1. Fracture Classification

Question 1

strength of bone is dependent on

Answer 1

material properties
structural properties
rate of load applied (viscoelastic)
orientation of load applied (anisotropic)

Question 2

tension force
causes ______ fractures
occurs at?

Answer 2

avulsion fractures (especially in skeletally immature animals)
apophyses (olecranon, calcaneus, tibial tuberosity)

Question 3

compression force causes _____ fractures

occurs at?

Answer 3

short oblique

typically only in the spine b/c most bones are so dense

Question 4

Shear forces

common fracture?

Answer 4

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

Question 5

bending forces

Answer 5

• compressive force on concave surface and tensile on convex.
• causes transverse or short oblique fractures

Question 6

torsion

Answer 6

rotational forces applied along long axis results in spiral fractures

Question 7

Incomplete fractures

Answer 7

greenstick (opposing cortices involved, especially young animals)
fissure (only one cortex)
- can be splinted/casted

Question 8

transverse fracture

Answer 8

perpendicular to long axis, smooth or serrated fracture surfaces

• result from bending forces
• stable to compressive forces, can be reduced

Question 9

oblique fracture

Answer 9

opposing cortices are in the same plane

• result of axial compression and bending forces
• NO STABILITY even when reduced, not even to compressive forces

Question 10

Spiral fracture

Answer 10

fracture line is also diagonal like oblique but the opposing cortices are in different planes.

• result of torsional force
• inherent stability if anatomicaly reduced

Question 11

comminuted fracture

Answer 11

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

Question 12

segmental fractures

Answer 12

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)

Question 13

Open fractures

Answer 13

• 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

Question 14

a fracture in which location will have the least help healing? (eg. blood supply, muscle attachments)

Answer 14

diaphyseal

Question 15

Salter Harris fracture Classifications

Answer 15

I- physis
II - meta/physis
III - Epi/physis
IV - all three
V - compression of physis

Question 16

Which side of the fracture has new cells?

calcification?

Answer 16

epiphysis - germinal/new cells
metaphysis - calcification

hypertrophic zone in between

Question 17

tell me about the hypertrophic zone

Answer 17

contains giant cells, because these cells are mostly comprised by water this part of the physis is the weakest

Question 18

In dogs there’s usually a certain type of salter harris fracture to occur

Answer 18

type V, closure of the growth plate, always damages the germinal cells
results in irregular conformation

Question 19

Articular fractures

Answer 19

involve articular cartilage and subchondral bone
important to recognize!!
DEMAND anatomi reduction and rigid stabilization

Question 20

diagnosis of fracture

Answer 20

hx
dysfunction (lameness/dyspnea/neurologic signs)
pain
trauma/swelling
abnormal conformation
crepitus ('potato chip' crunchy feeling)
radiographs

Question 21

fracture assessment score

Answer 21

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