1. Fracture Classification Flashcards
strength of bone is dependent on
material properties
structural properties
rate of load applied (viscoelastic)
orientation of load applied (anisotropic)
tension force
causes ______ fractures
occurs at?
avulsion fractures (especially in skeletally immature animals) apophyses (olecranon, calcaneus, tibial tuberosity)
compression force causes _____ fractures
occurs at?
short oblique
typically only in the spine b/c most bones are so dense
Shear forces
common fracture?
low energy
eccentric loading of bones surface- bone is weakest in this method of loading
- common in toy breeds that shear off the lateral condyle
bending forces
- compressive force on concave surface and tensile on convex.
- causes transverse or short oblique fractures
torsion
rotational forces applied along long axis results in spiral fractures
Incomplete fractures
greenstick (opposing cortices involved, especially young animals)
fissure (only one cortex)
- can be splinted/casted
transverse fracture
perpendicular to long axis, smooth or serrated fracture surfaces
- result from bending forces
- stable to compressive forces, can be reduced
oblique fracture
opposing cortices are in the same plane
- result of axial compression and bending forces
- NO STABILITY even when reduced, not even to compressive forces
Spiral fracture
fracture line is also diagonal like oblique but the opposing cortices are in different planes.
- result of torsional force
- inherent stability if anatomicaly reduced
comminuted fracture
at least three fracture segments with fracture lines that intersect
- caused by high energy trauma
- multiple forces involved
- often have lots of soft tissue damage
segmental fractures
at least three fracture segments with fracture lines that do not intersect
- caused by bending and other forces
- *May have large avascular segment (bc blood comes from within the medullary cavity)
Open fractures
- breaks through skin, look for gas in the soft tissue
Type I - clean soft laceration <1cm
Type II - laceration >1cm, mild trauma, no flaps/avulsion
Type III - severe soft tissue trauma, treat aggressively
a fracture in which location will have the least help healing? (eg. blood supply, muscle attachments)
diaphyseal
Salter Harris fracture Classifications
I- physis II - meta/physis III - Epi/physis IV - all three V - compression of physis
Which side of the fracture has new cells?
calcification?
epiphysis - germinal/new cells
metaphysis - calcification
hypertrophic zone in between
tell me about the hypertrophic zone
contains giant cells, because these cells are mostly comprised by water this part of the physis is the weakest
In dogs there’s usually a certain type of salter harris fracture to occur
type V, closure of the growth plate, always damages the germinal cells
results in irregular conformation
Articular fractures
involve articular cartilage and subchondral bone
important to recognize!!
DEMAND anatomi reduction and rigid stabilization
diagnosis of fracture
hx
dysfunction (lameness/dyspnea/neurologic signs)
pain
trauma/swelling
abnormal conformation
crepitus ('potato chip' crunchy feeling)
radiographsfracture assessment score
developed to assist surgeons in decision making
- high scores - young dog, good health, cancellous bone toy breeds, compression fractures, good client compliance
- low scores - old sick dog, cortical bone, non reducible, multiple limb injury, large dog, bad client
