Multiple lower-extremity and pelvic fractures increase pulmonary embolus risk

Obese adolescents have higher risk for femur fracture after motor vehicle collision

Background

Previous reports identified an association between obese adolescents (OAs) and lower extremity (LE) fractures after blunt trauma. However, the type of LE fracture remains unclear. We hypothesized that OAs presenting after motor vehicle collision (MVC) have a higher risk of severe LE fracture and will require a longer length of stay (LOS) and more support services upon discharge, compared to non-OAs.

Methods

The 2017-2019 Trauma Quality Improvement Program database was queried for adolescents (12-17-years-old) presenting after MVC. The primary outcome was LE fracture. A severe fracture was defined by abbreviated injury scale ≥3. OAs were defined by a body mass index (BMI) ≥30.

Results

From 22,610 MVCs, 3325 (14.7 %) included OAs. The rate of any LE fracture was higher for OAs (21.6 % vs. 18.8 %, p < 0.001). On subset analysis the only LE fracture at higher risk in OAs was a femur fracture (13 % vs. 9.1 %, p < 0.001). After adjusting for sex and age, the risk for severe LE fracture (OR 1.34, CI 1.18-1.53, p < 0.001) was higher for OAs. OAs with a femur fracture had a longer median LOS (5 vs. 4 days, p = 0.003) and were more likely discharged with additional support services including home-health or inpatient rehabilitation (30.6 % vs. 21.4 %, p < 0.001).

Conclusion

OAs sustaining MVCs have increased associated risk of femur fractures. OAs are more likely to have a higher-grade LE injury, experience a longer LOS, and require additional support services upon discharge. Future research is needed to determine if early disposition planning with social work assistance can help shorten LOS.

Development and validation of a predictive nomogram for lower extremity deep vein thrombosis dislodgement in orthopedic patients

Objective

To analyze the risk factors of lower extremity deep venous thrombosis (DVT) detachment in orthopedic patients, and to establish a risk nomogram prediction model.

Methods

The clinical data of 334 patients with orthopedic DVT admitted to the Third Hospital of Hebei Medical University from January 2020 to July 2021 were retrospectively analyzed. General statistics included gender, age, BMI, thrombus detachment, inferior vena cava filter window type, filter implantation time, medical history, trauma history, operation, use of tourniquet, thrombectomy, anesthesia mode, anesthesia grade, operative position, blood loss during operation, blood transfusion, immobilization, use of anticoagulants, thrombus side, thrombus range, D-dimer content before filter implantation and during removal of inferior vena cava filter. Logistic regression was used to perform univariate and multivariate analysis on the possible factors of thrombosis detachment, screen out independent risk factors, establish a risk nomogram prediction model by variables, and internally verify the predictability and accuracy of the model.

Results

Binary logistic regression analysis showed that Short time window filter (OR = 5.401, 95% CI = 2.338–12.478), lower extremity operation (OR = 3.565, 95% CI = 1.553–8.184), use of tourniquet (OR = 3.871, 95% CI = 1.733–8.651), non-strict immobilization (OR = 3.207, 95% CI = 1.387–7.413), non-standardized anticoagulation (OR = 4.406, 95% CI = 1.868–10.390), distal deep vein thrombosis (OR = 2.212, 95% CI = 1.047–4.671) were independent risk factors for lower extremity DVT detachment in orthopedic patients (P &lt; 0.05). Based on these six factors, a prediction model for the risk of lower extremity DVT detachment in orthopedic patients was established, and the risk prediction ability of the model was verified. The C-index of the nomogram model was 0.870 (95% CI: 0.822–0.919). The results indicate that the risk nomogram model has good accuracy in predicting the loss of deep venous thrombosis in orthopedic patients.

Conclusion

The nomogram risk prediction model based on six clinical factors, including filter window type, operation condition, tourniquet use, braking condition, anticoagulation condition, and thrombosis range, has good predictive performance.

Risk Factors of Deep Vein Thrombosis in Adults with Acute Compartment Syndrome Following Lower Extremity Fractures

This study aimed to identify the risk factors of deep vein thrombosis (DVT) in adults with acute compartment syndrome (ACS) following lower extremity fractures. We collected data on adults with ACS following lower extremity fractures in our hospital from November 2013 to January 2021. Patients were divided into the DVT group and the non-DVT group according to whether they had DVT or not. The demographics, comorbidities, and admission laboratory examinations were computed by univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis. In our study, the rate of DVT (26 of 110) was 23.6%. Univariate analysis showed that numerous factors were associated with the formation of DVT. Logistic regression analysis showed that patients with multiple fractures (P = .015, OR = 5.688), patients with a history of hypertension (P = .011, OR = 16.673), and patients with a higher BMI (P = .008, OR = 1.950) and FDP (P = .013, OR = 1.031) were relevant predictors of DVT. ROC curve analysis indicated 24.73 kg/m² and 28.33 μg/mL were the cutoff values of BMI and FDP to predict the DVT, respectively. Furthermore, the combination of BMI and FDP had the highest diagnostic accuracy. Our findings identified multiple fractures, BMI, and FDP as independent risk factors for DVT in patients with ACS following lower extremity fractures and determined the cutoff values of BMI and FDP, helping us individualize the assessment of the risk of DVT to manage early targeted interventions.

Preperitoneal Pelvic Packing is Associated With Increased Risk of Venous Thromboembolism

INTRODUCTION

Preperitoneal pelvic packing (PPP) is an important intervention for control of severe pelvic hemorrhage in blunt trauma patients. We hypothesized that PPP is associated with an increased incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

A retrospective cohort analysis of blunt trauma patients with severe pelvic fractures (AIS ≥4) using the 2015-2017 American College of Surgeons-Trauma Quality Improvement Program database was performed. Patients who underwent PPP within four hours of admission were matched to patients who did not using propensity score matching. Matching was performed based on demographics, comorbidities, injury- and resuscitation-related parameters, vital signs at presentation, and initiation and type of prophylactic anticoagulation. The rates of DVT and PE were compared between the matched groups.

RESULTS

Out of 5129 patients with severe pelvic fractures, 157 (3.1%) underwent PPP within four h of presentation and were matched with 157 who did not. No significant differences were detected between the two matched groups in any of the examined baseline variables. Similarly, mortality and end-organ failure rates were not different. However, PPP patients were significantly more likely to develop DVT (12.7% versus 5.1%, P = 0.028) and PE (5.7% versus 0.0%, P = 0.003).

CONCLUSIONS

PPP in severe pelvic fractures secondary to blunt trauma is associated with an increased risk of DVT and PE. A high index of suspicion and a low threshold for screening for these conditions should be maintained in patients who undergo PPP.

Preperitoneal Pelvic Packing for Hypotension Has a Greater Risk of Venous Thromboembolism Than Angioembolization: Management of Refractory Hypotension in Closed Pelvic Ring Injury

BACKGROUND

Patients with traumatic pelvic ring injury may present with hypotension secondary to hemorrhage. Preperitoneal pelvic packing (PPP) and angioembolization (AE) are alternative interventions for management of hypotension associated with pelvic ring injury refractory to resuscitation and circumferential compression. We hypothesized that PPP may be independently associated with increased risk of venous thromboembolism (VTE) compared with AE in patients with hypotension and pelvic ring injury.

METHODS

Adult patients with pelvic ring injury and hypotension managed with PPP or AE were retrospectively identified in the Trauma Quality Improvement Program (TQIP) database from 2015 to 2019. Patients were matched on a propensity score for receiving PPP based on patient, injury, and treatment factors. The primary outcome was the risk of VTE after matching on the propensity score for treatment. The secondary outcomes included inpatient clinically important deep vein thrombosis, pulmonary embolism, respiratory failure, mortality, unplanned reoperation, sepsis, surgical site infection, hospital length of stay, and intensive care unit (ICU) length of stay.

RESULTS

In this study, 502 patients treated with PPP and 2,439 patients treated with AE met inclusion criteria. After propensity score matching on age, smoking status, Injury Severity Score, Tile B or C pelvic ring injury, bilateral femoral fracture, serious head injury, units of plasma and platelets given within 4 hours of admission, laparotomy, and level-I trauma center facility designation, 183 patients treated with PPP and 183 patients treated with AE remained. PPP, compared with AE, was associated with a 9.8% greater absolute risk of VTE, 6.5% greater risk of clinically important deep vein thrombosis, and 4.9% greater risk of respiratory failure after propensity score matching.

CONCLUSIONS

PPP for the management of hypotension associated with pelvic ring injury is associated with higher rates of inpatient VTE events and sequelae compared with AE.

LEVEL OF EVIDENCE

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

Thromboembolic events in pelvic and acetabulum fractures: a systematic review of the current literature on incidence, screening, and thromboprophylaxis

PURPOSE

Rates of venous thromboembolic events (VTEs) as high as 41% deep vein thrombosis (DVT) were reported in association with pelvic and acetabular fractures (PAFs). There is no clear consensus on VTE prophylaxis for PAFs. Extracting evidence-based guidelines is key to overcome this challenging complication. The aims of this review are (A) to highlight the incidence of VTEs in PAFs, (B) to examine the screening and prophylaxis methods available in the current literature, and (C) direct future creation of a best practice protocol to reduce the risk of VTE in PAFs.

METHODS

We performed a systematic search of Medline, EMBASE databases, and the Cochrane library. MESH terms were used to identify studies pertinent to VTE in PAFs, including incidence, prophylaxis, and screening.

RESULTS

In total, 28 studies were identified and grouped into four categories including incidence, screening, prophylaxis, and the use of inferior vena cava filters (IVCFs). Incidence of VTE ranged from 0.21 to 41% for DVT and 0 to 21.7% for PE. Nine studies screened 1360 patients using different imaging modalities. Ten articles, 2836 patients, examined different thromboprophylaxis protocols. Two out of three studies investigating the use of IVCF showed significant reduction of the rates of PE.

CONCLUSION

Incidence of VTE in PAF varies significantly with different protocols. The current literature shows that screening is still controversial. The combination of chemical and mechanical prophylaxis starting at 24 hours from the injury would provide the best protection. Guidelines were extracted; however, higher level multicenter studies are still required to guide future protocols.

Trauma-induced pulmonary thromboembolism: What's update?

Trauma-induced pulmonary thromboembolism is the second leading cause of death in severe trauma patients. Primary fibrinolytic hyperactivity combined with hemorrhage and consequential hypercoagulability in severe trauma patients create a huge challenge for clinicians. It is crucial to ensure a safe anticoagulant therapy for trauma patients, but a series of clinical issues need to be answered first, for example, what are the risk factors for traumatic venous thromboembolism? How to assess and determine the status of coagulation dysfunction of patients? When is the optimal timing to initiate pharmacologic prophylaxis for venous thromboembolism? What types of prophylactic agents should be used? How to manage the anticoagulation-related hemorrhage and to determine the optimal timing of restarting chemoprophylaxis? The present review attempts to answer the above questions.

Assessment of deep vein thrombosis using routine pre- and postoperative duplex Doppler ultrasound in patients with pelvic trauma : a prospective study

AIMS

The aims of this study were to assess the pre- and postoperative incidence of deep vein thrombosis (DVT) using routine duplex Doppler ultrasound (DUS), to assess the incidence of pulmonary embolism (PE) using CT angiography, and to identify the factors that predict postoperative DVT in patients with a pelvic and/or acetabular fracture.

METHODS

All patients treated surgically for a pelvic and/or acetabular fracture between October 2016 and January 2020 were enrolled into this prospective single-centre study. The demographic, medical, and surgical details of the patients were recorded. DVT screening of the lower limbs was routinely performed using DUS before and at six to ten days after surgery. CT angiography was used in patients who were suspected of having PE. Age-adjusted univariate and stepwise multiple logistic regression analysis were used to determine the association between explanatory variables and postoperative DVT.

RESULTS

A total of 191 patients were included. A DVT was found preoperatively in 12 patients (6.3%), of which six were proximal. A postoperative DVT was found in 42 patients (22%), of which 27 were proximal. Eight patients (4.2%) had a PE, which was secondary to a DVT in three. None of the 12 patients in whom a vena cava filter was implanted prophylactically had a PE. Multivariate logistic regression analysis indicated that the association with the need for spinal surgery (odds ratio (OR) 19.78 (95% confidence interval (CI) 1.12 to 348.08); p = 0.041), intramedullary nailing of a long bone fracture (OR 4.44 (95% CI 1.05 to 18.86); p = 0.043), an operating time > two hours (OR 3.28 (95% CI 1.09 to 9.88); p = 0.035), and additional trauma surgery (OR 3.1 (95% CI 1.03 to 9.45); p = 0.045) were statistically the most relevant independent predictors of a postoperative DVT.

CONCLUSION

The acknowledgement of the risk factors for the development of a DVT and their weight is crucial to set a threshold for the index of suspicion for this diagnosis by medical staff. We suggest the routine use of the DUS screening for DVT in patients with a pelvic and/or acetabular fracture before and six to ten days after surgery. Cite this article: Bone Joint J 2022;104-B(2):283-289.

Early Pharmacologic Venous Thromboembolism Prophylaxis after Splenic Artery Embolization Is Not Associated with an Increased Risk of Rebleed

Venous thromboembolism (VTE) prophylaxis in the setting of blunt traumatic visceral injury remains controversial. A total of 181 patients underwent splenic artery embolization (SAE) and began pharmacologic VTE prophylaxis at a median time of 59.5 hours (interquartile range, 46 hours). Six patients required splenectomy for rebleed. Fifty-one patients underwent SAE but did not receive anticoagulation therapy since they were considered low risk for VTE, and no splenectomies were performed (P = 1). Multivariate analysis showed no increased risk of need for splenectomy after beginning anticoagulation within 24 hours after SAE (P =.441). This study suggests that patients found to be at a high VTE risk should be considered for thromboprophylaxis within 24 hours after SAE.

Deep Vein Thrombosis in the Uninjured Lower Extremity: A Retrospective Study of 1454 Patients With Lower Extremity Fractures

The purpose of this study was to identify patients at higher risk of deep venous thrombosis (DVT) in the uninjured lower extremity both preoperatively and postoperatively in patients with lower extremity fractures. We collected the clinical data of patients with lower extremities fractures who presented at Xi’an Honghui Hospital between 1 July, 2015 and 31 October, 2017. Doppler ultrasonography was used to diagnose the DVT. Patients were examined pre- and postoperatively. The patients were divided into thrombosis group and no thrombosis group according to the preoperative and postoperative ultrasonography results. The thrombosis group was defined as patients with DVT in the uninjured lower extremity and the no thrombosis group was defined as patients without DVT in the uninjured lower extremity. This study enrolled 1454 patients who met the inclusion criteria. The incidence of preoperative DVT in the uninjured lower extremity was 9.63% whereas the postoperative incidence was 20.29%. Age (OR = 0.965, 95 CI%: 0.954-0.977; P ≤ 0.001) and female (OR = 0.667, 95% CI: 0.451-0.986, P = 0.042) were independent risk factors for preoperative DVT in the uninjured lower extremity. Blood loss (OR = 0.997, 95 CI%: 0.995-1.000; P = 0.020), D-dimer level at admission (OR = 0.941, 95 CI%: 0.887-0.999; P = 0.045), and postoperative day 5 D-dimer level (OR = 0.889, 95 CI%: 0.819-0.965; P = 0.005), were independent risk factors for postoperative DVT in the uninjured lower extremity. For the patients with lower extremity fractures, age and female were associated with the preoperative DVT in the uninjured lower extremity. Blood loss, D-dimer at admission and postoperative day 5 D-dimer were associated with the postoperative DVT in the uninjured lower extremity.

A Water Slide Accident Resulting in an Open Book Pelvic Injury and Subsequent Pulmonary Embolus: A Case Report

Obesity and pelvic injuries are well-known independent risk factors for developing a pulmonary embolus; however, there is minimal literature with regard to obesity being a risk factor for suffering a pelvic injury from descending a water slide. We believe that obese patients are potentially at increased risk of receiving open book pelvic injuries on modern-day high-velocity water slides. To our knowledge, there are no other reports of a patient suffering an open book pelvic injury and a subsequent pulmonary embolus due to a water slide accident. We also propose a mechanism of injury for an obese person developing an open book pelvic injury from a water slide. An obese 46-year-old female descended on a thrill ride at a popular water park and sustained an open book pelvic injury. She subsequently developed a pulmonary embolus while awaiting open reduction and internal fixation of the anterior pelvic ring. One month post-injury, she had uneventful open reduction and internal fixation and went on to have an uneventful postoperative course. Patrons and amusement park owners should be aware of the increased risk an obese person is at when using a high-velocity water slide. There should be appropriate emergency personnel and equipment on site in anticipation of a possible high-energy injury.

Early Detection of Deep Venous Thrombosis in Trauma Patients

Background

This study was performed to determine whether trauma patients are at an increased risk of developing deep venous thrombosis (DVT) within the first 48 hours of hospitalization.

Materials and methods

A retrospective review was performed using a prospectively maintained database of patients admitted to a trauma center during a five-year time period. Patients hospitalized for greater than 48 hours who received a screening venous duplex for DVT were included in the study.

Results

There were 1067 venous duplex scans obtained, 689 (64.5%) within the first 48 hours of admission (early DVT group), 378 (35.4%) after the first 48 hours (late DVT group). Only 142 (13.2%) patients had a positive duplex scan for DVT, 55 (early group), 87 (late group). Comorbid conditions of congestive heart failure (P = 0.02), pelvic fractures (P = 0.04), and a lower initial systolic blood pressure on presentation (p = 0.04) were associated with early DVT. Head trauma (P < 0.01), mechanical ventilation (P < 0.001), and transfusion of blood products (P < 0.001), were predictors of DVT in the late group.

Conclusions

Trauma patients are at an increased risk of developing venous thrombosis early in the hospital course due to comorbidities associated with trauma. Whereas, venous thrombosis in trauma patients diagnosed after the first 48 hours of hospitalization appears to be associated with prolonged patient immobility.

Deep Vein Thrombosis in the Uninjured Limb in Patients with Lower Extremity Fractures: A Retrospective Study

Objective

This study is aimed at investigating the incidence of deep vein thrombosis (DVT) in the uninjured limb during hospitalization and 1 month after surgery in patients with lower extremity fractures.

Methods

We collected the clinical data of patients with lower extremity fractures in Xi'an Honghui Hospital. Doppler ultrasonography was used to diagnose DVT. According to the results of ultrasonography, the patients were divided into two groups: uninjured limb with DVT group and uninjured limb without DVT group.

Results

A total of 494 patients who met all inclusion criteria were included in this study. The incidence rate of DVT in the uninjured limb was 19.84% and 18.83% during hospitalization and 1 month after surgery, respectively. Age (OR = 1.035, 95% CI: 1.013–1.059; P = 0.002) and D-dimer level 1 day after surgery (OR = 1.065, 95% CI: 1.030–1.102; P < 0.001) were independent risk factors for DVT during hospitalization. Similarly, age (OR = 1.045, 95% CI: 1.021–1.070; P < 0.001) and D-dimer level 1 day after surgery (OR = 1.048, 95% CI: 1.014–1.083; P = 0.006) were independent risk factors for DVT 1 month after surgery. During hospitalization and 1 month after surgery, 15.79% and 12.35% of patients had double lower limb thrombosis and 4.04% and 6.48% of patients had DVT in the uninjured limb only, respectively.

Conclusion

The actual incidence of DVT in the uninjured limb in patients with lower extremity fractures cannot be ignored despite the use of anticoagulants for prevention or treatment during hospitalization. We should also be aware of DVT in the uninjured limb while focusing on DVT in the injured limb.

Venous thromboembolism after hospital discharge in pelvic and acetabular fracture patients treated operatively

PURPOSE

The purposes of this study were to determine the rate of venous thromboembolism (VTE) after discharge from the hospital in patients treated operatively with a pelvic ring or acetabular fracture and to define the main time frame in which VTE occurs within the 90-day period after hospital discharge.

METHODS

California and Florida State Inpatient Databases from 2005 to 2009 were used to identify patients with clinically significant VTEs within 90 days of hospital discharge. ICD-9 diagnosis codes identified patients with a pelvic ring or acetabular fracture and a VTE. Procedure codes distinguished patients having surgical fracture treatment. Deep vein thrombosis (DVT) and pulmonary embolus (PE) were included.

RESULTS

Overall, 13,589 patients had a pelvic ring or acetabular fracture and operative treatment. One hundred thirteen patients (0.83%) had a VTE within 90 days after hospital discharge: 69 (0.51%) had a DVT, 28 (0.21%) had a PE, and 16 (0.12%) had both. Twenty-four (28%) of DVTs and 10 (23%) of PEs occurred >35 days after discharge, being evenly distributed out to 90 days. There were five fatal PEs, occurring 2, 3, 7, 31, and 51 days after discharge. Therefore, overall, <0.2% of patients developed a DVT and <0.1% were diagnosed with a PE (only 1 fatal; <0.01%) >35 days after the index hospitalization.

CONCLUSIONS

A substantial proportion of VTE events occur over 35 days after discharge; however, the overall risk is low with fatal PE being extremely low (<0.01%). Given the diminished VTE risk after 35 days, the decision to further extend antithrombotic drug therapy may be guided by patient-specific factors, such as prolonged immobility.

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.

Incidence and Risk Factors Associated with Venous Thromboembolism After Orthopaedic Below-knee Surgery

INTRODUCTION

Among patients undergoing below-knee orthopaedic surgery, no consensus exists regarding the need for or type of postoperative prophylaxis to prevent venous thromboembolic (VTE) events. The purpose of this study was to assess the incidence and risk factors associated with symptomatic VTE among orthopaedic patients undergoing below-knee surgery who were subject to different types of pharmacologic thromboprophylactic strategies.

METHODS

A total of 20,043 adult patients who underwent surgery for a below-knee orthopaedic condition between August 2005 and August 2015 were identified. Retrospective chart review recorded patient demographics, comorbid data, and anatomic location of any procedures performed. Multivariable logistic regression analysis was used to determine factors associated with postoperative development of symptomatic VTE among patients receiving various thromboprophylactic regimens.

RESULTS

The incidence of symptomatic VTE in patients who underwent below-knee surgery was 2.5% (492/20,043). For patients who did not receive thromboprophylaxis, the incidence was 1.5% (134/9,127 patients). In this group, risk factors for developing VTE were male sex; nonwhite race; surgery performed below the knee but above the ankle; combination procedures of the forefoot/midfoot, hindfoot/ankle, and/or lower leg; history of VTE; and Charlson Comorbidity Index score greater than 2. Among patients who received an antiplatelet agent, the VTE incidence was 1.7% (33/1,992 patients). The incidence of VTE among patients who received an oral or injectable anticoagulant was 3.6% (325/8,924 patients). In this group, risk factors for developing VTE were male sex; surgery performed below the knee but above the ankle; combination procedures of the forefoot/midfoot, hindfoot/ankle, and/or lower leg; and history of VTE.

CONCLUSION

Allowing for different types of thromboprophylactic strategies, the results of this study demonstrate a higher rate of symptomatic thromboembolic disease compared with previously reported <1% VTE incidence rates among orthopaedic patients undergoing below-knee surgery. Certain patients are at higher risk for thromboembolic disease after below-knee orthopaedic surgery. This risk was not found to be lowered by thromboprophylaxis as performed in patients in this database. Future research should be directed at determining what the best thromboprophylactic strategies are for lowering this risk.

LEVEL OF EVIDENCE

Therapeutic study level III.

Dynamic Simulation of Biomechanical Behaviour of the Pelvis in the Lateral Impact Loads

The objective of this study was to develop and validate a novel 3D dynamic model of a pelvic side-impactor system. The biomechanical responses of a pelvic flexible model (having .mnf file suffix) under the lateral impact load for predicting the bone fracture mechanism are investigated as well. The 3D solid model of the side-impactor system was imported into MSC/ADAMS software for analyzing the dynamic model, and the pelvic flexible model was extracted from the CT images of a Chinese female volunteer. The flexible model of the pelvis system was developed considering a wide range of mechanical properties in the bone complex and soft tissue to achieve a realistic biomechanical response during a lateral impact. Good agreements were achieved between the dynamic simulations and the experimental results of pelvic side impacts, in terms of the biomechanical criteria. The dynamic model of impactor system could be employed to investigate the hip protector effectiveness, improving the vehicle safety, and biomechanical response of the other human organs.

Variables associated with pulmonary thromboembolism in injured patients: A systematic review

BACKGROUND

Pulmonary thromboembolism (PTE) is a dangerous complication of traumatic injury, with varied risk profiles and treatment options. This review aims to describe reported incidence and variables associated with PTE among severely injured patients.

METHODS

Searches were conducted using PubMed, Cochrane and MEDLINE. Relevant studies were identified by two independent reviewers based on predetermined inclusion criteria. Incidence of PTE was the primary outcome measure. Variables associated with PTE was the secondary outcome measure. The Newcastle-Ottawa Scale was used to assess quality of included studies.

RESULTS

There were eight studies that satisfied inclusion criteria. The diagnosed incidence of PTE in these populations ranged from 0.35 to 24%. The most common variables associated with PTE were pelvic or lower limb injury, chest injury, higher total Injury Severity Score, male sex and age. Variables that were less commonly associated with PTE were previous warfarin use, head injury, high serum lactate, soft tissue injury, more than one operation, more than three days on a ventilator, presence of a subclavian central venous catheter, need for a blood transfusion, systolic blood pressure <90mmHg, abdominal injury, presence of a deep venous thrombosis, inferior vena cava filter placement and isolated liver spleen or spinal injuries.

CONCLUSIONS

The reported incidence of PTE after major trauma is variable and dependent on inclusion criteria, diagnostic criteria and study design. Identified variables differed to those reported for venous thromboembolism in other populations. It is difficult to predict populations at risk of clinically significant PTE following injury using available evidence. Further studies linked to patient-specific variables will assist in more precise risk-stratification and interventions.

Thromboembolic Disease After Orthopedic Trauma

Orthopedic trauma results in systemic physiologic changes that predispose patients to venous thromboembolism (VTE). In the absence of prophylaxis, VTE incidence may be as high as 60%. Mechanical and pharmacologic thromboprophylaxis are effective in decreasing rates of VTE. Combined mechanical and pharmacologic thromboprophylaxis is more efficacious for decreasing VTE incidence than either regimen independently. If pharmacologic thromboprophylaxis is contraindicated, mechanical prophylaxis should be used. Patients with isolated lower extremity fractures who are ambulatory, or those with isolated upper extremity trauma, do not require pharmacologic prophylaxis in the absence of other VTE risk factors.

Venous thromboembolism after surgical treatment of non-spinal skeletal metastases - An underdiagnosed complication

INTRODUCTION AND AIM

Venous thromboembolism (VTE) is a severe complication associated both with major orthopaedic surgery and cancer. However, survival and postoperative complications of skeletal metastases despite their thrombogenic potential, have received little attention in both the clinical management and research setting. This single-centre observational cohort study aimed to evaluate the incidence and impact of VTE in association with cancer surgery targeted to the management of fractures secondary to skeletal metastases.

METHODS

Data were collected retrospectively from the medical database. We included consecutive 306 patients operated for 343 non-spinal skeletal metastases during a 15-year period (1999-2014). The incidence of VTE and its risk factors were assessed using binary logistic regression analysis. Kaplan-Meier and Cox regression analyses were used to evaluate variables affecting survival.

RESULTS

The rate of symptomatic VTE was 10% (30/306) during the 3-month postoperative period, while 79% received thromboprophylaxis. Fatal pulmonary embolism (PE) rate was high, 3.3% (10/306) after surgery. Intraoperative oxygen saturation drop, pulmonary metastases and intramedullary nailing were independent risk factors for VTE. Indicators of decreased survival were lung cancer, intramedullary nailing, multiple skeletal and pulmonary metastases, anaemia, leukocytosis, and PE.

CONCLUSION

Relationship between fractures secondary to skeletal metastases and VTE needs further clinical attention. Whether the survival of patients with fractures secondary to skeletal metastases can be improved by targeted thromboprophylactic means should be studied further.

Risk Factors for Deep Venous Thrombosis Following Orthopaedic Trauma Surgery: An Analysis of 56,000 patients

Background:

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are recognized as major causes of morbidity and mortality in orthopaedic trauma patients. Despite the high incidence of these complications following orthopaedic trauma, there is a paucity of literature investigating the clinical risk factors for DVT in this specific population. As our healthcare system increasingly emphasizes quality measures, it is critical for orthopaedic surgeons to understand the clinical factors that increase the risk of DVT following orthopaedic trauma.

Objectives:

Utilizing the ACS-NSQIP database, we sought to determine the incidence and identify independent risk factors for DVT following orthopaedic trauma.

Patients and Methods:

Using current procedural terminology (CPT) codes for orthopaedic trauma procedures, we identified a prospective cohort of patients from the 2006 to 2013 ACS-NSQIP database. Using Wilcoxon-Mann-Whitney and chi-square tests where appropriate, patient demographics, comorbidities, and operative factors were compared between patients who developed a DVT within 30 days of surgery and those who did not. A multivariate logistic regression analysis was conducted to calculate odds ratios (ORs) and identify independent risk factors for DVT. Significance was set at P < 0.05.

Results:

56,299 orthopaedic trauma patients were included in the analysis, of which 473 (0.84%) developed a DVT within 30 days. In univariate analysis, twenty-five variables were significantly associated with the development of a DVT, including age (P < 0.0001), BMI (P = 0.037), diabetes (P = 0.01), ASA score (P < 0.0001) and anatomic region injured (P < 0.0001). Multivariate analysis identified several independent risk factors for development of a DVT including use of a ventilator (OR = 43.67, P = 0.039), ascites (OR = 41.61, P = 0.0038), steroid use (OR = 4.00, P < 0.001), and alcohol use (OR = 2.98, P = 0.0370). Compared to patients with upper extremity trauma, those with lower extremity injuries had significantly increased odds of developing a DVT (OR = 7.55, P = 0.006). The trend toward increased odds of DVT among patients with injuries to the hip/pelvis did not reach statistical significance (OR = 4.51, P = 0.22). Smoking was not found to be an independent risk factor for developing a DVT (P = 0.1217).

Conclusions:

This is the largest study to date using the NSQIP database to identify risk factors for DVT in orthopaedic trauma patients. Although the incidence of DVT was low in our cohort, the presence of certain risk factors significantly increased the odds of developing a DVT following orthopaedic trauma. These findings will enable orthopaedic surgeons to target at-risk patients and implement post-operative care protocols aimed at reducing the morbidity and mortality associated with DVT in orthopaedic trauma patients.

Evaluation of nonpermanent inferior vena cava filter placement in patients with deep venous thrombosis after lower extremity fracture: A single-center retrospective study

OBJECTIVE

To investigate nonpermanent inferior vena cava (IVC) filter in the prevention of perioperative pulmonary embolism (PE) in patients of lower extremity and/or pelvic bone fracture with deep vein thrombosis (DVT).

METHODS

Lower extremity or pelvic bone fracture patients with lower extremity DVT hospitalized in our hospital from January 2003 to October 2014 were retrospectively analyzed. Data was analyzed for age, gender, position of fracture, position of proximal of thrombosis, indications of placement, complications, retrieval rate, and rate of entrapped filter clot. Patients who underwent IVC filter placement were selected as the filter group. The patients who did not perform IVC filter placement after 2008 and the cases between January 2003 and December 2007 were selected as control group 1 and control group 2, respectively. The incidence of perioperative symptomatic PE and mortality were analyzed.

RESULTS

A total of 2763 cases complicated with DVT underwent orthopedic surgery between January 2003 and October 2014. 823 nonpermanent filters were inserted. All filters were successfully deployed with no major complications. After a mean 14.2 days indwelling time, all of temporary filters were removed. Retrieval was attempted in 556 patients with retrievable filters and was successful in 545 (98%); mean indwelling time was 16.3 days. The total retrieval rate was 90%. The incidence of PE in the filter group was significantly lower compared with the two control groups. Among the patients who received chemical anticoagulant therapy, the incidence of PE in filter group, control group 1 and control group 2 were 0.14%, 1.60% and 2.10%, respectively. The incidence of PE in filter group was also significant lower compared with control groups.

CONCLUSION

Nonpermanent IVC filter placement seems like to be a safe and effective method for preventing perioperative symptomatic and fatal PE in bone fracture patients with DVT in the present retrospective study.