Wound ballistics of firearm-related injuries--part 1: missile characteristics and mechanisms of soft tissue wounding

Two Bullet Wounds, One Bullet: The Atypical Fragmentation of a .223 Caliber Ammunition

ABSTRACT

As the fifth leading cause of death in individuals aged 1 to 64 years in the United States, forensic pathologists frequently encounter firearm-related deaths and are trained to approach these cases by utilizing information from the investigation, radiographs, and autopsy findings to discern the logical sequence of events that lead to death. We also emphasize the importance and utility of various factors such as bullet wound characteristics, type of ammunition used, and type of tissues involved in a forensic pathologist's determination of events and in medicolegal investigations. However, the unusual presentations of firearm-related deaths can cause confusion and even frustration when there are contradicting circumstances or findings at work. We present the case of a 61-year-old woman with an atypical pattern of 2 distinct irregular entrance gunshot wounds determined to be caused by a single projectile.

Gunshot Injury to the Face With Atypical Non-linear Bullet Trajectory: A Case Report

The disruptive effect of firearm missiles on body tissues depends on many factors. However, it mainly relates to the bullet's physical and dynamic properties and tissue-related factors. We encountered an unusual case of a gunshot injury wherein the bullet traversed the neck with an upward and non-linear trajectory with an exit from the contralateral side of the neck without damaging any vital neck organs. A 26-year-old male presented with a gunshot wound to the chin from close range. A bullet entry hole was observed on the right side of the chin, encircled by the abrasion collar, with tattoo marks around the area. The patient was conscious, with normal vital signs and no injury to the cranial nerves or aerodigestive tract. The CT imaging of the patient revealed the injury tract traversing through the muscles of the floor of the mouth to involve the left carotid and left parapharyngeal space, along with the left sternocleidomastoid muscle, with an exit hole below the left mastoid in the posterior triangle of the neck. A bullet usually travels through the body in a straight line or pathway; however, its non-linear trajectories depend on the projectile's dynamics and its interaction with the body tissues. The present case emphasizes understanding wound ballistics to know the erratic bullet trajectories in the victim's body and their interpretation, irrespective of their entry site.

Surface wave analysis of the skin for penetrating and non-penetrating projectile impact in porcine legs

Secondary blast injuries may result from high-velocity projectile fragments which ultimately increase medical costs, reduce active work time, and decrease quality of life. The role of skin penetration requires more investigation in energy absorption and surface mechanics for implementation in computational ballistic models. High-speed ballistic penetration studies have not considered penetrating and non-penetrating biomechanical properties of the skin, including radial wave displacement, resultant surface wave speed, or projectile material influence. A helium-pressurized launcher was used to accelerate 3/8″ (9.525 mm) diameter spherical projectiles toward seventeen whole porcine legs from seven pigs (39.53 ± 7.28 kg) at projectile velocities below and above V₅₀. Projectiles included a mix of materials: stainless steel (n = 26), Si₃N₄ (n = 24), and acetal plastic (n = 24). Tracker video analysis software was used to determine projectile velocity at impact from the perpendicular view and motion of the tissue displacement wave from the in-line view. Average radial wave displacement and surface wave speed were calculated for each projectile material and categorized by penetrating or non-penetrating impacts. Two-sample t-tests determined that non-penetrating projectiles resulted in significantly faster surface wave speeds in porcine skin for stainless steel (p = 0.002), plastic (p = 0.004), and Si₃N₄ ball bearings (p = 0.014), while ANOVA determined significant differences in radial wave displacement and surface wave speed between projectile materials. Surface wave speed was used to quantify mechanical properties of the skin including elastic modulus, shear modulus, and bulk modulus during ballistic impact, which may be implemented to simulate accurate deformation behavior in computational impact models.

Pathophysiology, Classification and Comorbidities after Traumatic Spinal Cord Injury

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a spinal cord injury (SCI), supraspinal influences on the spinal segmental control system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, pain and dysesthesia, sympathetic blunting and parasympathetic dominance resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of traumatic SCI, current and emerging methods of classification, and its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue.

Management of Maxillofacial Gunshot Injuries With Emphasis on Damage Control Surgery During the Yemen Civil War. Review of 173 Victims From a Level 1 Trauma Hospital in Najran, Kingdom of Saudi Arabia

Study Design

Studies on the concept of Damage Control Surgery (DCS) in the management of firearm injuries to the oral and maxillofacial region are still scarce, hence the basis for the current study.

Objectives

The objectives of the current study is to share our experience in the management of maxillofacial gunshot injuries with emphasis on DCS and early definitive surgery.

Methods

This was a retrospective study of combatant Yemeni patients with maxillofacial injuries who were transferred across the border from Yemen to Najran, Kingdom of Saudi Arabia. Demographics and etiology of injuries were stored. Paths of entry and exit of the projectiles were also noted. Also recorded were types of gunshot injury and treatment protocols adopted. Data was stored and analyzed using IBM SPSS Statistics for Windows Version 25 (Armonk, NY: IBM Corp).

Results

A total of 408 victims, all males, were seen during the study period with 173 (42.4%) males sustaining gunshot injuries to the maxillofacial region. Their ages ranged from 21 to 56 years with mean ± SD (27.5 ± 7.6) years. One hundred and twenty-one (70.0%) victims had extraoral bullet entry, while 53 (30.0%) victims had intraoral entry route. Ocular injuries, consisting of 25 (14.5%) cases of ruptured globe and 6 (3.5%) cases of corneal injuries, were the most commonly associated injuries. A total of 78 (45.1%) hemodynamically unstable victims had DCS as the adopted treatment protocol while early definitive surgery was carried out in 47(27.2%) hemodynamically stable victims. ORIF was the treatment modality used for the fractures in 132 (76.3%) of the victims.

Conclusions

We observed that 42.4% of the war victims sustained gunshot injuries. DCS with ORIF was the main treatment protocol adopted in the management of the hemodynamically unstable patients.

Management of Civilian Low-Velocity Gunshot Injuries to an Extremity

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Despite an increasing rate of civilian low-velocity gunshot injuries, there remains a lack of evidence-based treatment standards.

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Most low-velocity gunshot-induced fractures of the extremity can be managed similarly to non-gunshot-induced fractures, with the goals of restoring function and minimizing complications.

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There are a limited number of high-quality studies to support the use of prophylactic antibiotics for nonoperatively treated gunshot wounds.

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Intra-articular retained bullets should be removed, while prophylactic irrigation and debridement for a transarticular bullet is not routinely warranted for infection prevention.

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Much of the literature on low-velocity gunshot wounds is Level-III or IV evidence, warranting the need for higher-powered, randomized, prospective investigations.

Gunshot wounds to the penis and scrotum: a narrative review of management in civilian and military settings

Gunshot wounds (GSW) to the penis and scrotum are present in two thirds of all genitourinary (GU) trauma, with a growing proportion of blast injuries in the military setting. Depending on the energy of the projectile, the injury patterns present differently for military and civilian GSWs. In this review, we sought to provide a detailed overview of GSWs to the external genitalia, from mechanisms to management. We examine how ballistic injury impacts tissues, as well as the types of injuries that occur, and how to assess these injuries to the external genitalia. If there is concern for injury to the deep structures of the penis or scrotum, operative exploration and repair is warranted. Relevant history and physical examination, role of imaging, and choice of conservative or surgical treatment options in the civilian and military setting are discussed, as well as guidelines for management set forth by the American Urological Association (AUA) and European Association of Urology (EAU).

The G2 research R.I.P. fragmenting bullet-radiographic features of a recently encountered projectile

Gunshot wounds (GSWs) are an important cause of disability and death in the USA. Although radiography is limited in its ability to detect bullet types, a projectile introduced during the last decade, the R.I.P. bullet by G2 Research, consists of a base slug connected to 6 to 8 sharp trocars designed to diverge within soft tissue following impact, resulting in what we believe to be a unique imaging appearance that can be confusing to those not familiar with this particular projectile. Furthermore, this bullet is 100% copper, which may allow for safe imaging with magnetic resonance imaging if correctly identified prior to scanning.

Mandibular traumas by gunshot. A systematic review with meta-analysis and algorithm of treatment

The treatment of mandibular fractures by gunshot ranges from late conservative repair to more aggressive early repair in a single stage. Treatments that preserve bony architecture as much as possible should be used, minimising patient morbidity and the complexity of future surgeries. The purpose of this study was to use a systematic review to determine which method of treatment was most effective for mandibular fractures by gunshot. Searches were conducted on Medline via PubMed, Scopus, Central Cochrane, and Sigle via Open Grey up to August 2019. Four studies were eligible to this systematic review, considering the previously establish inclusion and exclusion criteria. A total of 211 patients were evaluated. The mandibular body was the region more fractured followed by the symphyseal/parasymphyseal region. The closed treatment with intermaxillary fixation (IMF) was the most used followed by open surgery with internal rigid fixation (IRF) and external fixator. Considering the total adverse effects, the meta-analysis showed no statistically significant difference between the IMF and IRF groups (p=0.840), but IMF showed five times less infection and IRF six times less malunion. The algorithm was delineated from the types of injuries by gunshot, proposing forms of treatment from initial stabilisation to functional rehabilitation with implant-supported prostheses. The treatment of mandibular fractures by gunshot remains a challenge for surgeons. There was a statistically significant prevalence of success in the IRF group, however this group was also associated with a higher index of infection than the IMF group. New studies with high methodological quality and larger numbers of participants are needed to offer more safety for surgeons who treat patients with mandibular fractures by gunshot.

Unleaded hunting: Are copper bullets and lead-based bullets equally effective for killing big game?

Semi-jacketed lead-cored or copper-based homogenous rifle bullets are commonly used for hunting big game. Ever since their introduction in the 1990's, copper-based bullets have not been widely accepted by hunters due to limited supply, higher expense, and the perception that they exhibit inferior killing efficiency and correspondingly higher wounding rates. Here, we present data showing that animal flight distances for roe deer, red deer, brown bear, and moose dispatched with lead- or copper-based hunting bullets did not significantly differ from an animal welfare standardized animal flight distance based on body mass. Lead-cored bullets typical fragment on impact, whereas copper-based bullets retain more mass and expand more than their leaden counterparts. Our data demonstrate that the relative killing efficiency of lead and copper bullets is similar in terms of animal flight distance after fatal shots. Hunters that traditionally use lead bullets should consider switching to copper bullets to enhance human and environmental health.

[Update on gunshot wounds to extremities]

Due to recent rampage and terror attacks in Europe, gunshot wounds have become a focus of attention even though they are still rare in Europe. Approximately 50% of gunshot wounds affect the extremities and to understand the sequelae, a basic knowledge of wound ballistics is indispensable. The energy transmitted from the bullet to the tissue is responsible for the severity of the injury and is dependent on the type of weapon and ammunition. A differentiation is made between low-energy injuries caused, e.g. by pistols and high-energy injuries mostly caused by rifles. The higher energy transfer to the tissue in high-energy injuries, results in a temporary wound cavity in addition to the permanent wound channel with extensive soft tissue damage. High-energy gunshot fractures are also more extensive compared to those of low energy injuries. Debridement seems to be necessary for almost all gunshot wounds. Fractures should be temporarily stabilized with an external fixator due to contamination.

Defining animal welfare standards in hunting: body mass determines thresholds for incapacitation time and flight distance

Shooting is an important tool for managing terrestrial wildlife populations worldwide. To date, however, there has been few quantitative methods available enabling assessment of the animal welfare outcomes of rifle hunting. We apply a variety of factors to model flight distance (distance travelled by an animal after bullet impact) and incapacitation from the moment of bullet impact. These factors include body mass, allometric and isometric scaling, comparative physiology, wound ballistics and linear kinematics. This approach provides for the first time a method for quantifying and grading the quality of shooting processes by examining only body mass and flight distance. Our model is a universally applicable tool for measuring animal welfare outcomes of shooting regimes both within and among species. For management agencies the model should be a practical tool for monitoring and evaluating animal welfare outcomes regarding shooting of mammalian populations.

New fragmenting bullet leads to unexpected injury pattern: A case report involving the Radically Invasive Projectile

New developments in bullet technology are challenging what is commonly known about penetrating injuries from gunshot wounds. The so-called ‘bullet-rule’ posits the number of wounds and projectiles associated with a patient should add to an even number. This trauma paradigm is being shattered by the advent of new fragmenting projectiles. These frangible rounds break into several pieces after soft tissue penetration changing the expected trajectory, injury location, and extent of tissue damage. In this case report, the authors describe the case of a 15-year-old boy injured by a G2 Radically Invasive Projectile (RIP). The patient’s resultant pattern of injuries and the diagnostic utility of imaging were imperative for guiding his clinical management. The case serves as a useful example of the challenges and recommended strategies in managing a patient injured by a new fragmenting bullet.

Nonprojectile penetrating iron rod from the oral cavity to the posterior cranial fossa: a case report and review of literature

Introduction

Nonprojectile penetrating skull base injuries as a result of falls have rarely been confronted in normal neurosurgery although a few nonmissile injuries have been reported. These kinds of injuries represent a life-threatening emergency.

Case presentation

We present an unusual case of a 25-year-old male construction worker who suffered an accidental penetrating skull base injury when he fell on a metal rod while he was walking on a 2-meter-high platform. He was clinically stable at presentation. Skull radiograph showed a solid metallic bar, 30 cm long, that penetrated through the right anguli oris eminence and was lodged low in the right occipital bone.

Conclusion

Penetrating injury to the head is considered a form of severe traumatic brain injury. Although case of penetrating head injuries as a result of fall from heights are very rare, we anticipate the construction works on high-rise buildings are at maximum risk. We advise that removal of this kind of foreign bodies be done in the theater and not outside because of risk of involvement of larger vessels leading to fatal hemorrhage. We further suggest that patients with nonprojectile injuries should undergo a preoperative computed tomography-angiography to rule out any vascular injury.

Management of High-energy Avulsive Ballistic Facial Injury: A Review of the Literature and Algorithmic Approach

Background:

High-energy avulsive ballistic facial injuries pose one of the most significant reconstructive challenges. We conducted a systematic review of the literature to evaluate management trends and outcomes for the treatment of devastating ballistic facial trauma. Furthermore, we describe the senior author’s early and definitive staged reconstructive approach to these challenging patients.

Methods:

A Medline search was conducted to include studies that described timing of treatment, interventions, complications, and/or aesthetic outcomes.

Results:

Initial query revealed 41 articles, of which 17 articles met inclusion criteria. A single comparative study revealed that early versus delayed management resulted in a decreased incidence of soft-tissue contracture, required fewer total procedures, and resulted in shorter hospitalizations (level 3 evidence). Seven of the 9 studies (78%) that advocated delayed reconstruction were from the Middle East, whereas 5 of the 6 studies (83%) advocating immediate or early definitive reconstruction were from the United States. No study compared debridement timing directly in a head-to-head fashion, nor described flap selection based on defect characteristics.

Conclusions:

Existing literature suggests that early and aggressive intervention improves outcomes following avulsive ballistic injuries. Further comparative studies are needed; however, although evidence is limited, the senior author presents a 3-stage reconstructive algorithm advocating early and definitive reconstruction with aesthetic free tissue transfer in an attempt to optimize reconstructive outcomes of these complex injuries.

Chronic Expanding Hematoma in the Dorsal Cervicothoracic Region as a Long-Term Complication of Retained Bullet Fragments: Case Report

Chronic expanding hematoma is a rare pathology, which has not been previously described as a complication of gunshot injury with retained bullet fragments. Because of the similar characteristics of chronic expanding hematoma to malignancy, it can present a diagnostic challenge for clinicians. Imaging and biopsy evaluation is needed to reach a conclusive diagnosis and implement appropriate treatment. In this case report, we will discuss the development, diagnosis, and management of a chronic superficial cervicothoracic mass in a patient who presented 30 years post-gunshot injury with retained bullet fragments. 

Penetrating Thoracic Injury

This article discusses the role of radiology in evaluating patients with penetrating injuries to the chest. Penetrating injuries to the chest encompass ballistic and nonballistic injuries and can involve superficial soft tissues of the chest wall, lungs and pleura, diaphragm, and mediastinum. The mechanism of injury in ballistic and nonballistic trauma and the impact the injury trajectory has on imaging evaluation of penetrating injuries to the chest are discussed. The article presents the broad spectrum of imaging findings a radiologist encounters with penetrating injuries to the chest, with emphasis on injuries to the lungs and pleura, diaphragm, and mediastinum.

Firearms, bullets, and wound ballistics: an imaging primer

Based on its intrinsic mass and velocity, a bullet has an upper limit of wounding potential. Actual wound severity is a function of the bullet construction and trajectory, as well as the properties of the tissues traversed. Interpreting physicians must evaluate the bullet trajectory and describe patterns of injury resulting from the effect of energy transfer from the projectile into living tissue. A basic understanding of firearms, projectiles, and wound ballistics can help the interpreting physicians in conceptualizing these injuries and interpreting these cases.