Low molecular weight heparin for prevention of venous thromboembolism in patients with lower-limb immobilization

The effect and mechanism of low-molecular-weight heparin on the decidualization of stromal cells in early pregnancy

OBJECTIVE

This study aimed to analyze the effect of low-molecular-weight heparin (LMWH) on the decidualization of stromal cells in early pregnancy and explore the effect of LMWH on pregnancy outcomes.

METHODS

Recurrent spontaneous abortion (RSA) mouse model (CBA/J × DBA/2) and normal pregnant mouse model (CBA/J × BALB/c) were established. The female mice were checked for a mucus plug twice daily to identify a potential pregnancy. When a mucus plug was found, conception was considered to have occurred 12 h previously. The pregnant mice were divided randomly into a normal pregnancy control group, an RSA model group, and an RSA + LMWH experimental group (n = 10 mice in each group). Halfway through the 12th day of pregnancy, the embryonic loss of the mice was observed; a real-time quantitative polymerase chain reaction was used to detect the messenger ribonucleic acid (mRNA) expressions of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) in the decidua of the mice. Additionally, the decidual tissues of patients with RSA and those of normal women in early pregnancy who required artificial abortion were collected and divided into an RSA group and a control group. Decidual stromal cells were isolated and cultured to compare cell proliferation between the two groups, and cellular migration and invasion were detected by membrane stromal cells. Western blotting was used to detect the protein expressions of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteinase- (MMP) 2, and MMP-7 in stromal cells treated with LMWH.

RESULTS

Compared with the RSA group, LMWH significantly reduced the pregnancy loss rate in the RSA mice (p < 0.05). Compared with the RSA group, the LMWH + RSA group had significantly higher expression levels of PRL and IGFBP1 mRNA (p < 0.01). LMWH promoted the proliferation, migration, and invasion of human decidual stromal cells; compared with the control group, the expression levels of MMP-2, MMP-7, cyclin D1, and PCNA proteins in the decidual stromal cells of the LMWH group increased (p < 0.05).

CONCLUSIONS

The use of LMWH can improve pregnancy outcomes by enhancing the proliferation and migration of stromal cells in early pregnancy and the decidualization of stromal cells.

Effect of low-molecular-weight heparin calcium combined with magnesium sulfate and labetalol on coagulation, vascular endothelial function and pregnancy outcome in early-onset severe preeclampsia

OBJECTIVE

This paper was aimed at unveiling the effect of low-molecular-weight heparin calcium (LMWH) combined with magnesium sulfate and labetalol on coagulation, vascular endothelial function, and pregnancy outcome in early-onset severe preeclampsia (EOSP).

METHODS

Pregnant women with EOSP were divided into the control group and the study group, each with 62 cases. Patients in the control group were treated with labetalol and magnesium sulfate, and those in the study group were treated with LMWH in combination with the control grou Blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]), 24-h urine protein, coagulation indices [D-dimer (D-D), plasma fibrinogen (Fg), prothrombin time (PT), activated partial thromboplastin time (APTT), and prothrombin time (TT)], endothelial function [endothelin (ET-1) and nitric oxide (NO)], oxidative stress indices [oxidized low-density lipoproteins (ox-LDL), lipid peroxidation (LPO), superoxide dismutase (SOD), and malondialdehyde (MDA)], pregnancy outcome, and adverse effects occurred in the two groups were compared.

RESULTS

After treatment, lower SBP, DBP, and 24-h urine protein levels; lower Fg and D-D levels; higher PT, APPT, and TT levels; higher NO levels; lower ET-1 levels; lower ox-LDL, MDA, and LPO levels; higher SOD levels; and lower incidence of adverse pregnancy and adverse reactions were noted in the study group in contrast to the control group.

CONCLUSION

EOSP patients given with LMWH combined with magnesium sulfate and labetalol can effectively reduce the patient's blood pressure and urinary protein level; improve coagulation function, oxidative stress, and vascular endothelial function indices; reduce the adverse pregnancy outcomes; and improve the safety of treatment.

Integrated landscape of plasma metabolism and proteome of patients with post-traumatic deep vein thrombosis

Deep vein thrombosis (DVT) is a leading cause of morbidity and mortality after trauma. Here, we integrate plasma metabolomics and proteomics to evaluate the metabolic alterations and their function in up to 680 individuals with and without DVT after trauma (pt-DVT). We identify 28 metabolites and 2 clinical parameter clusters associated with pt-DVT. Then, we develop a panel of 9 metabolites (hexadecanedioic acid, pyruvic acid, L-Carnitine, serotonin, PE(P-18:1(11Z)/18:2(9Z,12Z)), 3-Hydroxycapric acid, 5,6-DHET, 3-Methoxybenzenepropanoic acid and pentanenitrile) that can predict pt-DVT with high performance, which can be verified in an independent cohort. Furthermore, the integration analysis of metabolomics and proteomics data indicates that the upregulation of glycolysis/gluconeogenesis-TCA cycle may promote thrombosis by regulating ROS levels in red blood cells, suggesting that interfering with this process might be potential therapeutic strategies for pt-DVT. Together, our study comprehensively delineates the metabolic and hematological dysregulations for pt-DVT, and provides potential biomarkers for early detection.

Long-term patient outcome is affected by deep venous thrombosis after Achilles tendon rupture repair

PURPOSE

The aim of the study was to examine the impact of a deep venous thrombosis (DVT) on patient outcomes 3 years after Achilles tendon rupture (ATR) repair and if there were continued improvements between 1 and 3 years after surgery. A secondary aim was to determine risk factors associated with impaired patient outcomes in the long term.

METHODS

This cohort study consisted of 181 ATR-repaired patients, from two large randomized clinical trials, who attended a 3-year follow-up evaluation. Patients were postoperatively randomized to two different weight-bearing interventions compared with immobilization in a below-knee plaster cast for 2 weeks. During immobilization, screening for DVT was performed with Doppler ultrasound. At 1 and 3 years postoperatively, functional- and patient-reported outcomes were evaluated by the validated heel-rise test and self-reported questionnaire, Achilles tendon Total Rupture Score (ATRS).

RESULTS

In total, 76 out of 181 (42%) patients exhibited a DVT at the 2- or 6-week screening after ATR surgery. Suffering from a DVT during immobilization resulted at 3 years in a worse limb symmetry index (LSI) of heel-rise total work compared to patients without DVT, adjusted for age (DVT mean LSI 68% vs. no DVT 78%, p = 0.027). At 3 years, patients with a DVT during immobilization displayed lower ATRS (DVT median 88 vs. no DVT 93, p = 0.046), which was not significant after adjustment for age. However, patients with DVT exhibited an improvement in ATRS, LSI total work, and LSI maximum height between 1 and 3 years, which was not seen among patients without DVT. Independent risk factors for reduced patient functional outcomes at 3 years were older age, greater calf muscle hypotrophy, and suffering a DVT.

CONCLUSIONS

DVT during immobilization affects patients' long-term functional outcomes 3 years after ATR repair. Clinicians should adequately address risk factors contributing to impaired patient outcomes in the long term, including calf muscle hypotrophy, DVT, and older age.

LEVEL OF EVIDENCE

Level Ⅲ.

How enoxaparin underdosing and sex contribute to achieving therapeutic anti-Xa levels

Introduction

Anti-Xa serves as a clinical surrogate for assessing the efficacy and bleeding risk in patients treated with enoxaparin for thromboembolic events. Evidence from the literature and empirical observations suggest that patients are underdosed in clinical practice to avoid bleeding complications. This study aimed to investigate such underdosing of enoxaparin and its potential impact on achieving therapeutic anti-Xa levels.

Methods

This multicentric, retrospective, observational study included patients with acute ischemic stroke due to atrial fibrillation. All patients received enoxaparin in the therapeutic setting with subsequent anti-Xa measurements. The one-sample, one-tailed Wilcoxon signed-rank test was used to identify a significant difference between the doses administered and the recommended daily dose. Logistic regression model analysis was performed to identify additional predictors affecting achievement of the therapeutic anti-Xa target range. Stepwise forward-backward selection with Akaike's information criterion as metric was applied to refine the logistic regression model.

Results

A total of 145 patients from the university hospitals of St. Pölten and Tulln in Lower Austria were included. The median daily enoxaparin dose administered was 1.23 mg/kg, resulting in an overall target range achievement rate of 66%. As compared to recommended therapeutic doses, significant underdosing of enoxaparin was evident in both participating centers (p < 0.001). The calculated threshold dose to achieve the therapeutic target range with a 90% probability was 1.5 mg/kg enoxaparin daily. Female sex was found to be a strong independent predictor of achieving a therapeutic target range (OR 9.44; 95% CI 3.40-30.05, p < 0.001).

Conclusion

Despite the underdosing observed in both centers, therapeutic anti-Xa levels were achieved with lower than recommended doses of enoxaparin, and women required even lower doses than men. These findings warrant further confirmation by prospective studies.

Traumatic Pulmonary Embolism

Pulmonary embolism (PE) is a life-threatening illness caused by a blood clot obstructing a pulmonary artery, resulting in decreased blood supply to the lungs. PE is a high-stakes diagnosis with considerable morbidity and death if left untreated. This case emphasizes the increased risk of PE associated with trauma and stresses the importance of this differential diagnosis in patients who report dyspnea following physical trauma. Understanding the risk factors and processes that contribute to PE in trauma patients is critical for accurate diagnosis and treatment.

Prospective randomized controlled trial: early weight bearing after conservative treatment of Weber B ankle fractures (pancake trial)

PURPOSE

Different studies have shown that weightbearing is safe in stable transsyndesmotic, isolated lateral simple ankle fractures. Despite this evidence, AO guidelines still recommend immobilization with above-the-knee cast for 4-6 weeks for these fractures. The objective of this study was to compare the outcomes of mobilization and weightbearing to those of immobilization and non-weightbearing in patients with stable transsyndesmotic, lateral isolated simple ankle fractures.

METHODS

Fifty patients were randomly assigned to permissive weightbearing in a walking boot or non-weightbearing immobilization using a below-the-knee cast. Primary outcome was ankle functionality as scored by the Olerud-Molander Ankle Score (OMAS). Secondary outcomes were radiological displacement of fracture, range of motion (ROM), calf circumference, and RAND 36-item health survey. Patients were in follow-up for 24 months.

RESULTS

Ankle functionality after six and twelve weeks was significantly higher for the intervention group, with respectively 30 points (p = 0.001) and 10 points (p = 0.015) of difference. ROM improved significantly in the intervention group after six weeks. All fractures showed radiological progression of fracture healing. RAND 36-item showed differences in both physical (60.3 vs. 46.3, p = 0.017) and mental (78.5 vs. 58.2, p = 0.034) components in favor of the intervention group. In 16% of patients who initially showed stable fractures on radiographic imaging, joint dislocation was identified on weightbearing radiographs prior to randomization, leading to exclusion.

CONCLUSION

Weightbearing and mobilization using a walking boot may be a safe treatment for patients with stable Weber B fractures.

Haemostatic, Inflammatory, and Haematological Biomarkers Among Orthopaedic Patients With Prolonged Immobilization and the Risk of Hypercoagulable States

Background Venous thromboembolism (VTE) is a common and potentially life-threatening complication in patients with lower limb traumatic fractures. Orthopaedic patients who experience trauma in the lower limbs with prolonged immobilization may experience a hypercoagulable state, which could eventually lead to the development of VTE. Therefore, this study aims to evaluate the changes in hypercoagulable markers, including haemostatic, inflammatory, and haematological biomarkers in orthopaedic trauma patients with prolonged immobilization. Materials/method This prospective cohort study was conducted at Hospital Universiti Sains Malaysia from August 2020 to March 2022. Every patient with fractures in the lower limbs was screened for eligibility, and patients who required immobilization for more than five days without receiving anticoagulant prophylaxis were recruited for this study. The laboratory tests, including D-dimer, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT), erythrocyte sedimentation rate (ESR), and platelet count, were serially measured on day one and day five of hospitalization. The biomarkers were analyzed using a paired t-test, with a p-value <0.05 as a significant result. Results A total of 54 patients with fractures in the lower limbs, ages ranging from 12 to 50 years old, were involved in this study. The paired t-test analysis demonstrated that several biomarkers showed a significant increase in mean difference between day one and day five of immobilization, which included fibrinogen, ESR, and platelet count. The mean differences for each biomarker with fibrinogen were 0.66 g/L (p<0.001, 95% CI of mean difference: -1.04, -0.27), ESR increased by 17.98mm/hr (p<0.001, 95% CI of mean difference: -24.69, -11.27), and platelet count increased by 128.59×109/L (p<0.001, 95% CI of mean difference: -166.55, -90.64) on day five of immobilization. D-dimer was elevated in all patients on both post-trauma days; however, no significant difference was observed in this biomarker between day one and day five of immobilization. Conclusion In conclusion, our study found that fibrinogen, ESR, and platelet count levels were significantly increased in orthopaedic trauma patients with prolonged immobilization. The increase in these biomarkers indicates the body's reaction to tissue injury after trauma, which may contribute to the hypercoagulable states. Further research with a larger sample size is warranted to assess the viability of these biomarkers as potential diagnostic indicators for the development of VTE related to hypercoagulability.

Venous thromboembolism following surgical management of proximal humerus fractures: a systematic review

Background

Currently, there is limited information on the incidence of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) after surgical treatment of proximal humerus fractures (PHFs). Therefore, the purpose of this systematic review is to evaluate the incidence of VTE, DVT, and PE following surgery for PHFs.

Methods

A comprehensive search of several databases was performed from inception to May 27, 2022. Studies were screened and evaluated by 2 reviewers independently utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Only original, English studies that evaluated the incidences of VTE following surgical management of PHFs were included. Surgical procedures consisted of shoulder arthroplasty (SA) including both hemiarthroplasty (Hemi) and reverse shoulder arthroplasty (RSA) in addition to open reduction and internal fixation (ORIF). A pooled incidence for postoperative DVT, PE, and overall VTE was reported.

Results

Twelve studies met the inclusion and exclusion criteria, encompassing a total of 18,238 patients. The overall DVT, PE, and VTE rates were 0.14%, 0.59%, and 0.7%, respectively. VTE was more frequently reported after SA than ORIF, (1.27% vs. 0.53%, respectively). Among SA patients, a higher rate of DVT was seen with RSA (1.2%) with the lowest DVT rate was observed for ORIF with 0.03%.

Conclusions

Symptomatic VTEs following surgical treatment of PHFs, are rare, yet still relevant as a worrisome postoperative complication. Among the various procedures, VTE was the most frequently reported after SA when compared to ORIF, with RSA having the highest VTE rate.

Guideline "Motor neuron diseases" of the German Society of Neurology (Deutsche Gesellschaft für Neurologie)

INTRODUCTION

In 2021, the Deutsche Gesellschaft für Neurology published a new guideline on diagnosis and therapy of motor neuron disorders. Motor neuron disorders affect upper motor neurons in the primary motor cortex and/or lower motor neurons in the brain stem and spinal cord. The most frequent motor neuron disease amyotrophic lateral sclerosis (ALS) is a rapidly progressive disease with an average life expectancy of 2-4 years with a yearly incidence of 3.1/100,000 in Central Europe (Rosenbohm et al. in J Neurol 264(4):749-757, 2017. https://doi.org/10.1007/s00415-017-8413-3 ). It is considered a rare disease mainly due to its low prevalence as a consequence of short disease duration.

RECOMMENDATIONS

These guidelines comprise recommendations regarding differential diagnosis, neuroprotective therapies and multidisciplinary palliative care including management of respiration and nutrition as well as provision of assistive devices and end-of-life situations.

CONCLUSION

Diagnostic and therapeutic guidelines are necessary due the comparatively high number of cases and the aggressive disease course. Given the low prevalence and the severe impairment of patients, it is often impossible to generate evidence-based data so that ALS guidelines are partially dependent on expert opinion.

Venous thromboembolism risk following temporary immobilisation after injury: evaluation of the Aberdeen VTE risk tool

BACKGROUND

Temporary lower limb immobilisation following injury is a risk factor for symptomatic venous thromboembolism (VTE). Pharmacological thromboprophylaxis can mitigate this risk but it is unclear which patients benefit from this intervention. The Aberdeen VTE risk tool was developed to tailor thromboprophylaxis decisions in these patients and this evaluation aimed to describe its performance in clinical practice. Secondarily, diagnostic metrics were compared with other risk assessment methods (RAMs).

METHODS

A prospective cohort service evaluation was conducted. Adult patients (≥16 years) managed with lower limb immobilisation for injury who were evaluated with the Aberdeen VTE risk tool prior to discharge from the ED were identified contemporaneously between February 2014 and December 2020. Electronic patient records were scrutinised up to 3 months after removal of immobilisation for the development of symptomatic VTE or sudden death due to pulmonary embolism (PE). Other RAMs, including the Thrombosis Risk Prediction for Patients with cast immobilisation (TRiP(cast)) and Plymouth scores, were assimilated retrospectively and diagnostic performance compared.

RESULTS

Of 1763 patients (mean age 46 (SD 18) years, 51% women), 15 (0.85%, 95% CI 0.52% to 1.40%) suffered a symptomatic VTE or death due to PE. The Aberdeen VTE tool identified 1053 (59.7%) patients for thromboprophylaxis with a sensitivity of 80.0% (95% CI 54.8% to 93.0%) and specificity of 40.4% (95% CI 38.1% to 42.6%) for the primary outcome. In 1695 patients, fewer were identified as high risk by the TRiP(cast) (33.3%) and Plymouth (24.4%) scores, but with greater specificity, 67.0% and 75.6%, respectively, than dichotomous RAMs, including the Aberdeen VTE tool.

CONCLUSION

Routine use of the Aberdeen VTE tool in our population resulted in an incidence of symptomatic VTE of less than 1%. Ordinal RAMs, such as the TRiP(cast) score, may more accurately reflect VTE risk and permit more individually tailored thromboprophylaxis decisions but prospective comparison is needed.

Risk factors and new inflammatory indicators of deep vein thrombosis after adult patella fractures

OBJECTIVE

This study aimed to investigate the association between new inflammatory indicators at admission and the occurrence of preoperative deep vein thrombosis (DVT) in patients with patella fractures.

METHODS

A retrospective analysis of the medical records of patients aged 18 years or older who underwent surgical treatment for unilateral closed patella fractures at our hospital between August 2016 and August 2020. The incidence of preoperative DVT was detected by Duplex ultrasound (DUS). Partial blood routine and biochemical indexes were collected at admission, and the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) of inflammatory indexes were also calculated. ROC was used to analyze the cut-off value NLR, MLR, and PLR for predicting preoperative DVT, and univariate and multivariate analyses of the risk factors for preoperative DVT of patella fractures, and to verify whether other risk factors affecting the relationship between validation indexes and preoperative DVT.

RESULTS

A total of 500 patients were included, of which 39 patients (7.8%) developed preoperative DVT. After univariate and multivariate analysis, preoperative time (in each day delay), male (vs. female), D-dimer > 0.6 mg/L, total cholesterol (TC) > 5.6 mmol/L, and PLR > 189.8 were the risk factors for preoperative DVT in patients with patella fracture. Inflammation index PLR combined with the other four risk factors significantly improved the predictive efficacy of preoperative DVT compared with PLR (P = 0.009).

CONCLUSION

Inflammatory index PLR is a risk factor for preoperative DVT in patients with patella fracture, and the efficacy of PLR in predicting DVT can be significantly improved when other risk factors (male, D-dimer > 0.6 mg/L, TC > 5.6 mmol/L, and PLR > 189.8 of preoperative time in each day delay) are combined. These data are useful for the clinical identification of patients at high risk of preoperative DVT in patella fractures.

Bone healing study of alendronate combined with enoxaparin sodium bone cement in rabbits with bone defects

BACKGROUND

To observe the effect of enoxaparin sodium-polymethyl methacrylate (ES-PMMA) bone cement supplemented with alendronate (AN) on bone repair of bone defects in New Zealand rabbits.

METHODS

Twenty-seven New Zealand rabbits were randomly divided into ES/AN, ES-PMMA and PMMA groups, with a total of 27 New Zealand rabbits. The drugs loaded in 40 g bone cement powder were as follows: ES/AN group 8000 AxaIU enoxaparin (ES) and 200 mg alendronate (AN), ES-PMMA group 8000 AxaIU enoxaparin (ES), PMMA group without drugs. A bone defect model with a length of 10 mm and a diameter of 5 mm was made from the left tibia of rabbits, and the prepared bone cement was placed in the tibia defect. At 4 weeks, 8 weeks and 12 weeks after the operation, 3 rabbits in each group were sacrificed, and left tibia samples were collected for histological scoring, HE staining and Masson staining. Bone mineral density and new bone volume were measured by imaging, and the related data were processed by one-way ANOVA and least significance difference (LSD) post hoc test.

RESULTS

(1) Bone mineral density (BMD, mg/mm3) around the bone defect: at the 4th week, BMD in the ES/AN group was higher than that in the PMMA group; at the 8th week, the BMD in the ES/AN group was significantly higher than that in the other two groups; and at the 12th week, the BMD in the ES/AN group was significantly higher than that in the other two groups. (2) New bone volume (BV, mm3): at the 4th week, BV in the ES/AN group was significantly higher than that in the other two groups, BV in the ES/AN group was significantly higher than that in the other two groups at the 8th and 12th weeks, and BV in the ES-PMMA group was higher than that in the PMMA group. (3) Histological score: at the 4th and 8th weeks, the histological score of the ES/AN group was higher than that of the PMMA group, and at the 12th week, the histological score of the ES/AN group was higher than that of the other two groups. (4) Cortical bone thickness (μm): at the 4th, 8th and 12th weeks, the cortical bone thickness in the ES/AN group was higher than that in the other two groups, and the cortical bone thickness in the ES-PMMA group was higher than that in the PMMA group. (5) The percentage of mature area of new bone in the ES/AN group was higher than that in the other two groups at the 4th week, and at the 8th and 12th weeks, the percentage of mature area of new bone in the ES/AN group and ES-PMMA group was significantly higher than that in the PMMA group.

CONCLUSION

(1) Enoxaparin sodium bone cement supplemented with alendronate was superior to enoxaparin sodium bone cement and PMMA bone cement in promoting bone repair of tibial bone defects in New Zealand rabbits. (2) Enoxaparin sodium bone cement is superior to PMMA bone cement in promoting bone repair, showing a certain osteogenic potential.

Forensic autopsy-confirmed thrombosis-related deaths: the danger in the bones

Thrombosis is a potentially life-threatening condition related to roughly a quarter of all deaths globally. Many of these deaths occur inside healthcare facilities due to possibly preventable causes. Therefore, understanding the etiological factors involved in excessive thrombosis may significantly contribute to the successful identification, management and education of people who have an increased risk of thrombosis. We performed a retrospective file-audit of all forensic autopsy reports conducted at the Free State Forensic Pathology Mortuary in Bloemfontein, South Africa, over 10 years. We collected the age at death, gender and ethnicity of each person included in the study. The presence and location of the thrombosis and any underlying disorder or disease were noted. The overall prevalence of thrombosis for the total study population was 0.97%. Pulmonary embolisms (PE's) were much more common than coronary thromboses. Most PE's had known contributory risk factors, where coronary thrombosis-related deaths occurred suddenly without known risk factors. Bone fractures were the most prominent risk factor associated with PE's. Females of African descent had a consistently high prevalence of thrombosis after the age of 30 years. Males of European descent showed an unexpected peak in prevalence during the 4th decade. Since most deaths occurred in patients with conditions known to contribute to venous thrombosis, we conclude that intensified public awareness efforts are required in our region to assist the general public in identifying risk factors for thrombosis, thereby decreasing the burden this potentially preventable disorder places on society.

The Auxiliary Role of Heparin in Bone Regeneration and its Application in Bone Substitute Materials

Bone regeneration in large segmental defects depends on the action of osteoblasts and the ingrowth of new blood vessels. Therefore, it is important to promote the release of osteogenic/angiogenic growth factors. Since the discovery of heparin, its anticoagulant, anti-inflammatory, and anticancer functions have been extensively studied for over a century. Although the application of heparin is widely used in the orthopedic field, its auxiliary effect on bone regeneration is yet to be unveiled. Specifically, approximately one-third of the transforming growth factor (TGF) superfamily is bound to heparin and heparan sulfate, among which TGF-β1, TGF-β2, and bone morphogenetic protein (BMP) are the most common growth factors used. In addition, heparin can also improve the delivery and retention of BMP-2 in vivo promoting the healing of large bone defects at hyper physiological doses. In blood vessel formation, heparin still plays an integral part of fracture healing by cooperating with the platelet-derived growth factor (PDGF). Importantly, since heparin binds to growth factors and release components in nanomaterials, it can significantly facilitate the controlled release and retention of growth factors [such as fibroblast growth factor (FGF), BMP, and PDGF] in vivo. Consequently, the knowledge of scaffolds or delivery systems composed of heparin and different biomaterials (including organic, inorganic, metal, and natural polymers) is vital for material-guided bone regeneration research. This study systematically reviews the structural properties and auxiliary functions of heparin, with an emphasis on bone regeneration and its application in biomaterials under physiological conditions.

Clinical use of low-dose parenteral anticoagulation, incidence of major bleeding and mortality: a multi-centre cohort study using the French national health data system

PURPOSE

Low-dose parenteral anticoagulation has demonstrated its efficacy for venous thromboembolism prophylaxis in randomized trials. However, current practice is not widely documented. In ambulatory settings, we aimed to provide an overview of the clinical use of low-dose parenteral anticoagulation in France and to assess the incidence of major bleeding and death rates.

METHODS

A population-based prospective cohort study using the French national health data system (SNIIRAM) identified 142,815 adults living in five well-defined geographical areas who had a course of low-dose parenteral anticoagulants (a total of 150,389 courses) in the period 2013-2015. The main outcome measures were the types of low-dose parenteral anticoagulant, the duration and the clinical context. Adjusted incidence rate ratios (IRR) were derived from Poisson models.

RESULTS

Enoxaparin was the most frequently prescribed anticoagulant (58.9%) followed by tinzaparin (27.3%) and fondaparinux (10.9%). Patients receiving unfractionated heparin (N = 766, 0.53%) were older, more frequently had renal disease (48.75%) and had a higher modified HAS-B(L)ED score (≥ 3 in 61.6%) than patients receiving low-molecular weight heparin (LMWH). Surgical thrombo-prophylaxis was the most frequent indication (47.6%), followed by medical prophylaxis (29.9%). Course durations were in line with regulatory agency specifications. Only 43 (0.028%) major bleeding events and 478 (0.32%) deaths were observed. Adjusted IRRs for major bleeding or death were not significantly different for dalteparin/nadroparin, tinzaparin or fondaparinux compared to enoxaparin.

CONCLUSION

Very low incidence rates of major bleeding and all-cause mortality were observed. Our study confirms the safety of LMWHs and fondaparinux in thrombo-prophylaxis in ambulatory settings.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02886533.

Incidence and risk factors of preoperative deep venous thrombosis in closed tibial shaft fracture: a prospective cohort study

OBJECTIVE

To investigate the preoperative morbidity of deep venous thrombosis (DVT) and predictive risk factors associated with DVT after closed tibial shaft fracture.

METHODS

Ultrasonography and blood analyses were performed preoperatively in patients who sustained tibial shaft fracture between October 2014 and December 2018. Univariate analyses were used in the data of demographics, comorbidities, mechanism of injury, concomitant fractures and laboratory biomarkers. Multivariate logistic regression analyses were conducted to determine the independent risk factors associated with DVT.

RESULTS

In total, 918 patients with an operatively treated tibial shaft fracture were included, among whom 122 patients had preoperative DVTs, indicating a crude morbidity of 13.3%. Ninety-two of 758 (12.1%) patients with isolated tibial shaft fracture developed DVT, while 30 of 160 (18.8%) patients with concurrent fracture presented with DVT. The average interval between fracture and initial diagnosis of DVT was 3.1 days (median, 2 days), ranging from 0 to 33 days. Among DVT-positive patients, 16 (13.1%) patients presented with proximal DVT and 106 (86.9%) patients had distal DVT. Multivariate logistic regression analysis showed four independent risk factors were significantly correlated to the development of DVT, including increased age (OR = 1.17, p = 0.003), diabetes (OR = 1.99, p = 0.009), serum hydroxybutyrate dehydrogenase > 182 U/L (OR = 1.83, p = 0.008), and delay to DUS (in each day) (OR = 1.13, p < 0.001).

CONCLUSION

In the present cohort study, the incidence of DVT was 12.1% in patients with isolated tibial shaft fracture. We suggest individualized risk stratification and early anticoagulation for patients with high risk factors including pre-existing diabetes, HBDH > 182 U/L, delay to DUS and older age.

LEVEL OF EVIDENCE

Level III, a prospective cohort study.

A Prospective Study Assessing Wound Complications in a Series of Foot and Ankle Patients Treated With Enoxaparin: A Baseline for Future Studies

Background and objective

Low-molecular-weight heparin (LMWH) prophylaxis has now become the gold-standard practice in patients requiring lower limb immobilization. We had noticed an increase in the incidence of wound-healing problems at our center, and the severity of the problems was found to be worse in patients undergoing foot and ankle surgery since we had adopted this practice. In this study, we aimed to describe the incidence and severity of wound-healing problems in this group of patients.

Methods

This was a prospective study and we collected data on the frequency and severity of wound problems occurring in patients undergoing a variety of foot and ankle operations. All patients underwent a standard agreed-on method of wound closure and dressings. Wounds were reviewed after two weeks and wound characteristics were noted using a rigid proforma. The primary outcome measure was to determine the incidence of delayed wound healing (DWH) and wound infections requiring antibiotics. Secondary outcomes were the characteristics of each delayed-healing wound.

Results

A total of 158 patients met the inclusion criteria of the study. One patient was not given postoperative LMWH and was excluded from the final analysis. Seven patients (4.5%) were noted to have DWH and four patients (2.6%) had a wound infection at the two-week postoperative follow-up. None of the patients required a second operation. Among patients with wound-healing problems, wound contour irregularities were noted in 51% and margin separation was noted in 65%.

Conclusion

The overall incidence of wound-healing problems such as DWH and wound infections was low in patients receiving prophylactic LMWH for foot and ankle surgery. Where postoperative wound problems did occur, these were associated with poor wound characteristics such as margin separation or contour irregularity. Further studies should be conducted to ascertain if the use of LMWH leads to problems with wound appearance.

Intervention to Improve Compliance With National Guidelines on Venous Thromboembolism Chemoprophylaxis for Patients With Operatively Managed Ankle Fractures

Background: Trauma and subsequent immobilization of the lower limb increase the risk of venous thromboembolism (VTE). Our aim was to evaluate compliance with national guidance on operatively managed ankle fractures and VTE chemoprophylaxis before and after implementation of a change in practice. Methods: We conducted an initial single-center audit of patients undergoing ankle fracture fixation. The primary outcome was quality of operation note documentation, and the secondary outcome was whether VTE chemoprophylaxis was prescribed on discharge. All stakeholders were educated on audit findings, new guidelines were synthesized, and the practice was re-audited. Results: A total of 137 patients were included in the initial audit, and 49 patients were included in the loop closure. The first audit highlighted that chemoprophylaxis prescription on discharge was significantly higher when both the agent and treatment duration were clearly stipulated in the operation note compared to when either treatment duration or both agent and treatment duration were omitted (97.2% vs 51.8% and 32.4%, respectively, P<0.001). Following our intervention, operation note documentation of agent and treatment duration improved from 29% to 90% (P<0.001). VTE chemoprophylaxis on discharge significantly improved from 57% to 98% (P<0.001). Conclusion: Our closed-loop audit identified suboptimal operation note documentation as the root cause of VTE noncompliance. The operation note is an important clinical interface between the operating theater and ward staff. We addressed these deficiencies with a basic intervention.

Association Between Maternal Weight Gain in Different Periods of Pregnancy and the Risk of Venous Thromboembolism: A Retrospective Case-Control Study

BACKGROUND

Venous thromboembolism (VTE) remains an important cause of maternal deaths. Little is known about the associations of specific periods of gestational weight gain (GWG) with the category of VTE, pulmonary embolism (PE), or deep venous thrombosis (DVT) with or without PE.

METHODS

In a retrospective case-control study conducted in Shanghai First Maternity and Infant Hospital from January 1, 2017 to September 30, 2021, cases of VTE within pregnancy or the first 6 postnatal weeks were identified. Controls without VTE were randomly selected from women giving birth on the same day as the cases, with 10 controls matched to each case. Total GWG and rates of early, mid, and late GWG values were standardized into z-scores, stratified by pre-pregnant body mass index (BMI). The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated through multivariate logistic regression models.

RESULTS

There were 196 cases (14.4 per 10,000) of VTE within pregnancy or the first 6 postnatal weeks were identified. Higher total weight gain was associated with increased risks of PE (aOR, 13.22; 95% CI, 2.03-85.99) and VTE (OR, 10.49; 95% CI, 1.82-60.45) among women with underweight. In addition, higher total weight gain was associated with increased risk of PE (aOR, 2.06; 95% CI, 1.14-3.72) among women with healthy weight. Similarly, rate of higher early weight gain was associated with significantly increased risk for PE (aOR, 2.15; 95% CI, 1.05-4.42) among women with healthy BMI. The lower rate of late weight gain was associated with increased risks of PE (aOR, 7.30; 95% CI, 1.14-46.55) and VTE (OR, 7.54; 95% CI, 1.20-47.57) among women with underweight. No significant associations between maternal rate of mid GWG and increased risk for any category of VTE, PE, or DVT with or without PE were present, regardless of maternal pre-pregnant BMI.

CONCLUSION

The GWG associations with the category of VTE, PE, or DVT with or without PE differ at different periods of pregnancy. In order to effectively improve maternal and child outcomes, intensive weight management that continues through pregnancy may be indispensable.

Analysis of Adherence to Thromboprophylaxis and Incidence of Venous Thromboembolism After Lower Limb Orthopaedic Surgery

Background The economic burden caused by venous thromboembolism (VTE) to the National Health Service (NHS) is approximately £640 million. There is a significant national drive for VTE prophylaxis prescription given the high morbidity and mortality rates associated with VTE following lower limb orthopaedic surgery. The primary objective of this analysis was to examine the adherence to the updated VTE guidelines, NG89, by the National Institute for Health and Care Excellence (NICE) regarding prophylaxis for patients undergoing lower limb orthopaedic surgery, where the weight-bearing status will be reduced postoperatively, in an urban community hospital. Methodology We looked at 586 patients who underwent elective lower limb orthopaedic surgeries over a two year time period. We reviewed their VTE prophylaxis administration. Results were shared with the Hospital Thrombosis Committee department. Education was provided to the relevant staff and hospital policy for VTE prophylaxis. The primary endpoint was to compare the proportion of patients receiving prophylaxis as per the hospital guidelines as well as complications arising from VTE. Results A total of 586 patients were included in this audit. Compliance with VTE pharmacological prophylaxis was recorded, as well as weight-bearing status advised postoperatively. Compliance with prophylaxis in patients who were non-weight-bearing postoperatively was 54.8%. There were three cases of recorded VTE; however, in all cases, appropriate VTE prophylaxis has been prescribed. Conclusion Increasing hospital-wide awareness and education of VTE and the fatal complications is imperative. All patients should be administered VTE prophylaxis as an inpatient and on discharge if their weight-bearing status is affected following lower limb orthopaedic surgery. Although our compliance rate for prescription of VTE prophylaxis did not achieve the standards set by NICE, all cases of recorded VTE had been correctly prescribed VTE prophylaxis on discharge.

Risque thromboembolique veineux chez les patients traumatisés d’un membre inférieur nécessitant une immobilisation : vers une approche individualisée

Un traumatisme d’un membre inférieur nécessitant une immobilisation est une situation à risque de développement de maladie thromboembolique veineuse (MTEV). Cependant, les recommandations et les pratiques varient notablement d’un pays à un autre et d’un centre à un autre. Cette revue narrative a pour objectifs de décrire l’épidémiologie, la prévention et les algorithmes de prédiction de la MTEV chez les patients traumatisés d’un membre inférieur nécessitant une immobilisation. L’incidence de la MTEV varie selon les études du fait de la grande hétérogénéité des patients inclus (de l’entorse de cheville à une lésion chirurgicale) et du fait des différents critères d’évaluation utilisés. L’incidence des événements thromboemboliques veineux symptomatiques est estimée à 2,0 % (intervalle de confiance à 95 % : 1,3 à 2,7). L’efficacité de la thromboprophylaxie a été démontrée dans des méta-analyses récentes. Cependant, la confiance à accorder à ces résultats est médiocre, car de nombreux essais présentaient des faiblesses méthodologiques. L’étude la plus importante et la plus récente ne montre pas de bénéfice de la prévention par héparine de bas poids moléculaire sur les événements symptomatiques dans une population non ciblée. Ces résultats suggèrent d’adopter une démarche personnalisée en réservant la prophylaxie aux patients à risque. Plusieurs scores existent pour évaluer le risque thromboembolique individuel. La prise en compte des caractéristiques du patient, du traumatisme et de l’immobilisation permet d’identifier un large sous-groupe de patients chez qui la prévention ne semble pas utile et un sous-groupe de patients à haut risque où la prévention devrait être prescrite, voire renforcée. En conclusion, lors d’un traumatisme d’un membre inférieur nécessitant une immobilisation, l’indication d’une thromboprophylaxie devrait être guidée par l’évaluation individuelle du risque thrombotique.

Incidence of Symptomatic Venous Thromboembolism in Proximal Hamstring Repair: A Prospective Cohort Study

Background:

Surgical repair of proximal hamstring avulsion injuries can enable the return to preinjury levels of sporting function and minimize the risk of recurrence in both professional and recreational athletes. While venous thromboembolism (VTE) is a recognized complication of surgical repair, the incidence thereof is poorly reported in the literature.

Purpose/Hypothesis:

To report the incidence of symptomatic VTE after proximal hamstring avulsion repair and assess the efficacy of our thromboprophylaxis protocol. It was hypothesized that the incidence of VTE after proximal hamstring avulsion repair is low and that aspirin is an adequate choice of chemical prophylaxis.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We performed a prospective cohort study of 2 groups of patients who underwent proximal hamstring avulsion (partial and complete) repair between 2000 to 2020 with different thromboprophylaxis protocols. No patients were routinely screened for VTEs, and VTE was investigated only if clinically indicated. Prospectively collected data included demographics, the mechanism and sport that caused injury, use of bracing, and clinical diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE). The first cohort (n = 380) was given mechanical prophylaxis in the form of compression stockings for 6 weeks postoperatively. The second cohort (n = 600) was given compression stockings and aspirin 150 mg once daily routinely, or prophylactic low–molecular weight heparin in high-risk individuals, until the 6-week follow-up. Patients in both cohorts underwent early mobilization after surgery; a hinged knee brace locked at 60° to 120° was provided if the tendon repair was under significant tension. The surgical technique and rehabilitation protocol remained consistent throughout the study.

Results:

The overall incidence of symptomatic VTE was 0.51%. A total of 5 patients developed symptomatic VTEs (3 DVTs, 2 PEs) in the first cohort, and no patients developed symptomatic VTEs in the second cohort (1.32% vs 0%; P = .0048).

Conclusion:

The incidence of symptomatic VTE after proximal hamstring avulsion repairs was extremely low. A combination of aspirin, early mobilization despite bracing, compression stockings, and good hydration was an effective thromboprophylaxis strategy.

The incidence and risk factors of deep venous thrombosis in lower extremities following surgically treated femoral shaft fracture: a retrospective case-control study

Background

There is still a lack of data on deep vein thrombosis (DVT) following surgically treated femoral shaft fracture (FSF). The goal of this study was to investigate the characteristics of postoperative DVT and the association between the occurrence of DVT and risk factors in patients undergoing surgical treatment for FSF.

Methods

This observational retrospective case-control study reviewed 308 patients who received surgical treatment of FSF between January 2016 and October 2020 at a university hospital. Univariate analyses were performed on the data of demographics, comorbidities, laboratory biomarkers, and operation-related indexes. The receiver operating characteristic (ROC) curve analysis, univariate analyses, and multivariate logistic regression analysis were employed to identify the independent risk factors associated with DVT.

Results

In total, 308 patients with surgically treated FSF were included, among whom 48 (15.6%) patients had postoperative DVTs. The univariate analyses showing significant differences regarding DVT were American Society of Anesthesiologists (ASA) classification, diabetes mellitus, current smoking, aspartate transaminase (AST), and very-low-density lipoprotein (VLDL) level among the 34 factors. According to the ROC results, the optimal cutoff values for intraoperative blood loss, d-dimer, and age were 350 ml, 1.08 μg/ml, and 35 years, respectively. The multivariable model demonstrated 4 significantly independent associations with postoperative DVT, including current smoking, intraoperative blood loss (> 550 ml), age (> 35 years), and d-dimer > 1.09 μg/ml.

Conclusion

These risk factors as screening tools contribute to risk stratification of the occurrence of thromboembolic events. In addition, our findings would help orthopedic surgeons make a cross-specialty decision and implement targeted precaution measures for patients with FSF.

STOP leg clots-Swedish multicentre trial of outpatient prevention of leg clots: study protocol for a randomised controlled trial on the efficacy of intermittent pneumatic compression on venous thromboembolism in lower leg immobilised patients

INTRODUCTION

Leg immobilisation in a cast or an orthosis after lower limb injuries is associated with a high risk of complications of venous thromboembolism (VTE) and hampered healing. Current pharmacoprophylaxes of VTE are inefficient and associated with adverse events. Intermittent pneumatic compression (IPC) could represent a novel, efficient and safe VTE-prophylactic alternative that may enhance injury healing. The aim of STOP leg clots is to assess the efficacy of adjuvant IPC-therapy on reduction of VTE incidence and improvement of healing in lower leg immobilised outpatients.

METHODS AND ANALYSIS

STOP leg clots is a multicentre randomised controlled superiority trial. Eligible patients (700 patients/arm) with either an acute ankle fracture or Achilles tendon rupture will be randomised to either addition of IPC during lower-leg immobilisation or to treatment-as-usual. The primary outcome will be the total VTE incidence, that is, symptomatic and asymptomatic deep venous thrombosis (DVT) or symptomatic pulmonary embolism (PE), during the leg immobilisation period, approximately 6-8 weeks. DVT incidence will be assessed by screening whole leg compression duplex ultrasound at removal of leg immobilisation and/or clinically diagnosed within the time of immobilisation. Symptomatic PE will be verified by CT.Secondary outcomes will include patient-reported outcome using validated questionnaires, healing evaluated by measurements of tendon callus production and changes in VTE-prophylactic mechanisms assessed by blood flow and fibrinolysis. Data analyses will be blinded and based on the intention-to-treat.

ETHICS AND DISSEMINATION

Ethical approval was obtained by the ethical review board in Stockholm, Sweden, Dnr 2016/1573-31. The study will be conducted in accordance with the Helsinki declaration. The results of the study will be disseminated in peer-reviewed international journals.

TRIAL REGISTRATION

NCT03259204.

TIME SCHEDULE

1 September 2018 to 31 December 2022.

The efficacy and safety of low-molecular-weight heparin calcium combined with Xueshuantong injections in the treatment of elderly acute deep venous thrombosis patients

OBJECTIVE

To explore the therapeutic effect of low-molecular-weight heparin calcium (LMWH-Ca) combined with Xueshuantong injections in treating elderly acute deep venous thrombosis (ADVT) patients, and to analyze the effect of this combination on the coagulation function, hemorheology, and safety.

METHODS

A total of 122 elderly patients with ADVT who were treated in our hospital were recruited as the study cohort. The patients were randomly divided into a control group (n=61) and an observation group (n=61). The patients in the control group were given abdominal subcutaneous injections of low-molecular-weight heparin calcium (LMWH-Ca). The patients in the observation group were given intravenous drips of LMWH-Ca (low-molecular-weight heparin calcium) and Xueshuantong injections. After the treatment, comparisons of the detumescence times of the affected limb, the differences in the circumferences of the lower limbs, the coagulation parameters, the overall response rates, the incidences of complications, and the hemorheological parameters were conducted between both groups.

RESULTS

After the treatment, the detumescence times and the average differences in the circumferences of the lower limbs were significantly reduced (P<0.001; all P<0.001), the prothrombin times (PT) and the activated partial thromboplastin times (APTT) were significantly extended (all P<0.01), the overall response rate was higher (all P<0.05), and the three hemorheological parameters (high shear viscosity, low shear viscosity, and plasma viscosity) were lower in the observation group than they were in the control group (all P<0.001), there were no statistical differences in the fibrinogen (FIB) levels, the incidences of complications, or the incidences of adverse drug reactions between the two groups (P>0.05; P=0.343; P=0.298).

CONCLUSION

To sum up, low-molecular-weight heparin combined with Xueshuantong injections can effectively treat elderly ADVT patients, reduce the differences in the circumferences of the lower limbs, regulate the coagulation function, and improve the blood viscosity, so it is worthy of clinical promotion.

A botanical medicine dragon's blood exhibited clinical antithrombosis efficacy similar to low molecular weight heparin

Deep vein thrombosis (DVT) is a common complication following traumatic fracture with a 0.5%-1% annual incidence. Low molecular weight heparin (LMWH) is the most commonly used anticoagulation drug for DVT prevention, but treatment with LMWH is invasive. Our aim is to compare the antithrombotic effect of dragon's blood, an oral botanical anticoagulant medicine approved by the Chinese FDA, with LMWH in patients undergoing hip fracture surgery and to explore the molecular mechanisms of anticoagulation treatment. Our study recruited patients and divided them into LMWH and dragon's blood treatment group. Coagulation index tests, Doppler ultrasound and mRNA sequencing were performed before and after anticoagulation therapy. There was no significant difference in postoperative DVT incidence between the two groups (23.1% versus 15.4%, P=0.694). D-dimer (D-D) and fibrinogen degradation product (FDP) showed significant reductions in both groups after anticoagulation treatments. We identified SLC4A1, PROS1, PRKAR2B and seven other genes as being differentially expressed during anticoagulation therapy in both groups. Genes correlated with coagulation indexes were also identified. Dragon's blood and LMWH showed similar effects on DVT and produced similar gene expression changes in patients undergoing hip fracture surgery, indicating that dragon's blood is a more convenient antithrombosis medicine (oral) than LMWH (hypodermic injection).

Venous thromboembolism in trauma patients with lower limb cast immobilization, associated risk reduction and complication using rivaroxaban

INTRODUCTION

Several studies have shown a reduction in the rate of thromboembolic events with LMWH thromboprophylaxis in patients immobilised in lower limb cast. However, the literature is limited on the use of rivaroxaban in this setting. Therefore the aim of this study was to assess the associated impact of rivaroxaban on the incidence of venous thromboembolism in trauma patients with lower limb cast immobilisation.

METHOD

Adult patients treated with lower limb cast immobilisation for different types of lower limb injuries were included in this study. One cohort of patients (n = 518) received rivaroxaban thromboprophylaxis. This was compared with a historical cohort (n = 486), who received no rivaroxaban for thromboprophylaxis.

RESULTS

The number of patients developing VTEs in the rivaroxaban group was zero, compared with 6 cases (1.2%) in the nonrivaroxaban group p = 0.013. There were no major or minor bleeding incidences; no wound complications reported in the rivaroxaban group. All the side effects reported in association with rivaroxaban use did not require further intervention.

CONCLUSION

This study has shown that rivaroxaban is associated with a significant reduction in the risk of VTEs in patients with lower limb cast immobilisation without increasing the risk of bleeding or associated untoward effect. Lower limb immobilisation is high risk factor for VTE per se. However, there is still limited data in the literature to make further recommendations.

Nonalcoholic steatohepatitis Fitness Intervention in Thrombosis (NASHFit): Study protocol for a randomized controlled trial of a supervised aerobic exercise program to reduce elevated clotting risk in patients with NASH

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide affecting upwards of one third the global population. For reasons not fully understood, individuals with NAFLD and its more severe variant, nonalcoholic steatohepatitis (NASH), are at increased risk for venous thromboembolism which significantly increases morbidity and mortality. Lifestyle changes centering around exercise training are the mainstay of treatment for NAFLD/NASH. While exercise training can lessen venous thromboembolic risk in healthy persons and those with cardiovascular disease, whether or not this benefit is seen in patients with NAFLD/NASH remains unknown. In order to better understand how exercise training impacts thrombosis risk in NAFLD, we present the design of a thirty-two week randomized controlled clinical trial of 42 sedentary subjects age 18-69 with biopsy proven NASH. The main aim is to determine the impact of an aerobic exercise training program on the abnormal hemostatic system unique to NAFLD/NASH. The main outcome is change in plasminogen activator inhibitor one level, an established marker for venous thromboembolism. Secondary outcomes include body composition, cardiorespiratory fitness, control of comorbid metabolic conditions (e.g., obesity, hypertension, hyperlipidemia, diabetes), dietary composition, health related quality of life, liver enzymes and histology, NAFLD/NASH disease activity (e.g., biomarkers, clinical decision aids), microbiome, other markers of hemostasis, and PNPLA3 gene expression. The study represents the first clinical trial of an exercise training program to reduce elevated clotting risk in subjects with NAFLD/NASH.

Clinical risk assessment model to predict venous thromboembolism risk after immobilization for lower-limb trauma

BACKGROUND

Patients with lower-limb trauma requiring immobilization have an increased risk of venous thromboembolism (VTE). While thromboprophylaxis for all patients seems not effective, targeted thromboprophylaxis in high risk patients may be an appropriate alternative. Therefore, we aimed to develop and validate a risk assessment model for VTE risk: the TRiP(cast) score (Thrombosis Risk Prediction following cast immobilization).

METHODS

In this prediction model study, for development, data were used from the MEGA study (case-control study into the etiology of VTE) and for validation, data from the POT-CAST trial (randomized trial on the effectiveness of thromboprophylaxis following cast immobilization) were used. Model discrimination was calculated by estimating the Area Under the Curve (AUC). For model calibration, observed and predicted risks were assessed.

FINDINGS

The TRiP(cast) score includes 14 items; one item for trauma severity (or type), one for type of immobilization and 12 items related to patients' characteristics. Validation analyses showed an AUC of 0.74 (95%CI 0.61-0.87) in the complete dataset (n = 1250) and 0.72 (95%CI 0.60-0.84) in the imputed data set (n = 1435). The calibration plot shows the degree of agreement between the observed and predicted risks (intercept 0.0016 and slope 0.933). Using a cut-off score of 7 points in the POT-CAST trial (incidence 1.6%), the sensitivity, specificity, positive and negative predictive values were 76.1%, 51.2%, 2.5%, and 99.2%, respectively.

INTERPRETATION

The TRiP(cast) score provides a helpful tool in daily clinical practice to accurately stratify patients in high versus low-risk categories in order to guide thromboprophylaxis prescribing. To accommodate implementation in clinical practice a mobile phone application has been developed.

FUNDING

ZonMW VIMP grant:17110200011.

Pharmacological thromboprophylaxis to prevent venous thromboembolism in patients with temporary lower limb immobilization after injury: systematic review and network meta-analysis

BACKGROUND

Thromboprophylaxis has the potential to reduce venous thromboembolism (VTE) following lower limb immobilization resulting from injury.

OBJECTIVES

We aimed to estimate the effectiveness of thromboprophylaxis, compare different agents, and identify any factors associated with effectiveness.

METHODS

We undertook a systematic review and network meta-analysis (NMA) of randomized trials reporting VTE or bleeding outcomes that compared thromboprophylactic agents with each other or to no pharmacological prophylaxis, for this indication. An NMA was undertaken for each outcome or agent used, and a series of study-level network meta-regressions examined whether population characteristics, type of injury, treatment of injury, or duration of thromboprophylaxis were associated with treatment effect.

RESULTS

Data from 6857 participants across 13 randomized trials showed that, compared with no treatment, low molecular weight heparin (LMWH) reduced the risk of any VTE (odds ratio [OR]: 0.52; 95% credible interval [CrI]: 0.37-0.71), clinically detected deep vein thrombosis (DVT) (OR: 0.39; 95% CrI: 0.12-0.94) and pulmonary embolism (PE) (OR: 0.16; 95% CrI: 0.01-0.74), whereas fondaparinux reduced the risk of any VTE (OR: 0.13; 95% CrI: 0.05-0.30) and clinically detected DVT (OR: 0.10; 95% CrI: 0.01-0.86), with inconclusive results for PE (OR: 0.40; 95% CrI: 0.01-7.53).

CONCLUSIONS

Thromboprophylaxis with either fondaparinux or LMWH appears to reduce the odds of both asymptomatic and clinically detected VTE in people with temporary lower limb immobilization following an injury. Treatment effects vary by outcome and are not always conclusive. We were unable to identify any treatment effect modifiers other than thromboprophylactic agent used.

Thromboprophylaxis in lower limb immobilisation after injury (TiLLI)

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures and result in significant loss of disability adjusted life years. Temporary lower limb immobilisation after injury is a significant contributor to the overall burden of venous thromboembolism (VTE). Existing evidence suggests that pharmacological prophylaxis could reduce overall VTE event rates in these patients, but the proportional reduction of symptomatic events remains unclear. Recent studies have used different pharmacological agents, dosing regimens and outcome measures. Consequently, there is wide variation in thromboprophylaxis strategies, and international guidelines continue to offer conflicting advice for clinicians. In this review, we provide a summary of recent evidence assessing both the clinical and cost effectiveness of thromboprophylaxis in patients with temporary immobilisation after injury. We also examine the evidence supporting stratified thromboprophylaxis and the validity of widely used risk assessment methods.

Early mobilization does not reduce the risk of deep venous thrombosis after Achilles tendon rupture: a randomized controlled trial

PURPOSE

The hypothesis was that early functional mobilization would reduce the incidence of deep venous thrombosis (DVT) during leg immobilization after Achilles tendon rupture surgery. A secondary aim was to evaluate if the amount of weightbearing and daily steps influenced the risk of sustaining a DVT.

METHODS

One-hundred and fifty patients with Achilles tendon rupture repair were randomized to treatment with early functional mobilization, encouraging full weightbearing and ankle motion in orthosis, or treatment-as-usual, i.e., 2 weeks of unloading in plaster cast followed by 4 weeks weightbearing in orthosis. At 2 and 6 weeks postoperatively, all patients were screened for DVT using compression duplex ultrasound. During the first 2 weeks postoperatively, patient-reported loading, pain and step counts were assessed.

RESULTS

At 2 weeks, 28/96 (29%) of the patients in early functional mobilization group and 15/49 (31%) in the control group (n.s) had sustained a DVT. At 6 weeks, the DVT rate was 35/94 (37%) in the early functional mobilization and 14/49 (29%) in the control group (n.s). During the first postoperative week, the early functional mobilization group reported low loading and higher experience of pain vs. the control group (p = 0.001). Low patient-reported loading ≤ 50% (OR = 4.3; 95% CI 1.28-14.3) was found to be an independent risk factor for DVT, in addition to high BMI and higher age.

CONCLUSIONS

Early functional mobilization does not prevent the high incidence of DVT during leg immobilization in patients with Achilles tendon rupture as compared to treatment-as-usual. The low efficacy of early functional mobilization is mainly explained by postoperative pain and subsequent low weightbearing. To minimize the risk of DVT, patients should be encouraged to load at least 50% of body weight on the injured leg 1 week after surgery.

LEVEL OF EVIDENCE

Therapeutic, level 1.

Deep venous thrombosis after Achilles tendon rupture is associated with poor patient-reported outcome

PURPOSE

The aim of this study was to investigate whether patient subjective and functional outcomes after Achilles tendon rupture (ATR) are related to deep venous thrombosis (DVT) during leg immobilization.

METHODS

A cohort study with prospectively collected randomized data was conducted between 2010 and 2017. Two-hundred and fifty-one Patients with an Achilles tendon rupture (mean age = 41 ± 8), treated with uniform surgical techniques, were retrospectively analyzed. DVT incidence at 2 and 6 weeks was assessed using compression duplex ultrasound. At 12 months patient-reported outcomes were assessed using the Achilles tendon Total Rupture Score (ATRS), Foot- and Ankle Outcome Score (FAOS), Physical Activity Scale (PAS) and functional outcome with the calf-muscle endurance test. ANOVA analyses were used and adjusted for assumed confounding factors (patient age, sex, BMI and rehabilitation).

RESULTS

The total DVT incidence was 122 out of 251 (49%). Patients suffering a DVT exhibited significantly lower ATRS at 1 year compared to patients without DVT (mean 76 vs 83, 95% CI 71-79 vs 80-87; p < 0.01). Sixty-seven percent (95% CI 57-77%) of the patients devoid of DVT reported a good outcome (ATRS > 80) compared to 51% (95% CI 41-61%) of the patients sustaining a DVT (p < 0.05). Quality of life displayed significantly better outcome in the non-DVT versus DVT patients (mean = 75 (95% CI 71-79) vs. mean = 68 (95% CI 64-72); p < 0.05). A significant difference in total concentric work was observed between non-DVT and DVT patients (median = 1.9 kJ (IQR = 0.9 kJ) vs. median = 1.6 kJ (IQR = 1.0 kJ); p < 0.01).

CONCLUSION

Sustaining a DVT during leg immobilization significantly impairs patient-reported outcome at 1 year after surgical repair of ATR.

LEVEL OF EVIDENCE

III.

Incidence of Deep Venous Thrombosis Associated With Proximal Hamstring Rupture

Background:

Rates of deep venous thrombosis (DVT) have been studied for most common orthopaedic injuries. However, rates and risk factors have not been published for proximal hamstring injuries.

Purpose:

To determine the incidence of symptomatic DVT associated with proximal hamstring rupture and associations with prophylactic anticoagulation.

Study Design:

Case series; Level of evidence, 4.

Methods:

Inclusion criteria included all complete and, in a separate cohort, partial proximal hamstring ruptures treated by the senior author from 2007 through 2018 with at least 8 weeks of follow-up. Tendinopathy without tear was excluded. No DVT screening was performed. Charts of patients with symptomatic DVT were reviewed for the treatment method, the presence of imaging-confirmed DVT or pulmonary embolism, and risk factors for DVT. No patients received postinjury DVT prophylaxis. Surgical patients were routinely instructed to take aspirin (325 mg bid) or apixaban (2.5 mg bid) for 4 weeks. Patients with risk factors for DVT received enoxaparin (40 mg daily) for 2 weeks followed by aspirin (325 mg bid) for 2 weeks.

Results:

A total of 144 complete proximal hamstring ruptures were included: 132 treated operatively and 12 treated nonoperatively. There were 10 DVTs associated with the injury, for an overall rate of 6.9%. Five of the DVTs were diagnosed preoperatively in patients who had not received DVT prophylaxis; the other 5 were diagnosed postoperatively in patients on DVT prophylaxis. Six of the 10 DVTs had identifiable risk factors. All patients with postoperatively diagnosed DVTs were on prophylactic aspirin or enoxaparin. In the partial proximal hamstring rupture cohort of 114 ruptures, there were no DVTs.

Conclusion:

There is a high incidence of DVT associated with complete proximal hamstring ruptures (6.9%) despite many patients receiving DVT prophylaxis. This is substantially higher than that in other lower extremity injuries. Clinicians should have a high index of suspicion for DVT after these injuries, and postinjury DVT prophylaxis may be warranted.

Different strategies for pharmacological thromboprophylaxis for lower-limb immobilisation after injury: systematic review and economic evaluation

BACKGROUND

Thromboprophylaxis can reduce the risk of venous thromboembolism (VTE) during lower-limb immobilisation, but it is unclear whether or not this translates into meaningful health benefit, justifies the risk of bleeding or is cost-effective. Risk assessment models (RAMs) could select higher-risk individuals for thromboprophylaxis.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of different strategies for providing thromboprophylaxis to people with lower-limb immobilisation caused by injury and to identify priorities for future research.

DATA SOURCES

Ten electronic databases and research registers (MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effects, the Cochrane Central Register of Controlled Trials, Health Technology Assessment database, NHS Economic Evaluation Database, Science Citation Index Expanded, ClinicalTrials.gov and the International Clinical Trials Registry Platform) were searched from inception to May 2017, and this was supplemented by hand-searching reference lists and contacting experts in the field.

REVIEW METHODS

Systematic reviews were undertaken to determine the effectiveness of pharmacological thromboprophylaxis in lower-limb immobilisation and to identify any study of risk factors or RAMs for VTE in lower-limb immobilisation. Study quality was assessed using appropriate tools. A network meta-analysis was undertaken for each outcome in the effectiveness review and the results of risk-prediction studies were presented descriptively. A modified Delphi survey was undertaken to identify risk predictors supported by expert consensus. Decision-analytic modelling was used to estimate the incremental cost per quality-adjusted life-year (QALY) gained of different thromboprophylaxis strategies from the perspectives of the NHS and Personal Social Services.

RESULTS

Data from 6857 participants across 13 trials were included in the meta-analysis. Thromboprophylaxis with low-molecular-weight heparin reduced the risk of any VTE [odds ratio (OR) 0.52, 95% credible interval (CrI) 0.37 to 0.71], clinically detected deep-vein thrombosis (DVT) (OR 0.40, 95% CrI 0.12 to 0.99) and pulmonary embolism (PE) (OR 0.17, 95% CrI 0.01 to 0.88). Thromboprophylaxis with fondaparinux (Arixtra®, Aspen Pharma Trading Ltd, Dublin, Ireland) reduced the risk of any VTE (OR 0.13, 95% CrI 0.05 to 0.30) and clinically detected DVT (OR 0.10, 95% CrI 0.01 to 0.94), but the effect on PE was inconclusive (OR 0.47, 95% CrI 0.01 to 9.54). Estimates of the risk of major bleeding with thromboprophylaxis were inconclusive owing to the small numbers of events. Fifteen studies of risk factors were identified, but only age (ORs 1.05 to 3.48), and injury type were consistently associated with VTE. Six studies of RAMs were identified, but only two reported prognostic accuracy data for VTE, based on small numbers of patients. Expert consensus was achieved for 13 risk predictors in lower-limb immobilisation due to injury. Modelling showed that thromboprophylaxis for all is effective (0.015 QALY gain, 95% CrI 0.004 to 0.029 QALYs) with a cost-effectiveness of £13,524 per QALY, compared with thromboprophylaxis for none. If risk-based strategies are included, it is potentially more cost-effective to limit thromboprophylaxis to patients with a Leiden thrombosis risk in plaster (cast) [L-TRiP(cast)] score of ≥ 9 (£20,000 per QALY threshold) or ≥ 8 (£30,000 per QALY threshold). An optimal threshold on the L-TRiP(cast) receiver operating characteristic curve would have sensitivity of 84-89% and specificity of 46-55%.

LIMITATIONS

Estimates of RAM prognostic accuracy are based on weak evidence. People at risk of bleeding were excluded from trials and, by implication, from modelling.

CONCLUSIONS

Thromboprophylaxis for lower-limb immobilisation due to injury is clinically effective and cost-effective compared with no thromboprophylaxis. Risk-based thromboprophylaxis is potentially optimal but the prognostic accuracy of existing RAMs is uncertain.

FUTURE WORK

Research is required to determine whether or not an appropriate RAM can accurately select higher-risk patients for thromboprophylaxis.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017058688.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Thromboprophylaxis an update of current practice: Can we reach a consensus?

Diagnosis, prophylaxis, and management of venous thromboembolism (VTE) in patients with fractures remain a highly controversial topic with little consensus in clinical practice or the literature. The following manuscript represents a summary of evidence presented at the 2017 OTA Annual Meeting Symposium; "Thromboprophylaxis an Update of Current Practice: Can We Reach A Consensus?" The need for prophylaxis in pelvic and acetabular fracture patients; the existing body of evidence related to VTE, pulmonary embolism (PE), and prophylaxis for patients with fractures about the knee; current evidence in Edinburgh Scotland, regarding VTE prophylaxis in patients with isolated ankle fractures and the risk of VTE in patients with a hip fracture are topics that are addressed. The reader will benefit from the wisdom of this compilation of global contributions on thromboprophylaxis.

Venous thromboembolism risk stratification for patients with lower limb trauma and cast or brace immobilization

BACKGROUND

Thromboprophylaxis for patients with non-surgical isolated lower-limb trauma requiring immobilization is a matter of debate. Our aim was to develop and validate a clinical risk- stratification model based on Trauma, Immobilization and Patients' characteristics (the TIP score).

METHODS

The TIP score criteria and the cut-off were selected by a consensus of international experts (n = 27) using the Delphi method. Retrospective validation was performed in a population-based case-control study (MEGA study). The potential score's impact in anticoagulant treatment was assessed in a prospective single-center observational cohort study.

FINDINGS

After four successive rounds, 30 items constituting the TIP score were selected: thirteen items for trauma, three for immobilization and 14 for patient characteristics were selected, each rated on a scale of 1 to 3. In the validation database, the TIP score had an AUC of 0·77 (95% CI 0.70 to 0.85). Using the cut-off proposed by the experts (≥5) and assuming a prevalence of 1·8%, the TIP scores had a sensitivity, specificity and negative predictive values of 89·9%, 30·7% and 99·4% respectively. In the prospective cohort, 84·2% (165/196) of all the patients concerned who presented at the emergency department had a low VTE risk not requiring thromboprophylaxis according to their TIP scores. The 3-month rate of symptomatic VTE was 1/196 [95% CI 0.1-2.8] this patient was in the sub-group TIP score ≥5.

CONCLUSION

For patients with non-surgical lower-limb trauma and orthopedic immobilization, the TIP score allows an individual VTE risk-assessment and shows promising results in guiding thromboprophylaxis.

Individual risk factors predictive of venous thromboembolism in patients with temporary lower limb immobilization due to injury: a systematic review

Essentials Thromboprophylaxis after lower limb injury is often based on complex risk stratification. Our systematic review identified variables predicting venous thromboembolism (VTE) in this group. Age and injury type were commonly reported to increase the odds of VTE (odds ratio 1.5-3.48). We found limited evidence to support the use of other risk factors within prediction models. SUMMARY: Background Patients immobilized after lower limb injury are at risk of venous thromboembolism (VTE). There is international variation in the use of thromboprophylaxis for such patients. Risk-based strategies have been adopted to aid decision making in many settings. The accuracy of these strategies is unclear. Objectives A systematic review was undertaken to identify all individual patient-identifiable risk factors linked to any VTE outcome following lower limb immobilization. Methods Several electronic databases were searched from inception to May 2017. Any studies that included a measurement of VTE as a patient outcome in adults requiring temporary immobilization (e.g. leg cast or brace in an ambulatory setting) for an isolated lower limb injury and reported risk factor variables were included. Descriptive statistics and thematic analysis were used to synthesize the evidence. Results Our database search returned 4771 citations, of which 15 studies reporting outcome data on 80 678 patients were eligible for analysis. Risk-factor associations were reported through regression analyses, non-parametric tests and descriptive statistics. All studies were assessed as at moderate or serious risk of bias using the ROBINS-I risk of bias tool. Advancing age and injury type were the only individual risk factors demonstrating a reproducible association with increased symptomatic and/or asymptomatic VTE rates. Several risk factors currently used in scoring tools did not appear to be robustly evaluated for subsequent association with VTE within these studies. Conclusions Clinicians should be aware of the limited evidence to support individual risk factors in guiding thromboprophylaxis use for this patient cohort.

Effects of Vapocoolant Spray Prior to SC LMWH Injection: An Experimental Study

The aim of this study was to evaluate the effects of vapocoolant spray administration prior to subcutaneous (SC) low molecular weight heparin injection on local ecchymosis, hematoma, and pain. This randomized controlled study was carried out on 64 patients (n = 128 injections) in an orthopedics and traumatology clinic. After randomization, vapocoolant spray and then heparin injection was applied on one arm. The second necessary dose of heparin was applied to his or her other arm as a placebo by a water spray. Then, the pain of the patients was assessed. After 2 days, ecchymosis and hematoma were evaluated. Significant lower pain scores were determined in applications in which the vapocoolant spray was used. There was no statically significant difference between the mean diameter values of ecchymosis in both arm groups. There was no hematoma on the injection site after injections. However, this method did not create any significant reductive effect on ecchymosis. Nurses are advised to take advantage of vapocoolant spray effects prior to SC heparin injection.

Thromboembolism prophylaxis in orthopaedics: an update

Venous thromboembolism (VTE) is a serious complication during and after hospitalization, yet is a preventable cause of in-hospital death.

Without VTE prophylaxis, the overall VTE incidence in medical and general surgery hospitalized patients is in the range of 10% to 40%, while it ranges up to 40% to 60% in major orthopaedic surgery. With routine VTE prophylaxis, fatal pulmonary embolism is uncommon in orthopaedic patients and the rates of symptomatic VTE within three months are in the range of 1.3% to 10%.

VTE prophylaxis methods are divided into mechanical and pharmacological. The former include mobilization, graduated compression stockings, intermittent pneumatic compression device and venous foot pumps; the latter include aspirin, unfractionated heparin, low molecular weight heparin (LMWH), adjusted dose vitamin K antagonists, synthetic pentasaccharid factor Xa inhibitor (fondaparinux) and newer oral anticoagulants. LMWH seems to be more efficient overall compared with the other available agents. We remain sceptical about the use of aspirin as a sole method of prophylaxis in total hip and knee replacement and hip fracture surgery, while controversy still exists regarding the use of VTE prophylaxis in knee arthroscopy, lower leg injuries and upper extremity surgery.

Cite this article: EFORT Open Rev 2018;3:136-148. DOI: 10.1302/2058-5241.3.170018