Blunt Force Trauma in theNeuro-Cranium:

Fracture Propagation Using Current Biomechanics

Research and Technology

Ina Keyser10144383

ANA 328University of Pretoria

5 November 2012

“When you see me smashing somebody’s skull, you enjoy it.”

- Mike Tyson [1]

Figure 1: Mike Tyson in the Ring with Evander Holyfield [1]

TABLE OF CONTEXT1. Introduction

2. Statement of purpose3. Literature Review4. Materials and Methods5. Ethical considerations6. Finances7. References

1. Introduction [2]

Recognition and interpretation of trauma = essential in forensic anthropology

Forensic anthropologists determine:› mechanism and cause (ballistic, blunt, sharp

or thermal trauma or a combination)

› when the injury occurred (ante-mortem, peri-mortem or post-mortem)

› substantiate or reject witness accounts in legal setting [3]

1. Introduction CONTINUED [2]

Traumatic brain injury (TBI) - result of cranial fractures obtained in:› falls› motor vehicle-related accidents› violent abuse (domestic and nondomestic)

claims ± 89 000 South African lives annually [4]

Cranium is often affected in blunt force trauma [5]

73% of fatal cranial fractures in SA → blunt force trauma [4]

Fracture patterns can be complicated and challenging to understand

Accurate interpretation of the fracture patterns aids in:› identification of the impact site location› sequencing blows› determining characteristics (such as size and shape) of the weapon or

object responsible for the destruction [6]

2. Statement of Purpose AIM:

Conduct an experimental study to determine, describe and illustrate the fracture patterns of blunt force trauma in the neuro-cranium through

fracture propagation using current biomechanics research and technology.

OBJECTIVES:› Re-evaluate the research done by Gurdjian and colleagues [7] regarding how the

cranial vault responds to blunt impact

› Utilize an engineering drop tower system, which accurately simulates blunt force trauma in a controlled environment

› Capture the fracturing in the bone using a high-speed video camera

› Compare all collected data with the results from the original studies as well as current SA forensic cases

› Create a clinical applicable and comprehensive characterising system to identify future blunt force patterns in forensic cases

3. Literature ReviewA. Gurdjian and Colleagues, Wayne State University

[7-9]

Gurdjian - neurosurgeon and anatomist at Wayne State University

Studies conducted in 1940s and 1950s Fascinated with the fracture patterns and mechanics of trauma

in the human skull

1945 : Gurdjian and Lissner developed the STRESS COAT METHOD

Tested on monkeys and dogs (wet specimens) and dry human crania

STRESS COAT = dry brittle varnish designed to indicate areas of tensile strain in the material (bone) that it coats

→ thus predict fracture patterns

3. Literature Review CONTINUED Stress coat was applied directly on top of the bone

Blunt force was exerted on the skulls [9]

Cracks → fracture lines in the stress coat determine the areas of the skull that were under the most strain

The force causes: Intending or ‘in-bending’ of the bone directly underneath

the impact site

Out-bending in the adjacent bone- further from the impact zone

Figure2: Cranium (roof detached) [10]

3. Literature Review CONTINUED

Gurdjian and Lissner’s Theory of MOA [7]

1. Initial impact creates an wave of energy that disperses through the adjacent bone

2. Remote areas experience a high concentration of these tensile forces

3. Out-bending initiates in these zones and then radiates back towards the original point of impact

Gurdjian and Lissner defined this pattern as:

“an undulating type of movement with simultaneous intending in the region of impact and out bending at the border of the area of intending’’ [7]

Figure 3: Tensile Forces exerted by Blunt force trauma [8]

3. Literature Review CONTINUED Simply:The direct blunt force impact of the skull first caused distortion and failure in the surrounding areas, then the fracture traveles back toward the impact site

The areas of out-bending =CONCENTRIC FRACTURES

Figure 4: Site of impact and concentric fractures due to blunt force trauma [7]

3. Literature Review CONTINUED

B. Gurdjian’s Followers: Theories Applied, Modified or Suggested [7-9]

Many scientists used Gurjian and colleagues’ findings at an exemplar for their own:› Berryman et al. [10]› Berryman and Symes [4}› Galloway - Broken Bones: Anthropological Analysis of Blunt Force Trauma [11]

› DiMaio and DiMaio[12]› Knight – “stuck hoop analogy”[13]

Figure 4: Blunt force trauma induced to cranium [8]

4. Materials and MethodsA. Materials

RACE SEX

AGE: 20-35 years (yrs)

AGE: 36-50 yrs

AGE: 51-65 yrs

AGE: 65-80 yrs

TOTAL

WhiteMale 7 7 7 7 28Female 7 7 7 7 28

BlackMale 7 7 7 7 28Female 7 7 7 7 28

112

Table1: Subdivision of Dry Crania Obtained from the Ramond Dart and Pretoria Skeletal Collections

4. Materials and Methods CONTINUED

Table 2: Subdivision of Cadaver Crania Obtained from the Anatomy Department of the University of Pretoria

RACE SEX

AGE: 20-40 years (yrs)

AGE: 41-80 yrs

TOTAL

WhiteMale 4 4 8

Female 4 4 8

BlackMale 4 4 8

Female 4 4 8

32

4. Materials and Methods CONTINUED

B. Methods

Engineering drop tower system - simulates blunt force trauma in a controlled environment› eliminates unpredictable variables (human error) that may

occur when propagating fractures manually

Monitored and recorded fracture event using a high-speed video camera› viewed and analysed repeatedly 

Analyses of results with› original studies (done by Gurdjian)› current known South African forensic cases (available from

the Department of Anatomy at the University of Pretoria

5. Ethical Considerations Ethical clearance will be obtained from the

Students Ethics Committee of the University of Pretoria

South African Police Departments and Laboratories where current forensic cases are stored.

6. Finances Department of Anatomy of the University of

Pretoria will cover all the financial costs towards this study

7. References1. Keaveny TM, Hayes WC. 1993. Mechanical properties of cortical and trabecular bone. In: Hall

BK, editor. Bone. Vol. 7. Boca Raton: CRC Press. p 285–344.2. LeCount ER, Apfelbach CW. 1920. Pathologic anatomy of traumatic fractures of cranial bones

and concomitant brain injuries. Jam Med Assoc 74:501–511.3. Turner CH, Burr DB. 1993. Basic biomechanical measurements of bone: A tutorial. Bone

14:595–608.4. Willinger R, Kang HS, Diaw B. 1999. Three-dimensional human head finite-element model

validation against two experimental impacts. Ann Biomed Eng 27:403–410.5. Moritz AR. 1954. The Pathology of Trauma. Philadelphia: Lea and Febiger. Oxnard CE. 1993.

Bone and bones: architecture and stress, fossils and osteoporosis. J Biomech 26(Suppl 1):63–79.

6. Gurdjian ES, Lissner HR. 1945. Deformation of the skull in head injury: A study with the stresscoat technique. Surg Gynecol Obstet 81:679–687.

7. Gurdjian ES, Lissner HR, Webster JE. 1947. The mechanism of production of linear skull fracture; further studies on deformation of the skull by the stresscoat technique. Surg Gynecol Obstet 85:195–210.

8. Gurdjian ES, Webster JE, Lissner HR. 1949. Studies on skull fracture with particular reference to engineering factors. Am J Surg 78:736–742.

9. Evans FG. 1970. Biomechanical implications of anatomy. Selected Topics on Biomechanics: Proceedings of the C.I.C. Symposium on Biomechanics.

10. Berryman HE, Symes SA, Smith OC, Moore SJ. 1991. Bone fracture II: Gross examination of fractures. 43rd Annual Meeting of the American Academy of Forensic Sciences, Anaheim, California.

11. Galloway A. 1999. Broken Bones. Springfield, IL: Charles C. Thomas.12. DiMaio VJ, DiMaio D. 2001. Forensic Pathology. Boca Raton: CRC Press.13. Knight B. 1996. Forenic Pathology. London: Arnold.

Thank You