Test 1: ex fix

Question 1

why use ex fix

Answer 1

easy to remove implants

can alter stability throughout healing process (start with a bunch of clamps very strong, then decrease as healing starts)

wound management/ open fracture

placed without a large incision

Question 2

parts of an ex fix

Answer 2

transfixation pin (goes through bone)

external connector bar

linkage devices (clamps)

Question 3

when to use smooth transfixation pin

Answer 3

young animals and simple fractures

exotics with small bones

cheaper but can loosen

Question 4

negative profile transfixation pin

Answer 4

thread is smaller then shaft diameter= weak point

Question 5

positive profile transfixation pins

Answer 5

thread bigger then shaft diameter

more expensive and can break cortical bone if inserted inproperly

Question 6

half vs full pins

Answer 6

half= go through both layers of bone but only attached to one bar

full= go through both layers of bone and attached at two sides

Question 7

what are connecting bars made of?

Answer 7

carbon fiber= light and less expensive

can be made of stainless steel, aluminum and graphite

Question 8

what can you use instead of connecting bar

Answer 8

acrylic or PMMA

can be placed in weird positions and for very small fractures

Question 9

Answer 9

type 1A- unilateral-uniplanar

single clamp

Question 10

Answer 10

Type 1A- unilateral-uniplanar

2 connection bars, stiffer but uncommon to use

Question 11

Answer 11

Type 1A- unilateral-uniplanar

double clamp
easier to place
very weak
not- commonly used

Question 12

Answer 12

type 1B: unilateral-biplanar

2 type IA configurations
at a 90 °angle to each other

Very strong in cranial- caudal bending

Question 13

Answer 13

type 2 bilateral- uniplanar

Question 14

Answer 14

type 3 bilateral-biplanar

Type II and IA (montage)

Interconnected for strength

Stiffest configuration

Question 15

Answer 15

tie in configuration

IM pin placed

Commonly used in the humerus and femur where large musculature and interference with thorax/abdomen prevent Types II and III

Question 16

surgical placement of ex fix

Answer 16

leg hanging- helps align/ reduce

can use closed, open or mini approach

try to decrease soft tissue and blood supply damage

Question 17

pins should not exceed — % of bone diameter

Answer 17

20

Question 18

connection bar should be placed — from the skin

Answer 18

0.5cm allows for swelling

Question 19

ex fix complications

Answer 19

pin lossening

infections

pin break

bone breaks at pin site

fracture nonunion

Question 20

staged disassembly/ dynamization

Answer 20

slowly take apart exfix as bone starts to heal

increase load on bone vs exfix over time

Question 21

Ilizarov

Answer 21

circular fixator
can lengthen bone by tightening bolts

Question 22

circular fixator

Answer 22

K-wires under tension attached to ring

can be used to lengthen bone

Question 23

Answer 23

hybrid fixator

combo of linear and ring fixator

used when distal fracture with a very small segment of bone or angular limb deformities

Question 24

distraction osteogenesis

Answer 24

used for bone lengthening/ straightening