Aspirin Is as Effective as and Safer Than Warfarin for Patients at Higher Risk of Venous Thromboembolism Undergoing Total Joint Arthroplasty

Low-Dose Aspirin Is the Safest Prophylaxis for Prevention of Venous Thromboembolism After Total Knee Arthroplasty Across All Patient Risk Profiles

BACKGROUND

The International Consensus Meeting on Venous Thromboembolism (ICM-VTE) in 2022 proclaimed low-dose aspirin as the most effective agent in patients across all risk profiles undergoing joint arthroplasty. However, data on large patient populations assessing trends in chemoprophylactic choices and related outcomes following total knee arthroplasty (TKA) remain scant. The present study was designed to characterize the clinical use of various chemoprophylactic agents in patients undergoing TKA and to determine the efficacy of aspirin compared with other agents in patient groups stratified by VTE risk profiles.

METHODS

This study utilized a national database to determine the proportion of patients undergoing TKA who received low-dose aspirin versus other chemoprophylaxis between 2012 and 2022. VTE risk profiles were determined on the basis of comorbidities established in the ICM-VTE. The odds ratios (ORs) and 95% confidence intervals (CIs) between various classes of thromboprophylaxis in patients with high and low risk of VTE were calculated. The odds of deep-vein thrombosis (DVT), pulmonary embolus (PE), bleeding events, infections, mortality, and hospitalizations were also assessed in the 90-day postoperative period for propensity-matched cohorts receiving low-dose (81 mg) aspirin only versus other prophylaxis, segregating patients by VTE risk profile.

RESULTS

A total of 126,692 patients undergoing TKA across 60 health-care organizations were included. The proportion of patients receiving low-dose aspirin increased from 7.65% to 55.29% between 2012 and 2022, whereas the proportion of patients receiving other chemoprophylaxis decreased from 96.25% to 42.98%. Low-dose-aspirin-only use increased to approximately 50% in both high-risk and low-risk populations but was more likely in low-risk populations (OR, 1.17; 95% CI, 1.15 to 1.20) relative to high-risk populations. Both low-risk and high-risk patients in the low-dose-aspirin-only cohorts had decreased odds of DVT, PE, bleeding, infections, and hospitalizations compared with other prophylaxis regimens.

CONCLUSIONS

The findings of the present study on a very large population of patients undergoing TKA support the recent ICM-VTE statement by showing that low-dose aspirin is a safe and effective method of prophylaxis in patients across various risk profiles.

LEVEL OF EVIDENCE

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

Perioperative Dexamethasone is Associated with a Decreased Risk of Pulmonary Embolism and Deep Vein Thrombosis Following Total Joint Arthroplasty: An Analysis of 70,000 High-Risk Patients

BACKGROUND

Dexamethasone (DEX) has demonstrated promise with respect to decreasing postoperative thromboembolic complications following total joint arthroplasty (TJA). Therefore, the aim of this study was to investigate the effects of perioperative intravenous DEX on rates of pulmonary embolism (PE) and deep vein thrombosis (DVT) after primary TJA in patients who have a history of venous thromboembolism (VTE).

METHODS

Patients who have a history of VTE who underwent primary, elective TJA from 2015 to 2021 were identified using a commercial healthcare database. Patients were divided based on receipt of perioperative intravenous DEX [DEX(+) versus DEX(-)] on the day of index TJA. Patient demographics and hospital factors were collected. The 90-day risk of postoperative complications, readmission, and in-hospital mortality were compared.

RESULTS

Overall, 70,147 patients who had a history of VTE underwent TJA, of which 40,607 (57.89%) received DEX and 29,540 (42.11%) did not. The DEX(+) patients were younger (67 ± 9.8 versus 68 ± 9.9 years, P < 0.001) and had a significantly shorter length of stay compared to the DEX(-) patients (1.8 ± 1.6 versus 2.2 ± 1.8 days, P < 0.001). The DEX(+) patients demonstrated lower rates of PE (1.37 versus 1.75%, P < 0.001) and DVT (2.37 versus 3.01%, P < 0.001) compared to DEX(-) patients. The DEX(+) patients experienced a lower risk of PE (adjusted odds ratio [aOR] 0.78, 95% confidence interval [95%-CI]: 0.66 to 0.93, P = 0.006) and DVT (aOR: 0.84, 95%-CI: 0.74 to 0.95, P = 0.006) compared to DEX(-) patients. The DEX(+) patients demonstrated no differences in the odds of surgical site infection, periprosthetic joint infection, or sepsis compared to the DEX(-) patients (P > 0.05).

CONCLUSION

The administration of DEX was associated with a decreased risk of PE and DVT in patients who have a history of VTE who underwent TJA. These data warrant further study investigating the postoperative benefits of perioperative DEX administration for high-risk patients undergoing TJA.

Preventive strategies to reduce the rate of periprosthetic infections in total joint arthroplasty; a comprehensive review

The increasing frequency of total hip (THA) and knee arthroplasties (TKA) is marred by the rise in periprosthetic joint infections (PJIs) and surgical site infections (SSIs), with PJIs incurring costs over $1.62 billion as of 2020 and individual case management averaging $90,000. SSIs additionally burden the U.S. healthcare economy with billions in expenses annually. PJI prevalence in primary THA and TKA ranges from 0.5% to 2.4%, spiking to 20% in revisions and representing 25% of TKA revision causes. Projections estimate up to 270,000 annual PJI cases by 2030. Often caused by gram-positive bacteria, particularly methicillin-resistant staphylococci, these infections demand preventive measures. This review dissects PJI prevention across preoperative, intraoperative, and perioperative phases, aligning with evidence-based CDC and WHO guidelines. Preoperative measures include managing diabetes, obesity, tobacco use, Staphylococcus aureus screening and nasal decolonization, nutritional optimization, and management of inflammatory arthropathies. Intraoperatively, antibiotic prophylaxis, skin preparation, operative room environmental controls, surgical technique precision, and irrigation options are scrutinized. Perioperative concerns focus on anticoagulation, blood management, and infection risk mitigation. Integrating these strategies promotes a patient-centric care model, aiming to reduce PJI incidence, improve patient outcomes, and increase care cost-effectiveness in joint arthroplasty.

Aspirin or enoxaparin for VTE prophylaxis after primary partial, total or revision hip or knee arthroplasty: A secondary analysis from the CRISTAL cluster randomized trial

BACKGROUND

This study compares aspirin to enoxaparin for symptomatic VTE prophylaxis within 90 days of any type of hip or knee arthroplasty performed for any diagnosis, in patients enrolled in the CRISTAL trial.

MATERIALS AND METHODS

CRISTAL was a cluster-randomised crossover, registry-nested non-inferiority trial across 31 hospitals in Australia. The primary publication was restricted to patients undergoing primary total hip or knee arthroplasty for a diagnosis of osteoarthritis. This report includes all enrolled patients undergoing hip or knee arthroplasty procedures (partial or total, primary or revision) performed for any indication. Hospitals were randomized to administer patients aspirin (100mg daily) or enoxaparin (40mg daily), for 35 days after hip arthroplasty and 14 days after knee arthroplasty. Crossover occurred after the patient enrolment target had been met for the first group. The primary outcome was symptomatic VTE within 90 days. Analyses were performed by randomization group.

RESULTS

Between April 20, 2019 and December 18, 2020, 12384 patients were enrolled (7238 aspirin group and 5146 enoxaparin). Of these, 6901 (95.3%) given aspirin and 4827 (93.8%) given enoxaparin (total 11728, 94.7%) were included in the final analyses. Within 90 days, symptomatic VTE occurred in 226 (3.27%) aspirin patients and 85 (1.76%) enoxaparin patients, significant for the superiority of enoxaparin (estimated treatment difference 1.85%, 95% CI 0.59% to 3.10%, p = 0.004). Joint-related reoperation within 90 days was lower in the enoxaparin group (109/4827 (2.26%) vs 171/6896 (2.47%) with aspirin, estimated difference 0.77%; 95% CI 0.06% to 1.47%, p = 0.03). There were no significant differences in the other secondary outcomes.

CONCLUSION

In patients undergoing hip or knee arthroplasty (of any type, performed for any indication) enrolled in the CRISTAL trial, aspirin compared to enoxaparin resulted in a significantly higher rate of symptomatic VTE and joint-related reoperation within 90 days. These findings extend the applicability of the CRISTAL trial results.

TRIAL REGISTRATION

Anzctr.org.au, identifier: ACTRN12618001879257.

Trends in Deep Vein Thrombosis Prophylaxis After Total Knee Arthroplasty: 2016 to 2021

BACKGROUND

In 2011, the American Academy of Orthopaedic Surgeons released a consensus recommending venous thromboembolism (VTE) prophylaxis after total knee arthroplasty (TKA). The purpose of our study was to examine (1) incidences of postoperative complications, including pulmonary embolism (PE), deep vein thrombosis (DVT), and transfusion rates; (2) trends from 2016 to 2021 in VTE prophylaxis; and (3) independent risk factors for 90-day total complications following TKA between aspirin, enoxaparin, rivaroxaban, and warfarin.

METHODS

Using a national, all-payer database from 2016 to 2021, we identified all patients who underwent primary TKA. Exclusions included all patients who had prescribed anticoagulants within 1 year prior to TKA, hypercoagulable states, and cancer. Data were collected on baseline demographics, including age, sex, diabetes, and a comorbidity index, in each of the VTE prophylaxis cohorts. Postoperative outcomes included rates of PE, DVT, and transfusion. Multivariable regressions were performed to determine independent risk factors for total complications at 90 days following TKA.

RESULTS

From 2016 to 2021, aspirin was the most used anticoagulant (n = 62,054), followed by rivaroxaban (n = 26,426), enoxaparin (n = 20,980), and warfarin (n = 13,305). The cohort using warfarin had the highest incidences of PE (1.8%) and DVT (5.7%), while the cohort using aspirin had the lowest incidences of PE (0.6%) and DVT (1.6%). The rates of aspirin use increased the most from 2016 to 2021 (32.1% to 70.8%), while the rates of warfarin decreased the most (19.3% to 3.0%). Enoxaparin, rivaroxaban, and warfarin were independent risk factors for total complications at 90 days.

CONCLUSIONS

An epidemiological analysis of VTE prophylaxis use from 2016 to 2021 shows an increase in aspirin following TKA compared to other anticoagulant cohorts in a nationally representative population. This approach provides more insight and a better understanding of anticoagulation trends over this time period in a nationally representative sample.

An analysis of risk factors for venous thromboembolism in primary versus revision total joint arthroplasty

Background

One of the most serious complications after primary or revision lower extremity total joint arthroplasty (TJA) is venous thromboembolism disease (VTE). Identifying patients at high risk for VTE allows tailoring of prophylactic anticoagulation regimens to those most vulnerable. This study aimed to identify risk factors for VTE in primary and revision lower extremity TJA.

Methods

The Electronic Medical Record was queried from a single academic institution for all patients who underwent a lower extremity TJA between 2007 and 2020. Demographics, comorbid conditions, perioperative characteristics, and postoperative complications were identified. An Elastic Net Multiple Logistic Regression Model was used to assess 49 covariates and predict those associated with a significant risk of VTE.

Results

We identified 4900 primary and revision total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients. There was no significant difference between primary and revision THA. Primary TKA had a higher rate of VTE than revision TKA. Significant risk factors identified for VTE in THA patients include histories of deep vein thrombosis (DVT), pulmonary embolism (PE), metastatic tumors, hemiplegia, and Hispanic ethnicity. Risk factors for VTE in TKA patients include histories of DVT, PE, metastatic tumors, and postoperative warfarin and heparin use. In all patients, age was a significant predictor of VTE risk.

Conclusion

Our work identifies many risk factors for VTE following TJA. While the increased rate of VTE in some populations may represent selection bias, it also highlights the incomplete understanding of the etiology and prevention of this complication in the joint arthroplasty population and requires further study.

Comparative effectiveness of aspirin for symptomatic venous thromboembolism prophylaxis in patients undergoing total joint arthroplasty, a cohort study

BACKGROUND

This study compares the symptomatic 90-day venous thromboembolism (VTE) rates in patients receiving aspirin to patients receiving low-molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs), after total hip (THA) and total knee arthroplasty (TKA).

METHODS

Data were collected from a multi-centre cohort study, including demographics, confounders and prophylaxis type (aspirin alone, LMWH alone, aspirin and LMWH, and DOACs). The primary outcome was symptomatic 90-day VTE. Secondary outcomes were major bleeding, joint related reoperation and mortality within 90 days. Data were analysed using logistic regression, the Student's t and Fisher's exact tests (unadjusted) and multivariable regression (adjusted).

RESULTS

There were 1867 eligible patients; 365 (20%) received aspirin alone, 762 (41%) LMWH alone, 482 (26%) LMWH and aspirin and 170 (9%) DOAC. The 90-day VTE rate was 2.7%; lowest in the aspirin group (1.6%), compared to 3.6% for LMWH, 2.3% for LMWH and aspirin and 2.4% for DOACs. After adjusted analysis, predictors of VTE were prophylaxis duration < 14 days (OR = 6.7, 95% CI 3.5-13.1, p < 0.001) and history of previous VTE (OR = 2.4, 95% CI 1.1-5.8, p = 0.05). There were no significant differences in the primary or secondary outcomes between prophylaxis groups.

CONCLUSIONS

Aspirin may be suitable for VTE prophylaxis following THA and TKA. The comparatively low unadjusted 90-day VTE rate in the aspirin group may have been due to selective use in lower-risk patients.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov, trial number NCT01899443 (15/07/2013).

Aspirin as a thromboprophylaxis agent after revision knee arthroplasty: A retrospective analysis

Introduction

Total knee arthroplasty is a common and effective procedure. Although complication rates are low, certain complications such as venous thromboembolism are potentially serious. The optimal prophylactic agent and dosage after revision knee arthroplasty remains unclear. The main objective of this work was to study the efficacy and safety of aspirin as a thromboprophylaxis agent following revision knee arthroplasties.

Patients and methods

A retrospective review of patients undergoing revision knee arthroplasty between 2013 and 2020at a University Teaching Hospital was undertaken. The primary outcome was the development of a symptomatic thromboembolic event requiring treatment within 90 days post-surgery. The secondary outcomes were adverse events associated with aspirin therapy: surgical site infection rate; incidence of major bleeding; readmission rate and mortality within 90 days post-surgery.

Results

490 patients were included. 374 (76.3%) received prophylactic aspirin (150 mg once daily for 28 days) and 75 (15.3%) patients received dalteparin for 28 days due to contraindication to aspirin use. Those already receiving other thromboprophylaxis agents for pre-existing comorbidities continued these after relevant medical consultation. The overall rates of venous thromboembolism and symptomatic DVT after aspirin prophylaxis were 0.6% (3/490) and 0.8% (3/374), respectively. VTE incidence did not significantly differ between those administered aspirin and other agents. No patient experienced major bleeding within 90 postoperative days. Only 2 of 490 (0.4%) patients had wound infection requiring readmission; neither received prophylactic aspirin.

Conclusion

Extended out-of-hospital thromboembolic prophylaxis with aspirin may be at least as effective as other agents in patients undergoing revision knee arthroplasty. Aspirin is safe, effective, and cheap compared with other agents.

Effect of Aspirin vs Enoxaparin on 90-Day Mortality in Patients Undergoing Hip or Knee Arthroplasty: A Secondary Analysis of the CRISTAL Cluster Randomized Trial

Importance

Ischemic heart disease remains the leading cause of mortality following hip and knee arthroplasty. Due to its antiplatelet and cardioprotective properties, aspirin has been proposed as an agent that could reduce mortality when used as venous thromboembolism (VTE) prophylaxis following these procedures.

Objective

To compare aspirin with enoxaparin in reducing 90-day mortality for patients undergoing hip or knee arthroplasty procedures.

Design, Setting, and Participants

This study was a planned secondary analysis of the CRISTAL cluster randomized, crossover, registry-nested trial performed across 31 participating hospitals in Australia between April 20, 2019, and December 18, 2020. The aim of the CRISTAL trial was to determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE following hip or knee arthroplasty. The primary study restricted the analysis to patients undergoing total hip or knee arthroplasty for a diagnosis of osteoarthritis only. This study includes all adult patients (aged ≥18 years) undergoing any hip or knee arthroplasty procedure at participating sites during the course of the trial. Data were analyzed from June 1 to September 6, 2021.

Interventions

Hospitals were randomized to administer all patients oral aspirin (100 mg daily) or subcutaneous enoxaparin (40 mg daily) for 35 days after hip arthroplasty and 14 days after knee arthroplasty procedures.

Main Outcomes and Measures

The primary outcome was mortality within 90 days. The between-group difference in mortality was estimated using cluster summary methods.

Results

A total of 23 458 patients from 31 hospitals were included, with 14 156 patients allocated to aspirin (median [IQR] age, 69 [62-77] years; 7984 [56.4%] female) and 9302 patients allocated to enoxaparin (median [IQR] age, 70 [62-77] years; 5277 [56.7%] female). The mortality rate within 90 days of surgery was 1.67% in the aspirin group and 1.53% in the enoxaparin group (estimated difference, 0.04%; 95% CI, -0.05%-0.42%). For the subgroup of 21 148 patients with a nonfracture diagnosis, the mortality rate was 0.49% in the aspirin group and 0.41% in the enoxaparin group (estimated difference, 0.05%; 95% CI, -0.67% to 0.76%).

Conclusions and Relevance

In this secondary analysis of a cluster randomized trial comparing aspirin with enoxaparin following hip or knee arthroplasty, there was no significant between-group difference in mortality within 90 days when either drug was used for VTE prophylaxis.

Trial Registration

http://anzctr.org.au Identifier: ACTRN12618001879257.

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.

Role of non-ASA VTE prophylaxis in risk for manipulation following primary total knee arthroplasty

INTRODUCTION

Stiffness and decreased range of motion frequently lead to hindrance of activities of daily living and dissatisfaction follow total knee arthroplasty (TKA). This study aims to evaluate the effect of non-aspirin (ASA) chemoprophylaxis and determine patient-related risk factors for stiffness and need for manipulation under anesthesia (MUA) following primary TKA.

MATERIALS AND METHODS

A review of all patients undergoing primary TKA from 2013 to 2019 at a single academic orthopedic hospital was conducted. The primary outcome measure was MUA performed post-operatively. Chi-square analysis and Mann-Whitney U test were used to determine statistically significant relationships between risk factors and outcomes. Significance was set at p < 0.05. Univariate logistic regression was performed to control for identified independent risk factors for MUA.

RESULTS

A total of 11,550 patients undergoing primary TKA from January 2013 to September 2019 at an academic medical center were included in the study. Increasing age and Charlson Comorbidity Index were associated with statistically significant decreased odds of MUA (0.93, 95% CI: 0.92-0.94, p < 0.001, OR 0.71, 95% CI 0.63-0.79, p < 0.001). Active smokers had a 2.01 increased odds of MUA (OR 2.01, 95% CI 1.28, 3.02, p < 0.001). There was no significant difference in rates of MUA between ASA and non-ASA VTE prophylaxis (p 0.108).

CONCLUSIONS

Younger age, lower CCI, and history of smoking are associated with a higher rate, while different chemical VTE prophylaxis does not influence rate of MUA after TKA. Arthroplasty surgeons should consider these risk factors when counseling patient preoperatively. Understanding each patients' risk for MUA allows surgeons to appropriately set preoperative expectations and reasonable outcome goals.

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.

Low-Dose NSAIDs Efficacy in Orthopedic Applications

Non-steroidal anti-inflammatory drugs (NSAIDs) [cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) inhibitors] and COXIBs (the COX-2 selective inhibitors) may induce several potentially severe and life-threatening issues especially in elderly patients. The use of low-dose NSAIDs is associated with lower risk of side effects compared to the standard dosage. Low-dose NSAIDs could minimize the side effects of these drugs while maintaining their clinical efficacy and effectiveness. The present study evaluates the effectiveness and safety of low-dose NSAIDs in musculoskeletal applications.

Routine Laboratory Tests are not Necessary After Primary Total Joint Arthroplasty: A Prospective Study Utilizing a Selective Algorithmic Approach

BACKGROUND

Laboratory tests are obtained following total joint arthroplasty (TJA) despite a lack of supporting evidence. No prior study has prospectively analyzed the effect of discontinuing routine laboratory tests. This study aimed to determine whether discontinuing routine laboratory tests in TJA patients resulted in a difference in 90-day complications.

METHODS

This was a prospective protocol change study at a high-volume center. Prior to protocol change, patients underwent routine laboratory tests following primary unilateral TJA (control group). After the change, an algorithmic approach was used to selectively order laboratory tests (protocol group). Patients with bleeding disorders, chronic obstructive pulmonary disease, arrhythmia, coronary artery disease, congestive heart failure, chronic renal failure, dementia, abnormal preoperative sodium, potassium, or hemoglobin <10 g/dL were excluded. In-hospital and 90-day data were collected. Student's t-test was used to analyze continuous variables and chi-squared test was used for categorical variables. A pre-hoc analysis examining the primary outcome required 607 patients per group to achieve 80% power.

RESULTS

The protocol group included 937 patients, whereas the control group included 891 patients. The protocol group had fewer females and total hip arthroplasties. There were no differences in age, body mass index, American Society of Anesthesiologists classification, tranexamic acid administration, or estimated blood loss between the protocol and control groups. There were also no differences in transfusions, electrolyte corrections, unplanned consults, length of stay, or transfers. The protocol cohort had more fluid boluses and home discharges. There was no difference in 90-day complications between the 2 groups.

CONCLUSIONS

This study utilizing an algorithmic approach to laboratory collection demonstrates that discontinuing routine laboratory tests following TJA is safe and effective. We believe this protocol can be implemented for most patients undergoing primary unilateral TJA.

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.

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 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.

Low-Dose Aspirin is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Knee Arthroplasty: A Retrospective Cohort Study

Venous thromboembolism (VTE) events are rare, but serious complications of total joint replacement affect patients and health care systems due to the morbidity, mortality, and associated cost of its complications. There is currently no established universal standard of care for prophylaxis against VTE in patients undergoing revision total knee arthroplasty (rTKA). The aim of this study was to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or sufficient in preventing VTE in patients undergoing rTKAs versus 325-mg ASA BID. In 2017, our institution adopted a new protocol for VTE prophylaxis for arthroplasty patients. Patients initially received 325-mg ASA BID for 1 month and then changed to a lower dose of 81-mg BID. A retrospective review from 2011 to 2019 was conducted identifying 1,438 consecutive rTKA patients and 90-day postoperative outcomes including VTE, gastrointestinal, and wound bleeding complications, acute periprosthetic joint infection, and mortality. In the 74 months prior to protocol implementation, 1,003 rTKAs were performed and nine VTE cases were diagnosed (0.90%). After 26 months of the protocol change, 435 rTKAs were performed with one VTE case identified (0.23%). There was no significant difference in rates or odds in postoperative pulmonary embolism (PE; p = 0.27), DVT (p = 0.35), and total VTE rates (p = 0.16) among patients using either protocol. There were also no differences in bleeding complications (p = 0.15) or infection rate (p = 0.36). No mortalities were observed. In the conclusion, 81-mg ASA BID is noninferior to 325-mg ASA BID in maintaining low rates of VTE and may be safe for use in patients undergoing rTKA.

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.

Patients Who Do Not Receive Aspirin Because of Allergy Have an Increased Risk of Venous Thromboembolism Following Total Joint Arthroplasty

BACKGROUND

Patient-reported allergies to aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) may preclude certain patients from receiving aspirin as venous thromboembolism (VTE) prophylaxis after total joint arthroplasty (TJA). The purpose of the study was to (1) determine whether the use of non-aspirin agents due to a self-reported aspirin or NSAID allergy was associated with a higher incidence of VTE and (2) determine the rate of true allergic reactions in patients who reported an allergy but still received aspirin.

METHODS

Prospectively collected data from 45,171 patients who underwent primary TJA between 2000 and 2019 were reviewed. Patients who reported an allergy to aspirin or NSAIDs were identified (n = 823). Using a validated VTE risk calculator, each patient was assigned a risk score based on 26 comorbidities. Bleeding complications, VTEs that occurred within 90 days postoperatively, and allergic reactions were collected as end points. Multivariable logistic regression was performed to determine the factors associated with VTE.

RESULTS

The overall incidence of aspirin or NSAID allergy was 1.8%. Only 80 of 267 patients (30%) reported an allergy to only aspirin and still received aspirin. Compared with patients who received aspirin without a history of allergy (n = 17,648), patients who received non-aspirin thromboprophylaxis due to allergy (n = 383) had a higher incidence of VTE (2.87% versus 0.24%, p < 0.001). On multivariable regression, these patients had an 8-fold increase in VTE risk (adjusted odds ratio, 7.94; 95% confidence interval, 2.86 to 22.07; p < 0.001). The incidence of true allergic reactions to aspirin among those with a reported allergy was 1.8% (number needed to harm = 55). No patients developed anaphylaxis or severe hypersensitivity reactions.

CONCLUSIONS

Patients with a self-reported allergy to aspirin or NSAIDs were at a significantly increased risk for VTE if they received non-aspirin thromboprophylaxis agents following TJA. Future research should evaluate the usefulness of preoperative allergy testing when selecting a VTE prophylactic agent in patients with self-reported allergies.

LEVEL OF EVIDENCE

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

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.

Equivalent VTE rates after total joint arthroplasty using thromboprophylaxis with aspirin versus potent anticoagulants: retrospective analysis of 4562 cases across a diverse healthcare system

BACKGROUND

Guidelines support aspirin thromboprophylaxis for primary total hip and knee arthroplasty (THA and TKA) but supporting evidence has come from high volume centers and the practice remains controversial.

METHODS

We studied 4562 Medicare patients who underwent elective primary THA (1736, 38.1%) or TKA (2826, 61.9%) at 9 diverse hospitals. Thirty-day claims data were combined with data from the health system's electronic medical records to compare rates of venous thromboembolism (VTE) between patients who received prophylaxis with: (1) aspirin alone (47.3%), (2) a single, potent anticoagulant (29%), (3) antiplatelet agents other than aspirin or multiple anticoagulants (21.5%), or (4) low-dose subcutaneous unfractionated heparin or no anticoagulation (2.2%). Sub-analyses separately evaluating THA, TKA and cases from lower volume hospitals (n = 975) were performed.

RESULTS

The 30-day VTE incidence was 0.6% (29/4562). VTE rates were equal in patients receiving aspirin and those receiving a single potent anticoagulant (0.5% in both groups). Patients with VTE were significantly older than patients without VTE (mean 76.5 vs. 73.1 years, P = 0.04). VTE rate did not associate with sex or hospital case volume. On bivariate analysis considering age, aspirin did not associate with greater VTE risk compared to a single potent anticoagulant (OR = 2.1, CI = 0.7-6.3) with the numbers available. Odds of VTE were increased with use of subcutaneous heparin or no anticoagulant (OR = 6.4, CI = 1.2-35.6) and with multiple anticoagulants (OR = 3.6, CI = 1.1-11.2). THA and TKA demonstrated similar rates of VTE (0.5% vs. 0.7%, respectively, P = 0.43). Of 975 cases done at lower volume hospitals, 387 received aspirin, none of whom developed VTE.

CONCLUSIONS

This study provides further support for aspirin as an effective form of pharmacological VTE prophylaxis after total joint arthroplasty in the setting of a multi-modal regimen using 30-day outcomes. VTE occurred in 0.7% of primary joint arthroplasties. Aspirin prophylaxis did not associate with greater VTE risk compared to potent anticoagulants in the total population or at lower volume hospitals.

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.

Aspirin Compared With Other Anticoagulants for Use as Venous Thromboembolism Prophylaxis in Elective Orthopaedic Hip and Knee Operations: A Narrative Literature Review

Although total hip and knee arthroplasty are effective methods for treating arthritis, they have an associated risk of venous thromboembolism (VTE). To reduce this risk, prophylactic agents including aspirin, low-molecular-weight Heparin, vitamin K antagonists, and direct oral anticoagulants are employed for up to 35 days after surgery. This narrative literature review utilised a systematic approach to critically assess the current evidence surrounding the use of aspirin for VTE prophylaxis compared to anticoagulants. An advanced multistage electronic search was performed in May 2021 using the OVID/Medline and Embase online libraries to identify available studies relevant to the subject from 1974. Additional studies identified during the review process were also included. The final studies meeting the inclusion criteria were then assessed using the Critical Appraisal Skills Programme tool. A total of 12 (60%) studies (two meta-analyses, three randomised trials, seven retrospective studies) favoured aspirin over anticoagulants for VTE prophylaxis. A total of 15 (75%) studies (two meta-analyses, three randomised trials, nine retrospective, one matched cohort) reported that aspirin had better bleeding profiles and complication rates, which was statistically significant in seven (46.7%) studies (one randomised trial, six retrospective studies). A total of eight studies (one randomised trial, six retrospective studies, one matched cohort) reported statistically significant results for aspirin. Five (62.5%) studies reported aspirin to be superior for VTE prophylaxis, while seven (87.5%) reported aspirin to be superior in terms of bleeding complications. The current evidence indicates that aspirin is superior to anticoagulants, in their various iterations, for VTE prophylaxis in terms of their bleeding profiles.

Low-Dose vs Regular-Dose Aspirin for Venous Thromboembolism Prophylaxis in Primary Total Joint Arthroplasty

BACKGROUND

Consensus on whether low-dose (81 mg) or regular-dose (325 mg) aspirin (ASA) is more effective for venous thromboembolism (VTE) chemoprophylaxis in primary total joint arthroplasties (TJAs) is not reached. The goal of this study is to evaluate the efficacy of low-dose and regular-dose ASA for VTE chemoprophylaxis in primary total hip arthroplasties and total knee arthroplasties.

METHODS

We retrospectively identified 3512 primary TJAs (2344 total hip arthroplasties and 1168 total knee arthroplasties) with ASA used as VTE chemoprophylaxis between 2000 and 2019. Patients received ASA twice daily for 4-6 weeks after surgery with 961 (27%) receiving low-dose ASA and 2551 (73%) receiving regular-dose ASA. The primary endpoint was 90-day incidence of symptomatic VTEs. Secondary outcomes were gastrointestinal (GI) bleeding events and mortality. The mean age at index TJA was 66 years, 54% were female, and mean body mass index was 31 kg/m². The mean Charlson Comorbidity Index was 3.5. Mean follow-up was 3 years.

RESULTS

There was no difference in 90-day incidence of symptomatic VTEs between low-dose and regular-dose ASA (0% vs 0.1%, respectively; P = .79). There were no GI bleeding events in either group. There was no difference in 90-day mortality between low-dose and regular-dose ASA (0.3% vs 0.1%, respectively; P = .24).

CONCLUSION

In 3512 primary TJA patients treated with ASA, we found a cumulative incidence of VTE <1% at 90 days. Although this study is underpowered, it appears that twice daily low-dose ASA was equally effective to twice daily regular-dose ASA for VTE chemoprophylaxis, with no difference in risk of GI bleeds or mortality.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Aspirin Use for Venous Thromboembolism Prevention Is Safe and Effective in Overweight and Obese Patients Undergoing Revision Total Hip and Knee Arthroplasty

BACKGROUND

Venous thromboembolism (VTE), defined as pulmonary embolism or deep venous thrombosis, is a rare but serious complication following revision total hip arthroplasty (RTHA) and revision total knee arthroplasty (RTKA). Previous studies show that obesity may be associated with an increased risk for pulmonary embolism, wound complications, and infection. With no current universal standard of care for VTE prophylaxis, we sought to determine whether aspirin prescribed (ASA) is safe and effective in obese patients undergoing RTHA/RTKA.

METHODS

A retrospective review of 1578 consecutive RTHA/RTKA cases (751 RTHAs and 827 RTKAs) was conducted identifying patients prescribed 325 or 81 mg ASA. Ninety-day postoperative VTE rates, bleeding, wound complications, deep infections, and mortality were collected. Cohorts were stratified according to body mass index (BMI): normal (18-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-34.9 kg/m²), severely obese (35-39.9 kg/m²), and morbidly obese (≥40 kg/m²).

RESULTS

The cohort comprised of 335 patients with a normal BMI, 511 were overweight, 408 obese, 232 severely obese, and 92 morbidly obese. Total VTE rates were statistically similar between BMI groups (0.90% vs 0.78% vs 0.74% vs 0.43% vs 0%, P = .89). There were no differences in bleeding rates (0.90% vs 0% vs 0% vs 0.43% vs 0%, P = .08), wound complications (0.30% vs 0.20% vs 0.25% vs 0% vs 0%, P = .93), infection (1.49% vs 1.57% vs 0.98% vs 1.29% vs 1.09%, P = .66), or mortality (0% vs 0.20% vs 0% vs 0% vs 0%, P = .72).

CONCLUSION

ASA is safe and effective for VTE prevention in obese patients with similar complication rates to nonobese patients undergoing RTHA/RTKA.

Aspirin Is Safe for Venous Thromboembolism Prophylaxis for Patients With a History of Gastrointestinal Issues

BACKGROUND

The safety of acetylsalicylic acid (ASA, aspirin) in patients with prior history of gastroesophageal reflux or peptic ulcer disease remains unclear. The purpose of this study was to determine the safety of ASA for venous thromboembolism (VTE) prophylaxis after total joint arthroplasty in patients with prior history of gastrointestinal (GI) issues.

METHODS

This was an institutional, retrospective cohort study of 19,044 patients who underwent primary total hip and total knee arthroplasty from 2013 to 2019. We divided the patients into two cohorts based on the presence or absence of pre-existing GI issues. Patient demographics, VTE prophylaxis, and postoperative complications were collected. The primary outcome measure was GI bleed.

RESULTS

In our series, 3090 patients had a preoperative GI issue and 15,954 did not have a GI issue. ASA was the most common mode of VTE prophylaxis (89%), followed by Coumadin (4.7%), direct oralanticoagulants (4.2%), low-molecular-weight heparin (1.7%), and others (0.4%). In the cohort of patients given ASA, there was no significant difference in postoperative GI bleeding between those with (2/1781, 0.11%) and without preoperative GI issues (8/7,628, 0.10%, P = 1.0). In the overall cohort, history of preoperative GI issues was associated with an increased risk of postoperative GI bleeding (0.32% vs 0.11%, P = .031). In logistic regression analysis, ASA was associated with a protective effect against GI bleed (OR = 0.09, 95% CI 0.01-0.40, P = .003).

CONCLUSION

ASA is safe for VTE prophylaxis after total joint arthroplasty in patients with history of GI issues and is not associated with an increased risk of postoperative GI bleeds.

Utilization Patterns, Efficacy, and Complications of Venous Thromboembolism Prophylaxis Strategies in Revision Hip and Knee Arthroplasty as Reported by American Board of Orthopaedic Surgery Part II Candidates

BACKGROUND

The optimum venous thromboembolism (VTE) prophylaxis strategy to minimize risk of VTE and bleeding complications following revision total hip and knee arthroplasty (rTHA/rTKA) is controversial. The purpose of this study is to describe current VTE prophylaxis patterns following revision arthroplasty procedures to determine efficacy, complication rates, and prescribing patterns for different prophylactic strategies.

METHODS

The American Board of Orthopaedic Surgery Part II (oral) examination case list database was analyzed. Current Procedural Terminology codes for rTHA/rTKA were queried and geographic region, VTE prophylaxis strategy, and complications were obtained. Less aggressive prophylaxis patterns were defined if only aspirin and/or sequential compression devises were utilized. More aggressive VTE prophylaxis patterns were considered if any of low-molecular-weight heparin (enoxaparin), warfarin, rivaroxaban, fondaparinux, or other strategies were used.

RESULTS

In total, 6387 revision arthroplasties were included. The national rate of less aggressive VTE prophylaxis strategies was 35.3% and more aggressive in 64.7%. Use of less aggressive prophylaxis strategy was significantly associated with patients having no complications (89.8% vs 81.9%, P < .001). Use of more aggressive prophylaxis patterns was associated with higher likelihood of mild thrombotic (1.2% vs 0.3%, P < .001), mild bleeding (1.7% vs 0.6%, P < .001), moderate thrombotic (2.6% vs 0.4%, P < .001), moderate bleeding (6.2% vs 4.0%, P < .001), severe bleeding events (4.4% vs 2.4%, P < .001), infections (6.4% vs 3.8%, P < .001), and death within 90 days (3.1% vs 1.3%, P < .001). There were no significant differences in rates of fatal pulmonary embolism (0.1% vs 0.04%, P = .474). Subgroup analysis of rTHA and rTKA patients showed similar results.

CONCLUSION

The individual rationale for using a more aggressive VTE prophylaxis strategy was unknown; however, more aggressive strategies were associated with higher rates of bleeding and thrombotic complications. Less aggressive strategies were not associated with a higher rate of thrombosis.

LEVEL OF EVIDENCE

Therapeutic Level III.

Aspirin versus enoxaparin for the initial prevention of venous thromboembolism following elective arthroplasty of the hip or knee: A systematic review and meta-analysis

BACKGROUND

Aspirin is perceived to be non-inferior to enoxaparin, a low-molecular-weight heparin, for the prevention of venous thromboembolism (VTE) following elective arthroplasty of the hip or knee and is recommended in clinical guidelines internationally. Previous systematic reviews of aspirin as VTE prophylaxis have been limited by the inclusion of heterogenous studies where aspirin is commenced after the initial high-risk postoperative period. The purpose of this systematic review and meta-analysis was to compare the efficacy and associated harms of aspirin and enoxaparin when used as VTE prophylaxis in the initial postoperative period following elective arthroplasty of the hip or knee. We sought to: (1) to compare the use of aspirin versus enoxaparin following elective joint replacement of the hip or knee on the primary outcomes of incidence of VTE and mortality up to 3 months postoperatively and (2) assess the efficacy of aspirin with respect to secondary outcomes such as major or minor bleeding events. We hypothesised that aspirin would have equivalent efficacy for the prevention of VTE when used as initial prophylactic agent, without increasing harm from bleeding events.

PATIENTS AND METHODS

We searched Pubmed, Embase, Medline and Cochrane Central for randomized controlled trials reporting the primary outcomes of VTE incidence and mortality. Secondary outcomes included major (compromise of organ, limb or muscle function requiring unplanned re-operation) and minor bleeding events (wound ooze, minor bleed, infection). Included trials underwent a risk of bias and quality of evidence assessment using the GRADE criteria.

RESULTS

Four trials involving 1507 participants who underwent elective lower limb arthroplasty were included. We did not detect a significant difference in overall VTE rates when comparing aspirin versus enoxaparin (RR, 0.84; 95% CI: 0.41 to 1.75; p=0.65). Mortality was reported by one study and no events were recorded. There were no significant differences in the rates of all major (RR, 0.84; 95% CI: 0.08 to 9.16) or minor (RR, 0.77; 95% CI: 0.34 to 1.72) bleeding events between the aspirin and enoxaparin groups. Included trials demonstrated a significant risk of bias, and Low to Very Low quality of evidence for primary outcomes, and Moderate to Very Low for secondary outcomes.

CONCLUSION

There is currently a lack of high quality randomised controlled trials supporting the use of aspirin as VTE chemoprophylaxis in the initial postoperative period for both total hip and total knee arthroplasty. The results of this meta-analysis provide cautious endorsement for the position that aspirin is likely a safe alternative to enoxaparin for TKA patients as part of a multimodal enhanced recovery protocol, but care is advised for THA patients owing to a lack of data from trials. Current evidence from randomized controlled trials is generally of low quality, and does not estimate critical event data for VTE incidence or mortality, as well as major and minor bleeding events with sufficient certainty. PROSPERO Registration CRD42018110784.

LEVEL OF EVIDENCE

II, systematic review.

Comparison of Surgical Site Infection Risk Between Warfarin, LMWH, and Aspirin for Venous Thromboprophylaxis in TKA or THA: A Systematic Review and Meta-Analysis

BACKGROUND

Infection following arthroplasty can have devastating effects for the patient and necessitate further surgery. Venous thromboembolism (VTE) prophylaxis is required to minimize the risk of deep venous thrombosis and pulmonary embolism. Anticoagulation has been demonstrated to interfere with wound-healing and increase the risk of infection. We hypothesized that different anticoagulation regimes will have differing effects on rates of periprosthetic joint infection. The aim of this study was to compare the surgical site infection risk between the use of warfarin, low-molecular-weight heparin (LMWH), and aspirin for VTE prophylaxis following total knee or hip arthroplasty.

METHODS

A systematic literature search was conducted in November 2018 using the PubMed, CINAHL, and Cochrane Central Register of Controlled Trials (CENTRAL) databases to identify studies that compared warfarin, LMWH, and/or aspirin with regard to surgical site infection rates following hip or knee arthroplasty. Meta-analyses were performed to compare the infection and VTE risks between groups.

RESULTS

Nine articles involving 184,037 patients met the inclusion criteria. Meta-analysis showed that warfarin prophylaxis was associated with a higher risk of deep infection (or infection requiring reoperation) (odds ratio [OR] = 1.929, 95% confidence interval [CI] = 1.197 to 3.109, p = 0.007) and surgical site infection overall (OR = 1.610, 95% CI = 1.028 to 2.522, p = 0.038) compared with aspirin in primary total joint arthroplasty, with similar findings also seen when primary and revision procedures were combined. There was no significant difference in infection risk between warfarin and LMWH and between LMWH and aspirin. There was a nonsignificant trend for VTE risk to be higher with warfarin compared with aspirin therapy for primary procedures (OR = 1.600, 95% CI = 0.875 to 2.926, p = 0.127), and this was significant when both primary and revision cases were included (OR = 2.674, 95% CI = 1.143 to 6.255, p = 0.023).

CONCLUSIONS

These findings caution against the use of warfarin for VTE prophylaxis for hip and knee arthroplasty. Further randomized head-to-head trials and mechanistic studies are warranted to determine how specific anticoagulants impact infection risk.

LEVEL OF EVIDENCE

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

Persistent Wound Drainage among Total Joint Arthroplasty Patients Receiving Aspirin vs Coumadin

BACKGROUND

Persistent wound drainage (PWD) is one of the major risk factors for periprosthetic joint infections (PJI), arguably the most dreaded complications after a total hip and knee arthroplasty (THA and TKA). The aim of this study is to identify the rates of PWD among THA and TKA patients who received aspirin (ASA) or Coumadin for postoperative venous thromboembolism (VTE) prophylaxis.

METHODS

Retrospective review of 5516 primary THA and TKA was performed. Patients with PWD were identified. Chi-square test was used to compare the incidences of PWD, 30-day VTE, and PJI at 6 months between the ASA and Coumadin groups. Multivariate regression model was used to identify independent risk factors for PWD using Charlson and Elixhauser comorbidity indexes.

RESULTS

The prevalence of PWD was 6.4% (353/5516). Patients receiving ASA had lower incidence of PWD (3.2% vs 8.5%, P < .0001) while having comparable rates of 30-day VTE (1.3% vs 1.4%, P = .722) and PJI at 6 months (1.8% vs 1.4%, P = .233) compared to those receiving Coumadin. Risk factors for PWD were diabetes (odds ratio [OR], 19.3; 95% confidence interval [CI], 11.8-23.2), rheumatoid arthritis (OR, 15.3; 95% CI, 10.8-17.2), morbid obesity (OR, 13.2; 95% CI, 9.7-17.5), chronic alcohol use (OR, 3.5; 95% CI, 1.8-5.5), hypothyroidism (OR, 1.9; 95% CI, 1.1-3.2), and Coumadin (OR, 1.7; 95% CI, 1.2-2.2).

CONCLUSION

Use of ASA is associated with significantly lower rates of PWD after THA and TKA when compared to Coumadin while being equally efficacious at preventing VTE. Coumadin was found to be an independent risk factor for PWD.

Venous thromboprophylaxis after total hip arthroplasty: aspirin, warfarin, enoxaparin, or factor Xa inhibitors?

INTRODUCTION

Debate over the ideal agent for venous thromboembolism (VTE) prophylaxis after total hip arthroplasty (THA) has led to changes in prescribing trends of commonly used agents. We investigate variation in utilisation and the differences in VTE incidence and bleeding risk in primary THA after administration of aspirin, warfarin, enoxaparin, or factor Xa inhibitors.

METHODS

8829 patients were age/sex matched from a large database of primary THAs performed between 2007 and 2016. Utilisation was calculated using compound annual growth rate. Incidence of postoperative deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding-related complications, postoperative anaemia, and transfusion were identified at 2 weeks, 30 days, 6 weeks, and 90 days.

RESULTS

Aspirin use increased by 33%, enoxaparin by 7%, and factor Xa inhibitors by 31%. Warfarin use decreased by 1%. Factor Xa inhibitors (1.7%) and aspirin (1.7%) had the lowest incidence of DVT followed by enoxaparin (2.6%), and warfarin (3.7%) at 90 days. Factor Xa inhibitors (12%) and aspirin (12%) had the lowest incidence of blood transfusion followed by warfarin (15%) and enoxaparin (17%) at 90 days. There was no difference in incidence of blood transfusion or bleeding-related complications nor any detectable difference in symptomatic PE incidence.

CONCLUSIONS

The utilisation of aspirin and factor Xa inhibitors increased over time. Aspirin and factor Xa inhibitors provided improved DVT prophylaxis with lower rates of postoperative anaemia compared to enoxaparin and warfarin.

Multimodal prophylaxis in patients with a history of venous thromboembolism undergoing primary elective hip arthroplasty

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Methods

Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality.

Results

Postoperative VTE was diagnosed in seven patients (2.5%): DVT in five, and PE with and without DVT in one patient each. After hospitalization, three patients required readmiss-ion for evacuation of a haematoma, one for wound drainage, and one for monitoring of an elevated international normalized ratio (INR). Seven patients died (2.5%). One patient died five months postoperatively of a PE during open thrombectomy. She had discontinued anticoagulation. One patient died of a haemorrhagic stroke while receiving Coumadin. PE or bleeding was not suspected in the remaining five fatalities.

Conclusion

Multimodal prophylaxis is safe and effective in patients with a history of VTE. Postoperative anticoagulation should be prudent as very few patients developed VTE (2.5%) or died of suspected or confirmed PE. Mortality during the first year was mostly unrelated to either VTE or bleeding. Cite this article: Bone Joint J 2020;102-B(7 Supple B):71–77.

Review of Therapeutic Options for the Prevention of VTE in Total Joint Arthroplasty

Hip and knee arthroplasty patients are at high risk of perioperative venous thromboembolic events (VTE). VTE has been well studied in this population and it is recommended that total joint arthroplasty recipients receive chemoprophylactic anticoagulation due to risk factors inherent to the surgical intervention. There are few concise resources for the orthopedic surgeon that summarize data regarding post-operative anticoagulation in the context of currently available therapeutic options and perioperative standards of practice. The periodic reexamination of literature is essential as conclusions drawn from studies predating perioperative protocols that include early mobilization and sequential compression devices as standards of practice in total joint arthroplasty are no longer generalizable to modern-day practice. We reviewed a large number of recently published research studies related to post-operative anticoagulation in total joint arthroplasty populations that received a high Level of Evidence grade. Current literature supports the use of oral aspirin regimens in place of more aggressive anticoagulants, particularly among low risk patients. Oral aspirin regimens appear to have the additional benefit of lower rates of bleeding and wound complications. Less consensus exists among high risk patients and more potent anticoagulants may be indicated. However, available evidence does not demonstrate clear superiority among current options, all of which may place patients at a higher risk of bleeding and wound complications. In this situation, chemoprophylactic selection should reflect specific patient needs and characteristics.

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.

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.

Lower limb joint repair and replacement: an overview

In the last few years, much has been published concerning total joint arthroplasty, and debates and discussions to new questions and points of view started many years ago. In this commentary, we report the latest evidence of best practice in the field of lower limb arthroplasty; this evidence is based on a literature search conducted by using PubMed and Scopus databases with a time limit of five years. We found novel evidence regarding cemented and not cemented implant, implant design, anticoagulant use, tourniquets, and other aspects of joints replacement surgery that we consider a common part of modern orthopedic practice. We specifically focus on lower limb joint replacement.

Aspirin alleviates orthopedic implant‑associated infection

Implant-associated infection (IAI), a common condition marked by progressive inflammation and bone destruction, is mentally and financially devastating to those it affects, causing severe morbidity, prolonged hospital admissions, significant hospital costs and, in certain cases, mortality. Aspirin, a popular synthetic compound with a history of >100 years, is antipyretic, anti-inflammatory and analgesic. It is the most active component of non-steroidal anti-inflammatory drugs. However, the effects of aspirin on IAI remain unknown. In the present study, an IAI animal model was used, in which a stainless steel pin coated with Staphylococcus aureus was implanted through the left shaft of the tibia in mice. The animals were then randomized into five groups and subjected respectively to IAI, IAI + 15 mg aspirin treatment, IAI + 30 mg aspirin treatment, IAI + 60 mg aspirin treatment and IAI + 120 mg aspirin treatment groups. Aspirin was injected intraperitoneally twice daily for 11 days. Micro-CT and histological assays were performed to assess the effects of aspirin on IAI. It was found that aspirin reduced osteolysis and periosteal reaction, inhibited the activation of osteoclasts, promoted the activation of osteoblasts and facilitated healing of the infected fracture.

The risk factors and an evidence-based protocol for the management of persistent wound drainage after total hip and knee arthroplasty

Background

Persistent wound drainage (PWD) is one of the major risk factors for periprosthetic joint infections (PJIs), arguably the most dreaded complication after total joint arthroplasty (TJA). The aim of this study was to identify the risk factors for PWD and provide a stepwise management protocol for it.

Methods

A retrospective review of 4873 TJAs was performed. After determining patients with PWD, a logistic regression model was designed to identify the risk factors using Charlson and Elixhauser comorbidity indexes. Finally, the protocol that was instituted for the management of PWD and its success rate was presented.

Results

The prevalence of PWD was 6.2% (302 of 4873). Of these, 196 did not require any surgical interventions, and drainage stopped with local wound care. 106 patients required surgical intervention, of which, 64 underwent superficial irrigation and debridement and 42 underwent deep irrigation and debridement with modular components exchange. Patients with PWD had significantly higher rates of PJI (odds ratio [OR]: 16.9; 95% confidence interval [CI]: 9.1-31.6). Risks factors were diabetes (OR: 21.2; 95% CI: 12.8-25.1), morbid obesity (OR: 17.3; 95% CI: 14.7-21.5), rheumatoid arthritis (OR: 14.2; 95% CI: 11.7-16.5), chronic alcohol use (OR: 4.3; 95% CI: 2.3-6.1), hypothyroidism (OR: 2.8; 95% CI: 1.3-4.2), and female gender (OR: 1.9; 95% CI: 1.1-2.2).

Conclusions

Several modifiable risk factors of PWD were identified. Surgeons must be cognizant of these comorbidities and optimize patients’ general health before an elective TJA. Our results demonstrated that PWD ceased in about 65% of the patients with local wound care measures alone. Patients with PWD were at substantially higher risk for PJI.