Incidence of Fat Embolism Syndrome in Femur Fractures and Its Associated Risk Factors over Time-A Systematic Review

Relationship between fat embolism and endothelial glycocalyx

Fat embolism (FE) is acknowledged as one of the significant causes of sudden death following traumatic injury. To clarify the relevance of vascular endothelial glycocalyx (EGC) damage and FE, temporal changes in the mRNA levels of inflammatory cytokines associated with EGC components were investigated in an experimental fat embolization rat model. Nine-week-old rats were used as FE models through triolein injection (TO) and femoral fracture (FX), and physiological saline was administered to the control group. RT-qPCR and fat staining were performed. The target genes were Il6, Il10, Tnf, Elane, Sdc1, Sdcbp, Vcan, Hyal1, Fn1, and CD14. Notably, FE was detected in 100% and 5.6% of the TO and FX groups, respectively, using fat staining. Bimodal peaks in the mRNA expression levels of Sdc1, Tnf, Elane, IL6, and IL10 were observed 4 and 20 h after treatment in both groups. In the TO group, mRNA expression peaked at 4 h and then declined to the lowest level at 16 h. The incidence of fat emboli due to trauma was consistent with that reported in previous studies. Bimodal mRNA peaks may correspond to FE progression, in which physical obstructions are followed by biochemical reactions. The fluctuation in Sdc1 expression suggests that the initial peak resulted from physical EGC damage. The subsequent peak could be because of EGC damage caused by the secretion of inflammatory cytokines induced by oleic acid from lipid droplet decomposition. These results suggest that EGC disorders caused by lipid droplets may induce lung damage during FE.

Epidemiology and risk factors for fat embolism in isolated lower extremity long bone fractures

PURPOSE

Fat embolism syndrome (FES) is a serious complication after orthopedic trauma. The aim of this study was to identify risk factors for FES in isolated lower extremity long bone fractures.

METHODS

The National Trauma Data Bank "NTDB" study included patients with isolated femoral and tibial fractures. A total of 344 patients with FES were propensity score matched with 981 patients without FES. Multivariate logistical regression was used to identify independent risk factors for FES.

RESULTS

FES was diagnosed in 344 (0.03%) out of the 1,251,143 patients in the study populations. In the two matched groups, the mortality was 7% in the FES group and 1% in the No FES group (p < 0.001). FES was associated with an increased risk of ARDS, VTE, pneumonia, AKI, and stroke. Younger age, femur fractures, obesity, and diabetes mellitus were independent predictors of FES. Early operative fixation (≤ 48 h) was protective against FES.

CONCLUSION

FES increases mortality by seven times. Young age, obesity, and diabetes mellitus are significant independent risk factors for FES. Early fixation is independently associated with a reduced risk of FES.

LEVEL OF EVIDENCE

Level III.

STUDY TYPE

Prognostic study.

A rare fatal cerebral fat emboli syndrome with large vessel occlusion post femur fracture plating in an older female: A case report

INTRODUCTION AND IMPORTANCE

Cerebral fat embolism syndrome is a rare complication of long bone fractures, often overlooked and found in late stages. We present patient with a late recognition of Cerebral Fat Embolism with Large vessel occlusion post femoral internal fixation.

CASE PRESENTATION

An elderly female suffered right intertrochanteric fracture after falling down. Open reduction internal fixation with Interlocking plate was performed at the fifth day. Upon returning to the ward, the patient did not regain full consciousness and apparent right hemiparesis were observed. A head Computed Tomography was performed and found left hemisphere ischemia consistent with middle cerebral artery occlusion. The patient condition worsened and died 3 days postoperatively.

CLINICAL DISCUSSION

Cases of fat embolism that occur purely isolated in the brain are rare cases that occur after internal fixation of the femur, so they are often not noticed by clinicians. Several factors can increase the risk of the event, delay in fixation and diabetes mellitus which was found in our patient could increase the risk of fat emboli syndrome. Apart from that, osteoporosis also increases the risk of fat embolism syndrome that was found in our subject.

CONCLUSIONS

Cerebral Large Vessel Occlusion Fat Embolism Syndrome is rare case occur following internal fixation. There is a need for early recognition to be carried out to treat early or prevent the occurrence of fat embolism.

Fat embolism syndrome and massive middle cerebral artery occlusion: a case report

Fat embolism syndrome (FES) is common with bones fractures. It often involves several symptoms like respiratory distress, neurological impairment, and cutaneous rash. The symptoms often start after several hours or days after the trauma or the bone reduction. Neurological damages can be seen better with MRI and the pattern is most of the time a diffuse one but changes according to timing. In our case, the symptoms started in the recovery ward and a complete flow interruption by adipose material was seen in the left middle cerebral artery.

Fat embolism: the hidden murder for trauma patients!

INTRODUCTION

fat embolism syndrome (FES) is an acute respiratory disorder that occurs when an inflammatory response causes the embolization of fat and marrow particles into the bloodstream. The exact incidence of FES is not well defined due to the difficulty of diagnosis. FES is mostly associated with isolated long bone trauma, and it is usually misdiagnosed in other trauma cases. The scope of this study was to identify and search the current literature for cases of FES in nonorthopedic trauma patients with the aim of defining the etiology, incidence, and main clinical manifestations.

METHODS

we perform a literature search via the PubMed journal to find, summarize, and incorporate reports of fat embolisms in patients presenting with non-orthopedic trauma.

RESULTS

the final literature search yielded 23 papers of patients presenting with fat embolism/FES due to non-orthopedic trauma. The presentation and etiology of these fat embolisms is varied and complex, differing from patient to patient. In this review, we highlight the importance of maintaining a clinical suspicion of FES within the trauma and critical care community.

CONCLUSION

to help trauma surgeons and clinicians identify FES cases in trauma patients who do not present with long bone fracture, we also present the main clinical signs of FES as well as the possible treatment and prevention options.

Occult hypoperfusion and changes of systemic lipid levels after severe trauma: an analysis in a standardized porcine polytrauma model

BACKGROUND

Occult hypoperfusion describes the absence of sufficient microcirculation despite normal vital signs. It is known to be associated with prolonged elevation of serum lactate and later complications in severely injured patients. We hypothesized that changes in circulating lipids are related to responsiveness to resuscitation. The purpose of this study is investigating the relation between responsiveness to resuscitation and lipidomic course after poly trauma.

METHODS

Twenty-five male pigs were exposed a combined injury of blunt chest trauma, liver laceration, controlled haemorrhagic shock, and femoral shaft fracture. After 1 h, animals received resuscitation and fracture stabilization. Venous blood was taken regularly and 233 specific lipids were analysed. Animals were divided into two groups based on serum lactate level at the end point as an indicator of responsiveness to resuscitation (<2 mmol/L: responder group (R group), ≧2 mmol/L: occult hypoperfusion group (OH group)).

RESULTS

Eighteen animals met criteria for the R group, four animals for the OH group, and three animals died. Acylcarnitines showed a significant increase at 1 h compared to baseline in both groups. Six lipid subgroups showed a significant increase only in R group at 2 h. There was no significant change at other time points.

CONCLUSIONS

Six lipid groups increased significantly only in the R group at 2 h, which may support the idea that they could serve as potential biomarkers to help us to detect the presence of occult hypoperfusion and insufficient resuscitation. We feel that further study is required to confirm the role and mechanism of lipid changes after trauma.

The Development of Fat Embolism Syndrome (FES) and Multiple Small Pulmonary Emboli Following Open Reduction Internal Fixation (ORIF) of a Left Femur Fracture: A Case Report

Fat embolism syndrome (FES) is a rare but potentially life-threatening complication that can occur following orthopedic procedures, such as long bone fracture repairs. FES is caused by the release of fat globules into the bloodstream, leading to the obstruction of blood vessels and subsequent tissue damage. Pulmonary embolism (PE), a condition in which a blood clot travels to the lungs, is another potential complication of orthopedic procedures due to the mobilization of blood clots during surgery. We report the case of a 56-year-old female who presented to the emergency department with a left femur fracture following a mechanical fall and underwent open reduction internal fixation (ORIF) surgery for the fracture. The procedure was complicated by the development of FES and multiple small pulmonary emboli. The patient was managed postoperatively in the ICU, requiring support with multiple vasopressors and mechanical ventilation. She remained in the ICU for three days postoperatively and was discharged on postoperative day six to an inpatient rehabilitation facility.

Complications associated using the reamer-irrigator -aspirator (RIA) system: a systematic review and meta-analysis

INTRODUCTION

Complications associated with the application of the Reamer-irrigator-Aspirator (RIA) system are described in the literature. However, to date a systematic review and meta-analysis to assess prevalence of complications associated with the use of the RIA system have not been conducted.

MATERIALS AND METHODS

The review is registered with PROSPERO (CRD42021269982). MEDLINE, the Web of Science Core Collection, and Embase were searched from the inception to 10 August 2021. The primary objective was to assess complications and blood loss associated with the use of the RIA system.

RESULTS

Forty-seven studies involving 1834 procedures performed with the RIA system were finally included. A total of 105 complications were reported, with a pooled estimated overall prevalence of 1.7% with a 95% confidence interval (CI) of 0.40 to 3.60, with cortex perforation being the largest reported complication with a total of 34 incidences. A significant subgroup difference was observed (p = 0.02). In subgroup 1 (bone graft harvesting), complication prevalence was 1.4% (95% CI 0.2-3.4); in subgroup 2 (clearance intramedullary canal) it was 0.7% (95% CI 0.00-6.30) and in subgroup 3 (reaming with RIA system prior to nail fixation) 11.9% (95% CI 1.80-26.40). No statistically significant difference for tibia and femur as RIA system application site was observed (CI 0.69-4.19). In studies reporting blood loss, a mean volume of 803.29 ml, a mean drop of hemoglobin of 3.74 g/dl and a necessity of blood transfusion in 9.72% of the patients were observed.

CONCLUSIONS

The systematic review and meta-analysis demonstrate a low overall prevalence rate of complications associated with the RIA system. However, especially the risk of cortical perforation and the frequently reported relevant intraoperative blood loss are complications that should be anticipated in perioperative management and ultimately considered when using the RIA system.

Management of Traumatic Femur Fractures: A Focus on the Time to Intramedullary Nailing and Clinical Outcomes

Background: Femur shaft factures (FSF) are common injuries following high-energy mechanisms mainly involving motor vehicle crashes (MVC). We evaluated the timings of nailing management and analyzed the pattern of fracture union and outcome in a level 1 trauma center. Methods: This was a retrospective observational study of all the admitted trauma patients who sustained femoral fractures between January 2016 and September 2020. Data were analyzed and compared based on time to Intramedullary Nailing (IMN) (<12 h, 12–24 h and >24 h) and outcomes of FSF (union, delayed union and nonunion). Results: A total of 668 eligible patients were included in the study, of which the majority were males (90.9%) with a mean age of 34.5 ± 15.8, and 54% of the injuries were due to MVCs. The chest (35.8%) was the most commonly associated injured body region, followed by the pelvis (25.9%) and spine (25.4%). Most of femur fractures (93.3%) were unilateral, and 84.4% were closed fractures. The complete union of fractures was observed in 76.8% of cases, whereas only 4.2% and 3.3% cases had delayed union and nonunion, respectively, on the clinical follow-up. Patients in the delayed IMN (>24 h) were severely injured, had bilateral femur fracture (p = 0.001) and had higher rate of external fixation, blood transfusion, pulmonary complications and prolonged hospitalization. Non-union proportion was greater in those who had IMN <24 h, whereas a delayed union was greater in IMN done after 24 h (p = 0.5). Those with a nonunion femur fracture were more likely to have bilateral fracture (p = 0.003), frequently had retrograde nailing (p = 0.01), and high-grade femur fracture (AO type C; p = 0.04). Conclusion: This study showed that femur fracture is not uncommon (8.9%), which is manifested with the variety of clinical characteristics, depending on the mechanism, management and outcome in our center. Bilateral fracture, retrograde nailing and AO classification type C were the significant risk factors of non-union in patients with diaphyseal fractures. The timing of IMN has an impact on the fracture union; however, it is not a statistically significant difference. Therefore, the treating physicians should consider the potential risk factors for a better outcome by careful selection of treatment in sub-groups of patients.

Fat Embolism Syndrome and in-Hospital Mortality Rates According to Patient Age: A Large Nationwide Retrospective Study

Introduction

Fat embolism syndrome (FES) is a rare life-threatening condition that can develop after traumatic orthopedic injuries. Controversy remains concerning the epidemiology in the elderly population. Therefore, this study aims to report FES related to in-hospital mortality stratified by age.

Methods

A retrospective trauma cohort study was conducted using data from the National Trauma Data Bank (NTDB) from 2007 to 2014. All FES cases were included in the study with the diagnosis of FES (ICD9 958.1). Death on arrival cases were excluded. Patients were stratified by age cohort: less than 40 (G1), 40–64 (G2), and greater than 65 (G3) years of age. The primary outcome evaluated was in-hospital mortality. Multivariable regression models were performed to adjust for potential confounders.

Results

Between 2007 and 2014, 451 people from a total of 5,836,499 trauma patients in the NTDB met the inclusion criteria. The incidence rate was 8 out of 100,000. The inpatient mortality rate was 11.8% for all subjects with the highest mortality rate of 17.6% in patients over 65. Multivariable analyses demonstrated that age greater than 65 years was an independent predictor of mortality (aOR 24.16, 95% CI 3.73, 156.59, p=0.001), despite higher incidence and injury severity of FES among patients less than 40. No significant association with length of hospital stay, length of intensive unit care, or length of ventilation use was found between the groups. Subgroup analysis of the elderly population also showed a higher mortality rate for FES in femoral neck fracture patients (18%) than other femoral fractures (14%).

Conclusion

In this retrospective cohort analysis, old age (≥ 65 years) was found to be an independent risk factor for in-hospital mortality among fat embolism syndrome patients. Elderly patients specifically with femoral neck fractures should be monitored for the development of FES.

Concomitant post-traumatic ocular and cerebral fat embolism syndrome and thrombotic pulmonary embolism: A case report

RATIONALE

Fat embolism syndrome (FES) is composed of a triad of symptoms, including respiratory distress, neurologic deficit, and petechiae. Respiratory distress usually presents first before the other symptoms. Thrombotic pulmonary embolism (TPE) is a differential diagnosis of FES. Trauma is a risk factor for both diseases; however, co-occurrence is rare.

PATIENT CONCERNS

A 35-year-old male patient presented with altered consciousness, focal neurologic deficit, and respiratory distress after a left femoral subtrochanteric fracture and subsequent open reduction and internal fixation with an intramedullary nail.

DIAGNOSIS

Computed tomography pulmonary angiography (CTPA) revealed lower pulmonary artery filling defects and ground-glass opacities in bilateral lung, indicating TPE and FES, respectively.

INTERVENTIONS

Heparin was initially added and subsequently switched to apixaban. The symptoms improved quickly without major bleeding complications.

LESSION SUBSECTIONS

Concomitant TPE and FES after trauma are rare and require different treatment approaches. Due to clinical similarities, prompt chest CTPA was advised to detect TPE that was treated with anticoagulant therapy instead of supportive care for FES.

Fatal Fulminant Fat Embolism Syndrome in Adult Spine Deformity Surgery: A Case Report

CASE

A 68-year-old woman was scheduled to undergo elective correction of coronal spinal malalignment after a previous lumbar instrumented fusion. In the final stages of the operation, the patient became hemodynamically unstable. Her systemic condition worsened subsequently, leading to cardiac arrest followed by unsuccessful resuscitation. An autopsy revealed a massive fat embolism in the lungs.

CONCLUSIONS

The diagnosis of fat embolism syndrome (FES) is clinical, and treatment is supportive, with no clinical or investigative criteria that can facilitate diagnosis in a patient under general anesthesia. This is the first description of FES in adult spinal deformity surgery.

Fat embolism syndrome in patients with bilateral femur fractures: a systematic review and case comparison

Objectives:

Fat embolism and fat embolism syndrome (FES) remain common complications following long bone fractures. Incidence is highest after bilateral femur fractures. We performed a systematic review of FES after bilateral femur fractures and present two cases.

Data sources:

Systematic literature search of the Cochrane, EMBASE, MEDLINE, Scopus, and, Web of Science Library databases was performed in August 2021. Terms used including plural and alternate spellings: “fat embolism,”“fat embolism syndrome,”“fat embolus,” and “bilateral femur fracture.” Articles in German and English were considered. No time frame was applied.

Study selection:

Original studies, case series and case reports on fat embolism after bilateral femur fracture were included. Insufficient documentation or patients with relevant previous heath conditions were excluded.

Data extraction:

Abstracts were organized using EndNote X9 by Carivate. Three authors independently screened the abstracts; cross check of the extracted data was performed by the senior author.

Data synthesis:

Scarcity of articles only allowed for a qualitative synthesis. Data was compared with our cases and situated within the scientific background.

Results:

Ten articles were included for qualitative synthesis (n = 144 patients). The symptoms were inhomogeneous with neurological deficits being most prominent. Degree of displacement was high, when reported. Although the modes and timing of surgery varied, this appeared unrelated with outcome.

Conclusions:

FES remains a relevant complication after bilateral femur fractures, despite damage control strategies and improved reaming techniques. Fracture displacement and reduction maneuvers might play a more substantial role in the formation than previously accredited.

Level of evidence:

4