Skeletal Trauma Flashcards
What is trauma?
an injury caused to living tissue by an outside force
Is postmortem damage trauma?
No!
Cause of death
the circumstance/event that resulted in a person dying
Manner of death
ex. natural causes, accident, suicide, homicide, unknown
Mechanism of death
actual medical circumstance that leads to a death
What are the two things that bone is made of?
collagen (organic, flexibility) & calcium hydroxyapatite (inorganic, strength)
What four factors affect skeletal trauma?
- direction of force
- speed of force
- type of bone, which bone, and location on bone
- age and pathological conditions
Why does age affect the impacts of skeletal trauma?
when you grow older, your bones decrease in strength and elasticity/give
What are the five mechanisms of force on bone?
- compression
- tension
- torsion
- bending
- shearing
Compression
forces that push down on bone, common on the skull
Tension
force that pulls on bone along its axis, common in accidents
What force is bone more suited to withstand, tension or compression?
compression (gravity is always acting upon us)
Torsion
twisting forces, common in cases of child abuse
Bending
force that hits the side of bone at a right angle causing a break through the cross section
Greenstick fractures
incomplete fractures commonly found in children, can be helpful in determining direction of force
Parry fractures
caused from defending of a blow
Bending is like a combination of ___ and ___.
compression and tension
Shearing
force that is similar to bending (force applied to one side of the bone), but part of the bone is immobile
Colles fracture
in distal radius, caused from catching yourself fall
TRUE or FALSE: shearing is also evident with sawing/cutting bone
TRUE
What are the two speeds of force?
- slow loaded (ex. punch, bat)
- rapid loaded (ex. bullets)
Describe the elastic region of a stress-strain curve?
the bone can go back like nothing happened
Describe the plastic region of a stress-strain curve?
the bone can go back a little but won’t look perfect
Describe what happens past the C region of a stress-stained curve?
the bone will break
Fracture
failure of bone resulting in discontinutiy
What are the four descriptions of fractures commonly used in forensic anthropology?
- complete v. incomplete
- simple v. comminuted
- direction of force
- open v. closed
Comminuted
bone fractured into more than two parts (crushed)
Oblique
diagonal fracture through bone
What are fracture lines?
lines that begin at the point of initial impact and dissipate the force through the bone
Radiating fractures
radiate off of main break to try to disperse force
Hoop/centric fractures
ripple off of main break (typical in cranial vault)
What are pathological fractures?
breaks in bones that are weakened by disease
What are stress fractures?
breaks caused by overuse of an area, common in athletes & factory workers
What are fatigue fractures?
breaks in bones due to intermittent stress of a long period of time (lifetime)
What is week 1 of the fracture healing process?
bruises & inflamation
What is week 2-3 of the fracture healing process?
soft callus consisting of a temporary network of tissues
What is week 4-16 of the fracture healing process?
hard callus
What is week 17 and beyond of the fracture healing process?
remodeling as primary osteons are replaced with secondary osteons
What are the four types of trauma?
- blunt
- sharp
- projectile
- miscellaneous/mixed force
How can you recognize antemortem trauma?
there will be evidence of healing such as porous bone, smooth edges, and bony calluses
How can you recognize perimortem trauma?
“green bone” response, sharp edges, inward bending, fracture lines, angled broken-bone ends
How can you recognize postmortem trauma?
dry bone fractures, no fracture lines, sharp edges, color changes in the break
Does perimortem just include the day of death?
No, about 2 wks before to 1 mnth later (beginning of healing to beginning of decomp)
