee arthroplasty (THA and TKA).

Methods: We searched RCTs assessing NOACs for VTE prophylaxis in adults undergoing THA and TKA in Medline, Embase, and Cochrane up to May 2021. Primary outcomes were VTE [included deep vein thrombosis (DVT) and pulmonary embolism (PE)], major VTE, and major bleeding. The rank probabilities of each treatment were summarized by the surface under the cumulative ranking curve area (SUCRA).

Results: 25 RCTs with 42,994 patients were included. Compared with non-NOAC, NOACs were associated with a decreased risk of VTE (RR 0.68; 95% CI 0.55–0.84) and major VTE (RR = 0.52; 95% CI 0.35–0.76). Additionally, rivaroxaban, apixaban, and edoxaban but not dabigatran and betrixaban, did confer a higher efficacy compared with non-NOAC. None of the individual NOACs increased the risk of bleeding, while apixaban and betrixaban were even associated with a decreased risk of bleeding. In the comparison of different NOACs, rivaroxaban was associated with the greatest benefits in VTE (SUCRA = 79.6), DVT (SUCRA = 88.8), and major VTE (SUCRA = 89.9) prevention. Furthermore, subgroup analysis confirmed that NOACs associated with a higher efficacy tendency in patients with follow-up duration <60 days than follow-up duration ≥60 days.

Conclusion: Evidence suggests that NOACs exert more benefits on VTE prophylaxis, and none of the individual NOACs increased hemorrhage compared with non-NOAC. Among various NOACs, rivaroxaban is recommended in patients with lower bleeding risk, and apixaban is recommended in patients with higher bleeding risk.

Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021266890].

Deep vein thrombosis after major orthopedic surgery in Taiwan: A prospective cross-sectional study and literature review

BACKGROUND/PURPOSE

Postoperative venous thromboembolism is an important complication in Taiwan. We prospectively investigated the occurrence of deep vein thrombosis (DVT) after major orthopedic surgery without pharmacologic thromboprophylaxis in a cohort of 120 patients (46 males, 74 females, median age 71 years) at our institute.

METHODS

Color duplex compression ultrasonography (CUS) was used to detect DVT before and after the operation, while contrast venography was performed postoperatively for comparison and validation.

RESULTS

Total knee arthroplasty (TKA, 57 cases) and total hip arthroplasty (23 cases) were the most commonly performed operations. The rate of postoperative DVT was 7.5% (9/120), including five with proximal DVT and four with distal DVT. All were detected in the limbs on the operated side. Four of them were symptomatic DVT cases. Venography was performed in 19 patients and confirmed most findings of CUS, indicating the effectiveness of CUS for detecting DVT. The type of surgery (TKA) was significantly correlated with postoperative DVT. No clinically symptomatic pulmonary embolism or sudden death events were noted.

CONCLUSION

Nine out of 120 (7.5%) orthopedic patients without pharmacologic thromboprophylaxis developed postoperative sonographic DVT in our study. The DVT rate is consistent with other reports from various Asian countries and evidence from meta-analyses.

Association Between Simultaneous Bilateral Total Hip Arthroplasty Without Any Anticoagulant or Antiplatelet Therapy and Deep Venous Thrombosis: A Cohort Study

Background

The association of simultaneous bilateral total hip arthroplasty (THA) with postoperative deep venous thrombosis (DVT) remains controversial. The aim of the study is to determine whether simultaneous bilateral THA without chemoprophylaxis has a higher risk than unilateral THA without chemoprophylaxis.

Methods

This is a population-based retrospective cohort study of all adults who underwent primary THA without any anticoagulant or antiplatelet therapy between July 2012 and March 2021 at the Department of Orthopedic Surgery, Toranomon Hospital, Tokyo, Japan. The association of simultaneous bilateral THA with postoperative DVT was examined by unadjusted analysis and overlap propensity score weighting. The primary outcome was the incidence of DVT (confirmed by ultrasonography of the lower limb veins) within 7 days postoperatively.

Results

Of the 557 consecutive patients who underwent primary THA in the study period, 458 met the inclusion criteria. The mean (standard deviation) age of these patients was 67 (11.7) years, and 364 (79.5%) were women; 75 (16.4%) of the 458 patients underwent simultaneous bilateral THA, and 383 (83.6%), unilateral THA. A total of 64 patients (14.0%) developed a postoperative venous thromboembolism, all of which were a distal DVT. The overlap weighting analysis found no significant difference in the incidence of postoperative DVT complications among patients who underwent simultaneous bilateral THA and those who underwent unilateral THA (31.1 [13.6%] vs 22.9 [10.0%], respectively; risk ratio, 1.36; 95% confidence interval, 0.67 to 2.77; P = .40).

Conclusions

Our findings indicate that the occurrence of DVT within 7 days after surgery is not significantly different between patients undergoing simultaneous bilateral THA or unilateral THA without any anticoagulant or antiplatelet therapy.

Level of Evidence

Level II-III.

Association between osteoporosis or osteopenia and taking antiplatelet agents in general US population of NHANES

BACKGROUND

Osteoporosis (OP) and osteopenia are common bone disorders in old age, and lots of patients suffering from OP or osteopenia need to take antiplatelet agents to treat basic diseases. However, clinical data on the link between osteopenia or OP and antiplatelet agents are limited.

METHODS

Data in this study were collected and screened from the NHANES from 2013 to 2014 and 2017 to 2018. The variables were extracted from interviews and compared between OP or osteopenia participants and normal. The relationship between OP or osteopenia and taking antiplatelet drugs was analyzed by weighted multivariate logistic regression.

RESULTS

After excluding individuals who were not eligible and had invalid data, we finally identified 894 participants for inclusion in the study. We found a negative association between OP or osteopenia and taking antiplatelet agents (OR = 0.53; 95% CI, 0.33-0.84; p < 0.05). These results did not change on multiple imputations (OR = 0.32, 95% CI, 0.19-0.56; p <0.01). In the subgroup analyses, the associations were more significant in women (OR = 0.18, 95% CI, 0.05-0.62; p <0.05).

CONCLUSION

This study demonstrated that the association between OP or osteopenia and taking antiplatelet agents was significant. Therefore, it is necessary to confirm the result by extending further research.

Aspirin thromboprophylaxis in joint replacement surgery

BACKGROUND

Aspirin is commonly used as the only pharmacologic agent for prevention of venous thromboembolism (VTE) after joint replacement surgery in the United States. Despite this, prospective studies investigating VTE events after aspirin-only thromboprophylaxis in joint replacement surgery are lacking in the real-world setting.

OBJECTIVES

The aim of this study was to estimate the risk of VTE with aspirin-only pharmacologic prophylaxis following joint replacement surgery.

METHODS

We carried out a prospective observational study of 350 low-risk patients (no prior history of VTE and low cardiovascular risk factors) who underwent total knee and total hip arthroplasty and received only aspirin for thromboprophylaxis postoperatively.

RESULTS

The observed risk of symptomatic VTE was 1.7% (95% confidence interval, 0.9%-3.3%) over 3 months of follow up, with only one major bleeding event and no surgical hematomas.

CONCLUSION

The risk of VTE with aspirin monotherapy for thromboprophylaxis in joint replacement surgery in this real-world cohort was higher than previously reported.

Efficacy and Safety of Thromboprophylaxis Post-Orthopedic Surgery

Given the high risk of venous thromboembolism (VTE) post-orthopedic surgery and the vital role of thromboprophylaxis in preventing VTEs, this meta-analysis aimed to assess the efficacy of thromboprophylaxis post major orthopedic surgery and the relevant safety measures. In this review, we conducted a computer-aided search of Google Scholar, PubMed, CINAHL, Cochrane, Medline, and EMBASE databases. We included all published randomized clinical trials (RCTs) that utilized enoxaparin, fondaparinux, dabigatran, rivaroxaban, apixaban, and aspirin for VTE prophylaxis in patients undergoing total hip arthroplasty (THA), hip fracture surgery, and total knee arthroplasty (TKA) based on primary and secondary outcomes. The Cochrane Collaboration tool was used to evaluate the risk of bias. All statistical analyses were performed using Review Manager Software. A total of 23 RCTs were included with a total sample of 48,424 patients and an overall low risk of bias. The efficacy of enoxaparin in preventing VTEs in the TKA group was significantly better than fondaparinux. In the THA group, the efficacy of enoxaparin was significantly better than apixaban. The efficacies of fondaparinux, dabigatran, rivaroxaban, apixaban, and aspirin were comparable to that of enoxaparin in reducing VTE-associated mortality, major bleeding, and adverse events. In conclusion, we found that all included drugs were non-inferior to enoxaparin in VTE-associated mortality, major bleeding, and adverse events.

Aspirina versus rivaroxabana na prevenção do tromboembolismo venoso após artroplastia total do joelho: Um ensaio clínico randomizado, controlado e duplo-cego

Objetivo A aspirina (ácido acetilsalicílico, AAS) e a rivaroxabana são anticoagulantes que vêm ganhando popularidade devido à facilidade de uso na prevenção do tromboembolismo venoso (TEV) após artroplastia total do joelho (ATJ). Este estudo teve como objetivo avaliar a eficácia do AAS em comparação com a da rivaroxabana na profilaxia de TEV em pacientes submetidos a ATJ.

Método Quarenta pacientes com osteoartrite primária do joelho, que seriam submetidos a ATJ, foram randomizados em dois grupos. No total, 20 pacientes do grupo AAS usaram aspirina oral, na dose de 300 mg/dia, para a profilaxia do TEV após ATJ; e 20 pacientes do grupo rivaroxabana receberam uma dose oral de 10 mg/dia. No 4° e 14° dias do pós-operatório, trombose venosa profunda (TVP) dos membros inferiores no lado da cirurgia foi detectada por meio de ultrassonografia duplex. Foram registradas outras complicações durante catorze dias.

Resultados Não foram detectados achados positivos de TVP com a ultrassonografia duplex nos grupos de pacientes, e não se observou a ocorrência de embolia pulmonar. No total, 4 pacientes apresentaram equimose subcutânea no 4° dia do pós-operatório (2 pacientes no grupo AAS e 2 pacientes no grupo rivaroxabana; p = 1,0), e outros 4 pacientes, no 14° dia do pós-operatório (1 paciente no grupo AAS e 3 pacientes no grupo rivaroxabana; p = 0,292). Nenhum paciente da amostra apresentou hematoma da ferida cirúrgica, sangramento de órgão importante, infecção da ferida, ou necessidade de nova cirurgia.

Conclusão A aspirina e a rivaroxabana apresentaram eficácia comparável na prevenção do TEV, sem aumentar a incidência de complicações da ferida e sangramento após ATJ.

A risk-stratified approach to venous thromboembolism prophylaxis with aspirin or warfarin following total hip and knee arthroplasty: A cohort study

INTRODUCTION

Venous thromboembolism (VTE) and bleeding events following total knee and hip arthroplasty (TKA/THA) are associated with significant morbidity. Clinical guidelines recommend administration of pharmacologic VTE prophylaxis post-operatively, although controversy exists regarding optimal prophylactic strategies.

METHODS

We performed a retrospective cohort study in patients who underwent elective TKA/TKA in an academic medical center. Patients were stratified by surgery type (TKA/THA) and VTE risk determined by a novel risk stratification protocol and compared pre- and post-protocol implementation. Patients received warfarin pre-protocol and either aspirin or warfarin post-protocol for VTE prophylaxis. Natural language processing identified VTE events and ICD codes were used to identify bleeding events, with all events validated manually.

RESULTS

A total of 1379 surgeries were included for analysis, 839 TKAs and 540 THAs. Post-protocol implementation, 445 (94.1%) patients following TKA and 294 (97.4%) patients following THA received aspirin for VTE prophylaxis. A significant reduction in bleeding events (hazard ratio [HR] = 0.19, p = 0.048) was observed in low-risk THA patients treated with aspirin (post-protocol) compared patients treated with warfarin (pre-protocol). Bleeding events did not differ significantly between low-risk TKA patients treated with aspirin or warfarin. No significant differences in VTE events were observed following the protocol implementation.

CONCLUSIONS

The use of a novel risk stratification system to guide VTE prophylaxis selection between aspirin or warfarin following TKA and THA appears safe and effective. Among low-risk patients, aspirin use was associated with fewer bleeding events following THA, without an observed increase in VTE events.