Skeletal Trauma and Timing of Bone Injury (Lab 12) Flashcards
_________ is defined as an injury or disruption caused to living tissue by any external force.
Trauma
________ is that which occurred prior to death
antemortem trauma
________ is that which occurred around the time of death
perimortem trauma
_______ is bone damage that occurred after the time of death
postmortem alteration
under ______ the ends of the bones are pulled apart, which stretches the collagen fibers along their length. Fractures caused by _______ are often clean breaks that have few secondary fracture lines.
tension
Under _________ the ends of the bone are pushed together causing multiple breaks and secondary fracture lines that radiate from the point of impact.
compression
Under ________ the force impacts the body at an oblique angle, which often causes the two fracture ends to be misaligned because they are pushed in opposite directions.
Shearing
Under _______ the force is also directed obliquely but with one end of the bone being stationary. This causes fracture lines to spiral down the axis of the bone shaft. In real life, most fractures result from a combination of these directional forces.
Torsion
Bone is a __________ material, which means it responds to force differently depending on the speed at which it impacts the body.
Viscoelastic
______ impact the body at low velocity for a relatively long period time (a blow to the head with a brick).
static forces
________ impact the body suddenly and quickly, but also dissipate rapidly (a bullet wound).
dynamic forces
when the bone bends, absorbs the energy, and returns to its original state without any permanent change to its structure is the __________ phase
elastic phase
during this phase when the force is removed the bone will not return to its original state. In other words, the bone is permanently deformed
plastic phase
when the bone has been stressed beyond its capacity to absorb energy. The force exceeds the structural strength of the bone and it gives way
fractured
_________ deform the bone prior to causing a fracture.
static forces
________ do not deform the bone but simply shatter it.
dynamic forces
If the discontinuity travels through the bone physically separating it into two pieces, it is called a ______
fracture
A _________ occurs when the two continuous bone surfaces no longer meet
displaced fracture
_______ fractures are those in which multiple fractures occur at a site of injury. In comminuted fractures the bone has fragmented into 2 or more pieces indicating a high level of energy was impacting the body, consistent with dynamic loading
Comminuted
A __________ is a special type of comminuted fracture of long bones typically resulting from blunt force trauma
butterfly fracture
A fracture in which the bone does not break the outer surface of the skin is called _______
closed
a fracture that breaks the skin is called _____
(have a much higher chance of secondary infection)
open
If the discontinuity does not completely separate the bone it is called an _______
infraction or incomplete fracture
A ___________results when the bone is impacted at an angle or is bent resulting in tension on one side of the bone and compression on the other side. An incomplete fracture with form transversely and often travel longitudinally up and down the shaft of the long bone. These types of fractures are more common in children.
greenstick fractures
A ____________ is specific to the cranial vault. It involves an injury that usually crushes the trabecular bone and some of the outer cortical bone but does not completely separate the fragments.
depression fracture
_________ result when the bone directly at the point of contact (bullet entry point) cannot absorb all of the energy imparted into the body through the formation of the primary fracture (bullet hole). (there are two types)
Secondary fracture lines
________ disperse outward from the site of impact and can usually be traced back to it. This fact is useful for identifying the site of impact if the damage to the body has result in extreme fragmentation.
Radiating Fractures
________ represent the energy traveling through the bone along the lines of least resistance - area of low bone density, low bone thickness, high proportions of trabecular bone, cranial sutures, and the numerous foramina located throughout the body.
radiating fractures
__________form concentric fracture lines that surround the site of impact. These lines are usually associated with high-velocity projectile and low-velocity blunt force trauma. (associated with high levels of energy impacting the body)
Concentric Fractures or Hoop Fractures
_____________ contributes to an investigation in two ways. First, if the trauma occurred well before the time of death there may be a medical history that can be matched to trauma that is observed on the body of an unknown decedent. That is, a fracture with a distinct pattern of healing could be compared to x-rays of an individual for whom a missing persons report has been filed. Second, trauma identified in various stages of healing may indicate a pattern of injury consistent with torture or domestic abuse. For child decedents, observation of antemortem trauma may indicate a history of child abuse and neglect.
Antemortem trauma
The challenge with identifying antemortem trauma is that it is entirely based on observations of_________ or signs of ______________ in response to the traumatic insult.
- bone healing
- secondary infection
_____________ is likely of greatest interest to the forensic anthropologist because it may directly relate to the cause of death. Observations of gunshot wounds, stab marks, or blunt force injuries would all be suggestive of the means by which the decedent died.
Perimortem trauma
________________ could be of forensic relevance, but it is less likely related to cause and manner of death.
Postmortem trauma
What is the primary goal of forensic anthropologists when analyzing trauma on skeletons?
To provide an accurate and complete description of the wounds.
How does bone typically respond to dynamic forces?
It shatters without bending or deforming.
Which type of fracture is characterized by multiple breaks and secondary fracture lines radiating from the point of impact?
compression fracture
What is the significance of identifying the sequence of injuries in forensic anthropology?
It addresses the fundamental question of what happened at the crime scene.
In the context of bone fracture, what does the term ‘viscoelastic’ imply?
Bone responds to force differently depending on the speed of impact.
What is the primary difference between perimortem and postmortem fractures?
The level of collagen content in the bone at the time of fracture.
Which type of fracture is more common in children due to their bone composition?
Greenstick fracture
How can forensic anthropologists differentiate between perimortem and postmortem trauma?
By examining the fracture profile angle and texture.
What role does the concept of ‘anisotropic’ play in understanding bone fractures?
It explains why bones fracture differently based on the direction of force applied.
The healing process and the body’s response to ____________ involve both osteoclasts (cells that remove bone) and osteoblasts (cells that make new bone).
secondary infection
increased porosity or pitting surrounding the fracture site, rounding of broken fracture margins, and the deposition of new bone (bony callus) to completely mend the fracture.
antemortem trauma is evidenced by these three macroscopic features of bone healing
______ refers to the shape of the broken edge
fracture profile texture
__________ refers to whether the color of the fractured edge is the same color as the exterior cortical surface.
fracture profile color
In _____________, the edge and exterior surface of the bone are exposed to the same burial environment.
perimortem trauma
In____________ the broken edge is smooth. In postmortem trauma, the broken edge is rough and ragged.
perimortem trauma
______________ fractures have the appearance of being roughly torn, reflecting the lack of elastic properties in the bone
postmortem
In ____________ trauma the exterior surface is exposed to burial color changes for a longer period of time than the fractured margin. Therefore, you expect the margin to be lighter in color than the exterior bone surface.
postmortem
has studied the effects of bullets on soft tissue.
forensics pathology
distance between shooter and victim, type of bullet fired, the caliber of weapon, velocity and angle of impact, presence of the intervening material, bullet behavior at the moment of impact (rotating, wobbling, tumbling)
extrinsic factors
skeletal element impacted, age of the decedent, health conditions affecting bone quality
intrinsic factors
inward beveling
entrance wound
outward beveling
exit wound
