The Effect of Soft Tissue on the Biomechanics of Skull Fracture due to Blunt Ballistic Impact: Preliminary Analysis and Findings

The majority of engineering studies that quantify the biomechanical response of the human head to blunt impacts have been focused primarily on replicating automotive-related trauma [1]. Relatively little biomechanical data exists on head response and skull fracture tolerance due to impacts with small surface area objects moving at high velocity, as can occur with the deployment of less-lethal kinetic energy munitions that are now available to police and military personnel. Law enforcement are trained to direct such munitions away from the head and at body regions least likely to sustain serious to life-threatening injury, such as the legs, however impacts to vital regions such as the head have occurred [2]. Previous research efforts have investigated facial impact response to blunt ballistic impacts however data regarding the temporo-parietal region are lacking and require study under these unique loading conditions [3]. Prior research has indicated that the scalp and soft tissue covering the skull are important factors to consider when studying impact response and skull fracture tolerance [4]. These data however have been limited primarily to impact velocities typical of the automotive crash environment. The purpose of this study is to evaluate the contribution of soft tissue to the biomechanical response and tolerance of the temporo-parietal region under blunt ballistic impact conditions.

Download Full-text

Biomechanics of Temporo-Parietal Skull Fracture From Blunt Ballistic Impact

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192966 ◽

2008 ◽

Author(s):

David E. Raymond ◽

Greg S. Crawford ◽

Chris A. Van Ee ◽

Cynthia A. Bir

Keyword(s):

Skull Fracture ◽

Ballistic Impact ◽

Minimal Risk ◽

Small Surface ◽

Human Skull ◽

Ballistic Impacts ◽

Body Regions ◽

Biomechanical Response ◽

Strain Data ◽

Fracture Tolerance

The majority of engineering studies that quantify the biomechanical tolerance of the human skull to blunt impacts have been focused primarily on replicating automotive-related trauma [1]. Relatively little biomechanical data exists on skull fracture tolerance due to impacts with small surface area objects moving at high velocity, previously defined as blunt, ballistic impacts [2]. These impacts can occur with the deployment of less-lethal kinetic energy munitions that are now available to police and military personnel. The goal of less-lethal munitions is to impart sufficient force to a subject to deter uncivil, or hazardous, behavior with minimal risk for serious or fatal injury. A basic understanding of human biomechanical response and tolerance to blunt ballistic impact is needed for all areas of the human body in order to guide the design of such munitions. Law enforcement are trained to direct such munitions away from the head and at body regions such as the legs, however impacts to the head have occurred [3]. Previous research efforts have investigated facial impact tolerance to blunt ballistic impacts [4] however data regarding the temporo-parietal region are lacking. The goal of this research project is to provide basic bone strain data on temporo-parietal skull fracture for the purpose of developing finite element models of the human skull and fracture criterion for future study of blunt ballistic head impact.

Download Full-text

Development of Biomechanical Response Corridors of the Head to Blunt Ballistic Temporo-Parietal Impact

Journal of Biomechanical Engineering ◽

10.1115/1.3194751 ◽

2009 ◽

Vol 131 (9) ◽

Cited By ~ 5

Author(s):

David Raymond ◽

Greg Crawford ◽

Chris Van Ee ◽

Cynthia Bir

Keyword(s):

Head Impact ◽

Ballistic Impact ◽

Peak Force ◽

Future Research ◽

Parietal Region ◽

Impact Studies ◽

Time Deformation ◽

Impact Condition ◽

Body Regions ◽

Biomechanical Response

There is a need to study the biomechanical response of the head to blunt ballistic impact. While the frequency of less-lethal munition impacts to the head may be less than other vital body regions, more serious injuries have been attributed to these impacts. This study aims to establish biomechanical response corridors for the temporo-parietal region for future development of biomechanical surrogate devices. Seven unembalmed post-mortem human subject specimens were exposed to blunt ballistic temporo-parietal head impact (103 g, 38 mm diameter impactor) to determine the force-time, deformation-time, and force-deformation responses. Comparisons were made to responses from prior blunt ballistic head impact studies, as well as automotive-related impact studies. Peak forces for impact condition A (19.5±2.6 m/s) were 3659±1248 N with deformations at peak force of 7.3±2.1 mm. Peak forces for impact condition B (33.6±1.4 m/s) were 5809±1874 N with deformations at peak force of 9.9±2.6 mm. Seven fractures were produced in the seven specimens. Depressed comminuted fracture types were documented in six of the seven cases. The average stiffness of the temporo-parietal region under blunt ballistic impact was 0.46±0.14 kN/mm. Stiffness results indicate that the response of the temporo-parietal region is similar to the forehead under blunt ballistic loading conditions. In addition, the response is significantly less stiff when compared with temporo-parietal impacts performed in automotive-related studies. These data provide the foundation for future research in the area of blunt ballistic head impact research including the development of biomechanical surrogates and computational models.

Download Full-text

Comparative study on ballistic impact response of neat fabric, compliant, hybrid compliant and stiff composite

Thin-Walled Structures ◽

10.1016/j.tws.2021.107986 ◽

2021 ◽

Vol 165 ◽

pp. 107986

Author(s):

Vishwas Mahesh ◽

Sharnappa Joladarashi ◽

Satyabodh M. Kulkarni

Keyword(s):

Comparative Study ◽

Ballistic Impact ◽

Impact Response

Download Full-text

The Hazards of Skateboard-Riding

PEDIATRICS ◽

10.1542/peds.57.5.793 ◽

1976 ◽

Vol 57 (5) ◽

pp. 793-793

Author(s):

◽

Fernando Atienza ◽

Calvin Sia

Keyword(s):

Emergency Department ◽

Soft Tissue ◽

Bone Fractures ◽

Tissue Injury ◽

Skull Fracture ◽

Soft Tissue Injury ◽

Soft Tissue Injuries ◽

Major Surgery ◽

Cerebral Concussion ◽

Tissue Injuries

Skateboard-riding has become increasingly popular among Hawaii's children. The thrill of the ride and the challenge of keeping one's balance and working intricate maneuvers while speeding down a hill captures the fancy of many of our young. This sport, however, has produced an alarmingly high toll of injury and illness. Pediatricians and emergency departments of our major hospitals have seen and taken care of large numbers of patients (aged between 3 years and 35 years, but with a distribution overwhelmingly pediatric) with significant injuries which include cerebral concussion, fractures, soft tissue injuries of varying degrees of severity and complications, and injury to internal organs. During a three-month period at the Kauikeolani Children's Hospital, July to August 1975, there were 16 patients admitted with the following: seven cerebral concussions, one skull fracture, five assorted bone fractures, one soft tissue injury and infection, one retroperitoneal hemorrhage, and one instance of major surgery for removal of the spleen. During the months of August and September 1975 the Emergency Department of Straub Clinic reported the following skateboard injuries: 14 fractures, 14 soft tissue injuries, 5 lacerations, and 2 cerebral concussions. Of the 35 patients seen, three were admitted—one with an open fracture, one with cerebral concussion, and one with a skull fracture. During a four-week period (two weeks in June and July and two weeks in August and September) at the Emergency Department of Kaiser Medical Center, 66 cases of skateboard injuries were seen with six patients requiring admission for fractures and brain concussion.

Download Full-text

Mechanical Strength Study of a Cranial Implant Using Computational Tools

Applied Sciences ◽

10.3390/app12020878 ◽

2022 ◽

Vol 12 (2) ◽

pp. 878

Author(s):

Pedro O. Santos ◽

Gustavo P. Carmo ◽

Ricardo J. Alves de Sousa ◽

Fábio A. O. Fernandes ◽

Mariusz Ptak

Keyword(s):

Structural Integrity ◽

Mechanical Performance ◽

Skull Fracture ◽

Human Head ◽

Element Model ◽

Von Mises Stress ◽

Cranial Implant ◽

Von Mises ◽

Two Parameters ◽

The Brain

The human head is sometimes subjected to impact loads that lead to skull fracture or other injuries that require the removal of part of the skull, which is called craniectomy. Consequently, the removed portion is replaced using autologous bone or alloplastic material. The aim of this work is to develop a cranial implant to fulfil a defect created on the skull and then study its mechanical performance by integrating it on a human head finite element model. The material chosen for the implant was PEEK, a thermoplastic polymer that has been recently used in cranioplasty. A6 numerical model head coupled with an implant was subjected to analysis to evaluate two parameters: the number of fixation screws that enhance the performance and ensure the structural integrity of the implant, and the implant’s capacity to protect the brain compared to the integral skull. The main findings point to the fact that, among all tested configurations of screws, the model with eight screws presents better performance when considering the von Mises stress field and the displacement field on the interface between the implant and the skull. Additionally, under the specific analyzed conditions, it is observable that the model with the implant offers more efficient brain protection when compared with the model with the integral skull.

Download Full-text

Injury Risk in New Zealand Rugby Union: A Nationwide Study of Injury Insurance Claims from 2005 to 2017

Sports Medicine ◽

10.1007/s40279-019-01176-9 ◽

2019 ◽

Vol 50 (2) ◽

pp. 415-428 ◽

Cited By ~ 2

Author(s):

Ken Quarrie ◽

Simon Gianotti ◽

Ian Murphy

Keyword(s):

New Zealand ◽

Soft Tissue ◽

Confidence Interval ◽

Large Scale ◽

Injury Rate ◽

Soft Tissue Injuries ◽

The Body ◽

Body Regions ◽

Accident Compensation ◽

Tissue Injuries

Abstract Objectives The Accident Compensation Corporation is a compulsory, 24-h, no-fault personal injury insurance scheme in New Zealand. The purpose of this large-scale retrospective cohort study was to use Accident Compensation Corporation records to provide information about rugby injury epidemiology in New Zealand, with a focus on describing differences in risk by age and gender. Methods A total of 635,657 rugby injury claims were made to the Accident Compensation Corporation for players aged 5–40 years over the period 2005–2017. Information about player numbers and estimates of player exposure was obtained from New Zealand Rugby, the administrative organisation for rugby in New Zealand. Results Over three quarters of claims (76%) were for soft-tissue injuries, with 11% resulting from fractures or dislocations, 6.7% from lacerations, 3.1% from concussions and 2.0% from dental injuries. Body regions injured included shoulder (14%), knee (14%), wrist/hand (13%), neck/spine (13%), head/face (12%), leg (11%) and ankle (10%). The probability of a player making at least one injury claim in a season (expressed as a percentage) was calculated under the assumption that the incidence of claims follows a Poisson distribution. Players aged 5–6 years had a probability of making at least one claim per season of 1.0%, compared to 8.3% for players aged 7–12 years, 35% for age 13–17 years, 53% for age 18–20 years, 57% for age 21–30 years and 47% for age 31–40 years. The overall probability of making at least one claim per season across all age groups was 29%. The relative claim rate for adults (players aged 18 years and over) was 3.92 (90% confidence interval 3.90–3.94) times that of children. Ten percent of players were female, and they sustained 6% of the injuries. Overall, the relative claim rate for female players was 0.57 times that of male players (90% confidence interval 0.56–0.58). The relative claim rate of female to male players tended to increase with age. There were very few female players aged over 30 years; however, those who did play had higher claim rates than male players of the same age group (1.49; 90% confidence interval 1.45–1.53). Conclusions Injuries resulting from rugby are distributed across the body, and most of the claims are for soft-tissue injuries. Rates of injury increase rapidly through the teenage years until the early 20 s; for male players they then decrease until the mid-30 s. For female players, the injury rate does not decrease as players move into their 30 s. Combining Accident Compensation Corporation injury claim data with national player registration data provides useful information about the risks faced by New Zealand’s community rugby players, and the insights derived are used in the development of rugby injury prevention programme content.

Download Full-text

Free versus Pedicled Perforator Flaps for Lower Extremity Reconstruction: A Multicenter Comparison of Institutional Practices and Outcomes

Journal of Reconstructive Microsurgery ◽

10.1055/s-0038-1639576 ◽

2018 ◽

Vol 34 (08) ◽

pp. 572-580 ◽

Cited By ~ 3

Author(s):

Keith Koh ◽

Terence Goh ◽

Christopher Song ◽

Hyun Suh ◽

Peter Rovito ◽

...

Keyword(s):

Soft Tissue ◽

Lower Extremity ◽

Soft Tissues ◽

Perforator Flap ◽

Free Flaps ◽

Careful Consideration ◽

Pedicled Flap ◽

Perforator Flaps ◽

Body Regions ◽

Significant Difference

Background Of all body regions, lower extremity wounds have been and remain the greatest challenge. Perforator free flaps have been accepted as a reasonable option to solve this dilemma but require the complexity of microsurgery. As a consequence, the possibility that pedicled perforator flaps could supplant even perforator free flaps has recently gained intense enthusiasm. Methods A retrospective investigation was undertaken to compare the validity for the use of perforator flaps of all types at three dissimilar institutions, that is, a university, a regional center, and a community hospital. All flaps performed in the 5-year period, 2011 to 2015, were included to allow at least 1-year follow-up before data analysis. A total of 433 free perforator flaps and 52 pedicled perforator flaps had been performed specifically for the lower extremity. Results Patient demographics, wound etiology, and comorbidities were similar for all institutions. Free flaps were more commonly needed after trauma and for chronic ulcers. Pedicled flaps were more likely an option after tumor excision. Large defects or those involving the foot were better served by free flaps. Overall success for free perforator flaps was 90.1% and for pedicled perforator flaps was 92.3%, with no significant difference noted (p = 0.606) between institutions. Peripheral vascular disease was the only significant comorbidity risk factor for both free and pedicled flap failure. Conclusion Perforator flaps in general have become a reasonable solution for soft tissue defects of the lower extremity. Following careful consideration of the etiology, dimensions, location, patient comorbidities, and presence of adequate perforators, a pedicled or free perforator flap could potentially be successful. Pedicled perforator flaps, if adequate healthy soft tissues remain adjacent to the defect, forecast a continuance of the evolution in seeking simplicity yet reliability by the best flap possible for soft tissue closure of the lower limb wound.

Download Full-text