Exam 2 - Goh Material

Question 1

what is direct healing

Answer 1

intramembranous ossification

Question 2

what is indirect healing?
what are the steps?

Answer 2

endochondral ossification
1. hematoma
2. fibrocartilaginous callus
3. bony callus
4. bone remodeling

Question 3

what dictates the type of healing?

Answer 3

fracture gap width and stability

Question 4

fracture gap strain formula

how much can lamellar bone have

Answer 4

change in gap width / original gap width

< 2% strain

Question 5

which healing has a faster speed of bone healing?

Answer 5

indirect/secondary is faster

Question 6

how can you reduce strain?

Answer 6

wider original fracture gap width
increase stability - bone callus diameter (because stabilizing influence is a factor of radius^4)

Question 7

majority of fractures are non-reconstructable or reconstructable?

Answer 7

non-reconstructable

Question 8

what initial stabilization do you use for an injury distal to the stifle or elbow?

Answer 8

robert jones bandage

Question 9

what initial stabilization do you use for an injury proximal to the stifle or elbow?

Answer 9

crate rest
analgesia
nursing support

Question 10

what injuries are good for a cast?

Answer 10

transverse fractures
fracture with internal support - metacarpals or paired bones
partial fractures

Question 11

what forces are cast good for

Answer 11

bending
rotation

Question 12

when can you use a cast relative to joints

Answer 12

fractures below the elbow or stifle
must immobilize the joint above and below the fracture

Question 13

what can you add to a cast to prevent digits from contacting the ground with fractures distal to carpus or tarsus

Answer 13

walking bars

Question 14

what is unique about toy breeds

Answer 14

poor blood supply to distal radius and ulna
slow bone healing
avoid coaptation

Question 15

when can you use a splint instead of a cast

Answer 15

soft tissue injury - strain or sprain

Question 16

what are half pins?

Answer 16

end threaded
dont go through both sides of bone

Question 17

what are full pins?

Answer 17

centrally threaded
go through both sides of bone

Question 18

pros of an ESF

Answer 18

affordable, reusable
closed, minimally invasive
improved access to wound
can adjust stability for phases of healing
minor procedure to remove

Question 19

cons of an ESF

Answer 19

pins can cause soft tissue irritation or infection
not good for all bones or patients
eccentric position of connecting bar is weak
weekly post op care

Question 20

what forces does an ESF combat

Answer 20

all forces

Question 21

indications for ESF

Answer 21

ALD correction
limb lengthening
tib/fib & radius/ulna
mandible
birds
open fx

Question 22

list ESF configurations

Answer 22

unilateral
bilateral (must have > 1 full pin)
uniplanar
biplanar

Question 23

other ESF classifications

Answer 23

linear
circular
hybrid (both)
freeform (acrylic)

Question 24

describe staged disassembly of ESF

Answer 24

Frame gradually dismantled to allow increased loading by the healing fracture
Remove pins causing morbidity
Downgrade frame configuration

Question 25

pros of IM pin + cerclage wire

Answer 25

affordable somewhat simple

Question 26

cons on IM pin + cerclage wire

Answer 26

limited fx scenarios required rapid healing limited stability prone to complications

Question 27

what fractures can you use an IM pin + wire

Answer 27

long oblique oblique butterfly long spiral

Question 28

for an IM pin + wire the fracture line length must be at least _____

Answer 28

2x the diameter of the bone

Question 29

can you use an IM pin and wire on a comminuted fx?

Answer 29

NO requires complete/perfect reconstruction

Question 30

what spacing is required for cerclage wire

Answer 30

at least 2 wires spaced 1/2 bone diameter apart

Question 31

differentiate between an ILN and IM pin

Answer 31

ILN - IM pin + bolts that lock into the IM pin

Question 32

an IM pin should fill what % of the canal

Answer 32

60-70%

Question 33

do tight or loose cerclage wire impede blood supply

Answer 33

loose wires devascularize & disrupt callus formation

Question 34

pros of bone plate + screws

Answer 34

suitable for reconstruction or bridging highly stable/durable early return to limb use low post-op maintenance

Question 35

cons of bone plate + screws

Answer 35

expensive extensive inventory challenging

Question 36

compression plating technique

Answer 36

ideal load sharing reconstructable simple transverse fx dynamic compression plates (DCP)

Question 37

how do dynamic compression plates work

Answer 37

tighten eccentrically placed screw slides plate along bone = compressing the fx

Question 38

neutralization plating technique

Answer 38

partial load sharing reconstructable butterfly fx doesn't compress or distract, just holds everything in place

Question 39

buttress/bridge plating technique

Answer 39

non-load sharing non-reconstructable comminuted fx plate prevents collapse of fx all weight-bearing forces are transmitted through plate/screws

Question 40

how does a lag screw work

Answer 40

compress fragments (interfragmentary compression) screw threads don't engage side of bone closest to head

Question 41

what forces do bone plates + screws combat

Answer 41

all - bending, rotation, compression, tension

Question 42

what are unique features about a locking screw/plate system

Answer 42

rigid link fixed screw angle bone plate functions as an internal fixator

Question 43

delayed union and non-union treatment

Answer 43

prevention

Question 44

delayed union and non-union prognosis is based on

Answer 44

neuro exam muscle contracture

Question 45

types of malunions

Answer 45

varus valgus procurvatum recurvatum pronation supination bone shortening torsional

Question 46

malunion prognosis

Answer 46

procurvatum/recurvatum well tolerated varus better than vargus torsional NOT well tolerated short hind limb better than forelimb