Clinical predictors for deep vein thrombosis on admission in patients with intertrochanteric fractures: a retrospective study

TLR2 promotes traumatic deep venous thrombosis of the lower extremity following femoral fracture by activating the NF‑κB/COX‑2 signaling pathway in rats

Endothelial cells (ECs) are crucial for maintaining the integrity of blood vessel walls and reducing thrombosis. Deep venous thrombosis (DVT) is a common thrombotic disease and its diagnosis and treatment remain at the stage of coagulation function examination and post-onset treatment. Thus, identifying the pathogenesis of DVT is important. The present study investigated the significance of the Toll-like receptor 2 (TLR2)/nuclear factor kappa B (NF-κB)/cyclooxygenase-2 (COX-2) signaling pathway in a human umbilical vein EC (HUVECs) oxygen glucose deprivation (OGD) model and femoral fractures were induced in anesthetized rats using a quantifiable impact device delivering 5 J of energy to each side of the proximal outer thigh, followed by external fixation with a hip spica cast to create a traumatic deep venous thrombosis (TDVT) animal model. Rats were subjected to quantitative impact fixation to establish a TDVT model. The rats were treated with a TLR2 agonist (Pam3CSK4) and a TLR2 inhibitor (C29) via intraperitoneal injection and thrombus formation was examined. HUVECs were subjected to OGD and treated with Pam3CSK4 or C29 and cell viability and apoptosis were assessed. Western blotting, immunofluorescence and reverse transcription-quantitative PCR were used to examine the inflammatory responses and signaling pathways. In vivo experiments showed that Pam3CSK4 promoted thrombus formation and increased the mRNA and protein expression of NF-κB, COX-2, Tissue factor (TF), IL-6 and P-selectin compared with the model and C29 groups. In vitro experiments showed that Pam3CSK4 treatment resulted in a higher number of apoptotic cells than C29 treatment and that it increased the levels of NF-κB, COX-2, IL-6 and P-selectin, whereas C29 decreased them. Thus, TLR2 promotes the inflammatory response in EC through the NF-κB/COX-2 signaling pathway, which may lead to EC apoptosis and the occurrence of TDVT.

Incidence of and risk factors for preoperative deep vein thrombosis in elderly patients with end-stage osteoarthritis following total knee arthroplasty: a retrospective cohort study

BACKGROUND

Deep vein thrombosis (DVT) is a common and serious risk in elderly patients with knee osteoarthritis (OA), making preoperative detection crucial. Despite this, identifying OA patients at high risk for preoperative DVT and appropriately targeting them for venous ultrasound screening remains a challenge. There is limited research-based evidence on the risk factors for preoperative DVT in elderly patients with end-stage OA. We examined the incidence of and risk factors for preoperative DVT in elderly patients with end-stage OA scheduled for total knee arthroplasty.

METHODS

We retrospectively analyzed the demographic data (age, sex, body mass index, current smoking, alcohol consumption, walking status, and Barthel index score), medical history, and laboratory test indices of 1411 patients with end-stage OA aged ≥ 60 years scheduled for total knee arthroplasty from January 2015 to December 2018. Risk factors for preoperative DVT were evaluated by univariate and multivariate logistic analyses. Receiver operating characteristic analysis was performed to determine optimal cut-off values.

RESULTS

The incidence of preoperative DVT was 4.5% (63 of 1411 patients). Seven independent risk factors were correlated with preoperative DVT in the multivariate logistic regression: age (odds ratio [OR], 1.073; P = 0.002), D-dimer concentration (OR, 1.173; P = 0.003), hyperlipidemia (OR, 2.038; P = 0.045), atrial fibrillation (OR, 4.004; P = 0.033), chronic renal failure (OR, 6.732; P = 0.008), chronic obstructive pulmonary disease (COPD) (OR, 8.721; P = 0.001), and walking status (wheelchair) (OR, 2.697; P = 0.002). The optimal cut-off values for predicting preoperative DVT were 0.585 µg/mL for the D-dimer concentration (area under the curve [AUC], 0.769; P < 0.001) and 72.5 years for age (AUC, 0.668; P < 0.001).

CONCLUSION

Among elderly patients with end-stage OA, venous ultrasonography to rule out DVT risk should be prioritized in those with a high D-dimer concentration (> 0.585 µg/mL), high age (> 72.5 years), hyperlipidemia, atrial fibrillation, chronic renal failure, COPD, and walking status (wheelchair).

Prevalence and risk factors for proximal deep vein thrombosis at admission in patients with traumatic fractures: a multicenter retrospective study

Objective

This study aimed to determine the associated risk factors for proximal deep vein thrombosis (DVT) in patients with lower extremity and pelvic-acetabular fractures.

Methods

The medical records of 4,056 patients with lower extremity and pelvic-acetabular fractures were retrospectively reviewed. The patients were classified into proximal or non-proximal DVT groups. Logistic regression models were used to determine the independent risk variables for proximal DVT. The predictive value of the related risk factors was further analyzed using receiver operating characteristic curves.

Results

The prevalence of proximal DVT was 3.16%. Sex, body mass index (BMI), fracture site, injury mechanism, diabetes, coronary heart disease (CHD), injury-to-admission interval, hematocrit, platelet counts, and D-dimer levels differed significantly between the two groups. BMI ≥ 24.0 kg/m2, femoral shaft fractures, high-energy injury, diabetes, injury-to-admission interval >24 h were independent risk factors for proximal DVT. CHD decreased the risk of proximal DVT. The platelet and D-dimer had high negative predictive value for predicting proximal DVT formation, with cut-off values of 174 × 109/L and 2.18 mg/L, respectively.

Conclusion

BMI ≥ 24.0 kg/m2, femoral shaft fractures, high-energy injury, diabetes, injury-to-admission interval >24 h were independent risk factors for proximal DVT in patients with lower extremity and pelvic-acetabular fractures. Platelet count and D-dimer level were effective indicators for excluding proximal DVT occurrence. CHD decreased the risk of proximal DVT.

The admission pH is a risk factor of preoperative deep vein thrombosis in geriatric hip fracture: a retrospective cohort study

This study evaluated the association between body pH value and preoperative deep vein thrombosis (DVT) in geriatric hip fractures. Older adult patients with hip fractures were screened between January 2015 and September 2019. The demographic and clinical characteristics of the patients were collected. Multivariate binary logistic regression and generalized additive models were used to identify the linear and nonlinear associations between pH value and preoperative DVT. Analyses were performed using EmpowerStats and R software. A total of 1465 patients were included in the study. DVT occurred in 476 (32.6%) of these admitted older adults. We observed a nonlinear association between the serum pH value and preoperative DVT in geriatric patients with hip fractures. A pH value of 7.39 was the inflection point in the curve, with pH highly correlated with DVT at pH < 7.39 (odds ratio [OR] 19.47; 95% confidence interval [CI] 1.45-260.91; P = 0.0249). Patients with lower pH had a lower chance of preoperative DVT formation, and the risk of DVT increased 18.47-fold for every 0.1 unit change in pH. Although at pH > 7.39, pH was not correlated with DVT (OR 1.26; 95% CI 0.85-1.86; P = 0.2561), the odds of DVT did not vary with pH, and the highest risk of thrombosis was reached. The body pH value is nonlinearly associated with preoperative DVT in geriatric patients with hip fractures, and it could be considered a predictor of the risk of DVT.Registered information This study is registered in the website of Chinese Clinical Trial Registry (ChiCTR: ChiCTR2200057323).

A nomogram to predict postoperative deep vein thrombosis in patients with femoral fracture: a retrospective study

OBJECTIVE

The implementation of more active anticoagulant prevention and treatment measures has indeed led to a significant reduction in the incidence of perioperative deep vein thrombosis (DVT) among patients with bone trauma. However, it is important to note that despite these efforts, the incidence of DVT still remains relatively high. According to the Caprini score, all patients undergoing major orthopedic surgery were defined as the high-risk group for DVT. Stratifying the risk further within high-risk groups for DVT continues to present challenges. As a result, the commonly used Caprini score during the perioperative period is not applicable to orthopedic patients. We attempt to establish a specialized model to predict postoperative DVT risk in patients with femoral fracture.

METHODS

We collected the clinical data of 513 patients undergoing femoral fracture surgery in our hospital from May 2018 to December 2019. According to the independent risk factors of DVT obtained by univariate and multivariate logistic regression analysis, the corresponding nomogram model was established and verified internally. The discriminative capacity of nomogram was evaluated by receiver operating characteristic (ROC) curve and area under the curve (AUC). The calibration curve used to verify model consistency was the fitted line between predicted and actual incidences. The clinical validity of the nomogram model was assessed using decision curve analysis (DCA) which could quantify the net benefit of different risk threshold probabilities. Bootstrap method was applied to the internal validation of the nomogram model. Furthermore, a comparison was made between the Caprini score and the developed nomogram model.

RESULTS

The Caprini scores of subjects ranged from 5 to 17 points. The incidence of DVT was not positively correlated with the Caprini score. The predictors of the nomogram model included 10 risk factors such as age, hypoalbuminemia, multiple trauma, perioperative red blood cell infusion, etc. Compared with the Caprini scale (AUC = 0.571, 95% CI 0.479-0.623), the calibration accuracy and identification ability of nomogram were higher (AUC = 0.865,95% CI 0.780-0.935). The decision curve analysis (DCA) indicated the clinical effectiveness of nomogram was higher than the Caprini score.

CONCLUSIONS

The nomogram was established to effectively predict postoperative DVT in patients with femoral fracture. To further reduce the incidence, more specialized risk assessment models for DVT should take into account the unique risk factors and characteristics associated with specific patient populations.

Prevalence of preoperative deep vein thrombosis in long bone fractures of lower limbs: a systematic review and meta-analysis

BACKGROUND

There is a paucity of data regarding the prevalence of preoperative deep vein thrombosis (DVT) in patients with long bone (including femur, tibia and fibula) fractures of the lower limbs. We performed a meta-analysis to address the issue.

METHODS

Electronic databases, including PubMed, EMBASE, the Web of Science, the Cochrane Library, the VIP database, CNKI, and the Wanfang database, were systematic searched for original articles that reported the prevalence of preoperative DVT in long bone fractures of the lower limbs from January 2016 to September 2021. The prevalence of preoperative DVT was pooled using random-effects models, and subgroups were established according to study type, detection method, sample size and fracture site.

RESULTS

Twenty-three articles reporting on 18,119 patients were eligible. The overall pooled preoperative DVT prevalence was 24.1% (95% CI 19.3-28.8%). In different subgroups, the preoperative DVT prevalences were 18.2-27.3%, 15.2-28.6%, 23.1-24.9%, 18.2-26.0% and 23.2-23.4% for different study designs, sample sizes, age groups, detection methods and fracture sites, respectively.

CONCLUSIONS

Despite the heterogeneity among studies, this systematic review suggests that the prevalence of preoperative DVT, which may seriously affect the prognosis of patients, is high. Therefore, greater efforts should be devoted to the improvement of screening and prevention strategies for preoperative DVT in lower-extremity long bone fractures.

LEVEL OF EVIDENCE

Level III. Trial Registration The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database with the registration number CRD42022324706.

Comparison of the predictive power of the 2005 and 2010 Caprini risk assessment models for deep vein thrombosis in Chinese orthopedic patients at admission: A prospective cohort study

INTRODUCTION

Several DVT risk assessment tools have been developed and validated to stratify the patients. The 2005 and 2010 Caprini risk assessment models (RAMs) proved reliable in detecting deep vein thrombosis (DVT) and are widely used worldwide. Although the 2010 version was recently modified, the 2005 version is still more exact and popular in the surgical population. This study aimed to compare the predictive power of the 2005 and 2010 Caprini RAMs in Chinese orthopedic patients at admission and describe the incidence of DVT during hospitalization.

STUDY DESIGN

This prospective cohort study involved 2733 patients from the Arthritis Clinic and Research Center, Orthopedics and Traumatology Department, Orthopedic Oncology Department, and Spinal Surgery Department of Peking University People's Hospital from September 2018 to January 2019. The DVT risk scores and levels were determined for all patients using the 2005 and 2010 Caprini RAMs at admission. The sensitivity and specificity of the two tools were calculated. The patients were divided into the screened and unscreened groups according to whether or not a Doppler ultrasound (DUS) was performed. Depending upon the DUS results, the patients were divided into the DVT and non-DVT groups. The receiver operation characteristic (ROC) curve and the area under the curve (AUC) were evaluated to compare the predictive power.

RESULTS

Eighty-four patients had DVT in the four orthopedic departments, and the incidence of DVT was 3.1 %-17.2 %. The scores between the 2005 and 2010 Caprini RAMs differed (P < 0.001) among orthopedic patients at admission. Among DVT patients, the highest-risk patients accounted for 63.5 % and 52.9 % based on the 2005 and 2010 Caprini RAMs, respectively. The AUCs of the 2005 and 1020 Caprini RAMs were 0.669 ± 0.030 and 0.648 ± 0.032, respectively. There were no significant differences between the two ROC curves (P = 0.164).

CONCLUSION

The 2005 and 2010 Caprini RAMs showed a similar predictive power in detecting DVT, but neither met the high sensitivity criteria for screening DVT in orthopedic patients. The incidence of DVT in orthopedic patients was relatively high during hospitalization.

Quality evaluation of clinical practice guidelines for thromboprophylaxis in orthopaedic trauma based on AGREE II and AGREE-REX: a systematic review protocol

INTRODUCTION

Orthopaedic trauma patients are at high risk of venous thromboembolism (VTE). As VTE prophylaxis has gradually raised public concerns, guidelines related to this topic have increased over time. However, the existing recommendations of thromboprophylaxis guidelines in orthopaedic trauma patients are still inconsistent, and the quality of the guidelines and recommendations for the topic still lacks comprehensive assessments. This review aims to critically appraise clinical practice guidelines for thromboprophylaxis in orthopaedic trauma patients.

METHODS AND ANALYSIS

We will conduct a comprehensive literature search up to 31 October 2022 in databases (PubMed, EMBASE, CINAHL, Web of Science, the Cochrane Library, etc), academic websites and guideline repositories. The quality of the guidelines and recommendations will be assessed by five reviewers independently using the Appraisal of Guidelines Research and Evaluation II instrument (AGREE-II) and the AGREE - Recommendation EXcellence (AGREE-REX). We will summarise the characteristics of the guidelines and compare the differences between these recommendations.

ETHICS AND DISSEMINATION

This study will follow the Declaration of Helsinki and has received approval from the Ethics Committee on Biomedical Research, West China Hospital, Sichuan University (ethics approval no. 2021-989). The results will be summarised as a paper, disseminated through peer-reviewed journals, and will help guide further research in the future.

PROTOCOL REGISTRATION NUMBER

CRD42021273405.

Muscular Calf Vein Thrombosis Is Associated With Increased 30-Day Mortality But Not 90-Day Mortality in Older Patients With Hip Fracture

Calf deep vein thrombosis (DVT) is common in patients with hip fractures. However, studies on whether calf DVT has an impact on the prognosis are limited. This retrospective cohort study explored the association between calf DVT and 30-day and 90-day all-cause mortality in older patients with hip fractures. A total of 564 consecutive patients who underwent ultrasound examination were identified from our hip fracture database and categorized into patients with calf DVT (axial DVT, muscular DVT) and no DVT. Of these, 86 patients (15.2%) had ultrasound-confirmed calf DVT, including 66 patients with muscular DVT, and 20 patients with axial DVT. The 30-day and 90-day all-cause mortality were 2.5% and 6.0%, respectively. Multivariate Cox analysis showed that calf DVT was significantly associated with an increased risk of 30-day mortality (hazard ratio [HR] 3.21, 95% confidence interval [CI] 1.05 to 9.84, p = 0.04), but this risk relationship did not persist at 90-day follow-up (HR 1.59, 95% CI 0.69 to 3.71, p = 0.28). When calf DVT was further categorized, muscular DVT remained an independent risk factor for 30-day mortality (HR 3.95, 95% CI 1.18 to 13.15, p = 0.03), whereas this relationship was not found in axial DVT (HR 1.79, 95% CI 0.21 to 15.02, p = 0.59). In conclusion, calf DVT, especially muscular calf DVT but not axial DVT, is independently associated with an increased risk of 30-day mortality in older patients with hip fracture, but this risk relationship did not persist at 90-day follow-up.

In response to letter to the editor: calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

We appreciate the interest by Drs. Hagiyama and coauthors in our work entitled "Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures". They discussed several pertinent points and it is our pleasure to respond their concerns in order. Firstly, we agree that calcar fracture gap and anteromedial cortical support are different concepts, though both of them were used to evaluate the displacement of fracture reduction quality. Secondly, our primary outcome parameter was the threshold distance of calcar fracture gapping in anteroposterior and lateral fluoroscopies, which was calculated based on sensitivity and specificity by receiver operating characteristic curves. Thirdly, we took immediate post-operative fluoroscopic images in 3 views to describe the initial reduction quality as baseline to compare and calculate the changes with three-dimensional computed tomography, which was taken about one week after operation for confirming secondary stability after head-neck sliding and impaction. Lastly, the parameters selected in multivariable analysis. Future work with better study-design is needed to improve the prediction of patient outcomes.

Risk factors for preoperative deep venous thrombosis in hip fracture patients: a meta-analysis

Study design

A meta-analysis.

Background

Hip fracture (HF), as common geriatric fracture, is related to increased disability and mortality. Preoperative deep vein thrombosis (DVT) is one of the most common complications in patients with hip fractures, affecting 8–34.9% of hip fracture patients. The study aimed to assess the risk factors of preoperative DVT after hip fractures by meta-analysis.

Methods

An extensive search of the literature was performed in the English databases of PubMed, Embase, and the Cochrane Library; and the Chinese databases of CNKI and WAN FANG. We collected possible predictors of preoperative DVT from included studies, and data analysis was conducted with RevMan 5.3 and STATA 12.0.

Results

A total of 26 English articles were included, and the rate of DVT was 16.6% (1627 of 9823 patients) in our study. Our findings showed that advanced age [p = 0.0003, OR = 0.13 95% CI (0.06, 0.21)], female patients [p = 0.0009, OR = 0.82 95% CI (0.72, 0.92)], high-energy injury [p = 0.009, OR = 0.58 95% CI (0.38, 0.87)], prolonged time from injury to admission [p < 0.00001, OR = 0.54 95% CI (0.44, 0.65)], prolonged time from injury to surgery [p < 0.00001, OR = 2.06, 95% CI (1.40, 2.72)], hemoglobin [p < 0.00001, OR = − 0.32 95% CI (− 0.43, − 0.21)], coronary heart disease [p = 0.006, OR = 1.25 95% CI (1.07, 1.47)], dementia [p = 0.02, OR = 1.72 95% CI (1.1, 2.67)], liver and kidney diseases [p = 0.02, OR = 1.91 95% CI (1.12, 3.25)], pulmonary disease [p = 0.02, OR = 1.55 95% CI (1.07, 2.23)], smoking [p = 0.007, OR = 1.45 95% CI (1.11, 1.89)], fibrinogen [p = 0.0005, OR = 0.20 95% CI (0.09, 0.32)], anti-platelet drug [p = 0.01, OR = 0.51 95% CI (0.30, 0.85)], C-reactive protein [p = 0.02, OR = 5.95 95% CI (1.04, 10.85)], < 35 g/l albumin [p = 0.006, OR = 1.42 95% CI (1.1, 1.82)], and thrombosis history [p < 0.00001, OR = 5.28 95% CI (2.85, 9.78)] were risk factors for preoperative DVT.

Conclusions

Many factors, including advanced age, female patients, high-energy injury, prolonged time from injury to admission, prolonged time from injury to surgery, patients with a history of coronary heart disease, dementia, liver and kidney diseases, pulmonary disease, smoking, and thrombosis, fibrinogen, C-reactive protein, and < 35 g/l albumin, were found to be associated with preoperative DVT. Our findings suggested that the patient with above characteristics might have preoperative DVT.

Level of evidence: Level III.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10195-022-00639-6.

Low Mean Platelet Volume is Associated with Deep Vein Thrombosis in Older Patients with Hip Fracture

This study aimed to explore the association between mean platelet volume (MPV) and preoperative deep vein thrombosis (DVT) in older patients with hip fracture. A total of 352 consecutive older patients with hip fracture were included from January 2014 to December 2020. MPV values were measured on admission, and color Doppler ultrasonography was performed for DVT screening before the planned surgery. The receiver operating characteristic (ROC) curve was used to establish the optimal cut-off value for the prediction of DVT. Univariate and multivariate logistic regression analysis were used to examine the association between factors and DVT. The overall prevalence of preoperative DVT was 15.1%, and patients with DVT had a lower value of MPV than non-DVT patients (11.6 ± 1.2 fL vs 12.3 ± 1.4 fL, P < .01). The cut-off point according to the ROC curve for MPV was 13.3 fL, and multivariate logistic regression analysis showed that MPV level < 13.3 fL was significantly associated with an increased risk of DVT (OR = 4.857, 95% CI: 1.091-21.617, P = .038), and with every 1.0 fL decrease in MPV, the risk increased by 27.7% (OR = 1.277, 95% CI: 1.001-1.629, P = .047). Our findings indicate that a low MPV level is associated with DVT in older patients with hip fracture. As MPV is a simple indicator that can be calculated from the blood routine test, it may be a potential biomarker of DVT with the combination of other tests, further studies are needed to confirm these results.

Association Between Monocyte Count and Preoperative Deep Venous Thrombosis in Older Patients with hip Fracture: A Retrospective Study

Purpose

To analyze the relationship between monocyte count and preoperative deep venous thrombosis (DVT) in older patients with hip fracture.

Methods

Consecutive older patients with hip fracture undergoing surgery were included from January 2014 to December 2021. Monocyte count was measured on admission, and Doppler ultrasonography was performed for DVT screening prior to surgery. Univariate and multivariate logistic regression analyses were used to assess the association between monocyte count and DVT.

Results

A total of 674 patients were finally included, and 128 patients (19.0%) were diagnosed with preoperative DVT. Patients with DVT exhibited a higher monocyte count than patients without DVT [0.55 (0.43-0.72) × 10⁹/L versus 0.49 (0.38-0.63) × 10⁹/L, P = 0.007]. Multivariate logistic regression analysis showed that a high monocyte count (> 0.6 × 10⁹/L) was independently associated with a higher risk of DVT (OR = 1.705, 95% CI: 1.121-2.593, P = 0.013), and for every 0.1 × 10⁹/L increase in monocyte count, the risk of DVT increased by 8.5% (OR = 1.085, 95% CI: 1.003-1.174, P = 0.041). Other risk factors associated with DVT included intertrochanteric fracture (OR = 1.596, 95% CI: 1.022-2.492, P = 0.040), and elevated fibrinogen level (OR = 1.236, 95% CI: 1.029-1.484, P = 0.023).

Conclusion

A high monocyte count is associated with an increased risk of DVT in older patients with hip fracture. Future studies should evaluate the potential role of monocyte in the prevention and treatment of thrombosis.

Risk factors and new diagnostic index for deep venous thrombosis of lower extremities in elderly patients with traumatic femoral neck fracture

Purpose

To determine the incidence and risk factors of deep vein thrombosis (DVT) of lower extremities at admission in elderly Chinese patients with femoral neck fracture, and to establish and evaluate a new DVT predictor based on these risk factors.

Methods

Patients who were hospitalized from January 2018 to December 2020 at three independent centers were reviewed. According to the results of lower extremities vascular ultrasound at admission, they were divided into DVT group and non-DVT group. Single and multivariate logistic regression analysis were applied to identify independent risk factors for DVT occurrence, and then a prediction formula for DVT based on the risk factors was developed. The new predictive index of DVT was calculated by the formula. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of different factors and the new predictive index.

Results

There were 203 elder patients were included in the final analysis after application of the exclusion criteria. Thirty seven patients (18.2%) were diagnosed as DVT by ultrasound, including 33 patients (89.2%) of peripheral type, 1 patient (2.7%) of central type and 3 patients (8.1%) of mixed type.Multivariate logistic regression analysis showed that four factors including injured side, hemoglobin, fibrinogen, d-dimer were the independent risk factors for the incidence of DVT. On this basis, a new formula for DVT predictive factor was constructed: New predictive index = 0.895 * injured side (right = 1, left = 0) + 0.899 * hemoglobin (<109.5 g/L = 1, > 109.5 g/L = 0) + 1.19 * fibrinogen (>4.24 g/L = 1, < 4.24 g/L = 0) + 1.221* d-dimer (>2.4 mg/L = 1, < 2.4 mg/L = 0). The AUC value of this new developed index was 0.735.

Conclusions

This work showed that the incidence of DVT in elderly patients with femoral neck fracture in China was high at admission. New DVT predictive value can be used as an effective diagnosis strategy for evaluation of thrombosis at admission.