Cost-effective prophylaxis against venous thromboembolism after total joint arthroplasty: warfarin versus aspirin

The Financial Burden of Aspirin versus Oral Factor Xa Inhibitors for Thromboprophylaxis Following Total Knee Arthroplasty

BACKGROUND

Aspirin and oral factor Xa inhibitor thromboprophylaxis regimens are associated with similarly low rates of venous thromboembolism following total knee arthroplasty (TKA). However, the rate of prosthetic joint infection (PJI) is lower with aspirin use. This study aimed to compare the cost differential between aspirin and factor Xa inhibitor thromboprophylaxis with respect to PJI management.

METHODS

We used previously published rates of PJI following aspirin and factor Xa inhibitor thromboprophylaxis in primary TKA patients at a single, large institution. Prices for individual drugs were obtained from our hospital's pharmacy service. The cost of PJI included that of 2-stage septic revision, with or without the cost of 1-year follow-up. National data were obtained to determine annual projected TKA volume.

RESULTS

The per-patient costs associated with a 28-day course of aspirin versus factor Xa inhibitor thromboprophylaxis were $17.36 and $3,784.20, respectively. Including cost of follow-up, per-patient costs for a 28-day course of aspirin versus factor Xa inhibitors increased to $73,358.76 and $77,125.60, respectively. The weighted average per-patient costs for a 28-day course were $237.38 and $4,370.93, respectively. The annual cost difference could amount to over $14.1 billion in the United States by 2040.

CONCLUSIONS

The per-patient cost associated with factor Xa inhibitor thromboprophylaxis is as much as 1,980.6% higher than that of an aspirin regimen due to increased costs of primary treatment, differential PJI rates, and high costs of management. In an era of value-based care, the use of aspirin is associated with major cost advantages.

Aspirin prophylaxis is not associated with increased risk of venous thromboembolism in arthroplasty for femoral neck fractures: a non-inferiority study

PURPOSE

Venous thromboembolism (VTE) is a known complication of hip arthroplasty for femoral neck fractures (FNF) with various prophylactic anticoagulants utilized to decrease risk. The purpose of this study was to assess the efficacy and perioperative outcomes associated with aspirin for VTE prophylaxis following arthroplasty for FNF.

METHODS

Medical records of 1,220 patients who underwent hip hemiarthroplasty (HHA) or total hip arthroplasty (THA) at an urban academic center from 2011 to 2022 were retrospectively reviewed. Patient characteristics and perioperative outcomes, including length of stay (LOS), VTE, 90-day hospital encounters, and discharge disposition, were collected. Outcomes for patients prescribed aspirin (n = 214) were compared to those prescribed non-aspirin VTE prophylaxis (n = 1006) using propensity score matching.

RESULTS

Patients who received aspirin had higher rates of THA (36.0 vs 26.7%; p = 0.008). There were no significant risk-adjusted differences in the incidence of VTE (0.5 vs 0.5%, p = 1.000) and 90-day readmissions (10.4 vs 12.3%, p = 0.646) between patients prescribed aspirin and non-aspirin VTE prophylaxis, respectively. Patients prescribed non-aspirin agents had higher rates of non-home discharge (73.9 vs 58.5%; p < 0.001) and longer LOS (143.5 vs 124.9 h; p = 0.005). Sub-analysis of patients prescribed aspirin and non-aspirin prophylaxis based on comorbidity scores demonstrated no difference in VTE incidence for low (0.0 vs 1.6%, p = 1.000) and high scores (0.0 vs 0.0%, p = 1.000), respectively.

CONCLUSION

Aspirin is not associated with increased incidence of VTE after HHA or THA for FNF. Aspirin prophylaxis should be considered in hip fracture patients to mitigate bleeding risk, particularly those with low to intermediate VTE risk.

LEVEL OF EVIDENCE

Level III, Retrospective study.

Aspirin is a safe and effective thromboembolic prophylaxis after total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Patients undergoing total knee arthroplasty (TKA) are at high risk for thromboembolic events compared to non-surgical patients. Both anticoagulants and antiplatelet agents are used as antithrombotic prophylaxis in TKA. The aim of this review is to understand the role of aspirin in the prevention of thromboembolic events and to compare its efficacy and safety with the main anticoagulants used in antithromboembolic prophylaxis in TKA.

METHODS

A systematic review and meta-analysis was performed according to the PRISMA guidelines. An electronic systematic search was conducted using PubMed, Scopus, and the Cochrane Central Registry to evaluate studies that compared aspirin with other anticoagulants, in terms of deep venous thrombosis and pulmonary embolism after TKA. The meta-analysis compared the rate of complications between aspirin and other anticoagulants.

RESULTS

Thirteen studies were included in the systematic review for a total of 163,983 patients, and 10 studies were included in the meta-analysis. The meta-analysis demonstrated no statistically significant differences between aspirin and other anticoagulants in terms of the rate of deep venous thrombosis (OR 0.93, 95% CI 0.81-1.08, p = 0.35) and pulmonary embolism (OR 0.89, 95% CI 0.56-1.41, p = 0.61).

CONCLUSION

Aspirin is safe, effective, and not inferior to other main anticoagulants in preventing thromboembolic events following TKA.

Study on the safety and effectiveness of low-dose vs. regular-dose fondaparinux in preventing venous thromboembolism prophylaxis following total knee arthroplasty

Background

This study aims to evaluate the effectiveness and safety of low-dose (1.5 mg) fondaparinux for venous thromboembolism (VTE) prophylaxis in patients post-total knee arthroplasty (TKA).

Methods

We retrospectively identified 314 patients who carried out the primary TKAs and received fondaparinux for VTE chemoprophylaxis between July 2020 and December 2021. A total of 141 TKA patients were excluded according to the exclusion criteria. Two groups of patients were established: the low-dose group included 84 patients who injected 1.5 mg of fondaparinux, and the regular-dose group included 89 patients who injected 2.5 mg of fondaparinux. The pre-operative blood analysis and coagulation assays were performed. The surgical time, the incidence of symptomatic VET, blood loss, wound complication, bleeding, drainage, and mortality of patients were determined and assessed.

Results

The pre-operative blood analysis, body mass index, sex, age, and coagulation assays of patients in both groups were comparable. In terms of symptomatic pulmonary embolism and deep vein thrombosis, there was no significant difference (variation) between the two groups. However, patients in both groups showed a substantial difference in terms of blood loss, drain volume, wound complication, and transfusion rate.

Conclusion

In prevention of VET in patients post-TKA, low-dose fondaparin is as effective as conventional dose fondaparinux. A significant decrease in blood loss, post-surgical transfusion rates, and wound complications were detected in patients given low-dose fondaparinux compared to those receiving regular-dose fondaparinux.

Discontinued Use of Outpatient Portable Intermittent Pneumatic Compression Devices May Be Safe for Venous Thromboembolism Prophylaxis in Primary Total Knee Arthroplasty Using Low-Dose Aspirin

Venous thromboembolism (VTE) is a rare, but serious complication following total knee arthroplasty (TKA). Current VTE guidelines recommend pharmacologic agents with or without intermittent pneumatic compression devices (IPCDs). At our institution, both 81-mg aspirin (ASA) twice a day (BID) and portable IPCDs were previously prescribed to TKA patients at standard risk for VTE, but the IPCDs were discontinued and patients were treated with ASA alone going forward. The aim of this study is to determine if discontinued use of outpatient IPCDs is safe and does not increase the rate of VTE or any other related complications in patients following TKA. A retrospective review of 2,219 consecutive TKA cases was conducted, identifying patients with VTE, bleeding complications, infection, and mortality within 90 days postoperatively. Patients were divided into two cohorts. Patients in cohort one received outpatient IPCDs for a period of 14 days (control), while those in cohort two did not (ASA alone). All study patients received inpatient IPCDs and were maintained on 81-mg ASA BID for 28 days. A posthoc power analysis was performed using a noninferiority margin of 0.25 (α = 0.05; power = 80%), which showed that our sample size was fully powered for noninferiority for our reported deep vein thrombosis (DVT) rates, but not for pulmonary embolism (PE) rates. A total of 867 controls and 1,352 patients treated with ASA alone were identified. Only two control patients were diagnosed with a PE (0.23%), while one patient in the ASA alone group had DVT (0.07%). There was no statistical difference between these rates (p = 0.33). Furthermore, no differences were found in bleeding complications (p = 0.12), infection (p = 0.97), or 90-day mortality rates (p = 0.42) between both groups. The discontinued use of outpatient portable IPCDs is noninferior to outpatient IPCD use for DVT prophylaxis. Our findings suggest that this protocol change may be safe and does not increase the rate of VTE in standard risk patients undergoing TKA while using 81-mg ASA BID.

Aspirin monotherapy is a suitable standard thromboprophylactic agent following total hip arthroplasty

INTRODUCTION

Aspirin is increasingly recognised as an efficacious thromboprophylactic agent with a superior safety profile compared to alternatives. Following our institution's previously published experience we implemented a risk-stratified protocol utilising aspirin as standard. We now present retrospective review of standard use of aspirin on fatal pulmonary embolism, all-cause mortality, and venous thromboembolism (VTE) following total hip arthroplasty (THA).

METHODS

A consecutive series of elective THAs was identified. Prospectively maintained databases were analysed to yield demographic data and identify deaths or readmission data. Patients who died within 90 postoperative days underwent review of the complete medical record.

RESULTS

4204 THAs were included in the study cohort. VTE prophylaxis prescription was available in 3805. 2560 received aspirin (67.3%), 1049 enoxaparin (27.6%) and 193 warfarin (5.1%); there were no differences in 90-day all-cause mortality (p = 0.780) or VTE (p = 1) between groups.

CONCLUSION

Our large series continues to demonstrate that aspirin for thromboprophylaxis following THA is effective in risk-stratified patients. Furthermore, we demonstrate that introduction of a departmental protocol establishing aspirin as standard practice was not associated with increased mortality or incidence of thromboembolism. Taken in conjunction with our previous cohort our series encompasses 11,420 consecutive THAs. There has been a single death following fatal PE in the aspirin group (0.02%) compared to 5 in the LMWH group (0.2%) and 1 in the warfarin group (0.06%). We join calls for large-scale randomised controlled trials to elucidate the place of aspirin in VTE prevention following hip arthroplasty.

Aspirin Thromboprophylaxis Is Associated With Less Major Bleeding Events Following Total Joint Arthroplasty

BACKGROUND

There is ongoing debate on what is optimal prophylactic agent to reduce venous thromboembolism (VTE) following total joint arthroplasty (TJA). Although many studies assess the efficacy of these agents in VTE prevention, no attention is given to their adverse effect on major bleeding events (MBEs). This study compared the incidence of MBE in patients receiving aspirin as VTE prophylaxis vs other chemoprophylaxis.

METHODS

A single-institution, retrospective study of 35,860 patients undergoing TJA between 2009 and 2020 was conducted. Demographic variables, co-morbidities, type of chemoprophylaxis, and intraoperative factors were collected. MBE was defined using the 2010 criteria for major bleeding in surgical patients presented by the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. To enhance capture rate, comprehensive queries utilizing MBE keywords were conducted in clinical notes, physician dictations, and phone call logs. Univariate followed by multivariate regression was performed as well as propensity score matched analysis.

RESULTS

Overall, 270 patients (0.75%) in this cohort developed MBE. The MBE rate was 0.5% in the aspirin group and 1.2% in the non-aspirin group. After adjusting for confounders, multiple logistic regression and propensity score matched analysis revealed almost 2 times lower odds of MBE in patients who received aspirin. Variables independently associated with increased MBE risk included increasing age, body mass index, American Society of Anesthesiologists score, revision surgery, peptic ulcer disease, coagulopathy, intraoperative blood transfusion, and active smoking.

CONCLUSION

Administration of aspirin for VTE prophylaxis, compared to other chemoprophylaxis agents may have an association with lower risk of major bleeding following TJA. Future randomized controlled trials should examine these findings.

Non-Inferiority of Aspirin for Venous Thromboembolism Prophylaxis After Hip Arthroplasty in a Statewide Registry

BACKGROUND

Uncertainty remains surrounding the use of aspirin as a sole chemoprophylactic agent to reduce the risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) and bleeding after primary total hip arthroplasty.

METHODS

We performed a non-inferiority analysis of a retrospective cohort of patients undergoing total hip arthroplasty from April 1, 2013 to December 31, 2018. Cases were retrieved from the Michigan Arthroplasty Registry Collaborative Quality Initiative database and performed by 355 surgeons at 61 hospitals throughout Michigan. Surgical setting ranged from small community hospitals to large academic and non-academic centers. The primary outcomes were post-operative venous thromboembolism event or death and bleeding event.

RESULTS

Of the 59,747 patients included, 32,878 (55.03%) were female, and the mean age was 64.5. A total of 462 (0.77%) composite venous thromboembolism events occurred. There were 221 (0.71%) and 129 (0.80%) venous thromboembolism events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for composite venous thromboembolism events (odds ratio 0.99, 95% confidence interval 0.79-1.26, P < .001). Bleeding events occurred in 767 (1.28%) patients, with 304 (0.97%) and 281 (1.74%) bleeding events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for bleeding events (odds ratio 0.62, 95% confidence interval 0.52-0.74, P < .001).

CONCLUSION

Aspirin is not inferior to other anticoagulants as pharmacologic venous thromboembolism prophylaxis with regards to post-operative risk of venous thromboembolism or bleeding. Sole use of aspirin for venous thromboembolism prophylaxis after total hip arthroplasty should be considered in the appropriate patient.

Legal Implications in the Care of Orthopedic Patients: Serious Complications

To help reduce potentially devastating outcomes from spinal complications and venous thromboembolism, it is essential for the bedside nurse to have a comprehensive understanding of risk factors and assessments. The orthopedic nurse carries a responsibility for accurately assessing, documenting, and mobilizing the team when abnormal changes occur. Nurses act as patient advocates. The bedside nurse must communicate with the physician. If a patient or family sues the health care team, after a careful screening of the case for merit, the legal process begins. A health care provider should never give in to the temptation to alter medical records.

Stratifying Venous Thromboembolism Risk in Arthroplasty: Do High-Risk Patients Exist?

BACKGROUND

While there are many possible complications associated with total joint arthroplasty (TJA), venous thromboembolism (VTE) is both frequent and potentially severe. Despite this importance, there are inconsistent recommendations for prophylaxis based on patient risk factors.

METHODS

A predictive model was constructed to compare low-molecular-weight heparin(LMWH) and aspirin (ASA) for prevention of VTE-associated complications following TJA.The model used risks from prior prophylaxis studies to estimate the risk of developing a symptomatic deep vein thrombosis, pulmonary embolism, thrombocytopenia, and operative or nonoperative site bleeding. We also evaluated the progression to 4 possible final health states: postphlebitis syndrome, intracranial hemorrhage, death, or baseline health. Within published ranges, we selected assumptions that were favorable to LMWH such that these analyses represent a best case scenario for LMWH or an alternative more aggressive low-molecular-weight heparin alternative (LMWHA). Events and outcomes were assigned quality-adjusted life-year (QALY) losses according to prior studies to determine the effect on patients' outcomes for ASA and LMWHA prophylaxis.

RESULTS

Assessing VTE risk populations from 0.2% to 2% with life expectancies ranging from 5 to 40 years postoperatively, patients with a risk ratio less than 3.7 showed increased expected QALY with ASA compared to LMWHA. For patients with a baseline VTE risk of 1% and a 15 year life expectancy, a risk ratio of 13.4 was needed to identify patients that would benefit from LMWHA. With life expectancy increased to 30 years, the risk ratio needed to idetify these patients was 7.4.

CONCLUSION

Patients undergoing TJA should receive ASA chemoprophylaxis in nearly all situations, unless the patient has a significantly increased VTE risk compared to the baseline population and a long life expectancy.

Low-Dose Aspirin Is Adequate for Venous Thromboembolism Prevention Following Total Joint Arthroplasty: A Systematic Review

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) are at risk of developing venous thromboembolism (VTE) without adequate prophylaxis. Since the American Academy of Orthopedic Surgeons issued guidelines in 2007 recommending aspirin 325 mg bis in die for 6 weeks, aspirin has been favored as the main VTE prophylaxis. However, the appropriate dose and duration of aspirin are not well-studied. This systematic review aims to identify any differences between high and low dose as well as duration for aspirin thromboprophylaxis after TJA as outlined by previous studies.

METHODS

A search was performed using Ovid MEDLINE, EMBASE, and PubMed, including articles up to July 2016. Studies were included if they contained at least 1 cohort that underwent TJA with aspirin as the sole chemoprophylaxis and reported either (1) symptomatic VTE or (2) secondary outcomes such as major bleeding or 90-day mortality.

RESULTS

Forty-five papers were included. There were no significant differences in symptomatic pulmonary embolism, symptomatic deep vein thrombosis, 90-day mortality, or major bleeding between patients receiving low-dose or high-dose aspirin. Patients treated with aspirin for <4 weeks had a higher risk of major bleeding (1.59%) vs patients treated for 4 weeks (0.15%), which may be attributed to premature cessation or differential reporting. Patients treated with aspirin for <4 weeks had a statistically higher 90-day mortality (1.95%) vs patients treated for 4 weeks (0.07%). There was no significant difference between incidence of pulmonary embolism or deep vein thrombosis and the durations of aspirin treatment.

CONCLUSION

This review suggests that low-dose aspirin is not inferior to high-dose aspirin for VTE thromboprophylaxis in TJA patients. Additionally, patients treated with aspirin for less than 4 weeks may have a higher risk of major bleeding and 90-day mortality compared to patients treated for a longer duration.

Thrombosis rates using aspirin and a compression device as multimodal prophylaxis for lower limb arthroplasty in a screened population

BACKGROUND

Venous thromboembolism (VTE) (Deep vein thrombosis (DVT), and pulmonary embolism (PE)), is a common complication in patients undergoing total joint arthroplasty (TJA). Recently, aspirin was recommended by the American Academy of Orthopaedic Surgeons (AAOS) as VTE prophylaxis following TJA. This study investigates VTE rates in TJA patients using as thromboprophylaxis.

METHODS

DVT was screened for in 396 consecutive total hip or knee arthroplasty procedures. Patients were treated with early mobilisation, calf compression device and 300 mg aspirin for 5 days and then 100 mg aspirin for 5 weeks. All patients received lower-limb duplex ultrasonography prior to discharge. Patients were clinically evaluated at 6 weeks post-op documenting any VTE.

RESULTS

51 TJA's (12.87%) were complicated by VTE: one proximal, 47 distal DVT and 3 PE. No fatal PE occurred. Only four DVT were symptomatic. Of 159 THA, 2 (1.25%) had VTE: one distal DVT and one PE. Of 237 TKA, 49 (20.67%) had VTE: 1 proximal, 46 distal DVT and 2 PE. Patients with a history of diabetes and those receiving TKA were at higher risk of DVT.

CONCLUSION

Multimodal VTE prophylaxis demonstrated a low rate of proximal DVT, PE and bleeding complications. The rate of asymptomatic DVT was high, but most were distal and unlikely to be clinically significant. Patients with diabetes and those receiving TKA could be at higher risk of asymptomatic DVT, and may benefit from closer clinical assessment. These findings suggest aspirin is safe and efficacious when used in combination with mechanical compressors and early mobilisation. However, our findings require further validation, particularly with larger, prospective comparative studies.

Intraoperative Practice Variability in Total Knee Arthroplasty

BACKGROUND

Considerable practice variability exists among orthopedic surgeons performing total knee arthroplasty (TKA). The purpose of this study is to understand what TKA surgical and perioperative techniques are standard among high-volume academic knee arthroplasty surgeons.

METHODS

A written survey with 59 questions regarding management preferences in TKA was distributed by the 2018 John N. Insall Traveling Fellows to all arthroplasty-trained attending physicians at 13 medical centers, with 45 responses recorded.

RESULTS

Surveyed surgeons performed unicompartmental knee arthroplasty (88%) and bilateral TKA (87%). Most surveyed surgeons rarely or never performed outpatient primary TKA (71%). Conventional alignment guides and cemented implants were used by 80% of respondents. Most surgeons used posterior-stabilized implants (67%), followed by cruciate-retaining (20%), ultracongruent (20%), and medial congruent or medial pivot designs (17.8%). Surveyed surgeons frequently or always resurfaced the patella (73%), used a tourniquet for the entire case (73%), and used tranexamic acid for all TKAs (91%). The most common locations for intra-articular anesthetic injection were the arthrotomy (91%), the periosteum (84%), and the medial posterior capsule (82%). Saline (62%) and dilute iodine (47%) were the most common irrigation fluids. The arthrotomy was most commonly closed with running barbed suture (60%) followed by interrupted vicryl (40%). Skin closure was predominantly with running monocryl (60%) followed by staples (29%). Anticoagulation for TKA was primarily aspirin 81 mg BID (60%).

CONCLUSION

There was considerable variability among surgeons polled although a strong preference for more conventional and less developmental techniques prevailed.

Highlighting the Roles of Anemia and Aspirin in Predicting Ninety-Day Readmission Following Aseptic Revision Total Joint Arthroplasty

BACKGROUND

Revision total joint arthroplasties (TJAs) are associated with an increased rate of complications. To date, it is unclear what drives readmission after aseptic revision arthroplasty and what measures can be taken to possibly avoid them. The purpose of this study is to (1) determine the reasons for readmission after aseptic revision TJA and (2) identify patient-specific or postoperative risk factors through a multivariate analysis.

METHODS

A retrospective study examined 1503 cases of aseptic revision TJA between 2009 and 2016 at an urban tertiary care hospital. Eighty-seven cases (5.8%) of readmission within 90 days of index surgery were identified. Bivariate and multivariate analyses were performed to assess independent risk factors for readmission.

RESULTS

The reasons for readmission were infection (38%), wound complications (22%), and dislocation/instability of the prosthetic joint (13%). Only preoperative anemia was associated with an increased odds ratio (OR) of readmission (OR 1.82, 95% confidence interval [CI] 1.126-2.970, P = .015), whereas postoperative venous thromboembolism prophylaxis with aspirin (OR 0.58, 90% CI 0.340-0.974, P = .039) and discharge to an inpatient rehab facility (OR 0.22, 95% CI 0.051-0.950, P = .042) were associated with significantly lower odds of readmission.

CONCLUSION

Based on this single institutional study, addressing preoperative anemia and considering the implementation of aspirin for venous thromboembolism prophylaxis may be 2 targets to potentially reduce readmission after aseptic revision TJA.

Clinical efficacy of risk-stratified prophylaxis with low-dose aspirin for the management of symptomatic venous thromboembolism after total hip arthroplasty

BACKGROUND

Pulmonary thromboembolism (PTE) and deep vein thrombosis (DVT) are serious complications after total hip arthroplasty (THA). Aspirin has been considered a safe and cost-effective prophylaxis for venous thromboembolism (VTE), and there have been some reports about the incidence of PTE (0%-0.57%) and DVT (0.1%-0.35%) with low-dose aspirin for prophylaxis after THA. The aim of this study was to investigate the incidence of postoperative symptomatic VTE in our hospital and to evaluate the clinical efficacy of our prophylactic regimen.

PATIENT AND METHODS

We retrospectively reviewed the medical records of consecutive patients who underwent THA in our hospital between 2011 and 2016. A total of 3295 hips (male: 337 patients, 365 hips; female: 2527 patients, 2930 hips) were enrolled in this study. Patients were divided into low-risk and high-risk groups. Low-risk patients were administered aspirin (100 mg/day) for 28 days postoperatively. High-risk patients, such as those diagnosed with obesity and/or with a history of VTE, received anticoagulants (enoxaparin or edoxaban) for 5 days postoperatively, followed by a dose of aspirin for 28 days. Based on our criteria, 218 of 3295 hips were considered high risk.

RESULTS

No VTE-related mortality was observed. One patient developed symptomatic PTE, and one patient developed symptomatic DVT. Both were successfully treated. Postoperative fatal bleeding or bleeding from any organ such as gastrointestinal and cerebral hemorrhage were not observed. A low incidence (0.03%) was observed for symptomatic DVT and PTE.

CONCLUSIONS

This study demonstrated that the hospital's risk-stratified protocol using low-dose aspirin or anticoagulants was clinically effective in preventing symptomatic VTE. These results were considerably better than those reported from Western countries. However, all patients in this study were the Japanese. It was unclear whether similar results were given to non-Japanese patients. Therefore, this protocol needs severe carefulness to be applied to non-Japanese populations.

Cost-Effectiveness of Alternative Anticoagulation Strategies for Postoperative Management of Total Knee Arthroplasty Patients

OBJECTIVE

To evaluate the cost-effectiveness of prolonged (35-day) and standard-duration (14-day) anticoagulation therapy following total knee arthroplasty (TKA).

METHODS

Using Markov modeling, we assessed clinical and economic outcomes of 14-day and 35-day anticoagulation therapy following TKA with rivaroxaban, low molecular weight heparin (LMWH), fondaparinux, warfarin, and aspirin. Incidence of complications of TKA and anticoagulation therapy (deep vein thrombosis [DVT], pulmonary embolism [PE], prosthetic joint infection [PJI], and bleeding) were derived from published literature. Daily costs ranged from $1 (aspirin) to $43 (fondaparinux). Primary outcomes included quality-adjusted life years (QALYs), direct medical costs, and incremental cost-effectiveness ratios (ICERs) at 1 year post-TKA. The preferred regimen was the regimen with highest QALYs maintaining an ICER below the willingness-to-pay threshold ($100,000/QALY). We conducted probabilistic sensitivity analyses, varying complication incidence and anticoagulation efficacy, to evaluate the impact of parameter uncertainty on model results.

RESULTS

Aspirin resulted in the highest cumulative incidence of DVT and PE, while prolonged fondaparinux led to the largest reduction in DVT incidence (15% reduction compared to no prophylaxis). Despite differential bleeding rates (ranging from 3% to 6%), all strategies had similar incidence of PJI (1% to 2%). Prolonged rivaroxaban was the least costly strategy ($3,300 at 1 year post-TKA) and the preferred regimen in the base case. In sensitivity analyses, prolonged rivaroxaban and warfarin had similar likelihoods of being cost-effective.

CONCLUSION

Extending postoperative anticoagulation therapy to 35 days increases QALYs compared to standard 14-day prophylaxis. Prolonged rivaroxaban and prolonged warfarin are most likely to be cost-effective post-TKA; the costs of fondaparinux and LMWH precluded their being preferred strategies.

Association of Aspirin With Prevention of Venous Thromboembolism in Patients After Total Knee Arthroplasty Compared With Other Anticoagulants: A Noninferiority Analysis

Importance

There has been significant debate in the surgical and medical communities regarding the appropriateness of using aspirin alone for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA).

Objective

To determine the acceptability of aspirin alone vs anticoagulant prophylaxis for reducing the risk of postoperative VTE in patients undergoing TKA.

Design, Setting, and Participants

Noninferiority study of a retrospective cohort of TKA cases submitted to the Michigan Arthroplasty Registry Collaborative Quality Initiative at 29 member hospitals, ranging from small community hospitals to large academic and nonacademic medical centers in Michigan. The study included 41 537 patients who underwent primary TKA between April 1, 2013, and October 31, 2015. Clinical events were monitored for 90 days after surgery. Data were analyzed between September and October 2016.

Exposures

The method of pharmacologic prophylaxis: neither aspirin nor anticoagulants for 668 patients (1.6%), aspirin only for 12 831 patients (30.9%), anticoagulant only (eg, low-molecular-weight heparin, warfarin, and Xa inhibitors) for 22 620 patients (54.5%), and both aspirin/anticoagulant for 5418 patients (13.0%). Most patients were also using intermittent pneumatic compression stockings.

Main Outcome and Measures

The primary composite outcome was the first occurrence of VTE or death. The noninferiority margin was specified as 0.3. The secondary outcome was bleeding events.

Results

Of the 41 537 patients, 14 966 were men (36%), and the mean age was 65.8 years. A VTE event occurred in 573 of 41 537 patients (1.38%); 32 of 668 (4.79%) who received no pharmacologic prophylaxis, 149 of 12 831 (1.16%) treated with aspirin alone, 321 of 22 620 (1.42%) with anticoagulation alone, and 71 of 5418 (1.31%) prescribed both aspirin and anticoagulation. Aspirin only was noninferior for the composite VTE outcome compared with those receiving other chemoprophylaxis (adjusted odds ratio, 0.85; 95% CI, 0.68-1.07, P for inferiority = .007). Bleeding occurred in 457 of 41 537 patients (1.10%), 10 of 668 (1.50%) without prophylaxis, 116 of 12 831 (0.90%) in the aspirin group, 258 of 22 620 (1.14%) with anticoagulation, and 73 of 5418 (1.35%) of those receiving both. Aspirin alone was also noninferior for bleeding complications (adjusted odds ratio, 0.80; 95% CI, 0.63-1.00, P for inferiority <.001).

Conclusions and Relevance

In this study of patients undergoing TKA, aspirin was not inferior to other anticoagulants in the postoperative rate of VTE or death. Aspirin alone may provide similar protection from postoperative VTE compared with other anticoagulation treatments.

The Use of Aspirin for Prophylaxis Against Venous Thromboembolism Decreases Mortality Following Primary Total Joint Arthroplasty

BACKGROUND

The use of aspirin as prophylaxis against venous thromboembolism (VTE) following total joint arthroplasty (TJA) has increased in popularity; however, the potential cardioprotective effects of aspirin when administered as VTE prophylaxis remain unknown. The present study investigated the influence of VTE prophylaxis, including aspirin, on mortality following TJA.

METHODS

We retrospectively reviewed 31,133 patients who underwent primary TJA from 2000 to 2017. Patient demographics, body mass index, and comorbidities were obtained from an electronic chart query. Patients were allocated into 2 cohorts on the basis of the VTE prophylaxis administered: aspirin (25.9%, 8,061 patients) and non-aspirin (74.1%, 23,072 patients). Mortality was assessed with use of an institutional mortality database that is updated biannually. Univariate and multivariate regression analyses were performed.

RESULTS

The overall mortality rate was 0.2% and 0.6% at 30 days and 1 year after TJA, respectively. The use of aspirin was independently associated with lower risk of death at both 30 days (odds ratio [OR], 0.39; p = 0.020) and 1 year (OR, 0.51; p = 0.004). Patients in the non-aspirin cohort showed 3 times the risk of death at 30 days compared with the aspirin cohort (0.3% compared with 0.1%; p = 0.004), and twice the risk of death at 1 year (0.7% compared with 0.3%; p < 0.001). At 1 year, the primary cause of death in the non-aspirin group was cardiac-related (46 of 23,072, 0.20%). In the aspirin group, the rate of cardiac-related death was almost 5 times lower (3 of 8,061, 0.04%; p = 0.005). Risk factors for mortality at 1 year included higher age (p < 0.001), male sex (p = 0.020), history of congestive heart failure (p = 0.003), cerebrovascular disease (p < 0.001), malignancy (p < 0.001), and history of prior myocardial infarction (p < 0.001).

CONCLUSIONS

The present study demonstrates that the use of aspirin as prophylaxis against VTE following TJA may reduce the risk of mortality. Given the numerous options available and permitted by the current guidelines, orthopaedic surgeons should be aware of the potential added benefits of aspirin when selecting a VTE-prophylactic agent.

LEVEL OF EVIDENCE

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

Aspirin versus rivaroxaban in postoperative bleeding after total knee arthroplasty: a retrospective case-matched study

BACKGROUND

Venous thromboembolic disease (VTE) is a complication not uncommon following total knee arthroplasty. Postoperative bleeding-related complications are a concern in many guidelines. The authors aimed to compare the amount of postoperative drainage from closed suction drainage, transfusion rate, and postoperative complications between aspirin and rivaroxaban as VTE prophylaxes after total knee arthroplasty.

METHODS

This study was a retrospective case-matched study of 155 patients. The data were collected between 2008 and 2015 from patients who had total knee arthroplasty using aspirin or rivaroxaban as the VTE prophylaxis. Seventy-nine patients received aspirin, and 76 patients received rivaroxaban. A single surgeon operated on all patients with the same surgical technique and patient care protocol.

RESULTS

The total closed suction drainage outputs at 48 h were not significantly different between the aspirin and rivaroxaban groups (p = 0.10). Eighteen percent of patients in the aspirin group and 25% of patients in the rivaroxaban group received blood transfusions (p = 0.37). There were no bleeding-related complications or VTE in either group.

CONCLUSIONS

Aspirin and rivaroxaban were effective and safe as VTE chemoprophylaxis in total knee arthroplasty.

Intermittent pneumatic compression is a cost-effective method of orthopedic postsurgical venous thromboembolism prophylaxis

Background

Venous thromboembolism (VTE) is a major complication after lower-limb arthroplasty that increases costs and reduces patient’s quality of life. Using anticoagulants for 10–35 days following arthroplasty is the standard prophylaxis, but its cost-effectiveness after accounting for bleeding complications remains unproven.

Methods

A comprehensive, clinical model of VTE was created using the incidences, clinical effects (including bleeding), and costs of VTE and prophylaxis from randomized controlled trials, meta-analyses, and large observational studies. Over 50 years, the total health care costs and clinical impact of three prophylaxis strategies, that are as follows, were compared: low-molecular-weight heparin (LMWH) alone, intermittent pneumatic compression (IPC), and IPC with LMWH (IPC+LMWH). The cost per VTE event that was avoided and cost per quality-adjusted life year (QALY) gained in both the US and Australian health care settings were calculated.

Results

For every 2,000 patients, the expected number of VTE and major bleeding events with LMWH were 151 and 6 in the USA and 160 and 46 in Australia, resulting in a mean of 11.3 and 9.1 QALYs per patient, respectively. IPC reduced the expected VTE events by 11 and 8 in the USA and Australia, respectively, compared to using LMWH alone. IPC reduced major bleeding events compared to LMWH, preventing 1 event in the US and 7 in Australia. IPC+LMWH only reduced VTE events. Neither intervention substantially impacted QALYs but both increased QALYs versus LMWH. IPC was cost-effective followed by IPC+LMWH.

Conclusion

IPC and IPC+LMWH are cost-effective versus LMWH after lower-limb arthroplasty in the USA and Australia. The choice between IPC and IPC+LMWH depends on expected bleeding risks.

Aspirin provides adequate VTE prophylaxis for patients undergoing hip preservation surgery, including periacetabular osteotomy

There are no clear guidelines regarding optimal venous thromboembolism (VTE) prophylaxis for patients undergoing hip preservation surgery (HPS), in particular pelvic osteotomy, which is considered to be a major orthopaedic procedure. The aim of this study was to determine the efficacy of aspirin for VTE prophylaxis in a large cohort of patients undergoing femoroacetabular osteoplasty (FAO) and periacetabular osteotomy (PAO). This was a retrospective study of prospectively collected data on patients undergoing HPS. A total of 603 patients (643 cases) underwent FAO and 80 patients (87 cases) underwent PAO between 2003 and 2016. The mean age of patients was 34.3 years (range 14.3–68.1 years). The type of VTE prophylaxis administered changed over time with earlier patients receiving warfarin (44 cases), followed by aspirin at 325 mg twice daily (448 cases), and most recently aspirin 81 mg twice daily (238 cases). The complications of symptomatic pulmonary embolism (PE), deep venous thrombosis (DVT) and major bleeding events within 90 days of surgery were documented. There were zero patients that developed major bleeding events or required evacuation of a hematoma. One patient who underwent FAO and received aspirin 325 mg, developed post-operative symptomatic DVT. One patient who underwent PAO and received aspirin 325 mg developed DVT and PE. This study demonstrates that the incidence of VTE following joint preservation procedure is acceptably low. Administration of aspirin to patients undergoing FAO or PAO appears to be adequate in reducing the risk of VTE. Only two patients in this cohort developed VTE following HPS.

Aspirin and the prevention of venous thromboembolism following total joint arthroplasty: commonly asked questions

The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences.

Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents.

The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use.

There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE.

Cite this article: Bone Joint J 2017;99-B:1420–30.

A Comparison of Two Dosing Regimens of ASA Following Total Hip and Knee Arthroplasties

BACKGROUND

The purpose of this study was to compare short-term side effects of aspirin (ASA) 325 mg vs ASA 81 mg orally twice daily (PO BID) when used as thromboembolic prophylaxis following primary total joint arthroplasty.

METHODS

A 1-year prospective cohort study was performed on 643 primary unilateral total joint arthroplasty patients operated on by a single surgeon. Two hundred eighty-two patients were administered ASA 325 mg PO BID and 361 patients were administered ASA 81 mg PO BID for 1 month. A questionnaire assessing the side effects of ASA intake was administered 1 month postoperatively.

RESULTS

The overall rate of gastrointestinal side effects (GI upset and nausea) was 1.9%, but ASA 325 mg had a higher rate 9/282 (3.2%) than ASA 81 mg 3/361 (0.8%), P = .04. Overall GI bleeding was 0.9%, with 2/282 (0.7%) in the ASA 325 mg group, vs 4/361 (1.1%) in the ASA 81 mg group, P = .70. One patient in the ASA 81 mg group (0.3%) developed a deep vein thrombosis. No patient developed pulmonary embolism, periprosthetic joint infection, tinnitus, wheezing and/or shortness of breath, chest pain, or headaches. In the ASA 325 mg group, 9/282 (3.2%) discontinued ASA and in the ASA 81 mg group, 8/361 (2.2%) discontinued ASA, P = .47. Four patients in the ASA 325 group (1.4%) changed to ASA 81 mg.

CONCLUSION

ASA 81 mg is associated with significantly less GI distress and nausea compared with ASA 325 mg. GI bleeding was equally prevalent between the 2 dosing regimens, so patients need to be informed of this risk regardless of the ASA dose.

Is combined use of intravenous and intraarticular tranexamic acid superior to intravenous or intraarticular tranexamic acid alone in total knee arthroplasty? A meta-analysis of randomized controlled trials

BACKGROUND

Tranexamic acid (TXA) has been proven to be effective in reducing blood loss and transfusion rate after total knee arthroplasty (TKA) without increasing the risk of deep vein thrombosis (DVT) and pulmonary embolism (PE). Recently, an increasing number of studies have been interested in applying combined intravenous (IV) with intraarticular (IA) tranexamic acid in total knee arthroplasty. The purpose of this meta-analysis was to compare the blood loss and complications of combined TXA with IV TXA or IA TXA on TKA.

METHODS

Systematic search of literatures were conducted to identify related articles that were published in PubMed, MEDLINE, Embase, the Cochrane Library, SpringerLink, ClinicalTrials.gov, and Ovid from their inception to September 2016. All studies that compare blood loss and complications of combined TXA and IV TXA or IA TXA on TKA were included. Main outcomes were collected and analyzed by the Review Manager 5.3.

RESULTS

Five studies were included in the present meta-analysis. There was significant difference in total blood loss and blood volume of drainage when compared combined TXA group with IV TXA group or IA TXA group (P < 0.05). There was no difference in transfusion rate and thromboembolic complications when comparing combined TXA with IV TXA or IA TXA alone (P > 0.05).

CONCLUSIONS

Compared with administration of IA TXA or IV TXA alone on TKA, combined use of TXA has advantages in reducing total blood loss and blood volume of drainage without increasing the incidence of thromboembolic complications. We recommend combined TXA as the preferred option for patients undergoing TKA.

Low-Dose Aspirin Is Effective Chemoprophylaxis Against Clinically Important Venous Thromboembolism Following Total Joint Arthroplasty: A Preliminary Analysis

BACKGROUND

Aspirin is a safe and effective prophylaxis for the prevention of venous thromboembolism following total joint arthroplasty. The optimal dose of aspirin prophylaxis is unknown. Our hypothesis was that lower-dose aspirin is as effective as higher-dose aspirin for the prevention of venous thromboembolism and is associated with fewer gastrointestinal side effects.

METHODS

In a prospective, crossover study, we analyzed 4,651 primary total joint arthroplasty cases performed from July 2013 to June 2015. For 4 weeks, 3,192 patients received enteric-coated 325-mg aspirin twice daily (the 325-mg aspirin group) and 1,459 patients received 81-mg aspirin twice daily (the 81-mg aspirin group). There were no significant differences (p > 0.05) in sex, body mass index, or Charlson Comorbidity Index between the two patient populations. Recorded complications occurring within 90 days postoperatively included symptomatic venous thromboembolism (deep venous thrombosis and pulmonary embolism), gastrointestinal complications, acute periprosthetic joint infection, and death.

RESULTS

The incidence of venous thromboembolism of 0.1% (95% confidence interval [CI], 0% to 0.3%) in the 81-mg aspirin group (1 with deep venous thrombosis and 1 with pulmonary embolism) was not significantly different (p = 0.345) from 0.3% (95% CI, 0.1% to 0.6%) in the 325-mg aspirin group (7 with deep venous thrombosis and 5 with pulmonary embolism). The incidence of gastrointestinal bleeding or ulceration of 0.3% (95% CI, 0% to 0.5%) in the 81-mg aspirin group was slightly, but not significantly (p = 0.66), lower than the 0.4% (95% CI, 0.2% to 0.6%) in the 325-mg aspirin group. The incidence of acute periprosthetic joint infection was 0.2% (95% CI, 0% to 0.4%) in the 81-mg aspirin group compared with 0.5% (95% CI, 0.2% to 0.7%) in the 325-mg aspirin group (p = 0.28). The 90-day mortality rate was similar in both groups at 0.1% (95% CI, 0% to 0.2%) in the 81-mg aspirin group and 0.1% (95% CI, 0% to 0.2%) in the 325-mg aspirin group (p = 0.78).

CONCLUSIONS

Our study demonstrates that low-dose aspirin is not inferior to high-dose aspirin for venous thromboembolism prophylaxis following total joint arthroplasty. This is not unexpected, as the available literature demonstrates that low-dose aspirin is as effective as higher-dose aspirin in the prevention of acute coronary syndrome and cerebrovascular events.

LEVEL OF EVIDENCE

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

Economic Decision Model Suggests Total Shoulder Arthroplasty is Superior to Hemiarthroplasty in Young Patients with End-stage Shoulder Arthritis

BACKGROUND

Young patients with severe glenohumeral arthritis pose a challenging management problem for shoulder surgeons. Two controversial treatment options are total shoulder arthroplasty (TSA) and hemiarthroplasty. This study aims to characterize costs, as expressed by reimbursements for episodes of acute care, and outcomes associated with each treatment.

QUESTIONS/PURPOSES

We asked: for patients 30 to 50 years old with severe end-stage glenohumeral arthritis refractory to conservative management, (1) are more years of patient-derived satisfactory outcome by the Neer criteria and quality-adjusted life-years (QALYs) achieved using a TSA or a hemiarthroplasty; (2) does a TSA or a hemiarthroplasty result in a greater number of revision procedures; and (3) does a TSA or a hemiarthroplasty result in greater associated costs to society?

METHODS

The incidence of glenohumeral arthritis among 30- to 50-year-old patients, outcomes, reoperation probabilities, and associated costs from TSA and hemiarthroplasty were derived from the literature. A Markov chain decision tree model was developed from these estimates with number of revisions, cost of management for patients to 70 years old as defined by reimbursement for acute-care episodes, years with "satisfactory" or "excellent" outcome by the modified Neer criteria, and QALYs gained as principle outcome measures. A Monte Carlo simulation was conducted with a cohort representing the at-risk population for shoulder arthritis between 30 and 50 years old in the United States.

RESULTS

During the lifetime of a cohort of 5279 patients, hemiarthroplasty as the initial treatment resulted in 59,574 patient years of satisfactory or excellent results (11.29 per patient) and average QALYs gained of 6.55, whereas TSA as the initial treatment resulted in 85,969 patient years of satisfactory or excellent results (16.29 per patient) and average QALYs gained of 7.96. During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as the initial treatment led to 2090 lifetime revisions (0.4 per patient), whereas a TSA as the initial treatment led to 1605 lifetime revisions (0.3 per patient). During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as initial treatment resulted in USD 132,500,000 associated direct reimbursements (USD 25,000 per patient), whereas a TSA as initial treatment resulted in USD 125,500,000 associated direct reimbursements (USD 23,700 per patient).

CONCLUSIONS

Treatment of end-stage glenohumeral arthritis refractory to conservative treatment in patients 30 to 50 years old in the United States with TSA, instead of hemiarthroplasty, would result in greater cost savings, avoid a substantial number of revision procedures, and result in greater years of satisfactory or excellent patient outcomes and greater QALYs gained. On a population level, TSA is the cost-effective treatment for glenohumeral arthritis in patients 30 to 50 years old.

LEVEL OF EVIDENCE

Level II, economic and decision analysis study.

Aspirin as Thromboprophylaxis in Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Venous thromboembolism (VTE) comprises pulmonary embolism and deep vein thrombosis and is a complication of particular concern in lower limb arthroplasty. In recent years, aspirin has emerged as a potential alternative thromboprophylactic agent, particularly after its acceptance as a recommended agent by the American College of Chest Physicians. Aspirin is favorable due to its relative cost-effectiveness and convenience compared to novel oral anticoagulants and warfarin. However, its efficacy since its inclusion in the American College of Chest Physicians guidelines remains unclear. The present systematic review aimed to establish the efficacy of aspirin in preventing VTE in total hip and knee arthroplasty.

METHODS

Electronic searches were performed using 6 databases from up to June 2015, identifying all relevant studies. Data were extracted and meta-analyzed.

RESULTS

Eleven relevant studies were identified for inclusion in the present meta-analysis. The overall rate of deep vein thrombosis and pulmonary embolism in both hip and knee arthroplasty was 1.2% and 0.6%, respectively. The rate of major bleeding was 0.3%. Pooled mortality rate was 0.2%. All findings demonstrated a high and significant degree of heterogeneity.

CONCLUSION

Aspirin, both alone and in multimodal approaches to thromboprophylaxis, confers a low rate of VTE, with a low risk of major bleeding complications. However, the evidence for its use is limited by the low quality of studies and variation in dose in dosing regimes. Future randomized controlled trials should investigate the efficacy of aspirin, as well as the ideal dosing protocol for its use in thromboprophylaxis in arthroplasty.

Impact of recent guideline changes on aspirin prescribing after knee arthroplasty

BACKGROUND

Prior to 2012, the American Academy of Orthopaedic Surgeons (AAOS) and American College of Chest Physicians (ACCP) differed in their recommendations for postoperative pharmacologic venous thromboembolism prophylaxis (VTEP) after total joint arthroplasty. More specifically, aspirin (ASA) monotherapy was not endorsed by the ACCP as an acceptable prophylaxis. In 2012, the ACCP supported ASA monotherapy compared with no prophylaxis. Our aim was to investigate the impact of the convergence of ACCP and AAOS recommendations on surgeon prescribing patterns after knee arthroplasty (KA).

METHODS

This is a retrospective chart review. We collected data to assess preoperative VTE risk and examined VTEP prescriptions on postoperative day 1 (POD1) and at discharge (D/C) from 7/2008 to 12/2011 (pre-period) and 1/2012 to 7/2014 (post-period). Adult patients undergoing primary and revision KA were identified by ICD-9 procedure codes. Patients on preoperative full-dose anticoagulation and with hypercoagulability disorders were excluded.

RESULTS

Of 368 records reviewed, 329 were included in the analysis. There were no differences between the two period groups for age, sex, BMI, estrogen therapy, malignancy, smoking status, prior VTE, bilateral procedures, or surgery within 3 months. On POD1, in the pre-period, 4.6 % were prescribed ASA monotherapy versus 44.4 % in the post-period (p < 0.001). On D/C, in the pre-period, 13.9 % were prescribed ASA versus 55.6 % in the post-period (p < 0.001).

CONCLUSIONS

Our results indicate a statistically significant change in orthopedist prescribing patterns after guideline convergence. Furthermore, there was no apparent change in VTE risk between the two study groups when excluding patients necessitating full anticoagulation. Prior literature has shown that the divergence in guidelines influenced physicians away from ASA and toward more potent anticoagulants in order to avoid potential litigation. Once its role in VTEP was supported by the ACCP, it appears that ASA monotherapy was readily and rapidly incorporated into clinical practice. ASA may be favored over other VTEP agents for its lower bleeding risk profile and cost. This study highlights the profound impact clinical practice guidelines have on clinician prescribing patterns. Although prospective randomized trials are needed to compare the efficacy of ASA with other VTEP agents, ASA is now a predominant part of the VTEP armamentarium after KA.

The constraints on day-case total knee arthroplasty: the fastest fast track

Total knee arthroplasty (TKA) is a major orthopaedic intervention. The length of a patient's stay has been progressively reduced with the introduction of enhanced recovery protocols: day-case surgery has become the ultimate challenge. This narrative review shows the potential limitations of day-case TKA. These constraints may be social, linked to patient's comorbidities, or due to surgery-related adverse events (e.g. pain, post-operative nausea and vomiting, etc.). Using patient stratification, tailored surgical techniques and multimodal opioid-sparing analgesia, day-case TKA might be achievable in a limited group of patients. The younger, male patient without comorbidities and with an excellent social network around him might be a candidate. Demographic changes, effective recovery programmes and less invasive surgical techniques such as unicondylar knee arthroplasty, may increase the size of the group of potential day-case patients. The cost reduction achieved by day-case TKA needs to be balanced against any increase in morbidity and mortality and the cost of advanced follow-up at a distance with new technology. These factors need to be evaluated before adopting this ultimate 'fast-track' approach.

Thromboembolism Prophylaxis in Hip Arthroplasty: Routine and High Risk Patients

This study's purpose was to present the use of a risk stratification protocol in which "routine" risk patients receive a mobile compression device with aspirin and "high" risk patients receive warfarin for thromboprophylaxis after hip arthroplasty. 1859 hip arthroplasty patients were prospectively enrolled (1402 routine risk--75.4%, 457 high risk--24.6%). The cumulative rate of venous thromboembolism events was 0.5% in the routine versus 0.5% in the high-risk cohort within 6weeks postoperatively (P=1.00). Patients in the routine risk cohort had a lower rate of major bleeding (0.5% versus 2.0%, P=0.006) and wound complications (0.2% versus 1.2%, P=0.01). Use of our risk stratification protocol allowed the avoidance of more aggressive anticoagulation in 75% of patients while achieving a low overall incidence of symptomatic VTE.

The influence of VKORC1 and CYP2C9 mutations on warfarin response after total hip and knee arthroplasty

AIMS

This study characterizes the influence of genotype at two loci on warfarin response after arthroplasty.

METHODS

121 postarthroplasty patients given warfarin thromboprophylaxis were reviewed for international normalized ratio (INR) values on the first three days postoperatively. Significant differences among genotypes in INR values on each of the first three postoperative days were assessed.

RESULTS

Wild-type patients at both loci (∼23% of patients) had yet to reach therapeutic INR (1.5-2.0) by postoperative day three more frequently than those with a mutation conferring hyper-responsiveness (61% vs. 30%; P ≤ .01).

CONCLUSIONS

Wild-type patients are not anticoagulated in a sufficiently prompt manner after arthroplasty.

Venous thromboembolism prophylaxis after total joint arthroplasty

Venous thromboembolism (VTE) prophylaxis after total joint arthroplasty is considered best practice. However, over the past 5 years, there has been considerable debate about the ideal prophylactic regimen or modality. The American Academy of Orthopaedic Surgeons and the American College of Chest Physicians published their most recent clinical practice guidelines about VTE prophylaxis in 2011 and 2012, respectively. In addition, the Surgical Care Improvement Project published their latest recommendations in 2014. In this review, commonly used VTE prophylaxis options and the latest clinical guidelines will be discussed.