Final Exam Flashcards
(72 cards)
Antemortem
trauma that occurs before death, there is visible healing
Perimortem
event that occurs at or around the time of death because of the properties of bone, the timing of the injury is less precise when evaluating bone than when evaluating soft tissue. 1. a lack of healing or infectious response 2. the presence of fresh bone fracture characteristics 3. the absence of dry bone fracture characteristics
Postmortem
injuries occurring after death
What is blunt force trauma?
is produced by low velocity impact from a blnt object the low velocity impact of a body with a blunt surface
Key features of BTF?
- Bone that exhibits plastic deformation indicative of low velocity impact
- delamination of bone
- fracture patterns indicating a low velocity site
- location and characteristics of known clinical fracture
- tools or marks or tool impression indicating impact site
- beveling of concentric fractures
BFT intrinsic factors(5)
Bone geometry, bone thickness, bone density, buttresses and struts
Plastic deformation
bending of the bone with permanent deformation
elastic deformation
resilient bending of the bone
fracture
bone failure
Butterfly fractures
failure occurs first on the tension site which on the opposite side of impact * in longbones fractures are initiated on the tension side
classification of forces: Compression
squeezing of the bone along the axis, involved in falls
classification of forces: Tension
pulling apart of the bone
classification of forces: Rotation
twisting of the bone, one end held stationary while the other end twists
classification of forces: Shear
tissue tears apart by sliding one portion
classification of forces: Bending
bone subjected to compression to concave side
Cranial fracture initiation theory
fracture initiate away from point of impact and propagate back towards the point of impact (E.S Gurdjian)
outbending
where fractures initiate because this is where the tension is
BFT extrinsic factors
- shape, weight and material of implement
- rates and duration of loading at impact site
- energy of blow
classification of fracture: Incomplete
doesn’t separate fully, greenstick, depressed
classification of fracture: Complete
bone breaks into 2 or more pieces, transverse, spiral, comminuted, butterfly
classification of fracture: Cranial
linear, diastatic(separation/ fracture/widening of suture) depressed( caving in of vault), stellate( impact and radiating fractures)
GSW: entrance
generally smaller than exit wound and does not have beveling
types of beveling: Outward
seen in the exit wounds, in GSW to the head is on the ectocranial surface
types of beveling: Reverse
is the opposite if what you would expect= is fairly typical in tangential GSW