Thromboprophylaxis with dabigatran leads to an increased incidence of wound leakage and an increased length of stay after total joint replacement

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.

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).

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.

Incidence and risk factors associated with venous thromboembolism following primary total hip arthroplasty in low-risk patients when using aspirin for prophylaxis

AIMS

The primary aim was to assess the incidence of venous thromboembolism (VTE) following total hip replacements (THR) in a low-risk patient group when using 150 mg aspirin as the pharmacological component of VTE prophylaxis on discharge. The secondary aim was to identify factors associated with an increased risk of a VTE event in this low-risk group.

PATIENTS AND METHODS

Retrospective review of a consecutive cohort of patients undergoing THR during a 63-month period. Patient demographics, socio-economic status, ASA grade, type of anaesthetic, length of surgery and BMI were recorded. A diagnosis of VTE was assigned to symptomatic patients with positive imaging for a deep vein thrombosis (DVT) and/or a pulmonary embolism (PE) within 8 weeks of surgery. Multivariate logistic regression modeling was used to identify factors associated with VTE after THR.

RESULTS

3880 patients underwent THR during the study period, of which 2740 (71%) were low risk and prescribed aspirin for VTE prophylaxis. There were 34 VTE events, of which 15 were DVTs and 18 were PEs, with 1 patient diagnosed with both. The incidence of VTE was 1.2%, with no VTE-related deaths. Patients incurring a VTE postoperatively were more likely to be male (odds ratio [OR] 2.06, p = 0.022), of older age (OR 0.43, p = 0.047) and were more likely to be socially deprived (OR 0.32, p = 0.006). There was no significant difference with patients given low-molecular-weight heparin (LMWH) as an inpatient prior to discharge on aspirin (p = 0.806), nor any difference with the type of anaesthetic used during surgery (p = 0.719).

CONCLUSIONS

Aspirin is a relatively safe and effective choice for VTE prophylaxis in low-risk patients undergoing THR. Male sex and age >70 years were twice as likely to sustain a VTE and patients from the most deprived socio-economic background are 3 times as likely.

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.

Comparison of Surgical Site Complications With Negative Pressure Wound Therapy vs Silver Impregnated Dressing in High-Risk Total Knee Arthroplasty Patients: A Matched Cohort Study

BACKGROUND

Closed incision negative pressure wound therapy (ciNPWT) may reduce surgical site complications following total joint arthroplasty. Although unlikely necessary for all patients, the criteria for utilizing ciNPWT in primary total knee arthroplasty (TKA) remain poorly defined. This study's purpose was to compare the incidence of incisional wound complications, non-incisional complications (ie, dressing reactions), reoperations, and periprosthetic joint infections (PJIs) among a group of high-risk primary TKA patients treated with ciNPWT vs an occlusive silver impregnated dressing.

METHODS

One hundred thirty high-risk primary TKA patients treated with ciNPWT were 1:1 propensity matched and compared to a historical control group treated with an occlusive silver impregnated dressing. High-risk criteria included the following: active tobacco use, diabetes mellitus, body mass index >35 kg/m², autoimmune disease, chronic kidney disease, Staphylococcus aureus nasal colonization, and non-aspirin anticoagulation.

RESULTS

Age, gender, and risk factor profile were comparable between cohorts. The ciNPWT cohort had significantly fewer incisional wound complications (6.9% vs 16.2%; P = .031) and significantly more non-incisional complications (16.9% vs 1.5%; P < .001). No dressing reactions required clinical intervention. There were no differences in reoperations or periprosthetic joint infections (P = 1.000). In multivariate analysis, occlusive silver impregnated dressings (odds ratio 2.9, 95% confidence interval 1.3-6.8, P = .012) and non-aspirin anticoagulation (odds ratio 2.5, 95% confidence interval 1.1-5.6, P = .028) were associated with the development of incisional wound complications.

CONCLUSION

Among high-risk patients undergoing primary TKA, ciNPWT decreased incisional wound complications when compared to occlusive silver impregnated dressings, particularly among those receiving non-aspirin anticoagulation. Although an increase in dressing reactions was observed, the clinical impact was minimal.

Prevention of venous thromboembolism with aspirin following knee surgery: A systematic review and meta-analysis

Venous thromboembolism (VTE) is a well-known complication following orthopaedic surgery. The incidence of this complication has decreased substantially since the introduction of routine thromboprophylaxis. However, concerns have been raised about increased bleeding complications caused by aggressive thromboprophylaxis.Attention has grown for aspirin as a safer thromboprophylactic agent following orthopaedic surgery.A systematic review using MEDLINE, Embase and Web of Science databases was undertaken to compare the effectiveness of aspirin prophylaxis following knee surgery with the current standard prophylactic agents (low molecular weight heparin [LMWH], vitamin K antagonists and factor Xa inhibitors).No significant difference in effectiveness of VTE prevention was found between aspirin, LMWH and warfarin. Factor Xa inhibitors were more effective, but increased bleeding complications were reported.As evidence is limited and of low quality with substantial heterogeneity, further research with high-quality, adequately powered trials is needed. Cite this article: EFORT Open Rev 2021;6:892-904. DOI: 10.1302/2058-5241.6.200120.

Wound complications and bleeding with new oral anticoagulants in patients undergoing total joint arthroplasty: A systematic review and meta-analysis of randomized controlled trials

AIMS

The results of associations between new oral anticoagulants (NOACs) and wound complications after total joint arthroplasty remain inconsistent. We conducted a systematic review and meta-analysis of randomized controlled trials to make comparisons with low molecular weight heparins (LMWH) on the clinical outcomes of total wound complications, together with other efficacy and safety endpoints to further evaluate the safety and efficacy of NOACs.

METHODS

This meta-analysis was conducted based on a published protocol (PROSPERO: CRD42019140841). We searched for available articles in PubMed, Embase and Cochrane Library through Jun 62 021. Random-effects meta-analyses, including subgroup analyses, were conducted to estimate the pooled relative risk (RR) and 95% confidence interval (CI) for specific doses of NOACs.

RESULTS

We retrieved 1683 studies, of which 20 were eligible for inclusion. We found that apixaban was associated with a lower incidence of total wound complications compared with LMWH (RR = 0.81; 95% CI: 0.65-1.00), while dabigatran and rivaroxaban did not increase the risk of total wound complications. In addition, apixaban was associated with a reduction in the risk of major/clinically relevant nonmajor bleeding events compared to LMWH (RR = 0.80, 95% CI: 0.65-0.99), while rivaroxaban increased the risk for major/clinically relevant nonmajor bleeding events (RR = 1.23, 95% CI: 1.02-1.50). Moreover, all 4 NOACs were associated with lower incidences of major venous thromboembolism compared with LMWH.

CONCLUSION

A lower risk of wound complications was detected for apixaban, while dabigatran and rivaroxaban did not increase the risk when compared with LMWH. The efficacy of 4 NOACs was broadly similar.

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.

Impact of Weight-Band Dosing of Tinzaparin for Venous Thromboembolism Prophylaxis on Persistent Wound Drainage in Adult Patients Undergoing Hip and Knee Arthroplasty

BACKGROUND

Persistent wound drainage and venous thromboembolism (VTE) are potential complications of total joint arthroplasty, and these risks can be challenging to balance in clinical practice. Anecdotal observation has suggested that following joint arthroplasty, persistent wound drainage occurs more frequently with higher body weight and higher doses of tinzaparin when compared with lower body weight and lower doses of tinzaparin.

OBJECTIVE

The overall purpose of this study was to describe the impact of a tinzaparin weight-band dosing table for VTE prophylaxis on wound healing, thrombosis, and bleeding outcomes in patients undergoing total joint arthroplasty.

METHODS

This retrospective chart review included patients who underwent total hip or knee arthroplasty and received tinzaparin for thromboprophylaxis per their weight-banding category. The primary outcome was the incidence of persistent wound drainage. Secondary outcomes include the occurrence of VTE and clinically important bleeding during hospital admission.

RESULTS

A total of 231 patients were included in the analysis. There was no significant difference in persistent wound drainage between the 3 weight categories, and there were no differences in rates of VTE or clinically important bleeding. Concurrent use of low-dose acetylsalicylic acid was associated with a 3-fold increased risk of persistent wound drainage (risk ratio = 3.35; 95% CI = 2.14-5.24; P = 0.00003).

CONCLUSION AND RELEVANCE

In joint arthroplasty patients, we observed no significant difference in rates of persistent wound drainage between various weight categories receiving different weight-banded doses of tinzaparin. Our results do not suggest that the current weight-band dosing table for tinzaparin needs to be adjusted to optimize patient outcomes.

Does venous thromboembolism prophylaxis affect the risk of venous thromboembolism and adverse events following primary hip and knee replacement? A retrospective cohort study

BACKGROUND

The optimum chemical venous thromboembolism (VTE) prophylactic agents following total hip and knee replacement (THR and TKR) remain unknown. NICE recommends multiple agents, including direct oral anticoagulants (DOACs), low-molecular weight heparin (LMWH), and aspirin. We assessed whether VTE prophylaxis affected the risk of VTE and adverse events following primary THR and TKR.

MATERIALS AND METHODS

We reviewed 982 elective primary THRs (59%) and TKRs (41%) at a large tertiary centre during 2018. The primary outcome was any VTE (DVT and/or PE) within 90-days. Secondary outcomes were adverse events within 90-days (major bleeding and wound complications). The association between VTE prophylaxis and outcomes was assessed.

RESULTS

The overall prevalence of VTE and adverse events were 2.7% (n = 27) and 15.2% (n = 136) respectively. The most common agents used were DOAC ± LMWH (50.7%, n = 498), followed by aspirin ± LMWH (35.5%, n = 349) and LMWH alone (4.7%, n = 46). The risk of VTE (aspirin ± LMWH = 3.7%, DOAC = 2.0%, LMWH = 2.2%) was not significantly different between agents (p = 0.294). The risk of any adverse event was significantly higher (p < 0.001) with aspirin ± LMWH (16.1%; n = 56) and LMWH (28.3%; n = 13) compared with DOACs ± LMWH (7.0%; n = 35) in TKRs only, there was no differences between agents for adverse events in THRs (p = 0.644).

CONCLUSIONS

Choice of thromboprophylaxis did not influence the risk of VTE following primary THR and TKR. DOACs (+/- LMWH) were associated with the lowest risk of adverse events. Large multicentre trials are still needed to assess the efficacy and safety of these agents following THR and TKR.

Analysis of the fluid biochemistry in patients with prolonged wound drainage after hip hemiarthroplasty

INTRODUCTION

The origin and content of prolonged wound drainage (PWD) after arthroplasty remain uncertain. In this study, we performed the biochemical, biological and advanced proteomic analysis of the drainage fluid collected from PWD patients following hip hemiarthroplasty (HA).

METHODS

Data of 28 patients who developed PWD after HA were prospectively analyzed. After examining the biochemical content of the drainage fluid collected on postoperative day 6, to find out if the drainage fluid was transudate or exudate, it was compared with the patient's serum values according to the Light criteria. Subsequently, biological and proteomic analyzes of both drainage fluid and serum were performed. The similarities and differences in terms of protein concentrations, protein identities were examined. In the drainage fluid, we analyzed lymph-specific proteins.

RESULTS

16 patients with PWD were male (61.1%), 12 were female (38.9%), and the mean age of all patients was 79.64 ± 8.44 (65-95). Biochemical test results of the drainage fluid / serum were as follows: Total protein: 2.1 / 5.2 g/dl, albumin: 1.3 / 3.1 g/dl, lactate dehydrogenase (LDH): 121/324 U/l, cholesterol: 28/160 mg/dl, triglyceride: 37/122 mg/dl, sodium (Na): 140/ 140mg/dl, potassium (K): 4.1/ 4.1 mg/dl. pH of the drainage fluid was 7.6. According to these biochemical values, drainage fluid was classified as transudate. As a result of protein identification, fibrinogen beta chain, keratin type 1, creatine kinase M-type protein were detected in drainage fluid. Subsequent western analysis revealed that, gliseraldehyde-3-phosphate dehydrogenase (GAPDH) and beta actin antibody were detected in the drainage fluid but not in serum.

CONCLUSION

Despite the similarity in serum and transudative PWD fluid in terms of biochemical content, we found that when we carried out further proteomic analysis, PWD contains lymph-specific proteins. Unlike PWD, these proteins were not determined in serum. PWD fluid can be also called as lymphorrhea. PWD fluid with abundant proteins may also provide an appropriate environment for the growth of microorganisms.

A Prospective Cohort Comparative Study of Rivaroxaban, Dabigatran, and Apixaban Oral Thromboprophylaxis in 2431 Hip and Knee Arthroplasty Patients: Primary Efficacy Outcomes and Safety Profile

BACKGROUND

Direct oral anticoagulants (DOACs) have promised superior efficacy to low molecular weight heparins in the prevention of venous thromboembolism (VTE) in total hip and knee arthroplasty. However, there are concerns about raised associated bleeding and wound problems with these agents. This study aims to evaluate and compare the efficacy and safety of the 3 DOAC drugs: rivaroxaban, dabigatran and apixaban.

METHODS

The primary outcome measures were rate of symptomatic VTE and major bleeding. Secondary outcome measures were wound healing problems and requirement for return to theater. A total of 2431 patients received one of the DOAC drugs as thromboprophylaxis following total hip arthroplasty (35 days) or total knee arthroplasty (14 days) between 2011 and 2015. Binary variables were compared between the 3 groups by using the chi-squared test or Fisher's exact test. Relative risks of selected primary and secondary end points were also calculated for the prespecified pairwise comparison.

RESULTS

The overall symptomatic VTE rate was 2%. Rivaroxaban had a statistically significant superior efficacy for overall VTE prevention (0.8% vs 2.6%) compared with dabigatran (P < .01) and apixaban (P < .01), and deep vein thrombosis prevention (0.3% vs 2.2%) over dabigatran (P < .01). The overall rate of major bleeding was 1.2% with no significant difference observed between the 3 studied drugs.

CONCLUSION

All 3 drugs had symptomatic VTE rates comparable with low molecular weight heparin from the published literature. Rivaroxaban appears to have superior efficacy in VTE prevention over apixaban and dabigatran. No statistical difference was observed for major bleeding with any of the 3 agents.

Real-world effectiveness and safety of pharmacological thromboprophylaxis in patients undergoing primary total hip and knee arthroplasty: A narrative review

In this narrative review of the real-world effectiveness and safety of pharmacological thromboprophylaxis following primary total hip and knee arthroplasty, a total of 12 non-interventional observational studies were included. Pharmacological thromboprophylaxis included warfarin, heparins, dabigatran, rivaroxaban, apixaban, acetylsalicylic acid, and fondaparinux. The absolute risks varied across the included studies. These variations can be explained by differences in patient populations, drug exposure, follow-up time, and definition of outcomes, which makes it a challenge to compare the risk estimates. These findings emphasize the need for a large population-based real-world study to provide comparable risk estimates associated with different pharmacological thromboprophylaxis.

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.

Should we use dabigatran or aspirin thromboprophylaxis in total hip and knee arthroplasty? A natural experiment

Background

Despite long clinical experience some authorities recommend against the use of aspirin for perioperative VTE prophylaxis and favour alternatives such as dabigatran. A change from Dabigatran to an Aspirin based protocol in a British district general hospital created the conditions of a natural experiment.

Methods

We conducted a single centre, retrospective study of 6-months using a dabigatran based protocol (THA n = 191, TKA n = 155) and 6-months using and aspirin based protocol (THA n = 165, TKA n = 136). Outcomes addressed include: VTE used, VTE events within 90-days, 30-day return to theatre (RTT) rates, and 90-day mortality.

Results

Pre-intervention, the dabigatran prescription rate was 73% (n = 139) and 78% (n = 123) with aspirin prescription post-intervention in 67% (n = 110) and 70% (n = 90) for THA and TKA respectively. We found a similar VTE rate when comparing dabigatran and aspirin groups for THA (2.2% vs. 0%, p = 0.17) and TKA (0.64% vs. 0%, p = 0.32). Similarly, no difference in the RTT rate was seen for THA (0.7% vs.2.7%, p = 0.23) or TKA (1.6% vs. 3.2%, p = 0.38).

Conclusion

No significant differences in safety were found comparing aspirin to dabigatran for VTE prophylaxis for lower limb arthroplasty which, has not been previously reported and represents significant cost saving implications.

Evaluation of early wound leakage as a risk factor for prosthetic joint infection

BACKGROUND AND PURPOSE

Prosthetic joint infection (PJI) is a serious complication resulting from total knee arthroplasty (TKA) or total hip arthroplasty (THA). In this study, patients with a PJI are compared with patients with an uncomplicated postoperative course to identify relevant risk factors for PJI.

METHODS

A matched case-control study was performed with patients undergoing fast-track, elective unilateral TKA or THA. The following data were collected: demographics, surgery-related characteristics (perioperative blood loss, use of cement, body temperature), and postoperative characteristics (hematoma formation, wound leakage, blood transfusion, length of stay [LOS]).

CONCLUSIONS

When the PJI group was compared with the control group, there was significantly more wound leakage during hospital stay (88% vs. 36%, p = .001) and early wound dressing changes in the first 3 days after surgery (88% vs. 40%, p = .002). Hematoma formation was observed more in the PJI patients group (44% vs. 10%, p = .005). A trend test revealed a significant association between the total number of wound dressing changes and development of PJI (p < .001); 72% of PJI patients had a length of stay of ≥4 days compared with 34% of controls (odds ratio 10.5; 95% CI [2.1-52.3]; p = .004).

IMPLICATIONS FOR PRACTICE

Early postoperative wound drainage and hematoma formation directly correlate with PJI. This resulted in a significantly higher number of dressing changes and longer LOS. The nurse practitioner has a central role in postoperative care and is the first to recognize signs of an adverse postoperative clinical course.

Thromboprophylaxis for Total Knee Arthroplasty

The authors report an update of the main methods for preventing deep vein thrombosis after total knee replacement, which are divided into mechanical and pharmacological methods. The current principal used drugs, their dosages, and the comparative risks and benefits are also reported.

Clinical Effectiveness of Aspirin as Multimodal Thromboprophylaxis in Primary Total Hip and Knee Arthroplasty: A Review of 6078 Cases

BACKGROUND

Venous thromboembolism is a serious complication after total hip and knee arthroplasty. There is still no consensus regarding the best mode of thromboprophylaxis after lower limb arthroplasty. The aim of this study was to ascertain the efficacy, safety profile, and rate of adverse thromboembolic events of aspirin as extended out-of-hospital pharmacological anticoagulation for elective primary total hip and knee arthroplasty patients and whether these rates were comparable with published data for low-molecular-weight heparin (LMWH).

METHODS

Data were extracted from a prospective hospital-acquired thromboembolism database. The period of study was from January 1, 2013 to December 31, 2016, and a total of 6078 patients were treated with aspirin as extended thromboprophylaxis after primary total hip and knee arthroplasty.

RESULTS

The primary outcome measure of deep vein thrombosis and pulmonary embolism within 90 days postoperatively was 1.11%. The secondary outcome rates of wound infection, bleeding complications, readmission rate, and mortality were comparable to published results after LMWH use.

CONCLUSION

The results of this study clearly show that aspirin, as part of a multimodal thromboprophylactic regime, is an effective and safe regime in preventing venous thromboembolism with respect to risk of deep vein thrombosis or pulmonary embolism when compared to LMWH. It is a cheaper alternative to LMWH and has associated potential cost savings.

A risk-stratification algorithm to reduce superficial surgical site complications in primary hip and knee arthroplasty

BACKGROUND

Surgical site complications (SSCs) are the most common cause for readmission after total joint arthroplasty (TJA), increasing costs while predisposing to inferior long-term outcomes. Prophylactic use of closed-incision negative pressure therapy (ciNPT) may lower the risk of these complications, especially in high-risk populations, but appropriate-use guidelines are lacking for patients undergoing primary TJA. We sought to develop a risk-stratification algorithm to guide use of ciNPT dressings and test its use in normalizing the rate of superficial SSCs among high-risk groups.

METHODS

We reviewed 323 consecutive primary TJAs, where 38% of those patients considered at elevated risk were risk-stratified to receive ciNPT dressings. An individual risk score was developed, assigning points based on patient-specific risk factors. We identified a historical control population of 643 patients who all received the same postoperative dressing to test the impact of this risk score.

RESULTS

Compared with historical controls, we observed a modest but significant improvement in superficial SSCs after implementation of risk-stratification (12.0% vs 6.8%; P = .013). Among high-risk patients, there was a marked improvement in SSCs when treated prophylactically with ciNPT dressings as compared with historical controls (26.2% vs 7.3%; P < .001). Low-risk patients, who continued to be treated with standard postoperative dressings, demonstrated no significant improvement (8.6% vs 6.5%; P = .344).

CONCLUSIONS

ciNPT dressings are effective at reducing and normalizing risks of superficial SSCs among high-risk primary arthroplasty patients. The proposed risk-stratification algorithm may help identify those patients who benefit most from these dressings.

Similar thromboprophylaxis with rivaroxaban and low molecular weight heparin but fewer hemorrhagic complications with combined intra-articular and intravenous tranexamic acid in total knee arthroplasty

PURPOSE

To evaluate the efficacy of the combined intravenous and intra-articular administration of tranexamic acid (TXA) to control the collateral effects and complications of rivaroxaban (RIV) after total knee arthroplasty (TKA) and to compare thromboprophylaxis schemes with and without TXA, RIV and low molecular weight heparin (LMWH).

MATERIALS AND METHODS

We prospectively studied 158 TKA patients from 2014 to 2018. The patients were randomly assigned into three groups. Group A (46 patients) was administered intravenous and intra-articular TXA and RIV postoperatively; group B (58 patients) was administered TXA as in group A and LMWH postoperatively; and group C (54 patients) was administered saline as in group A and RIV postoperatively. We evaluated blood loss, transfusion requirements and hemorrhagic complications.

RESULTS

Hct and Hb values significantly decreased in group C compared to groups A and B, without any difference between groups A and B. Suction drain blood volume output was significantly higher in group C compared to group A and B, without any difference between group A and B. Hemorrhagic complications were more common in group C. No patient experienced clinical findings of VTE.

CONCLUSION

Combined intravenous and intra-articular administration of TXA is safe and effective in TKA, with fewer hemorrhagic complications compared to placebo. Thromboprophylaxis with RIV and LMWH is similar.

Incidence of symptomatic venous thromboembolism in 2372 knee and hip replacement patients after discharge: data from a thromboprophylaxis registry in Montreal, Canada

Background

Low-molecular-weight heparin (LMWH) is a recommended anticoagulant for thromboprophylaxis after major orthopedic surgery. Dabigatran etexilate is an oral anticoagulant recognized as noninferior to LMWH. We aimed to assess the incidence of symptomatic venous thromboembolic events (VTEs) after discharge in patients who underwent joint replacement, using a hospital registry.

Patients and methods

Patients who underwent total knee and hip arthroplasty between September 2011 and March 2015 were selected. Subcutaneous enoxaparin (30 mg twice daily) was given during hospitalization. At discharge, patients received either enoxaparin 30 mg twice daily/40 mg once daily or dabigatran 220 mg/150 mg once daily. Patients were seen or called at 2, 6, and 12 weeks after surgery. Outcomes were the number of VTEs, including deep venous thrombosis, pulmonary embolism, and the number of major/minor bleeding events after discharge.

Results

After discharge, 1468 patients were prescribed enoxaparin and 904 dabigatran (1396 total knee arthroplasty and 976 total hip arthroplasty patients). Mean age was 66±10 years, and 60% were female. The cumulative incidence of VTEs during the 12-week follow-up was 0.7%. One patient sustained a VTE during the switch window. Seven patients sustained a pulmonary embolism (0.3%). There was no statistical difference between the total knee arthroplasty and total hip arthroplasty groups. The incidence of major and minor bleeding events during follow-up was 0.3% and 30.3%, respectively. These events had a higher incidence in the dabigatran group compared to the enoxaparin group after discharge (p<0.05), but not between knee and hip replacement groups for major bleeding events.

Conclusion

A pharmaceutical prophylaxis protocol using LMWH and dabigatran during the post-discharge period resulted in low incidences of VTE and equivalence between treatments. However, the increased number of major and minor bleeding events in patients taking dabigatran is of concern regarding the safety and needs to be evaluated using analyses adjusted for risk factors.

Effect of oral factor Xa inhibitor and low-molecular-weight heparin on surgical complications following total hip arthroplasty

This prospective study was conducted to report the effect of oral factor Xa inhibitor and low-molecular-weight heparin (LMWH) on surgical complications following total hip arthroplasty (THA). The patients with an age < 60 years were randomly assigned to three groups (rivaroxaban, enoxaparin, and placebo) and the patients with an age ≥ 60 years were assigned to two groups (rivaroxaban and enoxaparin). All drug regimens started at 12 hours postoperatively and continued for two weeks after surgery. Primary measure outcome was major surgical wound complications defined as haematoma requiring any intervention, superficial wound infection, deep periprosthetic infection, and increased wound bleeding. Secondary measured outcome included minor surgical complications (swelling, drainage, erythema, and oozing), organ bleeding, and venous thromboembolic (VTE) events. A total of 184 patients aged < 60 years and 167 patients aged ≥ 60 years were included as the analysis population per group. Up to 14 days after surgery, the overall incidence of major surgical complications associated with thromboprophylaxis was 6.5 % (58/886). There were no significant differences in the rate of major surgical complications among all the three groups of the patients aged < 60 years and between two groups of the patients aged ≥ 60 years. For the patients aged < 60 years, wound oozing continued significantly longer in the pharmacological group than in the placebo group, but wound infection did not occur in any case. The VTE events were similar in all the groups.

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.

Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis - A 12year study

BACKGROUND

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital.

METHODS

We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results.

RESULTS

The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE's occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%).

CONCLUSIONS

Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.

A comparison of apixaban and dabigatran etexilate for thromboprophylaxis following hip and knee replacement surgery

INTRODUCTION

Patients who have undergone hip or knee replacement surgery are exposed to a high risk of developing a post-operative venous thromboembolus and so have a need for an effective, medication-based, thrombosis prophylaxis. New orally active anticoagulants have been available for a few years now. These specific substances directly block either thrombin (e.g., dabigatran etexilate) or Factor Xa (e.g., apixaban). It is not clear whether there are any efficacy differences between these two substances because there have never been any head-to-head studies carried out.

MATERIALS AND METHODS

We have carried out a study comparing two new orally active anticoagulants dabigatran etexilate (Pradaxa^®) and apixaban (Eliquis^®) that were each given to two groups of 200 patients respectively, who had undergone elective hip or knee arthroplasty (100 each). Each patient was assessed for pre- and post-operative hemoglobin concentrations, post-operative blood loss, the number of transfused erythrocyte concentrates, the duration of wound secretion, clinical thromboembolic complications (deep vein thrombosis, pulmonary embolism, myocardial infarct), as well as gastrointestinal, intracranial or wound-related bleeding complications.

RESULTS

Dabigatran etexilate treatment led to a significant increase in the duration of wound secretion in both arthroplasty groups when compared to apixaban: wound secretion lasted 1.2 days longer on average in the dabigatran etexilate group than in the apixaban group (4.1 ± 2.1 vs. 2.9 ± 1.8 days). There were no significant differences observed between the two anticoagulant groups when comparing pre- and post-operative Hb values, post-operative blood loss and the other clinical parameters.

CONCLUSIONS

Thus, it appears that the direct thrombin inhibitor, dabigatran etexilate, is associated with a longer period of wound secretion following the implantation of hip and knee endoprostheses than that associated with the Factor Xa inhibitor, apixaban.

Aspirin Can Be Used as Prophylaxis for Prevention of Venous Thromboembolism After Revision Hip and Knee Arthroplasty

BACKGROUND

The optimal prophylaxis for prevention of venous thromboembolic events (VTEs) after revision total joint arthroplasty (TJA) remains unknown. The objective of this study was to evaluate whether aspirin, known to be effective for prevention of VTEs after primary arthroplasty, is also effective after revision TJA.

METHODS

We studied 2997 consecutive patients who underwent revision TJA between 2005 and 2013 and were treated with intermittent pneumatic compression devices and either aspirin (534 patients) or warfarin (2463 patients) for VTE prophylaxis. Pertinent data including the incidence of symptomatic VTEs, bleeding events, infection, and mortality were retrieved from our prospectively collected database.

RESULTS

The incidence of symptomatic VTEs was significantly higher in the warfarin group at 1.75% (43 of 2463) compared with 0.56% (3 of 534) in the aspirin group (odds ratio: 3.2; 95% CI: 1.03-16.3; P = .03). There was a higher rate of bleeding events with administration of warfarin (1.5%) compared with aspirin (0.4%; P = .02; odds ratio: 4.1; 95% CI: 1.2-34.0). The rate of surgical site infection was similar between the aspirin group and the warfarin group (1.61% and 1.70%, respectively).

CONCLUSION

Administration of aspirin as prophylaxis against VTEs after revision arthroplasty may be a viable option as it appears to be more effective than warfarin in prevention of symptomatic VTEs and is associated with a lower rate of complications.

Systematic review of aspirin for thromboprophylaxis in modern elective total hip and knee arthroplasty

Aims

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

Materials and Methods

A search of literature published between 2004 and 2014 was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 13 studies were eligible for inclusion.

Results

Evidence from one good quality randomised controlled trial (RCT) showed no difference in rates of venous thrombo-embolism (VTE) in patients given aspirin or low molecular weight heparin (LMWH) following TKA. There was insufficient evidence from trials with moderate to severe risk of bias being present to suggest aspirin is more or less effective than LMWH, warfarin or dabigatran for the prevention of VTE in TKA or THA. Compared with aspirin, rates of asymptomatic deep vein thrombosis (DVT) in TKA may be reduced with rivaroxaban but insufficient evidence exists to demonstrate an effect on incidence of symptomatic DVT. Compared with aspirin there is evidence of more wound complications following THA and TKA with dabigatran and in TKA with rivaroxaban. Some studies highlighted concerns over bleeding complications and efficacy of aspirin.

Conclusion

The results suggest aspirin may be considered a suitable alternative to other thromboprophylactic agents following THA and TKA. Further investigation is required to fully evaluate the safety and efficacy of aspirin. Cite this article: Bone Joint J 2016;98-B:1056–61.

Aspirin for thromboprophylaxis after primary lower limb arthroplasty: early thromboembolic events and 90 day mortality in 11,459 patients

AIMS

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

PATIENTS AND METHODS

We analysed the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) then compared the 90-day all-cause mortality with the corresponding data in the National Joint Registry for England and Wales (NJR).

RESULTS

The incidence of PE was 0.6% after THA, 1.47% after TKA and 1.2% after UKA. The 90-day mortality was 0.39% after THA and 0.44% after TKA. No deaths occurred after UKA. The main causes of death were ischaemic heart disease and respiratory failure. PE was responsible for only 18% of deaths. There was a decline in 90-day mortality, from 0.64% between 2002 and 2007, to 0.21% between 2008 and 2013 after THA, and from 0.47% to 0.39% after TKA for the corresponding period. The standardised mortality ratio (SMR) declined from 86.5 (confidence interval (CI) 63.0 to 137.7) to 39.7 (CI 31.2 to 54.3) p = 0.024. The incidence of proximal DVT was 0.3%.

TAKE HOME MESSAGE

With individualised risk assessment and as part of a multimodal approach, Aspirin is safe to use as the main thromboprophylactic agent in primary arthroplasty. It is not associated with an increased incidence of symptomatic DVT, PE or death.

Fatal pulmonary embolism following elective total hip arthroplasty

Aims

The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime.

Patients and Methods

A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death.

Results

During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction.

Conclusion

We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8.

Unfractionated heparin and mechanical thromboprophylaxis in hip arthroplasty

OBJECTIVE:

To evaluate the efficacy and safety of unfractionated heparin associated with mechanical prophylaxis as a method for preventing venous thromboembolism in hip arthroplasty.

METHOD:

We retrospectively reviewed the records of 181 hip arthroplasties out of 216 consecutive cases performed over a period of 39 months in our hospital. We excluded 35 cases due to non-adherence to the standardized method of thromboprophylaxis or loss to follow-up. All arthroplasties evaluated completed one-year follow-up after surgery with five consultations at predefined periods. Efficacy of the proposed method was evaluated by the occurrence of symptomatic venous thromboembolism confirmed by specific tests and safety was determined by the lack of occurrence of major bleeding according to criteria established by the International Society on Thrombosis and Haemostasis.

RESULTS:

There were four cases of symptomatic venous thromboembolism (2.2%), with three cases of deep vein thrombosis (1.65%) and one case of pulmonary embolism (0.55%). We found one case of severe bleeding (0.55%).

CONCLUSION:

Unfractionated heparin associated with mechanical prophylaxis proved to be an effective and safe method for preventing venous thromboembolism in patients undergoing hip arthroplasty, presenting rates of thromboembolic complications and major bleeding within the range reported with other methods currently used of thromboprophylaxis. Level of Evidence IV, Case Series

Common contra-indications and interactions of drugs in orthopaedic practice

Drug therapy forms an integral part of the management of many orthopaedic conditions. However, many medicines can produce serious adverse reactions if prescribed inappropriately, either alone or in combination with other drugs. Often these hazards are not appreciated. In response to this, the European Union recently issued legislation regarding safety measures which member states must adopt to minimise the risk of errors of medication. In March 2014 the Medicines and Healthcare products Regulatory Agency and NHS England released a Patient Safety Alert initiative focussed on errors of medication. There have been similar initiatives in the United States under the auspices of The National Coordinating Council for Medication Error and The Joint Commission on the Accreditation of Healthcare Organizations. These initiatives have highlighted the importance of informing and educating clinicians. Here, we discuss common drug interactions and contra-indications in orthopaedic practice. This is germane to safe and effective clinical care.