Is damage control orthopedics essential for the management of bilateral femoral fractures associated or complicated with shock? An animal study

Immunopathophysiology of trauma-related acute kidney injury

Physical trauma can affect any individual and is globally accountable for more than one in every ten deaths. Although direct severe kidney trauma is relatively infrequent, extrarenal tissue trauma frequently results in the development of acute kidney injury (AKI). Various causes, including haemorrhagic shock, rhabdomyolysis, use of nephrotoxic drugs and infectious complications, can trigger and exacerbate trauma-related AKI (TRAKI), particularly in the presence of pre-existing or trauma-specific risk factors. Injured, hypoxic and ischaemic tissues expose the organism to damage-associated and pathogen-associated molecular patterns, and oxidative stress, all of which initiate a complex immunopathophysiological response that results in macrocirculatory and microcirculatory disturbances in the kidney, and functional impairment. The simultaneous activation of components of innate immunity, including leukocytes, coagulation factors and complement proteins, drives kidney inflammation, glomerular and tubular damage, and breakdown of the blood-urine barrier. This immune response is also an integral part of the intense post-trauma crosstalk between the kidneys, the nervous system and other organs, which aggravates multi-organ dysfunction. Necessary lifesaving procedures used in trauma management might have ambivalent effects as they stabilize injured tissue and organs while simultaneously exacerbating kidney injury. Consequently, only a small number of pathophysiological and immunomodulatory therapeutic targets for TRAKI prevention have been proposed and evaluated.

Evaluation of inflammatory response in patients undergoing surgical treatment for early and delayed femoral fractures

INTRODUCTION

It has been shown that long bone fractures are correlated with the inflammatory response. In the initial injury, surgical reduction and fixation of fractures induce the immunoinflammatory response. This study aimed to evaluate serum variation of inflammatory markers in patients undergoing surgical treatment for early and delayed femoral fractures.

MATERIAL AND METHODS

This study aimed to evaluate serum variation of inflammatory markers in patients undergoing surgical treatment for early and delayed femoral fractures. The patients were randomly divided into two groups using the method of block randomization including early surgery (within 24 h) and delayed surgery (after 48 h). Serum levels of inflammatory markers in both groups including interleukin (IL)-1, 5, 6, tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) were determined using specific kits. From each patient 10 ml blood was collected for cytokine assay in their serum.

RESULTS

Our findings suggest that serum levels of IL-8 were markedly decreased from 12 h until 48 h postoperatively (p < 0.05). Moreover, the results indicated that serum levels of TNF-α were significantly increased in the early hours, but after 48 h a decreasing trend was detected (p < 0.05). Furthermore, serum levels of IL-10, IFN-γ, and IL-6 were significantly increased from 12 h until 48 h postoperatively (p < 0.05).

CONCLUSIONS

The inflammatory status of the patient may be a useful adjunct in clinical decisions. With an improved understanding of the molecular basis of the inflammatory response, and by identifying relevant clinical markers of inflammation, surgeons can better manage the timing of surgical stabilization.

Serum miR-146a and miR-150 as Potential New Biomarkers for Hip Fracture-Induced Acute Lung Injury

Background

Acute lung injury (ALI) and subsequent pulmonary infection are the most severe and usually fatal complications for elderly hip fracture patients. It is necessary to find some biomarkers for early diagnosis and prognosis of it.

Objective

This study is aimed at examining the differential expression of miR-146a, miR-150, and cytokines (IL-6 and IL-10) between younger and elderly rats suffering from hip fracture and investigating the possible meaning of them in early diagnosis and prognosis of ALI after hip fracture.

Methods and Subjects

Elderly rats and younger rats were randomly divided into sham group and fracture group, respectively. Two fracture groups received hip fracture operations. The damage degree of ALI was evaluated by histological observation and pathological score. Cytokines were measured by ELISA; miR-146a and miR-150 were analysed by qRT-PCR.

Results

After treatment, compared with the corresponding sham groups, the pulmonary histological score, the serum miR-146a concentrations, and the cytokine (IL-6 and IL-10) levels in serum and BALF were significantly higher (the miR-150 were lower) in the fracture groups (with the exception of IL-6 of the younger fracture group at 72 h, all P < 0.05). Meanwhile, compared with the younger fracture group, the aforementioned variables were significantly higher (the miR-150 levels were lower) in the elderly fracture group (with the exception of serum IL-10 and pulmonary histological score at 8 h, all P < 0.05). The results of linear regression analysis showed that serum miR-146a and miR-150 were significantly associated with pulmonary histological score.

Conclusion

Hip fracture can result in significant systemic inflammation and ALI in the rats. Compared to the younger rats, the elderly rats suffered a more remarkable ALI after hip fracture. It may be related to the abnormal expression of miR-146a and miR-150. Serum miR-146a and miR-150 are potential biomarkers for diagnosis and prognosis of ALI after hip fracture.

Epigallocatechin Gallate Attenuates Hip Fracture-Induced Acute Lung Injury by Limiting Mitochondrial DNA (mtDNA) Release

BACKGROUND To study the protective effects and explore the mechanism of epigallocatechingallate (EGCG) on the hip fracture-induced acute lung injury. MATERIAL AND METHODS Thirty male Sprague-Dawley (SD) rats were randomly divided into the control group, hip fracture group, and hip fracture + EGCG (10 mg/Kg) group. After 24 h, blood samples, bronchoalveolar lavage fluid (BALF), and lung tissue were collected. Serum mitochondrial DNA (mtDNA) was measured by RT-PCR and BALF was used to perform cytological analysis and enzyme-linked immunosorbent assay (ELISA) assay. Lung tissue was used to evaluate the injury level. RESULTS EGCG significantly reduced the hip fracture-induced high level of serum mtDNA (p<0.05). HE staining showed protective effects of EGCG. Lower lung injury score and wet/dry ratio were identified in the hip fracture + EGCG group than in the hip fracture group (p<0.05). We found significantly lower levels of infiltration of inflammatory cells and production of inflammatory cytokines in the BALF of the hip fracture + EGCG group than in the hip fracture group (p<0.05). CONCLUSIONS Our study found that EGCG had protective effects on hip fracture-induced acute lung injury and suggests that EGCG exerts its protective effects through limiting the release of mtDNA. Our results provide a novel pharmacological agent to attenuate hip fracture-induced acute lung injury, as well as a potential theory to better explain the anti-inflammatory property of EGCG.

Treatment with a neutralising anti-rat interleukin-17 antibody after multiple-trauma reduces lung inflammation

BACKGROUND

It has been well recognised that a deficit of numbers and function of CD4(+)CD25(+)Foxp3(+) cells (Treg) is attributed to the development of autoimmune diseases and inflammatory diseases; additionally, IL-17-producing cells (Th17) have a pro-inflammatory role. The balance between Th17 and Treg may be essential for maintaining immune homeostasis and has long been thought as one of the important factors in the development/prevention of autoimmune diseases and inflammatory diseases. In our previous research, we explored that cytokines (IL-17) and the balance of Treg/Th17 had a significant relevance with tissue (lung) inflammation and injury in acute-phase after multiple-trauma.

OBJECTIVE

To more verify whether an imbalance of Treg/Th17 is characteristic of rats suffering from multiple trauma.

METHODS AND SUBJECTIVE

Using IL-17 monoclonal antibody (IL-17mAb)-treated multiple-trauma rat, we tested the pathogenic role of IL-17 in the development of multiple-trauma. Rat models were treated respectively with IL-17mAb or rat IgG 2A isotype control or phosphate-buffered solution after model was established. Normal rats only received anaesthesia and cannulation were taken as sham. Rats in each group were killed respectively at the end of 1h, 4h, 8h after injection. Collected serum and lung samples for assessment dynamically of MPO, IL-17, IL-6, and TGF-β-mRNA, and cytokine (IL-17, IL-6, TGF-β) and lung tissue for pulmonary histological analysis.

RESULTS

Neutralisation of IL-17 with anti-IL-17 can decrease serum IL-17 level and the IL-17-mRNA transcript level in lung, and ameliorate tissue inflammatory, defer disease course.

CONCLUSION

Our data suggest that IL-17 is crucially involved in the pathogenesis of multiple-trauma in rat, IL-17 inhibition might ameliorate the lung inflammation in acute-phase after multiple-trauma.

The Immediate Intramedullary Nailing Surgery Increased the Mitochondrial DNA Release That Aggravated Systemic Inflammatory Response and Lung Injury Induced by Elderly Hip Fracture

Conventional concept suggests that immediate surgery is the optimal choice for elderly hip fracture patients; however, few studies focus on the adverse effect of immediate surgery. This study aims to examine the adverse effect of immediate surgery, as well as to explore the meaning of mtDNA release after trauma. In the experiment, elderly rats, respectively, received hip fracture operations or hip fracture plus intramedullary nail surgery. After fracture operations, the serum mtDNA levels as well as the related indicators of systemic inflammatory response and lung injury significantly increased in the rats. After immediate surgery, the above variables were further increased. The serum mtDNA levels were significantly related with the serum cytokine (TNF-α and IL-10) levels and pulmonary histological score. In order to identify the meaning of mtDNA release following hip fracture, the elderly rats received injections with mtDNA. After treatment, the related indicators of systemic inflammatory response and lung injury significantly increased in the rats. These results demonstrated that the immediate surgery increased the mtDNA release that could aggravate systemic inflammatory response and lung injury induced by elderly hip fracture; serum mtDNA might serve as a potential biomarker of systemic inflammatory response and lung injury following elderly hip fracture.

Morbidity and Mortality of Bilateral Femur Fractures

Bilateral femur fractures have been associated with frequent morbidity and mortality. Associated injuries and massive hemorrhage contributed to mortality rates that were as high as 27% in previous reports. The goals of this study were to determine the frequency of associated complications, including mortality, and to identify which patient and injury features are associated with increased morbidity and mortality. The authors proposed that some patients with bilateral femur fractures may undergo early definitive fixation with an acceptable rate of complications. Patients who had bilateral femur fractures during the same injury event were retrospectively reviewed. Demographic characteristics, associated injuries, and the type and timing of treatment were determined. Complications were identified. The authors identified 50 men and 22 women, with a mean age of 41.5 years, who had high-energy bilateral femur fractures. These patients accounted for 5.5% of all femur fractures treated at the authors' institution over a period of 11 years. Two patients died before fixation. In addition, 13 other patients (19%) had 21 complications, including pneumonia in 6 (8.6%) and deep venous thrombosis in 7 (10%). No patient had adult respiratory distress syndrome, but 2 died of multiple organ failure. All patients with pulmonary complications had an underlying chest injury (P=.004). The overall mortality rate was 6.9%, and mortality was associated with higher mean age and higher Injury Severity Score (ISS). Of the 60 patients who had definitive fixation within 24 hours of injury, 53 (88%) had no complications. Complication rates were similar to those reported in the literature, with a mortality rate of 6.9%, including 3 patients who died after femoral fixation. Mortality was associated with advanced age and higher ISS. Chest injuries were associated with pulmonary complications. Most patients had early definitive fixation without complications, but it is not possible to predict which patients may be safely treated on an early basis.

Ultrastructural lung pathology following brain injury combined with femur shaft fracture in a rat model

BACKGROUND

This study aimed to explore the early pathologic changes in the lung ultrastructure in rat models of isolated or multiple traumatic injuries.

METHODS

Ninety-six rats were divided into a control group, a unilateral femur fracture group, a brain injury group, and a unilateral femur fracture combined with brain injury group. At 1, 6, 12, and 24 hours following model creation, the rat lungs were isolated and examined under a transmission electron microscope. A lung injury scoring model was used to evaluate the ultrastructural changes in the organelles of Type II alveolar epithelial cells (AEC-II). The ultrastructural changes and lung injury scores were compared among the four groups.

RESULTS

Mild ultrastructural damage was seen in the single-trauma groups. In the unilateral femur fracture group, the organelle morphology alleviated within 24 hours. The brain injury group showed more obvious ultrastructural changes, and some organelles were irreversibly damaged. This ultrastructural damage to the AEC-II was significantly augmented in the combined injury group; in this group, the damage was most obvious, occurred the earliest, involved the widest area, continued to progress throughout the study, and apparently worsened in 24 hours. The lung injury scores increased at all the time points in the three experimental groups compared with the control group and were significantly higher in the combined injury group than in the other groups.

CONCLUSION

Ultrastructural AEC-II damage was significantly augmented in the combined injury model compared with the single-injury models. The pulmonary condition should be considered when treating this type of injury.

A risk-adapted approach is beneficial in the management of bilateral femoral shaft fractures in multiple trauma patients: an analysis based on the trauma registry of the German Trauma Society

BACKGROUND

Today, there is a trend toward damage-control orthopedics (DCO) in the management of multiple trauma patients with long bone fractures. However, there is no widely accepted concept. A risk-adapted approach seems to result in low acute morbidity and mortality. Multiple trauma patients with bilateral femoral shaft fractures (FSFs) are considered to be more severely injured. The objective of this study was to validate the risk-adapted approach in the management of multiple trauma patients with bilateral FSF.

METHODS

Data analysis is based on the trauma registry of the German Trauma Society (1993-2008, n = 42,248). Multiple trauma patients with bilateral FSF were analyzed in subgroups according to the type of primary operative strategy. Outcome parameters were mortality and major complications as (multiple) organ failure and sepsis.

RESULTS

A total of 379 patients with bilateral FSF were divided into four groups as follows: (1) no operation (8.4%), (2) bilateral temporary external fixation (DCO) (50.9%), bilateral primary definitive osteosynthesis (early total care [ETC]) (25.1%), and primary definitive osteosynthesis of one FSF and DCO contralaterally (mixed) (15.6%). Compared with the ETC group, the DCO group was more severely injured. The incidence of (multiple) organ failure and mortality rates were higher in the DCO group but without significance. Adjusted for injury severity, there was no significant difference of mortality rates between DCO and ETC. Injury severity and mortality rates were significantly increased in the no-operation group. The mixed group was similar to the ETC group regarding injury severity and outcome.

CONCLUSION

In Germany, both DCO and ETC are practiced in multiple trauma patients with bilateral FSF so far. The unstable or potentially unstable patient is reasonably treated with DCO. The clearly stable patient is reasonably treated with nailing. When in doubt, the patient is probably not totally stable, and the safest precaution may be to use DCO as a risk-adapted approach.

LEVEL OF EVIDENCE

Therapeutic study, level IV. Epidemiologic study, level III.

Patterns of cytokine release and evolution of remote organs from proximal femur fracture in COPD rats

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is at increased risk for developing osteoporosis (OP) with subsequent proximal femur fracture. The presence of COPD is suggested to be a strong risk factor for proximal femur fracture or hip fracture. However, what happen behind it is not clearly understood.

OBJECTIVE

To investigate the pattern of cytokine (TNF-a, IL-6, and IL-10) releases in pulmonary and hepatic in rats with COPD suffering from proximal femur fracture, and its possible adverse effect on pulmonary and hepatic.

METHODS AND SUBJECTIVE

This paper has two parts. In the first part, we describe the procedure of COPD model in detail. In the second part, we study the influences of fracture on the COPD rats. 5 months WISTAR rats with 37 weeks cigarette smoking exposure (CS group) were dynamically determined for pulmonary function, inflammatory response in bronchoalveolar lavage fluid (BALF), histological changes in pulmonary in the first part. When the COPD model is proved to be successful, we begin the second part. COPD rats were euthanized at 2, 24, 48, 72, and 96h after proximal femur fracture (fracture group) or anaesthesia (control group). Cytokines (TNF-a, IL-6, and IL-10) and myeloperoxidase activity of pulmonary and hepatic (MPO) were measured with enzyme-liked immunosorbent assay technique. Permeability changes of the lung were assessed via bronchoalveolar lavage, and those of the liver via assessment of oedema formation. Tissues were further examined microscopically.

RESULTS

The current sidestream cigarette smoke induced rat COPD model has been proved an adequate animal model with several advantages as assessed by dynamically monitored lung mechanics and pathological changes for 37 weeks. In the second part, TNF-a, IL-6, and IL-10 levels of pulmonary tissue were significantly increased after proximal femur fracture compared to control rats. TNF-a, and IL-6 levels in pulmonary peaked at 2h, 24h in fracture group, whereas IL-10 level peaked at 24h and 96h. Pulmonary myeloperoxidase activity, permeability and histological score in fracture group were remarkably elevated, and peaked at 24h. In addition to TNF-a, all above parameters did not return to normal through our study. Hepatic in COPD rats showed notable increase of cytokines (TNF-a, IL-6, and IL-10), myeloperoxidase activity, histological score, and permeability in fracture group compared to control rats, and severity of these changes were much lower than in pulmonary. Apart from TNF-a, the peak of these parameters was at 24h after fracture. Changes of cytokines, MPO activity, permeability and histological score in pulmonary and hepatic in control rat were little changed.

CONCLUSION

COPD rats produced a remarkably increase of inflammatory response (TNF-a, IL-6, IL-10) in lung (liver) after proximal femur fracture, which lead to lung (liver) injury, as evidence by changes of MPO, permeability, and histological scores in local organs.