Sustained pain and macrophage infiltration in a mouse muscle contusion model.

INTRODUCTION/AIMS: Prior studies have emphasized the role of inflammation in the response to injury and muscle regeneration, but little emphasis has been placed on characterizing the relationship between innate inflammation, pain, and functional impairment. The aim of our study was to determine the contribution of innate immunity to prolonged pain following muscle contusion. METHODS: We developed a closed-impact mouse model of muscle contusion and a macrophage-targeted near-infrared fluorescent nanoemulsion. Closed-impact contusions were delivered to the lower left limb. Pain sensitivity, gait dysfunction, and inflammation were assessed in the days and weeks post-contusion. Macrophage accumulation was imaged in vivo by injecting i.v. near-infrared nanoemulsion. RESULTS: Despite hindpaw hypersensitivity persisting for several weeks, disruptions to gait and grip strength typically resolved within 10 days of injury. Using non-invasive imaging and immunohistochemistry, we show that macrophage density peaks in and around the affected muscle 3 day post-injury and quickly subsides. However, macrophage density in the ipsilateral sciatic nerve and dorsal root ganglia (DRG) increases more gradually and persists for at least 14 days. DISCUSSION: In this study, we demonstrate pain sensitivity is influenced by the degree of lower muscle contusion, without significant changes to gait and grip strength. This may be due to modulation of pain signaling by macrophage proliferation in the sciatic nerve, upstream from the site of injury. Our work suggests chronic pain developing from muscle contusion is driven by macrophage-derived neuroinflammation in the peripheral nervous system.

Betulin Accelerated the Functional Recovery of Injured Muscle in a Mouse Model of Muscle Contusion.

Muscle contusion is an injury to muscle fibers and connective tissues. It commonly happens in impact events, and could result in pain, swelling, and limited range of motion. Diclofenac is one of commonly used nonsteroidal anti-inflammatory drugs to alleviate pain and inflammation after injury. However, it can potentially cause some side effects including gastrointestinal complications and allergy. Betulin is a lupine-type pentacyclic triterpenoid. It is showed to have valuable pharmacological effects, but the physiological effect of betulin on muscle contusion has not been reported. This study aimed to explore the therapeutic effects of betulin on muscle contusion that produced by the drop-mass method in mice. C57BL/6 mice were randomly assigned to control (no injury), only drop-mass injury (Injury), diclofenac treatment (Injury+diclofenac), and betulin treatment (Injury+betulin) groups. Injury was executed on the gastrocnemius of the right hind limb, and then phosphate-buffered saline (PBS), diclofenac, or betulin were oral gavage administrated respectively for 7 days. Results revealed that betulin significantly restored motor functions based on locomotor activity assessments, rota-rod test, and footprints analysis. Betulin also attenuated serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels after muscle injury. Neutrophil infiltration was alleviated and desmin levels were increased after betulin treatment. Our data demonstrated that betulin attenuated muscle damage, alleviated inflammatory response, improved muscle regeneration, and restored motor functions after muscle contusion. Altogether, betulin may be a potential compound to accelerate the repair of injured muscle.

Earthquake-related isolated blunt thoracic trauma patients: A special population study in the emergency department.

OBJECTIVE: The objective of this study is to compare patients with severe and mild blunt thoracic trauma, who survived an earthquake and presented to the emergency department (ED), in order to identify factors influencing the severity of trauma in earthquake-related thoracic injuries. METHODS: This retrospective, cross-sectional, observational comparative study included patients with isolated thoracic injuries due to the February 6th Kahramanmaras earthquake. The patients were categorized into severe and mild groups based on chest trauma scoring (CTS), and their characteristics were compared. RESULTS: The study included 53 patients, with 43 (88.1%) classified as having mild thoracic trauma and 10 (18.9%) classified as having severe thoracic trauma. There was no significant difference in the duration of entrapment between the groups (p = 0.824). The incidence of hemothorax, pneumothorax, rib fractures, and pneumomediastinum did not differ significantly between the two groups (p > 0.05). However, severe thoracic trauma was associated with a higher rate of lung contusion compared to the mild group (p = 0.045). The severe group exhibited significantly higher median scores for lung contusion, rib fractures, and total CTS compared to the mild group (p < 0.001). The mortality rate was significantly higher in the severe group (40%, n = 4) compared to the mild group (2.3%, n = 1) (p = 0.003). CONCLUSION: The duration of entrapment did not significantly affect the severity of thoracic injuries in earthquake-related blunt thoracic trauma. However, lung contusion was found to be a more prominent feature in these injuries compared to other clinical conditions such as hemothorax and pneumothorax. These findings highlight the distinct clinical implications of earthquake-related thoracic trauma and may have implications for management strategies in these cases.

Impact Location Dependence of Behind Armor Blunt Trauma Injury Assessed Using a Human Body Finite Element Model.

Behind armor blunt trauma (BABT), resulting from dynamic deformation of protective ballistic armor into the thorax, is currently assessed assuming a constant threshold of maximum backface deformation (BFDs) (44 mm). Although assessed for multiple impacts on the same armor, testing is focused on armor performance (shot-to-edge and shot-to-shot) without consideration of the underlying location on the thorax. Previous studies identified the importance of impacts on organs of animal surrogates wearing soft armor. However, the effect of impact location was not quantified outside the threshold of 44 mm. In the present study, a validated biofidelic advanced human thorax model (50th percentile male) was utilized to assess the BABT outcome from varying impact location. The thorax model was dynamically loaded using a method developed for recreating BABT impacts, and BABT events within the range of real-world impact severities and locations were simulated. It was found that thorax injury depended on impact location for the same BFDs. Generally, impacts over high compliance locations (anterolateral rib cage) yielded increased thoracic compression and loading on the lungs leading to pulmonary lung contusion (PLC). Impacts at low compliance locations (top of sternum) yielded hard tissue fractures. Injuries to the sternum, ribs, and lungs were predicted at BFDs lower than 44 mm for low compliance locations. Location-based injury risk curves demonstrated greater accuracy in injury prediction. This study quantifies the importance of impact location on BABT injury severity and demonstrates the need for consideration of location in future armor design and assessment.

Bone bruise vs. non-displaced fracture on MRI: a novel grading system for predicting return-to-play.

OBJECTIVE: To devise an MRI grading scheme for osseous contusion patterns in elite hockey players for predicting return-to-play (RTP). METHODS: A retrospective review was performed to identify traumatic lower extremity osseous injuries in professional hockey players. A total of 28 injuries (17 players) were identified over a 10-year period. All had MRIs acquired at ≥ 1.5 T within a mean interval of 2 days from initial injury. MRIs were retrospectively reviewed by 3 musculoskeletal radiologists for osseous contusion pattern, classified as grade 1 (mild), 2 (moderate), or 3 (severe). Grade 3 contusions were further subdivided by the presence or absence of fracture, defined as discrete cortical disruption on MRI or follow-up CT. RTP was calculated from date of injury to next game played based on game log data. Statistical analysis was performed using ANOVA and post hoc unpaired t test. RESULTS: Mean RTP for grade 1, 2, and 3 injuries was 2.8, 4.5, and 20.3 days, respectively. Grade 3 injuries without and with cortical fractures had mean RTP of 18.3 and 21.4 days, respectively. ANOVA analysis between groups achieved statistical significance (p < 0.001). Post hoc t test demonstrated statistically significant differences between grade 3 and grades 1 (p < 0.001) and 2 (p < 0.001) injuries. There was no statistical difference in RTP between grade 3 subgroups without and with fracture (p = 0.327). CONCLUSION: We propose a novel MRI grading system for assessing severity of osseous contusions and predicting RTP. Clinically, there was no statistically significant difference in RTP between severe osseous contusions and nondisplaced fractures in elite hockey players.

Contusion expansion, low platelet count and bifrontal contusions are associated with worse patient outcome following traumatic brain injury-a retrospective single-center study.

BACKGROUND: Cortical contusions are common in moderate-severe traumatic brain injury (TBI). Cortical contusions often expand, potentially causing neuro-worsening several hours to days post-trauma. While contusion expansion (CE) may affect outcome, potential clinical and radiological markers that can predict CE have been insufficiently explored. In the present single-center retrospective observational cohort study, we evaluated clinical outcome by the Glasgow Outcome Scale extended (GOSE) scale and evaluated risk factor for CE. METHOD: Adult TBI patients > 18 years of age, and of all injury severities, were included. Main variables of interest were low platelet count, defined as < 150 × 109/L, presence of bifrontal contusions and CE, defined as absolute contusion volume increase in cm3. Factors associated with CE and clinical outcome according to GOSE were analyzed. RESULTS: Between 2012-2022, 272 patients were included. Contusion size on admission correlated positively with CE, as did the Marshall and Rotterdam radiological classification scores. Bifrontal contusions were significantly larger at admission, experienced larger CE, and had a worse outcome than contusions in other locations. Patients with a platelet count < 150 × 109/L experienced a greater volume CE and had a worse outcome when compared to patients with a normal platelet count. In a multivariate analysis, CE remained significantly associated with a poor outcome six months post- injury. CONCLUSION: Contusion volume at admission, Marshall CT classification and Rotterdam CT score, positively correlated to CE. Bifrontal contusions and a platelet count < 150 × 109/L were associated with CE, and a poor clinical outcome. Large CE volumes were associated with a worse clinical outcome, and CE was per se associated with outcome in a multivariate analysis. Management of these risk factors for CE in the acute post-injury setting may be needed to attenuate contusion expansion and to improve clinical outcome in TBI patients suffering from cortical contusion injuries.

Clinical presentation, imaging characteristics, and short-term outcome of eight cats presented with suspected traumatic atlantoaxial hyperflexion.

Traumatic atlantoaxial hyperflexion is considered rare in cats, and only a few case reports have been published. There are other conditions that can result in a peracute onset of neurological signs localized to the cervical spinal cord segments, including acute noncompressive nucleus pulposus extrusion, ischemic myelopathy, or vertebral fractures. Appropriate treatment for these conditions can only be initiated after an accurate diagnosis has been obtained. The aim of this observational, retrospective, single-center, descriptive case series study was to describe the clinical presentation, imaging characteristics, and short-term outcome of eight cats presented with suspected traumatic atlantoaxial hyperflexion. Young male healthy domestic shorthair cats were overrepresented (7/8) and typically presented with a peracute, nonprogressive, nonpainful, nonlateralizing C1-C5 myelopathy (tetraplegia or nonambulatory tetraparesis) following a road traffic accident or head trauma. All MRI studies demonstrated a solitary, focal, ill-defined intramedullary lesion immediately dorsal to the dens of the axis, affecting both grey and white matter. All cats were treated medically. In 50% of the cats, the neurological grade improved at discharge or short-term follow-up, 25% of the cats recovered completely, one cat was static at short-term follow-up, and one cat was euthanized due to persistent forebrain signs and lack of neurological improvement.

Significance of Contusion at the Vocal Cord and Perivocal Cord Area in Cases of Non-intubated Death.

Every finding during a neck autopsy may be essential for accurately diagnosing and explaining the mechanism of death. In this prospective study in the Department of Forensic Medicine and Toxicology of Jordan University Hospital, 17 out of 95 neck autopsies revealed contusions of the laryngeal mucosa in the vocal or perivocal area. These contusions were found to be associated with various causes of death, including mechanical asphyxia (such as throttling, ligature strangulation, hanging, smothering, choking, plastic bag asphyxia, gagging, and inhalation of blood) and other causes (such as atypical drowning, carbon monoxide poisoning, head injury due to a road traffic accident, burns, electrocution, and brain edema). This study provides insight into the mechanisms of this important lesion and may contribute to a better understanding of the cause of death.

Effects of Bosentan on Hypoxia, Inflammation and Oxidative Stress in Experimental Blunt Thoracic Trauma Model.

Background and Objectives: In this study, we aimed to investigate the effects of bosentan, an endothelin receptor antagonist, on endothelin-1 (ET-1), hypoxia-inducible factor-1 (HIF-1), nuclear factor-kappa B (NF-κB), and tumor necrosis factor (TNF)-α as inflammation markers, pro-oxidant antioxidant balance (PAB), and total antioxidant capacity (TAC) levels as oxidative stress parameters in lung tissues of rats in an experimental model of pulmonary contusion (PC) induced by blunt thoracic trauma. Materials and Methods: Thirty-seven male Sprague-Dawley rats were divided into five groups. C: The control group (n = 6) consisted of unprocessed and untreated rats. PC3 (n = 8) underwent 3 days of PC. PC-B3 (n = 8) received 100 mg/kg bosentan and was given orally once a day for 3 days. The PC7 group (n = 7) underwent 7 days of PC, and PC-B7 (n = 8) received 100 mg/kg bosentan and was given orally once a day for 7 days. Results: ET-1, NF-κB, TNF-α, HIF-1α, and PAB levels were higher, while TAC activity was lower in all groups compared with the control (p < 0.05). There was no significant difference in ET-1 and TNF-α levels between the PC-B3 and PC-B7 groups and the control group (p < 0.05), while NF-κB, HIF-1α, and PAB levels were still higher in both the PC-B3 and PC-B7 groups than in the control group. Bosentan decreased ET-1, NF-κB, TNF-α, HIF-1α, and PAB and increased TAC levels in comparison to the nontreated groups (p < 0.05). Conclusions: Bosentan decreased the severity of oxidative stress in the lungs and reduced the inflammatory reaction in rats with PC induced by blunt thoracic trauma. This suggests that bosentan may have protective effects on lung injury mechanisms by reducing hypoxia, inflammation, and oxidative stress. If supported by similar studies, bosentan can be used in both pulmonary and emergency clinics to reduce ischemic complications, inflammation, and oxidative stress in some diseases that may be accompanied by ischemia.

Neuroanatomical zones of human traumatic brain injury reveal significant differences in protein profile and protein oxidation: Implications for secondary injury events.

Traumatic brain injury (TBI) causes significant neurological deficits and long-term degenerative changes. Primary injury in TBI entails distinct neuroanatomical zones, i.e., contusion (Ct) and pericontusion (PC). Their dynamic expansion could contribute to unpredictable neurological deterioration in patients. Molecular characterization of these zones compared with away from contusion (AC) zone is invaluable for TBI management. Using proteomics-based approach, we were able to distinguish Ct, PC and AC zones in human TBI brains. Ct was associated with structural changes (blood-brain barrier (BBB) disruption, neuroinflammation, axonal injury, demyelination and ferroptosis), while PC was associated with initial events of secondary injury (glutamate excitotoxicity, glial activation, accumulation of cytoskeleton proteins, oxidative stress, endocytosis) and AC displayed mitochondrial dysfunction that could contribute to secondary injury events and trigger long-term degenerative changes. Phosphoproteome analysis in these zones revealed that certain differentially phosphorylated proteins synergistically contribute to the injury events along with the differentially expressed proteins. Non-synaptic mitochondria (ns-mito) was associated with relatively more differentially expressed proteins (DEPs) compared to synaptosomes (Syn), while the latter displayed increased protein oxidation including tryptophan (Trp) oxidation. Proteomic analysis of immunocaptured complex I (CI) from Syn revealed increased Trp oxidation in Ct > PC > AC (vs. control). Oxidized W272 in the ND1 subunit of CI, revealed local conformational changes in ND1 and the neighboring subunits, as indicated by molecular dynamics simulation (MDS). Taken together, neuroanatomical zones in TBI show distinct protein profile and protein oxidation representing different primary and secondary injury events with potential implications for TBI pathology and neurological status of the patients.

The Role of Tumor Necrosis Factor Following Spinal Cord Injury: A Systematic Review.

Pre-clinical studies place tumor necrosis factor (TNF) as a central player in the inflammatory response after spinal cord injury (SCI), and blocking its production and/or activity has been proposed as a possible treatment option after SCI. This systematic review provides an overview of the literature on the temporal and cellular expression of TNF after SCI and clarifies the potential for its therapeutic manipulation in SCI. A systematic search was performed in EMBASE (Ovid), MEDLINE (Ovid), and Web of Science (Core Collection). The search terms were the MeSH forms of tumor necrosis factor and spinal cord injury in the different databases, and the last search was performed on February 3, 2021. We found twenty-four articles examining the expression of TNF, with most using a thoracic contusive SCI model in rodents. Two articles described the expression of TNF receptors in the acute phase after SCI. Twenty-one articles described the manipulation of TNF signaling using genetic knock-out, pharmaceutical inhibition, or gain-of-function approaches. Overall, TNF expression increased rapidly after SCI, within the first hours, in resident cells (neurons, astrocytes, oligodendrocytes, and microglia) and again in macrophages in the chronic phase after injury. The review underscores the complexity of TNF's role after SCI and indicates that TNF inhibition is a promising therapeutic option. This review concludes that TNF plays a significant role in the inflammatory response after SCI and suggests that targeting TNF signaling is a feasible therapeutic approach.

Kinin receptors regulate skeletal muscle regeneration: differential effects for B1 and B2 receptors.

OBJECTIVE AND DESIGN: After traumatic skeletal muscle injury, muscle healing is often incomplete and produces extensive fibrosis. Bradykinin (BK) reduces fibrosis in renal and cardiac damage models through the B2 receptor. The B1 receptor expression is induced by damage, and blocking of the kallikrein-kinin system seems to affect the progression of muscular dystrophy. We hypothesized that both kinin B1 and B2 receptors could play a differential role after traumatic muscle injury, and the lack of the B1 receptor could produce more cellular and molecular substrates for myogenesis and fewer substrates for fibrosis, leading to better muscle healing. MATERIAL AND METHODS: To test this hypothesis, tibialis anterior muscles of kinin receptor knockout animals were subjected to traumatic injury. Myogenesis, angiogenesis, fibrosis, and muscle functioning were evaluated. RESULTS: Injured B1KO mice showed a faster healing progression of the injured area with a larger amount of central nucleated fiber post-injury when compared to control mice. In addition, they exhibited higher neovasculogenic capacity, maintaining optimal tissue perfusion for the post-injury phase; had higher amounts of myogenic markers with less inflammatory infiltrate and tissue destruction. This was followed by higher amounts of SMAD7 and lower amounts of p-SMAD2/3, which resulted in less fibrosis. In contrast, B2KO and B1B2KO mice showed more severe tissue destruction and excessive fibrosis. B1KO animals had better results in post-injury functional tests compared to control animals. CONCLUSIONS: We demonstrate that injured skeletal muscle tissues have a better repair capacity with less fibrosis in the presence of B2 receptor and absence of B1 receptor, including better performances in functional tests.

Detection of multiple biomarkers associated with satellite cell fate in the contused skeletal muscle of rats for wound age estimation.

From the perspective of forensic wound age estimation, experiments related to skeletal muscle regeneration after injury have rarely been reported. Here, we examined the time-dependent expression patterns of multiple biomarkers associated with satellite cell fate, including the transcription factor paired box 7 (Pax7), myoblast determination protein (MyoD), myogenin, and insulin-like growth factor (IGF-1), using immunohistochemistry, western blotting, and quantitative real-time PCR in contused skeletal muscle. An animal model of skeletal muscle contusion was established in 30 Sprague-Dawley male rats, and another five rats were employed as non-contused controls. Morphometrically, the data obtained from the numbers of Pax7 + , MyoD + , and myogenin + cells were highly correlated with the wound age. Pax7, MyoD, myogenin, and IGF-1 expression patterns were upregulated after injury at both the mRNA and protein levels. Pax7, MyoD, and myogenin protein expression levels confirmed the results of the morphometrical analysis. Additionally, the relative quantity of IGF-1 protein > 0.92 suggested a wound age of 3 to 7 days. The relative quantity of Pax7 mRNA > 2.44 also suggested a wound age of 3 to 7 days. Relative quantities of Myod1, Myog, and Igf1 mRNA expression > 2.78, > 7.80, or > 3.13, respectively, indicated a wound age of approximately 3 days. In conclusion, the expression levels of Pax7, MyoD, myogenin, and IGF-1 were upregulated in a time-dependent manner during skeletal muscle wound healing, suggesting the potential for using them as candidate biomarkers for wound age estimation in skeletal muscle.

Prognostic significance of prolonged corrected QT interval in cerebral contusion.

Background & objectives: Cerebral contusion (CC) results in a release of catecholamines, autonomic dysfunction and neural stimulation that can lead to a number of cardiac adverse events, so it is critical to determine these. So the objective of this study was to investigate the prognostic significance of electrocardiographic changes, particularly the effects of a prolonged corrected QT (QTc) interval in CC. Methods: In this retrospective cohort study, 110 patients with CC were evaluated. Age, sex, concomitant diseases, Glasgow Coma Scale on admission, radiological assessment of the contusion (location, size, course and presence of cerebral oedema), need for surgical intervention, length of hospital stay and the extended Glasgow Outcome Scale (GOS-E) were statistically analysed within the QTc interval by routine electrocardiography (ECG) on admission. Results: The prolonged QTc interval was found to be associated with a higher incidence of cerebral oedema and a significantly higher risk of needing surgery. Patients with a prolonged QTc interval had a significantly larger contusion volume, greater midline shift and longer hospital stay, so their GOS-E score was significantly lower. A prolonged QTc interval on admission resulted in a hospital stay of more than eight days (sensitivity: 0.97 and specificity: 0.86), a higher risk of midline shift of more than 0.45 cm (P=0.006, sensitivity: 0.80 and specificity: 0.99) and a GOS-E score of <7 (sensitivity: 0.97 and specificity: 0.85). Interpretation & conclusions: ECG changes on admission showing a prolonged QTc interval have prognostic significance in CC. This simple and easily applicable information should be taken into consideration at the time of clinical decision making which may prevent an adverse events survivor.

Early surgery versus conservative treatment in patients with traumatic intracerebral hematoma: a CENTER-TBI study.

PURPOSE: Evidence regarding the effect of surgery in traumatic intracerebral hematoma (t-ICH) is limited and relies on the STITCH(Trauma) trial. This study is aimed at comparing the effectiveness of early surgery to conservative treatment in patients with a t-ICH. METHODS: In a prospective cohort, we included patients with a large t-ICH (< 48 h of injury). Primary outcome was the Glasgow Outcome Scale Extended (GOSE) at 6 months, analyzed with multivariable proportional odds logistic regression. Subgroups included injury severity and isolated vs. non-isolated t-ICH. RESULTS: A total of 367 patients with a large t-ICH were included, of whom 160 received early surgery and 207 received conservative treatment. Patients receiving early surgery were younger (median age 54 vs. 58 years) and more severely injured (median Glasgow Coma Scale 7 vs. 10) compared to those treated conservatively. In the overall cohort, early surgery was not associated with better functional outcome (adjusted odds ratio (AOR) 1.1, (95% CI, 0.6-1.7)) compared to conservative treatment. Early surgery was associated with better outcome for patients with moderate TBI and isolated t-ICH (AOR 1.5 (95% CI, 1.1-2.0); P value for interaction 0.71, and AOR 1.8 (95% CI, 1.3-2.5); P value for interaction 0.004). Conversely, in mild TBI and those with a smaller t-ICH (< 33 cc), conservative treatment was associated with better outcome (AOR 0.6 (95% CI, 0.4-0.9); P value for interaction 0.71, and AOR 0.8 (95% CI, 0.5-1.0); P value for interaction 0.32). CONCLUSIONS: Early surgery in t-ICH might benefit those with moderate TBI and isolated t-ICH, comparable with results of the STITCH(Trauma) trial.

Association Between Monocyte-to-Lymphocyte Ratio and Hematoma Progression After Cerebral Contusion.

BACKGROUND: The objective of this research was to examine the impact of the monocyte-to-lymphocyte ratio (MLR) on the advancement of hematoma after cerebral contusion. METHODS: The clinical information and laboratory test findings of people with cerebral contusion were retrospectively analyzed. Using the tertiles of MLR, the study participants were categorized into three groups, enabling the evaluation of the correlation between MLR and the advancement of hematoma after cerebral contusion. RESULTS: Among the cohort of patients showing progression, MLR levels were significantly higher compared with the nonprogress group (P < 0.001). The high MLR group had a significantly higher proportion of patients with hematoma progression compared with the medium and low MLR groups. However, the medium MLR group had a lower proportion of patients with hematoma progression compared with the low MLR group. High MLR levels were independently linked to a higher risk of hematoma progression (Odds Ratio 3.546, 95% Confidence Interval 1.187-10.597, P = 0.024). By incorporating factors such as Glasgow Coma Scale score on admission, anticoagulant/antiplatelet therapy, white blood cell count, and MLR into the model, the predictive performance of the model significantly improved (area under the curve 0.754). CONCLUSIONS: Our study suggests that MLR may serve as a potential indicator for predicting the progression of hematoma after cerebral contusion. Further research is necessary to investigate the underlying pathological and physiological mechanisms that contribute to the association between MLR and the progression of hematoma after cerebral contusion and to explore its clinical implications.

Risk factors and outcomes in pediatric blunt cardiac injuries.

PURPOSE: Unlike adults, less is known of the etiology and risk factors for blunt cardiac injury (BCI) in children. Identifying risk factors for BCI in pediatric patients will allow for more specific screening practices following blunt trauma. METHODS: A retrospective review was performed using the Trauma Quality Improvement Program (TQIP) database from 2017 to 2019. All patients ≤ 16 years injured following blunt trauma were included. Demographics, mechanism, associated injuries, injury severity, and outcomes were collected. Univariate and multivariate regression was used to determine specific risk factors for BCI. RESULTS: Of 266,045 pediatric patients included in the analysis, the incidence of BCI was less than 0.2%. The all-cause mortality seen in patients with BCI was 26%. Motor-vehicle collisions (MVCs) were the most common mechanism, although no association with seatbelt use was seen in adolescents (p = 0.158). The strongest independent risk factors for BCI were pulmonary contusions (OR 15.4, p < 0.001) and hemothorax (OR 8.9, p < 0.001). CONCLUSIONS: Following trauma, the presence of pulmonary contusions or hemothorax should trigger additional screening investigations specific for BCI in pediatric patients.

Pulmonary contusion: automated deep learning-based quantitative visualization.

PURPOSE: Rapid automated CT volumetry of pulmonary contusion may predict progression to Acute Respiratory Distress Syndrome (ARDS) and help guide early clinical management in at-risk trauma patients. This study aims to train and validate state-of-the-art deep learning models to quantify pulmonary contusion as a percentage of total lung volume (Lung Contusion Index, or auto-LCI) and assess the relationship between auto-LCI and relevant clinical outcomes. METHODS: 302 adult patients (age ≥ 18) with pulmonary contusion were retrospectively identified from reports between 2016 and 2021. nnU-Net was trained on manual contusion and whole-lung segmentations. Point-of-care candidate variables for multivariate regression included oxygen saturation, heart rate, and systolic blood pressure on admission. Logistic regression was used to assess ARDS risk, and Cox proportional hazards models were used to determine differences in ICU length of stay and mechanical ventilation time. RESULTS: Mean Volume Similarity Index and mean Dice scores were 0.82 and 0.67. Interclass correlation coefficient and Pearson r between ground-truth and predicted volumes were 0.90 and 0.91. 38 (14%) patients developed ARDS. In bivariate analysis, auto-LCI was associated with ARDS (p < 0.001), ICU admission (p < 0.001), and need for mechanical ventilation (p < 0.001). In multivariate analyses, auto-LCI was associated with ARDS (p = 0.04), longer length of stay in the ICU (p = 0.02) and longer time on mechanical ventilation (p = 0.04). AUC of multivariate regression to predict ARDS using auto-LCI and clinical variables was 0.70 while AUC using auto-LCI alone was 0.68. CONCLUSION: Increasing auto-LCI values corresponded with increased risk of ARDS, longer ICU admissions, and longer periods of mechanical ventilation.

Composite Fibrin/Carbon Microfiber Implants for Bridging Spinal Cord Injury: A Translational Approach in Pigs.

Biomaterials may enhance neural repair after spinal cord injury (SCI) and testing their functionality in large animals is essential to achieve successful clinical translation. This work developed a porcine contusion/compression SCI model to investigate the consequences of myelotomy and implantation of fibrin gel containing biofunctionalized carbon microfibers (MFs). Fourteen pigs were distributed in SCI, SCI/myelotomy, and SCI/myelotomy/implant groups. An automated device was used for SCI. A dorsal myelotomy was performed on the lesion site at 1 day post-injury for removing cloths and devitalized tissue. Bundles of MFs coated with a conducting polymer and cell adhesion molecules were embedded in fibrin gel and used to bridge the spinal cord cavity. Reproducible lesions of about 1 cm in length were obtained. Myelotomy and lesion debridement caused no further neural damage compared to SCI alone but had little positive effect on neural regrowth. The MFs/fibrin gel implant facilitated axonal sprouting, elongation, and alignment within the lesion. However, the implant also increased lesion volume and was ineffective in preventing fibrosis, thus precluding functional neural regeneration. Our results indicate that myelotomy and lesion debridement can be advantageously used for implanting MF-based scaffolds. However, the implants need refinement and pharmaceuticals will be necessary to limit scarring.

Diagnostic value of the lateral femoral notch sign and kissing contusion in patients with anterior cruciate ligament injuries: a case-control study.

INTRODUCTION: The lateral femoral notch sign (LFNS) and the kissing contusion (KC) are two indirect signs of anterior cruciate ligament (ACL) injuries. They can be used to diagnose ACL injuries. MATERIALS AND METHODS: A total of 1000 patients were enrolled in this study, including 500 patients with ACL injuries who assigned to experimental group and 500 patients with meniscal tear (MT) who allocated to control group. All the patients underwent magnetic resonance imaging (MRI) preoperatively, and the diagnosis was confirmed with the aid of arthroscopy. The depth of LFNS and the presence of KC were determined on MRI findings. The relationship and characteristics between these two indicators was explored. RESULTS: The notch depth of lateral femoral condyle in the experimental group (0.99 ± 0.56 mm) was significantly greater than that in the control group (0.49 ± 0.28 mm) (P < 0.05). The positive rate of KC in the experimental group (183/500) was markedly higher than that in the control group (3/500) (P < 0.05). The values of notch depth in patients who had ACL rupture concomitant lateral MT injuries and medial collateral ligament (MCL) injuries were 1.12 ± 0.64 and 1.23 ± 0.74 mm, respectively, which were significantly higher than those in patients with only ACL injury (0.89 ± 0.49 mm) (P < 0.05). It also was revealed that when the optimal cut-off point of LFNS was 0.72 mm (area under the curve (AUC) = 81%), the values of specificity and sensitivity were 67% and 84%, respectively. For KC, the corresponding values were 36.6% and 99.4%, respectively. The diagnostic outcome of LFNS was not in agreement with that of KC, as there was a poor coincidence according to the Kappa coefficient (Kappa = 0.155 < 0.4, P = 0.035). CONCLUSION: The LFNS and KC have strong clinical significance in the diagnosis of ACL injuries. A deeper notch often indicates a more complex knee injury. Notch depth equal to 0.72 mm can be basically considered as the optimal cut-off point for LFNS in statistics.