NEW ANTICOAGULANTS AS THROMBOPROPHYLAXIS AFTER TOTAL HIP OR KNEE REPLACEMENT

Cost-effectiveness of Single vs Double Debridement and Implant Retention for Acute Periprosthetic Joint Infections in Total Knee Arthroplasty: A Markov Model

Background

Periprosthetic joint infection (PJI) is a common cause of revision total knee surgery. Although debridement and implant retention (DAIR) has lower success rates in the chronic setting, it is an accepted treatment of acute PJI, whether postoperatively or with late hematogenous seeding. There are two broad DAIR strategies: single debridement and planned double debridement. The purpose of this study is to evaluate the cost-effectiveness of single vs double DAIR for acute PJI in total knee arthroplasty.

Methods

A decision tree using single or double DAIR as the treatment strategy for acute PJI was constructed. Quality-adjusted life years and costs associated with the two treatment arms were calculated. Treatment success rates, failure rates, and mortality rates were derived from the literature. Medical costs were derived from both the literature and Medicare data. A cost-effectiveness plane was constructed from multiple Monte Carlo trials. A sensitivity analysis identified parameters most influencing the optimal strategy decision.

Results

Double DAIR was the optimal treatment strategy both in terms of the health utility state (82% of trials) and medical cost (97% of trials). Strategy tables demonstrated that as long as the success rate of double debridement is 10% or greater than the success rate of a single debridement, the two-stage protocol is cost-effective.

Conclusions

A double DAIR protocol is more cost-effective than single DAIR from a societal perspective.

Economic Evaluation of New Oral Anticoagulants in Prevention of Venous Thrombosis Following Joint Replacement Surgery: A Systematic Review

PURPOSE

The main purpose of prescribing oral anticoagulants in patients undergoing total knee and total hip replacement surgery is to prevent venous thromboembolism (VTE). The present study aimed to summarize evidence from economic evaluations regarding new oral anticoagulants (NOACs) used in VTE prophylaxis after joint replacement surgery.

METHODS

To obtain relevant literature on economic evaluations of NOACs used in the prevention of VTE following joint replacement surgery, we searched the Cochrane Library, PubMed, Web of Science, Embase, and Scopus, as well as specialized economic evaluation databases, for articles published from January 2008 to December 2019. Next, 2 reviewers screened the titles and abstracts of studies, extracted data from the full-text articles, and assessed the quality of the methodologies using the Quality of Health Economic Studies checklist.

FINDINGS

Twenty-eight studies of economic evaluations met the inclusion criteria of the research. The quality assessment showed that 20 articles had scores within the range of 75 to 100 (high quality), and 9 studies had scores within the range of 50 to 74 (moderate quality). All of the identified studies had been carried out based on modelling, and 23 studies used decision trees to model acute events after surgery. In addition, 20 studies utilized a Markov model to capture long-term complications of VTE. The results showed that rivaroxaban was more cost-effective than apixaban and dabigatran from a perspective of the health care system in the prevention of VTE after total knee and total hip replacement surgery. In addition, apixaban was associated with a lower risk for bleeding events than other NOACs, making it the most cost-effective NOAC from the perspective of the payer.

IMPLICATIONS

The results suggest that NOACs are cost-effective alternatives to low-molecular-weight heparins. Rivaroxaban and dabigatran were assessed as the most and least cost-effective prophylaxis options, respectively, after joint replacement surgery for the prevention of VTE. It is recommended that future research be conducted on economic evaluations of edoxaban.

Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision

BACKGROUND

Periprosthetic joint infection (PJI) following total knee arthroplasty is a growing concern, as the demand for total knee arthroplasty (TKA) expands annually. Although 2-stage revision is considered the gold standard in management, there is substantial morbidity and mortality associated with this strategy. One-stage revision is associated with lower mortality rates and better quality of life, and there has been increased interest in utilizing the 1-stage strategy. However, surgeons are faced with a difficult decision regarding which strategy to use to treat these infections, considering uncertainty with respect to eradication of infection, quality of life, and societal costs with each strategy. The purpose of the current study was to use decision analysis to determine the optimal decision for the management of PJI following TKA.

METHODS

An expected-value decision tree was constructed to estimate the quality-adjusted life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created: Decision Tree 1 was constructed for all pathogens, and Decision Tree 2 was constructed solely for difficult-to-treat infections, including methicillin-resistant infections. Values for parameters in the decision model, such as mortality rate, reinfection rate, and need for additional surgeries, were derived from the literature. Medical costs were derived from Medicare data. Sensitivity analysis determined which parameters in the decision model had the most influence on the optimal strategy.

RESULTS

In both decision trees, the 1-stage strategy produced greater health utility while also being more cost-effective. In the Monte Carlo simulation for Decision Trees 1 and 2, 1-stage was the dominant strategy in about 85% and 69% of the trials, respectively. Sensitivity analysis showed that the reinfection and 1-year mortality rates were the most sensitive parameters influencing the optimal decision.

CONCLUSIONS

Despite 2-stage revision being considered the current gold standard for infection eradication in patients with PJI following TKA, the optimal decision that produced the highest quality of life was 1-stage revision. These results should be considered in shared decision-making with patients who experience PJI following TKA.

LEVEL OF EVIDENCE

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cost-Utility Analysis of Venous Thromboembolism Prophylaxis Strategies for People Undergoing Elective Total Hip and Total Knee Replacement Surgeries in the English National Health Service

Background: Major orthopedic surgery, such as elective total hip replacement (eTHR) and elective total knee replacement (eTKR), are associated with a higher risk of venous thromboembolism (VTE) than other surgical procedures. Little is known, however, about the cost-effectiveness of VTE prophylaxis strategies in people undergoing these procedures. Aim: The aim of this work was to assess the cost-effectiveness of these strategies from the English National Health Service perspective to inform NICE guideline (NG89) recommendations. Materials and Methods: Cost-utility analysis, using decision modeling, was undertaken to compare 15 VTE prophylaxis strategies for eTHR and 12 for eTKR, in addition to "no prophylaxis" strategy. The analysis complied with the NICE Reference Case. Structure and assumptions were agreed with the guideline committee. Incremental net monetary benefit (INMB) was calculated, vs. the model comparator (LMWH+ antiembolism stockings), at a threshold of £20,000/quality-adjusted life-year (QALY) gained. The model was run probabilistically. Deterministic sensitivity analyses (SAs) were undertaken to assess the robustness of the results. Results: The most cost-effective strategies were LMWH for 10 days followed by aspirin for 28 days (INMB = £530 [95% CI: -£784 to £1,103], probability of being most cost-effective = 72%) for eTHR, and foot pump (INMB = £353 [95% CI: -£101 to £665]; probability of being most cost-effective = 18%) for eTKR. There was considerable uncertainty regarding the cost-effectiveness ranking in the eTKR analysis. The results were robust to change in all SAs. Conclusions: For eTHR, LMWH (standard dose) for 10 days followed by aspirin for 28 days is the most cost-effective VTE prophylaxis strategy. For eTKR, the results are highly uncertain but foot pump appeared to be the most cost-effective strategy, followed closely by aspirin (low dose). Future research should focus on assessing cost-effectiveness of VTE prophylaxis in the eTKR population.

Oral anticoagulants for primary prevention, treatment and secondary prevention of venous thromboembolic disease, and for prevention of stroke in atrial fibrillation: systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Warfarin is effective for stroke prevention in atrial fibrillation (AF), but anticoagulation is underused in clinical care. The risk of venous thromboembolic disease during hospitalisation can be reduced by low-molecular-weight heparin (LMWH): warfarin is the most frequently prescribed anticoagulant for treatment and secondary prevention of venous thromboembolism (VTE). Warfarin-related bleeding is a major reason for hospitalisation for adverse drug effects. Warfarin is cheap but therapeutic monitoring increases treatment costs. Novel oral anticoagulants (NOACs) have more rapid onset and offset of action than warfarin, and more predictable dosing requirements.

OBJECTIVE

To determine the best oral anticoagulant/s for prevention of stroke in AF and for primary prevention, treatment and secondary prevention of VTE.

DESIGN

Four systematic reviews, network meta-analyses (NMAs) and cost-effectiveness analyses (CEAs) of randomised controlled trials.

SETTING

Hospital (VTE primary prevention and acute treatment) and primary care/anticoagulation clinics (AF and VTE secondary prevention).

PARTICIPANTS

Patients eligible for anticoagulation with warfarin (stroke prevention in AF, acute treatment or secondary prevention of VTE) or LMWH (primary prevention of VTE).

INTERVENTIONS

NOACs, warfarin and LMWH, together with other interventions (antiplatelet therapy, placebo) evaluated in the evidence network.

MAIN OUTCOME MEASURES

Efficacy Stroke, symptomatic VTE, symptomatic deep-vein thrombosis and symptomatic pulmonary embolism. Safety Major bleeding, clinically relevant bleeding and intracranial haemorrhage. We also considered myocardial infarction and all-cause mortality and evaluated cost-effectiveness.

DATA SOURCES

MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library, reference lists of published NMAs and trial registries. We searched MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library. The stroke prevention in AF review search was run on the 12 March 2014 and updated on 15 September 2014, and covered the period 2010 to September 2014. The search for the three reviews in VTE was run on the 19 March 2014, updated on 15 September 2014, and covered the period 2008 to September 2014.

REVIEW METHODS

Two reviewers screened search results, extracted and checked data, and assessed risk of bias. For each outcome we conducted standard meta-analysis and NMA. We evaluated cost-effectiveness using discrete-time Markov models.

RESULTS

Apixaban (Eliquis^®, Bristol-Myers Squibb, USA; Pfizer, USA) [5 mg bd (twice daily)] was ranked as among the best interventions for stroke prevention in AF, and had the highest expected net benefit. Edoxaban (Lixiana^®, Daiichi Sankyo, Japan) [60 mg od (once daily)] was ranked second for major bleeding and all-cause mortality. Neither the clinical effectiveness analysis nor the CEA provided strong evidence that NOACs should replace postoperative LMWH in primary prevention of VTE. For acute treatment and secondary prevention of VTE, we found little evidence that NOACs offer an efficacy advantage over warfarin, but the risk of bleeding complications was lower for some NOACs than for warfarin. For a willingness-to-pay threshold of > £5000, apixaban (5 mg bd) had the highest expected net benefit for acute treatment of VTE. Aspirin or no pharmacotherapy were likely to be the most cost-effective interventions for secondary prevention of VTE: our results suggest that it is not cost-effective to prescribe NOACs or warfarin for this indication.

CONCLUSIONS

NOACs have advantages over warfarin in patients with AF, but we found no strong evidence that they should replace warfarin or LMWH in primary prevention, treatment or secondary prevention of VTE.

LIMITATIONS

These relate mainly to shortfalls in the primary data: in particular, there were no head-to-head comparisons between different NOAC drugs.

FUTURE WORK

Calculating the expected value of sample information to clarify whether or not it would be justifiable to fund one or more head-to-head trials.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005324, CRD42013005331 and CRD42013005330.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Rivaroxaban for venous thromboembolism prevention after major orthopedic surgery: translating trial data into routine clinical practice

An established standard of care for the prevention of venous thromboembolism after major orthopedic surgery has been subcutaneous low-molecular-weight heparin. The non-vitamin K antagonist oral anticoagulant rivaroxaban has demonstrated superior efficacy and similar safety to all tested regimens of enoxaparin in large Phase III clinical studies of venous thromboembolism prevention after elective hip and knee arthroplasty. Despite regulatory approval of rivaroxaban for this indication, concerns remain among physicians regarding its optimal and effective use in routine clinical practice. Real-life studies, such as XAMOS and ORTHO-TEP, are providing physicians with more information on the routine use of rivaroxaban for venous thromboembolism prevention after orthopedic surgery, helping to establish its safety and effectiveness in everyday clinical care. Among the most important issues are the risk of bleeding complications, wound healing, timing of first dose, impact of type of anesthesia on thromboprophylaxis effectiveness, patient comorbidities and comedication use, periprocedural management, associated costs, and clinical outcomes in trauma-related fractures. Many of these issues are difficult to study in randomized, double-blind, Phase III trials, and can be assessed more readily using real-life data. In particular, real-life or noninterventional studies lack many of the strict inclusion and exclusion criteria associated with Phase III trials and involve unselected patients who often present with significant comorbidities or comedication use.

External Fixation vs. Skeletal Traction for Treatment of Intertrochanteric Fractures in the Elderly

BACKGROUND

Hip fractures are one of the causes of disability amongst elderly patients. External fixator and skeletal traction are two modes of treatment.

OBJECTIVES

The aim of this study is to compare two different treatment modes for intertrochanteric fractures in elderly patients.

PATIENTS AND METHODS

Sixty elderly patients with intertrochanteric fractures were randomized for treatment with either skeletal traction (Group A) or an external fixation (Group B). In this study patients at least 60 years of age, with AO/OTA A1 or A2 type fracture and intertrochanteric fracture as a result of minor trauma, were enrolled.

RESULTS

Acceptable reduction was achieved in eight and 26 patients of group A and B, respectively. The mean duration of hospitalization in Group A and Group B was 14.3 ± 1.1 and 2.2 ± 0.6 days, respectively. Significant differences between the two groups were observed, regarding acceptable reduction and duration of hospitalization. Less pain was observed in group B, at five days and twelve months after surgery; the average HHS was 57 and 66, in group A and B, respectively (P > 0.05).

CONCLUSIONS

Treatment with an external fixator is an effective treatment modality for intertrochanteric fractures in elderly high-risk patients. The advantages include rapid and simple application, insignificant blood loss, less radiation exposure, adequate fixation, pain reduction, early discharge from the hospital, low cost and more favorable functional outcome.

Rates of Deep Venous Thrombosis and Pulmonary Embolus After Anterior Cruciate Ligament Reconstruction: A Systematic Review

Context:

Venous thromboembolic (VTE) disease is thought to be an uncommon but serious problem after anterior cruciate ligament (ACL) reconstruction. Rates of VTE after ACL reconstruction are not well documented.

Objective:

To determine the rates of deep vein thrombosis (DVT) and symptomatic pulmonary emboli (PE) after ACL reconstruction.

Data Sources:

Five publicly available databases (PubMed, Cochrane Database of Systematic Reviews, Scopus, Embase, and CINAHL Complete) were utilized.

Study Selection:

All studies that screened patients for DVT and reported rates of DVT and PE after ACL reconstruction were eligible for inclusion. Level 5 evidence, cadaver, biomechanical, and basic science studies; studies reporting only multiligament reconstruction outcomes; studies where rates of DVT and PE could not be separated out from patients undergoing other types of arthroscopic knee procedures; and classification studies were excluded.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Data Extraction:

All study, subject, and surgical data were analyzed. Descriptive statistics were calculated.

Results:

Six studies met the inclusion criteria, with a mean Modified Colman Methodology Score of 30 ± 8.22. A total of 692 patients (488 men [70.5%]; mean age, 31.6 ± 2.82 years; mean follow-up, 7 ± 18.4 months) underwent ACL reconstruction using either semitendinosus-gracilis autograft (77.6%), bone–patellar tendon–bone (BTB) autograft (22%), or allograft (0.4%). No patient received postoperative pharmacological anticoagulation. Fifty-eight patients (8.4%) had a DVT (81% below knee and 19% above knee), while only 1 patient (0.2%) had a symptomatic PE. When reported, 27% of DVT episodes were symptomatic.

Conclusion:

The rate of DVT after ACL reconstruction in patients who did not receive postoperative pharmacological anticoagulation is 8.4%, while the rate of symptomatic PE is 0.2%. Of the DVT episodes that occurred, 73% were asymptomatic.

Treatment of intertrochanteric fractures in elderly highrisk patients: dynamic hip screw vs. external fixation

INTRODUCTION

Although the use of a dynamic hip screw (DHS) is considered to be the preferred treatment for intertrochanteric fractures, the external fixation device could produce clinical outcomes comparable to the outcomes obtained with conventional treatment. Furthermore, because external fixation is minimally invasive, we expected a lower rate of morbidity. Therefore, we compared the two treatments in a clinical trial of elderly patients with intertrochanteric fracture.

METHODS

60 elderly high-risk patients with an average age of 78 years were treated for intertrochanteric fracture, resulting from a low energy trauma. Patients were randomly divided in two groups regarding to treatment. In Group A the patients were treated with DHS, while in Group B were treated with external fixator.

RESULTS

The fixator was well accepted and no patient had significant difficulties while sitting or lying. The average intraoperative time was 73 min in Group A and 15 min in Group B (p<0.05). 27 patients of Group A need blood transfusion postoperatively and none in Group B (p<0.05). The mean duration of hospitalization in Group A and Group B was 8.4 and 2.2 days, respectively (p<0.05). 9 of patients Group B had pin-track infection grade 2 that all were treated by oral antibiotics. There were no differences in comorbidities, quality of reduction, screw cut out, bed sore and HHS between the two groups.

CONCLUSION

Treatment with external fixator is an effective treatment for intertrochanteric fractures in elderly highrisk patients. The advantages include quick and simple application, minimal blood loss, less radiation exposure, adequate fixation, pain reduction, early discharge from hospital, low costs and favourable functional outcomes.