42
standardised
8
layer
POP
cylinders
of
appropriate
dimensions
were
fabricated,
of
which
21
were
split
longitudinally.
The
splints
were
subjected
to
non-destructive
tests
in
4-point
bending
(Bending),
3-Point
Kinking
(kinking)
and
torsion
modes,
and
the
load
at
clinically
relevant
end-points
was
recorded.
These
simulated
the
deformity
at
which
the
splint
no
longer
provided
adequate
stability
and
alignment,
or
at
which
the
wearer
was
no
longer
protected.
The
splints
were
then
loaded
to
destruction
to
establish
the
mode
of
ultimate
failure.
Results:
The
mean
loads
at
the
clinical
end
points
for
split
POP
splints
were:
1375
N
in
Bending,
544
N
in
Kinking
and
12
Nm
in
Torsion
(equalling
67.3%,
70.4%
and
47.4%
of
the
equivalent
values
for
a
circumferential
splints).
Loads
were
in
excess
of
body
weight
for
most
paediatric
patients.
After
ultimate
failure,
the
proportion
of
casts
that
became
unstable
was
similar
(44%
of
full
casts
and
50%
of
split
casts).
Conclusion:
Split
POP
splints
which
have
not
been
spread,
provide
adequate
stabilisation
and
protection
of
paediatric
forearm
fractures,
and
do
not
routinely
require
completion