AO Principles

Question 1

How tight should a 2.0mm screw be?
A 2.7mm?
A 3.5?

Answer 1

2.0 = two finger
2.7 = three finger
3.5 = whole hand

Question 2

The AO drill guides are color coded. What color is the eccentric (load) side and how far off center is it?

What color is the concentric (neutral) side and how far off center is it?

Answer 2

Eccentric = gold, 1mm off center for compression

Concentric = green (neutral) 0.1mm off center so small amount of compression

Question 3

The universal drill guide is spring loaded. If you press it down, what are you getting?

Answer 3

Press down = outer sleeve against plate = neutral
If only inner sleeve is against hole you are doing compression.

Question 4

2.0 and 2.7mm DCPs can compress up to how much at fracture site?

How about 3.5 and 4.5?

Answer 4

2.0/2.7 = 0.8mm

3.5/4.5 = 1mm

Question 5

How much inclination in the longitudinal and transverse planes do you get with a DCP?

Answer 5

25 degrees longitudinal
7 degrees transverse