The experimental and numerical investigation on the ballistic limit of BB-Gun pellet versus skin simulant

Diagnostic and therapeutic considerations in cases of civilian intravascular ballistic embolism: a review of case reports

Background

Ballistic embolism (BE) is a rare complication of firearm injuries notoriously associated with a vexing clinical picture in the trauma bay. Unless considered early, the associated confusion can lead to needless delay in the management of the patient with a gunshot wound. Despite this known entity, there is a relative paucity of high-grade evidence regarding complications, management, and follow-up in these patients.

Methods

An electronic database literature search was conducted to identify cases of acute intravascular BE in pediatric and adult civilians occurring during index hospitalization, filtered to publications during the past 10 years. Exclusion criteria included non-vascular embolization, injuries occurring in the military setting, and delayed migration defined as occurring after discharge from the index hospitalization.

Results

A total of 136 cases were analyzed. Nearly all cases of BE occurred within 48 hours of presentation. Compared with venous emboli, arterial emboli were significantly more likely to be symptomatic (71% vs. 7%, p<0.001), and 43% of patients developed symptoms attributable to BE in the trauma bay. In addition, arterial emboli were significantly less likely to be managed non-invasively (19% vs. 49%, p<0.001). Open retrieval was significantly more likely to be successful compared with endovascular attempts (91% vs. 29%, p<0.001). Patients with arterial emboli were more likely to receive follow-up (52% vs. 39%) and any attempt at retrieval during the hospitalization was significantly associated with outpatient follow-up (p=0.034). All but one patient remained stable or had clinically improved symptoms after discharge.

Conclusion

Consideration for BE is reasonable in any patient with new or persistent unexplained signs or symptoms, especially during the first 48 hours after a penetrating firearm injury. Although venous BE can often be safely observed, arterial BE generally necessitates urgent retrieval. Patients who are managed non-invasively may benefit from follow-up in the first year after injury.

Finite element analysis of shank and ankle with different boot collar heights in parachuting landing on inversion ground surface

This study aimed to the biomechanics of the foot-ankle-shank complex with different boots collar heights in parachuting landing on inversion ground surface. A finite element model including tibia, fibula, ankle, foot and parachuting boot was developed. Three collar heights (low, medium, high) of the parachuting boot were simulated. Von-Mises stress, ankle inversion angle, ligament force and bone displacement were analyzed. Compared with that of the high and low collar heights, boots with medium collar height produced the lowest peak stress on the tibia and the articular cartilage of the subtalar joint. In addition, the medium collar height can better control the ankle inversion and minimize the tensile forces on the lateral ankle ligaments.

Epidemiology of Pediatric Nonballistic Firearm Injuries to the Upper Extremity in the United States From 2000 to 2017

Background: This study aimed to describe the epidemiology of pediatric upper extremity injury secondary to nonballistic firearms in the United States. Methods: The National Electronic Injury Surveillance Survey (NEISS) database was queried between 2000 and 2017 for injuries to the upper extremity from nonballistic firearms in patients aged ≤18 years. In total, 1502 unique cases were identified. Using input parameters intrinsic to the NEISS database, national weighted estimates were derived using Stata/IC 15.1 statistical software (StataCorp LLC, College Station, Texas), which yielded an estimate of 52 118 cases of nonballistic firearm trauma to the upper extremity who presented to US emergency departments over the study period. Descriptive statistics were performed using NEISS parameters. Results: An average of 2895 annual pediatric upper extremity nonballistic firearm injuries were identified between 2000 and 2017. Over 91% were sustained by men, and adolescents aged 12 to 18 were the most commonly injured (69.8%). Only 3.5% of all injuries required inpatient admission, and the most common sites of injury were the hand (41.1%), followed by fingers (35.9%). Conclusions: We conclude that nonballistic firearm injuries represent a significant burden of disease to adolescent men in the United States.

Percutaneous removal of air-bullet gunshot: case report and literature review

Background

Cardiac air bullet injuries are rare but can be associated with significant morbidity and mortality.

Case presentation

We are presenting a young male child who sustained an accidental injury to the chest by an air rifle. Bullet entered the right ventricle from the anterior part of the chest and was identified in the RV side of the interventricular septum by echocardiography and chest CT scan. There was mild pericardial effusion but no valvular injury. The bullet was removed in the cath lab, and the patient was discharged home on the second day.

Conclusions

It is reasonable to try foreign body removal in the cath lab, for certain cases, and avoid cardiac surgery.

Maximum tensile stress and strain of skin of the domestic pig-differences concerning pigs from organic and non-organic farming

The purpose of this work has been to determine differences in biomechanical properties of porcine skin from organic and non-organic farming as porcine skin is widely used as a model for human skin. A test apparatus was used, using gravity to stretch and finally tear a dumbbell-shaped specimen of prepared abdominal skin with a testing surface area of 25 × 4 mm. A total of 32 specimens were taken from seven individual pigs, three from organic and four from non-organic farming, in different orientations with respect to the Langer's lines. The tests were performed at a dynamic speed of around 1.66 m/s (corresponding to a nominal strain rate of 67 s^-1). Engineering strain at rupture was higher in pig skin from non-organic farming with values up to 321% as opposed to 90% in organic pig skin. The maximum tensile stress found in non-organic pig skin was lower than in pig skin from organic farming with maximum values of 34 MPa as opposed to 58 MPa. The reason for the difference in biomechanical properties is unclear; the effect of sunlight is discussed as well as other factors like age and exercise. It seems that the biomechanical properties of porcine skin from organic farming are more similar to those of human skin.