Friday, May 27, 2022

Responses: AFO for Tendo Achilles Injury

Troy Fink, CO

Yesterday I posted a question and have received numerous replies. thanks to
all who responded. There are some very insightful thoughts.

My plan is to use Double Adjustable Ankle Joints. This will allow me to
utilize all the possible configurations.

Thanks again,

Troy Fink, CO

ORIGINAL POST:

An orthopedic surgeon has written Rx for articulating AFO with plantarflexion
assist. Pt is otherwise active male, 3mos s/p injury with some heeling
evident. Doctor says it is okay for pt. to dorsiflex to neutral but not beyond.

I suggested dorsiflexion stop at about neutral and unrestricted
plantarflexion range of motion. I explained that a plantar assist would not be strong
enough to provide heel-off during stance phase. I also stated that I feared a
plantar assist would only complicate swing phase clearance.

The Doctor insists a plantarflexion assist is appropriate. I don’t feel good
about providing an orthosis in this configuration. I don’t think this is
appropriate as the patient will likely trip and fall.

Any thoughts? How would you treat a pt. with this diagnosis?

REPLIES:

I have done many of these for a foot and ankle orthopedist we work closely
with.
We make an articulated AFO with very heavy rubber bands (Otto Bock) spanning
the posterior opening to minimize dorsiflexion. It does not eliminate it but
does minimize the initial stretch and shock to TA during toe off. They have
worked extremely well for us.
*******************************
I would agree with you that pf assist probably not required. However….if
the physician wants pf assist he did not define the strength of pf assist. The
strength of the plantar assist is up to you. I would definitely start with very
light pf assist and with df stop at 0 degrees. Also add a contralateral
internal heel lift (6mm) to assist in clearing the affected / pf assisted
ankle/foot. If you use full foot plastic, you could add MTP extension 15-20 degrees to
assist toe clearance at initiation of swing.
*****************************************
ive used a double upright afo with double action ankle joints with pins ant
and springs post—–a sach heel can act as a plantar flexor———-
**********************************
I think I’d make the brace as the doctor ordered, but show it to him before
delivery to “make sure its what he wanted” and modify accordingly at that time.
Also, Otto Bock has a new DA joint out now that comes with springs with small
pins that fit inside the springs, so you can provide assist, but still limit
motion. That may be your best bet. I’ve used these joints, and they are quite
nice.
******************************************
Happy Medium, solid ankle. We do a lot of them with good results.
**********************************************
I am pleased to offer a general opinion. Without seeing the pt and
getting more Hx, I can only guess about these. I have had a number of
people come in with Achilles Tendon injuries (rupture, tendinitis), but
it sounds like this is more involved if the Dr. is asking for an AFO.
The normal treatment for either of these conditions is to put .25″
to .375″ heel lift bilaterally. This is to reduce the strain on the
Achilles Tendon. I would lower it gradually over a couple of months
until it is flat. If there is a risk of injury due to
inversion/eversion, a flare on the appropriate side could be added.
If you are looking at an AFO or some sort of articulated walking
cast, I would envision stopping motion at neutral with unrestricted
plantarflexion. I don’t know enough about the strength of
plantarflexion assist, so I can’t make any comments about what it does
to gait. Once the toe is off, the ankle is supposed to be dorsiflexed
for swing phase.
******************************************
Your physician is fruitty and doesn’t know what he is talking about. You need
to make the orthosis with cabability for both plantar assist and plantar
stop. Do your initial fitting with the AFO set-up for plantar resist and when the
expected problems appear, document the results and then make the appropriate
changes to the more appropriate plantar stop. Then discuss your decisions with
the patient (without making the physicisn seem like a complete jack-ass) and
then fax the notes of the fitting encounter to Dr. Jack-___. Hopefully, the
doctor will see the light and thank you for your wise judgement and refer all his
future brace patients to you and you will be invited to his home for
Thanksgiving and Christmas dinners with his family, but then again, maybe not. Have I
got stories?! Maybe some other time…
****************************************
I have used a metal short leg brace connected to a conventional shoe with a
heel lift. This way the patient can be as active as he wishes and not be able
to re-tear his achilles. One adult patient played an entire softball season
this way and a physical education teacher coached varsity soccer. The heal
elevation about one inch is essential, and can be put on both shoes for balance. The
metal short leg brace allows free plantar flexion so range of motion is
restored. The patient can work back up to neutral and dorsiflexion out of the brace
and non- weight bearing. Good luck.
*************************************************
We had a forestry firefighter with a similiar problem. We used a custom AFO
that was anterior and the dorsum of the foot with Tamarack joints (adding
Friddle fire truck transfer). It worked great and he loved it. It also fit into
fireboots.
***********************************************
I’d go ahead with your design using some metal free-motion jts. (gaffney or
eq.) and dorsi stop. Then add the assist with those rubber bands that you
would usually use for dorsi assist, but put them behind the ankle jts to
give you the plantar assist. Remember to mount them with the ankle in PF so
you’ll actually get some force. The heel off wont matter anyway, (as it is
really the 90 deg. dorsi stop that makes that happen) but you are right, you
would need some strong DF’s to overcome a PF assist… especially over time
and distance. Anyway, this would allow you to try it out with the MD to see
if the PF assist is even necessary, and if not, you can easily remove the
assist bands – and keep your still functional AFO, as well as your still
functional referral source!!! (When you end up being right, don’t jump up
and down and say “I told you so”…) Good luck!!!
************************************************
Sometimes we’re in these “Dr ordered” situations and they’re not nice. I
agree with you that providing a plantar assist will be a nightmare during
swing. I’d suggest that you make the afo with 90 degree dorsi stop, free
range plantar and then put some sort of elastic back check strap on it. In
this way you can show the Dr that his strap causes swing problems and you
still get the afo you (and I) would like to build. Sometimes you have to
give the people what they want to prove to them that your idea is actually
better. This is where, unfortunately, some referring drs should have more
faith in our knowledge and experience. Good luck!
****************************************
I would respectfully decline to provide this brace, and suggest that the
Doctor seek the opinion of other orthotists in the area. Perhaps after
three or four of them tell him he’s going about this wrong, he would step
down off his frigging pedestal and do something more conservative and
conventional.
**************************************
Diplomatically educate your doc: “Current orthotic technology does not
provide for plantar-flexion assist at this time. Strategically
stopping/resisting dorsi-flexion is the most appropriate/commonly
accepted means of accommodating/protecting/assisting compromised triceps
surae and facilitating mid-late stance. We would recommend managing
your patient with an articulated AFO with free plantar-flexion and
dorsi-flexion stop @ neutral…bla..bla” Send above letter with “Re:
orthotic prescription MODIFICATION request” along with new Rx and Doc
will likely oblige. And why articulate your orthosis? What significant
benefits does patient (or his compromised triceps surae) receive from
allowing plantar-flexion in early stance? Benefits are suspect. And
hope they significantly out way increased bulk, weight, cost and
decreased durability and cosmesis of artic vs. solid.
******************************************
During the past three decades I’ve seen dozens of these post-op. My usual
is what you are recommending. When serious protection is needed I use metal
sidebars and an extended steel shank in the shoe. I always recommend free
plantar flexion and a 90-degree dorsiflexion stop. This combination has the
effect of a toe-off (plantar flexion) assist.

Depending on his level of experience, I would guess that this is what the
doctor is thinking of. Your challenge is to diplomatically explain the
above then ask if this is what you should have understood him to say the
first time.
************************************************
I would suggest the cam type boot made specifically for achilles tendon
tears. This is made by bledsoe and has wedges that remove to eventually bring the
patient up into a neutral position. The AFO that you suggested with give the
patient a very unsymetrical gait and cause difficulty with rollover during
stance phase.

Hpoe this helps
***********************************************
You will be hard pressed to find a plantar assist joint/mechanism that can
overcome the patient’s weight at Terminal Stance. At best you might get
plantar resistance. And even then, like you said, unless you limit plantar
flexion as well, toe clearance during Swing would be an issue.
I agree with your recommendation: Dorsi stop with free plantar motion.

How good of a relationship do you have with this doc? It doesn’t sound like
he is apt to be open for a quick education on AFO’s and their effect on
gait…good luck!
**********************************************
A positive up-stop (dorsiflexion stop) is a must. A pre-tibial cuff is needed
to control upstop. I always recommend a 1/2 t0 1″ heel lift.
************************************************
Interesting dilemma. Could you post any replies you receive to this question?
Thanks.
*******************************************************
My recommendation is for a solid ankle AFO. The value of the solid ankle is
that the real potential for damage is with the activation of the
gastrocnemeus in the gait cycle. This extremely powerful muscle has the
capability of disrupting the compromised achilles tendon even after
significant time has elapsed for healing. If a ROM is allowed at the ankle
then the body will cause the gastroc to fire, thus putting the achilles
tendon at risk.
The angle of the ankle should be adjustable to carry the patient through the
rehab process, i.e., 15 degrees plantar flexion, then 10 degrees, 5 degrees,
zero, etc. There are several joints available that can be utilized in an
articulated AFO. Muscle strengthening will take place after complete
healing has occurred.
***************************************************
Sorry no bright thoughts or suggestions
Please publish the responses
I think this is a really important issue
**********************************************
I’ve fit several AFO’s that were designed to treat Achilles Tendon Injury /
repair. Initially, my concerns were the same as yours regarding clearance
during swing. I confirmed with the ordering physician that he was not
looking to provide a mechanism for active planterflexion at terminal stance,
rather he wanted to address the deficiency he saw late in loading response
through midstance. The thermoplastic AFO can be designed with you choice of
ankle joint that allows free ROM in the sagital plane. On the posterior of
the AFO we attached the mechanism (similar to a Gaffney flexor band) that
would resist dorsiflexion (thereby assisting the plantarflexors). It is key
to be able to adjust the resistance of the band and ROM at which it begins
to resist dorsiflexion during your fitting. I’ve found that depending on
the individual, the resistance varies widely, but the ROM is set somewhere
near neutral or in a few degrees of dorsiflexion so that clearance in swing
can be achieved. The resulting orthosis is one that assists the
plantarflexors in controling the progression of the body over the foot early
in stance. Hope that helps.
************************************************
We have for a couple of years now fitted ROM camwalkers for TA surgical
patients for one of our referring surgeons. The PF’n assist is not so much
for assist in push of but to pull the foot down into PF’n, as a protective
measure. The pt can PWB with crutches and passively stretch the TA by
allowing thw wt of the lsg to DF. The tension adjustable elastic strap is
attached to a calf band we add to the arms of the CW and passively pulls the
ankle back into DF’n when the weight of the limb is reduced or at rest. We
fit these about 10/7 post-op and have a -15 deg DF’n stop for the first 1-2
weeks. We then allow DF’n to 0 deg. Patients are encouraged to exercise by
actively DFing the ankle against the tension strap, hence the need to have
it adj so it’s not too hard to exercise against but strong enough to pull
the foot back into PF’n. We usually seet the PF’n stop to a comfortable
angle set usuallt a comfortable angle the foot/ankle is in after POP
removal. We fit the CW in the surgeons rooms at the time of POP removal.

The whole idea behind this method is early mobilisation of the achilles
tendon/surgical site. It does decrease the rehab time for our TA patients
when we compare them to the static fixed PF’n patients. The early
mobilisation reduces adhesions from the surgical site and “reported”
re-alignment of the collagen structures in the healing tendon.

There is an article, published about ?2-3y ago that outlines this process.
The CW altered was a DonJoy (any with an adj ROM joint will be fine). If you
have trouble searching for it e-mail me back and I will try and dig it up.

This technique has worked well for us and we continue to do these for this
particular surgeon.
*****************************************************
Form what you have written, I would agree with you. Is the requesting
physician a surgeon? I can’t think of any situation where a plantar flexion
assist is warranted, can you?
*************************************************
THAT’S ALL FOLKS!!

RECENT NEWS

Get unlimited access!

Join EDGE ADVANTAGE and unlock The O&P EDGE's vast library of archived content.

O&P JOBS

Welcome Back!

Login to your account below

Retrieve your password

Please enter your username or email address to reset your password.

The O&P EDGE Magazine
Are you sure want to unlock this post?
Unlock left : 0
Are you sure want to cancel subscription?