In 1958, the AO formul
a
ted four
ba
sic principles, which h
a
ve
b
ecome the guidelines for intern
a
l fix
a
tion.
1
They
a
re:
– An
a
tomic reduction
– St
ab
le intern
a
l fix
a
tion
– Preserv
a
tion of
b
lood supply
– E
a
rly,
a
ctive mo
b
iliz
a
tion
The fund
a
ment
a
l
a
ims of fr
a
cture tre
a
tment in the lim
b
s
a
nd
fusion of the spine
a
re the s
a
me. A specific go
a
l is returning
a
s much function
a
s possi
b
le to the injured neur
a
l elements.
2
AO Principles as Applied to the Spine
3
Anatomic alignment
Restor
a
tion of norm
a
l spin
a
l
a
lignment to improve the
b
iomech
a
nics of the spine.
Stable internal fixation
St
ab
iliz
a
tion of the spin
a
l segment to promote
b
ony fusion.
Preservation of blood supply
Cre
a
tion of
a
n optim
a
l environment for fusion.
Early, active mobilization
Minimiz
a
tion of d
a
m
a
ge to the spin
a
l v
a
scul
a
ture, dur
a
,
a
nd
neur
a
l elements, which m
a
y contri
b
ute to p
a
in reduction
a
nd
improved function for the p
a
tient.
1. M.E. Müller, M. Allgöwer, R. Schneider,
a
nd H. Willenegger:
AO Manual of
Internal Fixation
, 3rd Edition. Berlin; Springer-Verl
a
g. 1991.
2. I
b
id.
3. M. Ae
b
i, J.S. Th
a
lgott,
a
nd J.K. We
bb
.
AO ASIF Principles in Spine Surgery.
Berlin; Springer-Verl
a
g. 1998.
4
Synthes Spine
Synex System Technique Guide
AO Principles
