Friday, December 2, 2022

Replies to KDA query

David FM Cooney, PT, CPO

Many thanks to all who replied to my question. As is the nature of this
field, the respondents reflected the myriad of approaches to a single
entity, and to all I am much obliged. The original offering and the replies:

I would like to inquire of your successful fittings and or suggestions for
the clinical presentation as follows – 40 year old male s/p elective knee
disarticulation surgery after a protracted salvage history of the lower
extremity due to a motorcycle accident. Of significant note is a flail,
ipsilateral upper extremity from the same accident. He is well motivated
and in otherwise good shape. An attempt to myodese and secure the
patella distally was not successful as he exhibits selective AP movement of
the distal tissues. The resultant limb is conical, with shaved condylar
margins and end-bearing capacity. There is good muscle tone in the

Given his UE involvement and the length considerations with a KDA, my
first thoughts were to fashion a standard suction socket with pull-in
technique in a sub-schial design given the distal WB capabilities. I had
thought about a liner and the attendant suspension options, but was
concerned with his ability to unilaterally don a liner as well as the added
length it would incur to the socket as a whole.

-have you considered an expandable wall socket for suspension and easy
donning and doffing?

-Have you considered the Warren Flip using a Steifenefer cushion liner.
I’ve had one-handed pts manage this liner well. Adds limb comfort w/o
too much length compromise. I saw one of John Warren KD pts using
this @ Walter Reed…impressive & quick. Search Warren Flip
Sounds like a fun pt.

-Go back to basics. Medial door with P/E hinge and Velcro strap with chaff
& loop. No problem with donning and tightening one-handed. Even with
the condyles shaved there still should be variances in the condylar and
supra condylar M/Ls. You can add S/C padding later and change the P/E
hinge if it breaks. Do you impression weight-bearing with good S/C

-I guess what I would worry about with a gel liner flexible enough for him
to don one handed is that it would allow pistoning/A-P movement of the
distal tissues, given the insecurity of the patella, especially if you were to
use a locking liner. Then of course as you mentioned there is the issue of
knee center. Even a non- locking liner seems to drop knee center
although I have seen KD patients use them with suction and are happy
with the result. A liner that resists rotation and pistoning may be too firm
for him to roll up easily. However you could do a trial just to see if he is
capable of donning the liner. My other idea is to make a suction socket as
you mentioned and he could don it by way of using prosthetic lotion,
a “wet fit” I guess it’s called instead of pulling into it. Perhaps that would
be easier to do one handed. Just a suggestion.

-I have fit many end bearing kd cases with the ossur seal in liner/lynn
valve. I prefer the single flap over the 5 ring style. If you can teach him to
don the liner single handedly, it does not take up extra room distally, and
it beats the hell out of pulling in.

-My experience with Kd’s even with good surgical considerations as you
mention- shaved condyles and soft tissue coverage, the distal condyles
need some padding.
Even a quad amputee I am currently working with is able to reverse and
don his liner using his teeth and residual limbs. Design liners are a good
option because you can thin them out distally and fill in undercuts, adding
extra padding where needed.
With options such as the blue four hole plate from velocity labs and the
new threaded adapter from ossur, it’s possible to minimize build height
while not compromising alignability.
The subishial socket is by far more comfortable than the higher transfem
sockets and is the way to go with a well padded residual limb.
Hope this helps!

-We just completed a similar case with fantastic results. It is a small
custom urethane distal cup cemented to a socket which is essentially a
brim with a rigid medial strut attaching to a distal cup and NOTHING else.
It is cool, stays on with suction and he ran a half marathon last weekend
on it. I will dig up some photos, but my partner is out of town for a few
weeks and has the camera.

-My personal preference for a KD would be the skin/dry fit with pull-in
sleeve. Best control, can donn with contralateral UE, and in my opinion the
best control over his prosthesis for ambulating. I would use a hydraulic
knee and depending on his walking terrain a good energy storing foot
(many choices) or Endolite’s Echelon foot (a little heavy but an excellent
foot for uneven terrain and slopes).

That’s my two cents, good luck.

Again, the List is a welcomed respite from the mired feelings of “what to
do”. Thank you to all.



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