Firearms-related skeletal muscle trauma: pathophysiology and novel approaches for regeneration

Low-velocity nail penetration response of muscle tissue and gelatin

Quantitative estimation of soft tissue injuries due to penetration of sharp objects is a challenging task for forensic pathologists. The severity of injury depends on the force required to penetrate the tissue. This study focuses on investigating the amount of force required to penetrate porcine muscle tissue and gelatin simulants (10 % wt) to mimic human muscle tissue when subjected to sharp objects like nail at velocities below 5 m/s. A custom-made experimental setup was used to examine the influence of penetration velocity and nail diameter on penetration forces. Images captured by a high-speed camera were used to track the position and velocity of the nail. A finite element (FE) model was established to simulate the penetration behavior of the tissue and gelatin. The FE simulations of the nail penetration were validated through direct comparison with the experimental results. In tissues as well as in the simulant, penetration forces were seen to increase with increasing nail diameter and velocity. Porcine muscle tissue showed 23.9-46.5 % higher penetration forces than gelatin simulants (10 % wt) depending on nail diameter and velocity; the difference being higher for higher nail diameter and velocity. The ranges of maximum penetration forces measured were 8.6-59.1 N for porcine muscle tissue and 6.8-34.9 N for gelatin simulant. This study helps to quantify injuries caused by sharp nails at low velocities and offers insights with potential applications in injury management strategies and forensic studies.

Low energy gunshot injuries: Does removal of retained bullet fragmentation at the time of internal fixation reduce the risk of fracture related infection?

OBJECTIVE

To examine the effects of RBF (Retained Bullet Fragment) removal at the time of long bone fixation on FRI (fracture related infection) rates in low energy GSI (Gunshot Injury) related fractures.

DESIGN

Retrospective Cohort Study SETTING: Level 1 Academic Trauma Center INTERVENTION: Retrospective review of the impact of RBFs on the risk of FRI when employing internal fixation in low energy GSI (Gunshot Injury) related fractures. In situations where the injury pattern requires surgical fixation, the question arises as to whether or not the RBFs need to be removed to prevent FRI.

MAIN OUTCOME MEASURES

Whether or not the RBFs removed in our patient population prevented short- and long-term fracture related infection after low-energy gunshot injury (FRI-LGI).

RESULTS

Of the 2,136 GSI related fractures, 131 patients met inclusion criteria, 81 patients underwent removal (R) of RBFs at the time of internal fixation while 50 patients did not undergo any removal (NR) at time of internal fixation. Among the patients who underwent surgical intervention, (Open Reduction Internal Fixation) ORIF was performed in 55 cases (R: 39; NR: 16), and (Intramedullary Nail) IMN was performed in 76 cases (R: 42; NR: 34). The overall rate of deep FRI-LGI was 6.9 % of the 131-patient cohort. We found that removal of RBFs had a statistically significant impact on the rate of deep FRI-LGI when compared to the NR group (p = 0.031). In the RBF removal group, only two patients (2.4 %) developed deep FRI-LGIs, whereas in the NR group, seven patients (14.0 %) developed deep FRI-LGIs. The incidence of early FRI-LGI was higher in the NR group (median 0.6 months) compared to the R group, which was associated with late FRI-LGIs (median 10.1 months) when they occurred.

DISCUSSION

In our study population, we found a statistically significantly increased incidence of deep and early FRI-LGI when RBFs are not removed at the time of extra-articular long bone internal fixation. The presence of retained bullet fragments following internal fixation may pose a risk factor for future development of deep FRI-LGI. We believe a surgeon should use their best judgment as to whether a RBF can safely be removed at the time of long bone fixation. Based on our findings, if safely permitted, RBF removal should be considered at the time of GSI long bone fixation resulting from low energy hand gun injuries.

Skeletal muscle regeneration after extensive cryoinjury of caudal myomeres in adult zebrafish

Skeletal muscles can regenerate after minor injuries, but severe structural damage often leads to fibrosis in mammals. Whether adult zebrafish possess the capacity to reproduce profoundly destroyed musculature remains unknown. Here, a new cryoinjury model revealed that several myomeres efficiently regenerated within one month after wounding the zebrafish caudal peduncle. Wound clearance involved accumulation of the selective autophagy receptor p62, an immune response and Collagen XII deposition. New muscle formation was associated with proliferation of Pax7 expressing muscle stem cells, which gave rise to MyoD1 positive myogenic precursors, followed by myofiber differentiation. Monitoring of slow and fast muscles revealed their coordinated replacement in the superficial and profound compartments of the myomere. However, the final boundary between the muscular components was imperfectly recapitulated, allowing myofibers of different identities to intermingle. The replacement of connective with sarcomeric tissues required TOR signaling, as rapamycin treatment impaired new muscle formation, leading to persistent fibrosis. The model of zebrafish myomere restoration may provide new medical perspectives for treatment of traumatic injuries.

Peculiarities of treatment of maxillofacial polytrauma during wartime

OBJECTIVE

Aim: Analyzing of the last-time papers in this subject in organizing, diagnostic and surgery tactic is the aim of this work.

PATIENTS AND METHODS

Materials and Methods: The study analyzed the experience of treating patients with maxillofacial polytrauma before and after February 24, 2022. Research methods: bibliographic, systematic, comparative, general clinical, radiological and retrospective analysis.

CONCLUSION

Conclusions: Tactic of the multidisciplinal team should based on the principles of damage control, which involves the initial performance of manipulations and surgical interventions that ensure the patient's survival. Modern strategies for infusion-transfusion therapy play a significant role in severe trauma cases. Choosing the rational management of this therapy for severe trauma remains an important issue. Reconstructive surgeries are recommended to be performer deferred, after surgical wound management, neurosurgical interventions and stabilization of the patient common status. Patients with maxillofacial polytrauma needs in specialized medical care at all the levels. Active wound management aimed at creating favorable conditions for healing, comprehensive medical treatment, prevention, early detection and timely treatment of complications.

Effects and mechanisms of extremely cold environment on body response after trauma

With the outbreak of the Ukrainian crisis, extremely cold environment warfare has once again become the focus of international attention. People exposed to extremely cold environments may suffer from cold damage, further aggravate trauma, trigger high disability and mortality rates, and even cause serious sequelae. To declare the effects and mechanisms of the extremely cold environment on the body after trauma, this paper reviews, firstly, physiological reaction of human body in an extremely cold environment. Then, the post-traumatic body response in an extremely cold environment was introduced, and finally, the sequelae of trauma in extremely cold environment was further summarized in the paper. The results indicated that extremely cold environment can cause a series of damage to the body, especially the body after trauma. The extremely cold factor is a double-edged sword, showing a favorable and unfavorable side in different aspects. Moreover, in addition to the trauma suffered by the body, the subsequent sequelae such as cognitive dysfunction, anxiety, depression and even post-traumatic stress disorder may also be induced. The paper summarizes the human body's physiological response in an extremely cold environment, and declares the effects and mechanisms of the extremely cold environment on the body after trauma, which may provide a theoretical basis for effectively improving the level of combat trauma treatment in extremely cold regions.

Gunshot Wounds: Ballistics, Pathology, and Treatment Recommendations, with a Focus on Retained Bullets

As the epidemic of gunshot injuries and firearm fatalities continues to proliferate in the United States, knowledge regarding gunshot wound (GSW) injury and management is increasingly relevant to health-care providers. Unfortunately, existing guidelines are largely outdated, written in a time that high-velocity weapons and deforming bullets were chiefly restricted to military use. Advances in firearm technology and increased accessibility of military grade firearms to civilians has exacerbated the nature of domestic GSW injury and complicated clinical decision-making, as these weapons are associated with increased tissue damage and often result in retained bullets. Currently, there is a lack of literature addressing recent advances in the field of projectile-related trauma, specifically injuries with retained bullets. This review aims to aggregate the available yet dispersed findings regarding ballistics, GSW etiology, and treatment, particularly for cases involving retained projectiles.

Key concepts in muscle regeneration: muscle "cellular ecology" integrates a gestalt of cellular cross-talk, motility, and activity to remodel structure and restore function

This review identifies some key concepts of muscle regeneration, viewed from perspectives of classical and modern research. Early insights noted the pattern and sequence of regeneration across species was similar, regardless of the type of injury, and differed from epimorphic limb regeneration. While potential benefits of exercise for tissue repair was debated, regeneration was not presumed to deliver functional restoration, especially after ischemia-reperfusion injury; muscle could develop fibrosis and ectopic bone and fat. Standard protocols and tools were identified as necessary for tracking injury and outcomes. Current concepts vastly extend early insights. Myogenic regeneration occurs within the environment of muscle tissue. Intercellular cross-talk generates an interactive system of cellular networks that with the extracellular matrix and local, regional, and systemic influences, forms the larger gestalt of the satellite cell niche. Regenerative potential and adaptive plasticity are overlain by epigenetically regionalized responsiveness and contributions by myogenic, endothelial, and fibroadipogenic progenitors and inflammatory and metabolic processes. Muscle architecture is a living portrait of functional regulatory hierarchies, while cellular dynamics, physical activity, and muscle-tendon-bone biomechanics arbitrate regeneration. The scope of ongoing research-from molecules and exosomes to morphology and physiology-reveals compelling new concepts in muscle regeneration that will guide future discoveries for use in application to fitness, rehabilitation, and disease prevention and treatment.

Fatal and nonfatal firearm injuries in the eastern Democratic Republic of Congo: a hospital-based retrospective descriptive cohort study assessing correlates of adult mortality

Introduction

The Eastern Democratic Republic of Congo (DRC) has been the battleground for multiple armed conflicts, resulting in many fatal and nonfatal firearm injuries (F&NFFIs). Chronic insecurity has stressed the health system’s resources and created barriers to seeking, reaching, and receiving timely care further increasing the F&NFFI burden. Our institution is the largest trauma center in the region and receives the bulk of F&NFFI cases. We aimed to identify correlates of mortality in Congolese F&NFFI patients.

Methods

We included all F&NFFI patients admitted to our institution between 2017 and 2020. We extracted data from patient charts and admission logs. We identified mortality correlates using the two-sample t-test, Chi-square test, and multivariable regression analysis. A P-value of less than 0.05 was considered statistically significant.

Results

This study included 814 adult patients, mostly male (86%) with an average age of 34.5 years and living 154.4 km away from the hospital on average. The most affected anatomical sites were the lower limbs (48.2%) and upper limbs (23.2%). The median length of stay was 34.0 days, and the in-hospital mortality rate was 3.6%. In addition, mortality was negatively correlated with diastolic blood pressure (P = 0.01), SaO₂ (P < 0.001), and hemoglobin concentration (P = 0.002).

Conclusion

F&NFFIs cause an enormous burden in the region, and mortality is correlated with some clinical and biological variables. Thus, the study findings will inform F&NFFI referral, triage, and management in low-resource and mass casualty settings.

How COVID-19 highlighted the need for infection prevention and control measures to become central to the global conversation: experience from the conflict settings of the Middle East

Within just a few months, the coronavirus disease 2019 (COVID-19) pandemic managed to bring to the foreground the conversation that infection prevention and control (IPC) experts have been pushing for decades regarding the control of the spread of infections. Implementing the basics of IPC has been a challenge for all affected countries battling with an exponential COVID-19 curve of infection. Preventing nosocomial transmission of the disease has been difficult in highly resourced and stable contexts, but even more so in the conflict context of the Middle East. COVID-19 has added further challenges to the long list of existing ones, hindering the implementation of the optimal IPC measures that are necessary to break the chain of infection of both respiratory and non-respiratory infections in those settings. This paper outlines and gives examples of the challenges faced across the Middle East conflict setting and serves as a call for action for IPC to be prioritized, given the resources needed, and fed with contextualized evidence.