Calf WB AFO

Calf WB AFO

Molly Pitcher

11/8/1998

Dear list: Here's my original message and the many replies received.
Thanks to all who responded.
Original post: My patient has been using a rigid AFO for many years.
He
has chronic ankle pain from a series of sprains which occurred many
years ago while in the service. No surguries. Mild calf atrophy. No
swelling or contractures. Cannot WB without AFO. Pain with any motion.
He initially used a metal dbl upright/fixed jt but broke the stirrup
regularly. I switched him to a rigid poly PTB which he has done well
with...the PTB portion was trimmed down because of knee pain. Physician

could not identify problem but suggested it as an option. He still has
knee pain and now needs a new orthosis. The physician wants another PTB
design.
My ? is what experiences you have had with the Calf Corset WB/AFO
described in JPO, Vol4#1. I would like to use the rigid AFO design at
the ankle instead of fixed metal jts. Has anyone done this? problems?
other suggestions? Thanks, I will post the results. Molly Pitcher CPO

1.My facility has fitted quite a number of calf corset AFO's and it is
our
device of choice for unweighting the hindfoot and ankle complex. Our
method of fabrication is not too dissimilar to the original design - we
use
copolymer for the foot and calf shells moulded over USMC LM aluminium
uprights & modified stirrups. The internally articulated leather corset

laces up to provide suspension and the actual design of the articulation
is
quite important. We have tried calf corsets with velcro closures but
this
does not give the same positive grip as lacing. The leather calf
section
usually requires trimming once or twice during the first twelve months
due
to atrophy.
There is probably no reason why you couldn't utilise a composite
reinforced
polypro design but we have had really great results with the original
configuration. It is vastly superior to the PTB orthosis.
Don't forget to add material to the plantar surface of the hindfoot
before
moulding and to provide a small internal heel lift to the contralateral
side. If you need more info please email.

2. My facility has fitted quite a number of calf corset AFO's and it is
our
device of choice for unweighting the hindfoot and ankle complex. Our
method of fabrication is not too dissimilar to the original design - we
use
copolymer for the foot and calf shells moulded over USMC LM aluminium
uprights & modified stirrups. The internally articulated leather corset

laces up to provide suspension and the actual design of the articulation
is
quite important. We have tried calf corsets with velcro closures but
this
does not give the same positive grip as lacing. The leather calf
section
usually requires trimming once or twice during the first twelve months
due
to atrophy.
There is probably no reason why you couldn't utilise a composite
reinforced
polypro design but we have had really great results with the original
configuration. It is vastly superior to the PTB orthosis.
Don't forget to add material to the plantar surface of the hindfoot
before
moulding and to provide a small internal heel lift to the contralateral
side. If you need more info please email.
3. As far as the knee pain is concerned , it is not unusual for residual
knee
pain to persist when the pressure of the patient's weight is being born
unnaturally for an extended period of time. When comparing the
usefullness of
a PTB plastic orthosis to a leather lacer the most important factor is
going
to be whether your going to have trouble with your stirrups again and
whether
the cause of the paient 's knee pain can be adjusted or accounted for.
Second
is whether the continued reduction in size can be adequately
accommadated for
in the plastic orthosis.
The third problem will be whether the patient will accept a 70 to 100
percent
increase in weight betwee the two orthoses.
In my experience with the leather lacers they work well but do require
maintanence.
in particular leather breakdown and rivet replcaement. Also the need to
explain proper hygiene and sock wear with the orthosis. Most patients
who need
the continous support like the adjustability and their ability to
control
pressure which is definitely less with a plastic ptb orthosis.
As far as the knee pain I have had some patients say that the pain was
less
while wearing the leather lacer but when removed for rest or sleep it
came
back. Others have had enough of a reduction that the pain went away
altogether.
4. My experience was not successful. The patient found to make it work
the calf corset cut off his circulation.
-Be aware of the time it will make to fabricate it.
5. I've used that design successfully along with variations of it. Just
an
idea: Make a calf lacer for your patient using the PTB principles.
Then form your solid ankle (poly) AFO around the lacer and attach the
two suspending the lacer from the inside of the AFO. If you need more
rigidity, use carbon fibre or other composite material as inserts to
give strength. You would want to have plenty of strength from the poly
AFO to bear the weight of the leg semi suspended in the lacer(you may
not need full suspension).
6. Why does he need an AFO again? What was the orginal diagnosis? IE
     foot drop? Is the knee pain from wearing the PTB? Have you ever
     considered KAFO with an Ischial Gluteal seat?
7. In the practice I worked in SC we did quite a few calf-corsets and
they seemed to work ver
well. In fact, I think patient compliance was better in the leather
corset
than in the standard plastic and foam lined PTB orthosis. I skimmed
the
mention JPO article. We did not achieve 100% wt bearing at the calf
belly
as the authors describe. We split the load bearing between the gastrox
and
the medial tibial flare. We usually attached the uprights of the
orthosis
to the shoe in a conventional manner. We did not use a plastic insert
independent of the shoe as shown in the article. However, I think the
foot
and ankle design (conventional or plastic) are variable depending on
your
patient's needs.
8. Contact Roger Marzano, CPO at Yankee Bionics in Akron, OH (330)
668-4070.
He's very knowledgable and has had much experience in the use of this
orthosis
in the treatment of Charcot Arthropathy. He even wrote an article on
it; I
have a copy of it but there is no indication of where, or if it has ever
been
published.
9. we have used this design of an A.F.O. for almost 10 years. I first
saw this design when I was doing an internship at Gillette Childrens
Hospital in 1990. We call it a G.B.O. ( Gastroc Beraing Orthoses )
 I work at the V.A. Medical Center in Minneapolis, so my patient
population
is essentially geriatric. We see numerous charcot ankles and trauma
related foot-ankle malady. The G.B.O. design has increased patient
compliance tremendously. Patients that were non-compliant with a PTB
design, appreciate not having the knee involved in the unloading
process.
 The majority of the patients I see for G.B.O.'s have limited ankle ROM,

though we have fabricated G.B.O's with an articulated ankle.
 I suspend the calf corset with nylon webbing to the superstructure.
This
accomadates volume change in the extremity when necessary.
 I have done this (rigid poly AFO with PTB trimlines). I found
that I had most success when I reinforced across the ankle axis with a
corrugation moulded into the material by the impression of a piece of
3/16
cord tacked to the cast on both sides. This gave it the strength without

appreciably increasing bulk or weight. I have done this with both
Polyester
laminations and Polypropylene. However, something tells me that the knee

pain will not go away in your patient's case. I don't completely follow
why
a PTB is necessary; it is almost surely one of the reasons why he is
getting calf atrophy apart from the fixation of the ankle.
10. The calf lacer has worked well on a few patients. You may still get
some
flex at the ankle with poly pro depending on the size and weight of the
patient. A laminated AFO will give you the strength at the ankle
without
the bulk. You may also consider a rocker sole on the patients shoe to
aid
rollover. A prominent tibial crest may also warrant padding or
counter-relieving. Good Luck
11. I have had similar problems with a patient using a PTB design
that was made for me by OOS. When she required a new orthosis, she
developed non-specific knee pain that could not be dignosised. the pain
was
only present using the new orthosis. It turned out that the new
orthosis
put a slight varus stress on the knee aggravating some osteoarthritis in

the knee. A slight heel wedge in the shoe alleviated the problem. I
realize that I am not specifically answering your question, but it
should
be important to find out why your patient has knee pain before making
such
a drastic change in his orthosis
12. I have treated 6 or 8 patients with the design described by Marty
Carlson with
some modification from time to time. All in all, very good results.
Some issues that we have encountered are: vascular status is critical
whether
it has been an issue for the patient before or not...potential for
volume
fluctuations due to variable edema is directly correlated to vascular
status
(potential vascular insufficiencies, no matter how insignificant
previously
are magnafied)...patient requires reliable upper ext. function to
tighten the
system adequately (tightly!)...requires appropriate footwear to attatch
to...requires contralateral lift to equal leg lengths often...and it
tends to
be technically demanding to fabricate.
On the topic of ankle control, it seeems the ankle joint is invaluable
once
you have the patient ambulating, you can dynamically align and have the
ability to fine tune by adjusting the joints to optimum df/pf angle.
12.I have a question as to your patient's knee pain...is it pathologic
or
orthotic in origin?? I imagine it is orthotic due to the PTB trims but
if it's
pathological...this design offers little without significant
modifications.
Editorial: In use, I really felt like this was a far superior design to
the
PTB but it has some limitations. On the other hand, I have one patient
who
currently tolerates 100%
WB through the orthosis.
13. I have used that particularly design once. I had a Central Fab do
the work.
They did a fair job. It was fit about two years ago. It continues to
be
worn. The individual wearing it does not clean it well, nor does the
person
have good hygiene. But, he does manage to come in once a year to
complain
about cheap velcro and gets one strap repaired.

14. I cannot really say if the design works. This person never seemed
to
understand that it must be worn snug. When I snug it up it does
function as
the article described. I would be sure the plastic is very rigid.
Leave
plenty of space within also for the edema.
15. I have used it once.The patient has OA ankle with of pain++ on WB
and
with mov't. He had been fit with a number of AFOs previously to
immobilise the ankle. These had all helped to some degree. Tried the
calf corset WB/AFO with metal ankle hinges. This was worn for a period
of time with some success(some unweighting of the ankle and reduction in

pain). Eventually discontinued due to swelling in that limb, distally I
think. Patient lives a long way from clinic and has firm ideas about
what is going to do the job. Wont hesitate to modify an orthosis
himself. Not ideal test case.
In summary it can work but patient selection and regular follow-up are
crucial. Calf corset must be a very good fit and it's proximal posterior

trimline needs to be quite high and even flared so as not to dig in.
No experience with fixed ankle sorry.
Hope this is helpful.
16. Is your patient having a back bending moment of the knee? Where is
the knee pain? Since you are restricting dorsi flexion, did you put a
rocker
on the shoe? When you go PTB you are really positioning the knee in
space.
Does he walk to this leg or past it?