AFO's used with knee flexion contractures

AFO's used with knee flexion contractures

Don Freeman

6/17/1998

To O and P Community,

Here are the responses I received to the following posting.
Thank you all for your assistance.

Don Freeman,CP
Shriners Hospital for Children, Portland, Oregon
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> I am interested in your experience with using orthoses on
> patients with knee flexion contractures.
>
> Specifically, I have an active 14yr old male with
> myelomeningocele with 20 degree bilateral knee flexion
> contractures. Surgery is not an option to decrease the knee
> flexion contractures.
>
> ROM: Hips=normal,Knees=20 to 140,Ankles= normal
> MUSCLE TEST: Hips and knees= normal, Ankles: Dorsiflexiors = zero, Plantar flexors=trace
>
> Questions:
> 1) Has any research been done on the use of AFO’s with knee
> flexion contractures?
>
> 2) What has been your experience fitting AFO’s with 20
> degree knee flexion contractures?
>
> 3)If a Floor reaction AFO is used does it provide an
> adequate knee extension moment throughout the gait cycle to
> improve their gait?? If so what position is the ankle best
> set in?
>
> 4 What is the maximum knee flexion contracture that can be
> accommodated with a floor reaction AFO?
>
> 5) Any suggestions, Titles of journal articles(source and
> author), or clinical experience would be helpful and
> appreciated! I will post the responses I receive.
>
RESPONSES
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Hi Don. This really is a big problem, and GRAFOs set in a little
dorsiflexion seem to affect the crouching by about 50% but won't ever
totally fix it in this situation. It probably works a little better for
SB than CP; in CP you again get partial improvement but also they will
really tend to lever up onto their toes and have very nearly the same
actual knee flexion in stance. We have used Ultraflex at night to try to
work on the knee flexion contractures, and also work on any hamsting
tightness; the other thing is to correct *any* hip flexion contracture if
at all possible. Even 10 degrees at the hip will drive the whole crouch
posture to be much worse especially if hamstrings are also tight and often
the patients are totally unaware of it because they just arch the
back/tilt the pelvis to compensate. Best regards,
Vikki Stefans, pediatric physiatrist (rehab doc for kids) and working
Mom of Sarah T. and Michael C., aka <Email Address Redacted>
Arkansas Children's Hospital/ U of A for Medical Sciences, Little Rock
...and EVERY mom is a working mom! (OK, dads too...)


I have made AFOs for similar situations but usually with ankles in Pflexed
posture. In order to have hips over feet, must set in sufficient Dflexion.
I would not anticipate any ground reaction force of any significance due to
Plumb point being very close to ball of foot. The child will probably
ambulate okay. That is all. Let me know what is the final solution.
Pat
---------------------------------
Don,
If one of the purposes of the AFOs is the restrain excessive DF in stance,
then it will be difficult to overcome excessive anterior-proximal tibial skin
pressure. However, I would be willing to try if three elements were present:
     1. There is a parallel therapeutic or surgical program addressing the KF
contaracatures. Also, you must be sure the contractures are myostatic, not
bony.
     2. A large area and well padded pretibial shell be used to reduce DR
restraining pressure.
     3. The patient should be compliant in inspecting his/her own skin until
full tolerance is attained adn the patient not be obese.

Good luck,

Tom Lunsford, CO
------------------------------------------------------

Don:

We at Rancho Los Amigos have been conducting several studies on
myelomeningocele children and AFO designs. I have been working with Jack
Greenfield CO and Jacky Heino PT on one project assessing 3 types of AFO
designs (articulating, posterior rigid and floor-reaction) and some of
these kids have presented with knee flexion contractures. A full gait
assessment is performed with each child and this allows for extensive
comparison between the different designs. I would suggest contacting Jacky
Heino at the Pathokinesiology Lab (562) 401 7177 if you wish to discuss our
research further.

Adrian Polliack Ph.D.
Rehab Engineer
Rehabilitation Engineering Program
Rancho Los Amigos Medical Center
----------------------------------------------------------

Don,

Talk to your Orthotists and your Motion Analysis people there at the
Shrine. You CANNOT expect a floor/ground reaction AFO to CORRECT a knee
flexion contracture. Biomechanically immpossible. Recheck the hip for
contracure/weakness. They are probably adding to the biomechanical problem
you are dealing with.

As Harold said, the child may walk further, but you can only expect to hold
the degree of knee flexion that he has. If hip extensor muscles are not at
least good, he will continue to flex at his knees and hips. Or he'll have
to hold himself up with crutches.

I have worked with hundreds of kids like this. The most the you can expect
from a floor/ground reaction AFO is support for a weak quad, properseptive
feedback to the anterior tibial area, and to hold the foot at 90 during
swing. All of these will be compromised if there is other muscle weakness
or joint contractures.

Try the AFOs but don't expect miracles. Good luck!

Terry Supan, CPO
Associate Professor
Director, Orthotic Prosthetic Services
SIU School of Medicine
PO Box 19230
Springfield, IL., USA, 62794-1420
phone: (217) 782-5682
-------------------------------------------------------------

Don,

If this patient crouches more than 20 degrees, a floor reaction AFO
will help to hold him in as much an upright position as he can
achieve. This should help to prevent knee contractures from
increasing. I suspect that his ankles are also collapsing into
over pronation. If so, an attempt should also be made to control
this collapse.

I have followed a young man about the same age as your patient for
about 6 years. He was unable to tolerate complete control of his
over pronation nor full correction of his crouch(to the angle of his
contractures). His gait with his AFOs appeared very similar to his
gait without them. However, his AFOs allowed him to walk more
efficiently, using less energy and he didn't tire out as quickly with
them on.

Harold Anderson, CO
-------------------------------------------------------------------------------
A good bit of literature exists on the natural history of knee
flexion contractures in children with myelomeningocele, however none
comes to mind as to the use of below the knee (AFO, Floor reaction
AFO) orthoses. From the clinical picture your present, it seems like
a reasonable alternative. (Having said that, however, you may want
to re-assess the ankle motor power. If the child is 14 years old
with MMC, still ambulatory with below the knee orthoses, he's likely
a very low lumbar or even sacral functinal level. Thus, he would
likely have weakness in his hip extensors and abductors. This is
important because this is the major contributor to a Trendelenburg
Gait pattern, which in turn, places a rotary valgum/flexion moment on
the knee. THIS, in turn, commonly leads to the use of a Floor
Reaction AFO instead of just a solid ankle AFO.)
So, it seems that a Floor Reaction AFO, set in 10 degrees
dorsiflexion is worth considering. We've fit a number of low level
MMC children with this clinical picture successfully. Twenty degress
knee flexion IS just about the limit, as the basic rule of thumb is
to dorsiflex the ankle at about half the value of the measured knee
flexion contracture. Incidentally, the primary advantage of the FRO
over a standard solid ankle AFO is not only the higher lever arm for
a knee extension moment (which really is secondary in this case,
since the child should have normal strength quadriceps [L2,3-4]), but
primarily the broader distribution of extension force upon the tibia
(as apposed to a simple strap on an AFO).
Hope this helps, and good luck!
-Don Katz, C.O.
Texas Scottish Rite Hospital for Children
Dallas, Texas

---------------------------------------------------------------------------
Don,
First, It's good to hear from you! Hope all is well.
As far as AFO's for this use, I do not recall seeing this
done, but I won't say it's not possible. I should think that
one would use the same principles as when managing genu
recurvatum which is to approach the correction incrementally.
I would also think that an OOS or similar designed AFO would
be optimal due to its adjustability.
Good Luck!-- and stay in touch.
Robert
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Don, The obvious problem with a posterior trim line AFO is the flexion
moment that is generated after heel strike...this could destabilise your 14
year old considerably. Therefore, what about an anterior trim line AFO? The
knee flexion force is reduced at heel strike and providesa face to 'kneel
against' at foot flat. I don't know of any specific articles to which you
may refer, but I have had good assistance from Tim Bach, Biomechanic at the
National School of P & O here in Australia. I believe that his address is
<Email Address Redacted> Richard Ziegeler.
<Email Address Redacted>


----------------------
Don Freeman,CP
Shriners Hospital for Children, Portland,Oregon
<Email Address Redacted>