PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT): a randomised pragmatic trial protocol comparing aspirin versus low-molecular-weight heparin for blood clot prevention in orthopaedic trauma patients

Comparison of Different Thromboprophylaxis Regimens in Elderly Patients Following Hip Arthroplasty

Aims/Background Deep venous thrombosis (DVT) represents a significant postoperative complication after artificial femoral head replacement, with the incidence increasing proportionally with patient age. This study aimed to evaluate the effect of early postoperative use of intermittent pneumatic compression devices (IPC), followed by the combined use of low molecular weight heparin (LMWH) after 48 hours, for the prevention of postoperative lower limb DVT in elderly patients undergoing hip arthroplasty. Methods The retrospective study included 100 elderly patients who underwent unilateral femoral head replacement. The control group (n = 55) received combined LMWH initiated 12 hours postoperatively, while the observation group (n = 45) started combined LMWH 48 hours postoperatively. Changes in coagulation parameters, perioperative complications, and the incidence of postoperative lower limb DVT were compared between the two groups. Results Coagulation parameters showed significant changes post-intervention in both groups, with no statistically significant inter-group differences observed post-intervention (p > 0.05). The incidence of postoperative lower limb DVT did not differ significantly between the two groups (p > 0.05). However, the observation group demonstrated significantly lower postoperative blood loss, incidence of periwound hematoma, and transfusion rates compared to the control group (p < 0.05). Conclusion The sequential application of IPC in the early postoperative period, followed by combined LMWH administration after 48 hours, demonstrates comparable efficacy in preventing lower limb DVT formation in elderly patients undergoing hip arthroplasty when compared to the initiation of combined LMWH starting 12 hours postoperatively. In addition, this approach significantly reduces the risk of postoperative bleeding and exhibits a high safety profile.

Enoxaparin and Early Postoperative Tibial Nailing: Increased Nonunion Revision Rates

OBJECTIVES

To determine the association between postoperative enoxaparin use and the risk of requiring surgery for nonunion in patients treated with intramedullary nailing for midshaft fractures of the tibia.

METHODS

DESIGN

Retrospective cohort analysis.

SETTING

Data were sourced from the PearlDiver national database.

PATIENT SELECTION CRITERIA

Patients were identified through the PearlDiver database by using Current Procedural Terminology and International Classification of Diseases (ICD-10) codes. Included patients had undergone intramedullary nailing for midshaft fractures of the tibia between 2015 and 2020 and subsequently underwent revision surgery due to nonunion.

OUTCOME MEASURES AND COMPARISONS

The primary outcome measured in this study was the rate of nonunion following intramedullary nailing for the different types of tibial shaft fractures (closed, Type I/II open, Type III open). For each fracture subtype, the study compared nonunion rates between those who received enoxaparin in the postoperative period and those who did not receive enoxaparin at any time during the first 6 weeks postoperatively. Factors such as the timing and duration of enoxaparin therapy and demographic variables were also considered.

RESULTS

The study included 16,986 patients, average age was 49.2 years (SD 17.3); 43.1% were female. Five hundred four patients required revision surgery for nonunion (3.4%). Among patients who did not receive enoxaparin, the nonunion rates were 1.6%, 3.9%, and 6.9% for closed, Type I/II open, and Type III open fractures, respectively. For patients who received enoxaparin within the first 2 weeks, the nonunion rates were 2.6%, 4.7%, and 7.9% for closed (RR = 1.67, P < 0.0001), Type I/II open (RR = 1.21, P < 0.0001), and Type III open (RR = 1.17, P = 0.355) fractures, respectively. Logistic regression confirmed enoxaparin was independently associated with nonunion (odds ratios [OR] = 1.75, P = 0.0013 for closed fractures; OR = 1.51, P = 0.034 for Type I/II open fractures). Tobacco use was also a contributing factor (OR = 2.43, P < 0.0001 for closed fractures; OR = 2.00, P < 0.0001 for Type I/II open fractures; OR = 2.04, P = 0.0008 for Type III open fractures).

CONCLUSIONS

The postoperative use of enoxaparin was associated with an elevated risk of nonunion in patients treated with intramedullary nailing for fractures of the tibial shaft.

LEVEL OF EVIDENCE

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

Effect of Aspirin Versus Low-Molecular-Weight Heparin Thromboprophylaxis on Medication Satisfaction and Out-of-Pocket Costs: A Secondary Analysis of a Randomized Clinical Trial

BACKGROUND

Current guidelines recommend low-molecular-weight heparin for thromboprophylaxis after orthopaedic trauma. However, recent evidence suggests that aspirin is similar in efficacy and safety. To understand patients' experiences with these medications, we compared patients' satisfaction and out-of-pocket costs after thromboprophylaxis with aspirin versus low-molecular-weight heparin.

METHODS

This study was a secondary analysis of the PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT) trial, conducted at 21 trauma centers in the U.S. and Canada. We included adult patients with an operatively treated extremity fracture or a pelvic or acetabular fracture. Patients were randomly assigned to receive 30 mg of low-molecular-weight heparin (enoxaparin) twice daily or 81 mg of aspirin twice daily for thromboprophylaxis. The duration of the thromboprophylaxis, including post-discharge prescription, was based on hospital protocols. The study outcomes included patient satisfaction with and out-of-pocket costs for their thromboprophylactic medication measured on ordinal scales.

RESULTS

The trial enrolled 12,211 patients (mean age and standard deviation [SD], 45 ± 18 years; 62% male), 9725 of whom completed the question regarding their satisfaction with the medication and 6723 of whom reported their out-of-pocket costs. The odds of greater satisfaction were 2.6 times higher for patients assigned to aspirin than those assigned to low-molecular-weight heparin (odds ratio [OR]: 2.59; 95% confidence interval [CI]: 2.39 to 2.80; p < 0.001). Overall, the odds of incurring any out-of-pocket costs for thromboprophylaxis medication were 51% higher for patients assigned to aspirin compared with low-molecular-weight heparin (OR: 1.51; 95% CI: 1.37 to 1.66; p < 0.001). However, patients assigned to aspirin had substantially lower odds of out-of-pocket costs of at least $25 (OR: 0.15; 95% CI: 0.12 to 0.18; p < 0.001).

CONCLUSIONS

Use of aspirin substantially improved patients' satisfaction with their medication after orthopaedic trauma. While aspirin use increased the odds of incurring any out-of-pocket costs, it protected against costs of ≥$25, potentially improving health equity for thromboprophylaxis.

LEVEL OF EVIDENCE

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

Analysis of High-Risk Factors and Construction of a Nomogram Predictive Model for Deep Venous Thrombosis in Pelvic and Acetabular Fracture Patients Treated Conservatively

PURPOSE

This study aims to develop a predictive nomogram model to assist physicians in making evidence-based decisions and potentially reduce the incidence of deep venous thrombosis (DVT).

METHODS

We conducted a retrospective study, including patients admitted to the hospital from January 2014 to January 2022 with a closed, single pelvic or acetabular fracture. Comprehensive data were collected for each patient, encompassing demographics, injury characteristics, comorbidities, and results from laboratory tests and lower extremity ultrasounds. Potential risk factors were identified by univariate and multivariate logistic regression analyses. The predictive model was constructed and then internally validated. Calibration accuracy was assessed using a calibration slope and the Hosmer-Lemeshow goodness-of-fit test. The discrimination of the nomogram model was evaluated using the C-statistic.

RESULTS

Out of 232 individuals who underwent conservative treatment, 57 (24.6%) were classified into the DVT group and 175 (75.4%) into the non-DVT group based on lower extremity ultrasound findings. Predominantly, patients were aged between 41 and 65 in both groups. Body mass index (BMI) comparison showed that 54.29% (95/175) of the non-DVT group fell within the healthy weight range, while 45.61% (26/57) in the DVT group were overweight. Notably, the proportion of obesity in the DVT group was more than double that in the non-DVT group, indicating a higher DVT risk with increasing BMI (P=0.0215). Lower red blood cell (RBC) counts were observed in DVT patients compared to non-DVT ones (P<0.001). A similar pattern emerged for D-dimer, a marker for blood clot formation and dissolution, with significant differences noted (P=0.029). Multivariable analysis identified age, BMI, associated organ injury (AOI), American Society of Anesthesiologists score, hemoglobin (HGB), RBC, and D-dimer as candidate predictors. Significant variables included age (OR, 3.04; 95% CI, 1.76-5.26; P<0.001), BMI (OR, 1.97; 95% CI, 1.22-3.18; P=0.006), AOI (OR, 2.05; 95% CI, 1.07-3.95; P=0.031), and HGB (HR, 0.59; 95% CI, 0.39-0.88; P=0.010). The discrimination was 0.787, with a corrected c-index of 0.753. Calibration plots and the Hosmer-Lemeshow test indicated a good fit (P=0.7729). Decision curve analysis revealed a superior net clinical benefit when the predicted probability threshold ranged from 0.05 to 0.95.

CONCLUSIONS

We developed a nomogram predictive model, and it could act as a practical tool in clinical workflows to assist physicians in making favorable medical decisions, which potentially reduces the incidence of DVT in those patients with pelvic and acetabular fractures treated conservatively.

Advanced and alternative research methods for the acute care surgeon scientist

Clinical research has evolved significantly over the last few decades to include many advanced and alternative study designs to answer unique questions. Recognizing a potential knowledge gap, the AAST Associate Member Council and Educational Development Committee created a research course at the 2022 Annual Meeting in Chicago to introduce junior researchers to these methodologies. This manuscript presents a summary of this AAST Annual Meeting session, and reviews topics including hierarchical modeling, geospatial analysis, patient-centered outcomes research, mixed methods designs, and negotiating complex issues in multicenter trials.

Using Discrete Choice Experiments to Quantify Patient Preferences

Discrete choice experiments are a robust technique for quantifying preferences. With this method, respondents are presented with a series of hypothetical comparisons described by attributes with varying levels. The aggregated choices from respondents can be used to infer the relative importance of the described attributes and acceptable trade-offs between attributes. The data generated from discrete choice experiments can aid surgeons in aligning patient values with treatment decisions and support the design of research that is responsive to patient preferences. This article summarizes the application of discrete choice experiments to orthopaedics. We share best practices for designing discrete choice experiments and options for reporting study results. Finally, we suggest opportunities for this method within our field.

Management of Intraoperative Acetabular Fractures During Total Hip Arthroplasty

Intraoperative fractures of the acetabulum are a rare but serious complication during total hip arthroplasty. Acute fractures generally require attention with plating, whereas chronic acetabular fractures may be approached with distraction, a Burch-Schneider cage, or a custom implant. It is imperative for arthroplasty surgeons to possess a thorough understanding of how to identify and manage these injuries. Collaborating with an orthopedic traumatologist for assistance with plating the anterior or posterior column, if necessary, can be invaluable. Management options encompass conservative management, revision style acetabular component, screw/plating of anterior/posterior column, and the use of a larger cup with multiple screw augmentation options.

The Major Extremity Trauma Research Consortium: Development and Impact of an Orthopaedic Trauma Research Program

The Major Extremity Trauma Research Consortium (METRC) is a unique and ongoing military-civilian collaboration that resulted in the largest orthopaedic trauma research enterprise to date. The Consortium was established in September 2009 with funding from the Department of Defense. It employs a centralized data coordinating center and has grown into a network of nearly 400 investigators at 70 clinical centers. METRC conducts large multicenter clinical research studies selected and designed to improve outcomes among severely injured military and civilian patients with extremity trauma. Over the past decade, the consortium has implemented 35 such studies distributed among 19 principal investigators, enrolled more than 23,000 patients, published 61 articles, and received more than $150 million in funding from the Department of Defense, Patient Centered Outcomes Research Institute, and National Institutes of Health. This unique multidisciplinary research platform is a powerful community capable of addressing the challenging issues related to the evaluation, treatment, and recovery after severe extremity trauma. This body of work received the 2023 Elizabeth Winston Lanier Kappa Delta Award. An overview of the METRC development, organization, and research focus areas is presented.

Novel therapeutic medications for venous thromboembolism prevention in trauma patients: Findings from the Consensus Conference to Implement Optimal Venous Thromboembolism Prophylaxis in Trauma

ABSTRACT

Trauma patients are at high risk for venous thromboembolism (VTE). Despite evidence-based guidelines and concerted efforts in trauma centers to implement optimal chemoprophylaxis strategies, VTE remains a frequent diagnosis in trauma patients. Current chemoprophylaxis strategies largely focus on the subcutaneous injection of low-molecular-weight heparin, which is administered twice daily. Novel approaches to pharmacologic VTE prophylaxis have the potential to reduce VTE rates by improving patient compliance through oral administration or through their ability to target alternative pathways that mediate thrombosis. While novel pharmacologic VTE prophylaxis strategies have been studied in nontrauma patients, there is a paucity of literature in trauma patients where the risk of thrombosis versus hemorrhage must be carefully considered. As a component of the 2022 Consensus Conference to Implement Optimal VTE Prophylaxis in Trauma, this review provides an update of the novel chemoprophylaxis agents for potential use in trauma patients. Here, we will consider the relative risks and benefits related to the use of these drugs, evaluate the current literature in nontrauma patients, and consider future directions that could potentially improve posttrauma VTE prophylaxis.

Proceedings from the 2022 Consensus Conference to Implement Optimal Venous Thromboembolism Prophylaxis in Trauma

ABSTRACT

On May 4 and 5, 2022, a meeting of multidisciplinary stakeholders in the prevention and treatment of venous thromboembolism (VTE) after trauma was convened by the Coalition for National Trauma Research, funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health, and hosted by the American College of Surgeons in Chicago, Illinois. This consensus conference gathered more than 40 in-person and 80 virtual attendees, including trauma surgeons, other physicians, thrombosis experts, nurses, pharmacists, researchers, and patient advocates. The objectives of the meeting were twofold: (1) to review and summarize the present state of the scientific evidence regarding VTE prevention strategies in injured patients and (2) to develop consensus on future priorities in VTE prevention implementation and research gaps.To achieve these objectives, the first part of the conference consisted of talks from physician leaders, researchers, clinical champions, and patient advocates to summarize the current state of knowledge of VTE pathogenesis and prevention in patients with major injury. Video recordings of all talks and accompanying slides are freely available on the conference website ( https://www.nattrauma.org/research/research-policies-templates-guidelines/vte-conference/ ). Following this curriculum, the second part of the conference consisted of a series of small-group breakout sessions on topics potentially requiring future study. Through this process, research priorities were identified, and plans of action to develop and undertake future studies were defined.The 2022 Consensus Conference to Implement Optimal VTE Prophylaxis in Trauma answered the National Trauma Research Action Plan call to define a course for future research into preventing thromboembolism after trauma. A multidisciplinary group of clinical champions, physicians, scientists, and patients delineated clear objectives for future investigation to address important, persistent key knowledge gaps. The series of papers from the conference outlines the consensus based on the current literature and a roadmap for research to answer these unanswered questions.

Aspirin or Low-Molecular-Weight Heparin for Thromboprophylaxis after a Fracture

BACKGROUND

Clinical guidelines recommend low-molecular-weight heparin for thromboprophylaxis in patients with fractures, but trials of its effectiveness as compared with aspirin are lacking.

METHODS

In this pragmatic, multicenter, randomized, noninferiority trial, we enrolled patients 18 years of age or older who had a fracture of an extremity (anywhere from hip to midfoot or shoulder to wrist) that had been treated operatively or who had any pelvic or acetabular fracture. Patients were randomly assigned to receive low-molecular-weight heparin (enoxaparin) at a dose of 30 mg twice daily or aspirin at a dose of 81 mg twice daily while they were in the hospital. After hospital discharge, the patients continued to receive thromboprophylaxis according to the clinical protocols of each hospital. The primary outcome was death from any cause at 90 days. Secondary outcomes were nonfatal pulmonary embolism, deep-vein thrombosis, and bleeding complications.

RESULTS

A total of 12,211 patients were randomly assigned to receive aspirin (6101 patients) or low-molecular-weight heparin (6110 patients). Patients had a mean (±SD) age of 44.6±17.8 years, 0.7% had a history of venous thromboembolism, and 2.5% had a history of cancer. Patients received a mean of 8.8±10.6 in-hospital thromboprophylaxis doses and were prescribed a median 21-day supply of thromboprophylaxis at discharge. Death occurred in 47 patients (0.78%) in the aspirin group and in 45 patients (0.73%) in the low-molecular-weight-heparin group (difference, 0.05 percentage points; 96.2% confidence interval, -0.27 to 0.38; P<0.001 for a noninferiority margin of 0.75 percentage points). Deep-vein thrombosis occurred in 2.51% of patients in the aspirin group and 1.71% in the low-molecular-weight-heparin group (difference, 0.80 percentage points; 95% CI, 0.28 to 1.31). The incidence of pulmonary embolism (1.49% in each group), bleeding complications, and other serious adverse events were similar in the two groups.

CONCLUSIONS

In patients with extremity fractures that had been treated operatively or with any pelvic or acetabular fracture, thromboprophylaxis with aspirin was noninferior to low-molecular-weight heparin in preventing death and was associated with low incidences of deep-vein thrombosis and pulmonary embolism and low 90-day mortality. (Funded by the Patient-Centered Outcomes Research Institute; PREVENT CLOT ClinicalTrials.gov number, NCT02984384.).

A Prospective Randomized Controlled Trial Comparing Enoxaparin & Rivaroxaban for Venous Thromboembolism Prophylaxis in Orthopaedic Trauma

OBJECTIVES

To determine whether there is a difference in orthopaedic trauma patient medication satisfaction and adherence using an oral versus subcutaneous injectable anticoagulant for venous thromboembolism chemoprophylaxis.

DESIGN

Randomized controlled trial.

SETTING

Single academic Level 1 trauma center.

PARTICIPANTS

One hundred twenty adult orthopaedic trauma patients with operative pelvic or lower extremity fractures were randomized and completed the study.

INTERVENTION

Three weeks of either the service standard 40 mg once daily enoxaparin versus trial medication 10 mg once daily rivaroxaban postoperatively.

MAIN OUTCOME MEASURES

Patient satisfaction as measured by the Treatment Satisfaction Questionnaire for Medication (TSQM-9). Medication adherence as measured by the Morisky Medication Adherence Scale (MMAS-8).

RESULTS

Medication adherence was similar in both groups. Medication satisfaction was significantly higher in the oral rivaroxaban group based on the TSQM-9 and patient-reported data. Secondary outcomes found no significant difference in the incidence of bleeding events or clinically relevant venous thromboembolism. The enoxaparin group experienced more adverse medication-related events. The rivaroxaban medication regimen costs 7.5-10× less out of pocket for uninsured patients.

CONCLUSION

The results of this randomized controlled trial demonstrate that patients with surgical orthopaedic trauma prefer an oral anticoagulant for postoperative venous thromboembolism chemoprophylaxis and suggest that rivaroxaban may be a viable option. Furthermore, large-scale studies are needed to confirm safety and efficacy for rivaroxaban in this population as a potential alternative to enoxaparin and aspirin.

LEVEL OF EVIDENCE

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