Responses to water-proof componentry

Responses to water-proof componentry

Lynne Langschwager, CO, Resident Prosthetist

Thank you to all that responded.
 
Here's the original post:
 
 
What componentry is available for a transfemoral amputee that is
water-proof? So far, for knee units, I have found the 510 Aulie and the XT9 ESPK. Any
others? Also any recommendations for feet? This particular pt wants to
snow-board, rock climb, and not be concerned about getting his current
prosthesis, a C-leg, wet.
 
Lynne Langschwager, CO
Prosthetic Resident
 
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I think you have found the knees that are most durable in those
circumstances. The XT9 being a much more versatile knee. I would think that you need to
decide which foot would provide the most function (reasonably), then devise
a way to the elements.
You could also do a very simple manual lock or peg leg which would be as
durable as you could devise but provide stability ONLY.
Have you considered a Ferrier coupler so the expensive components could be
removed before these activities. Would need to know more about this patient
to provide additional input.
_______________
 
Remind him that his C-Leg knee unit is like a laptop computer. Laptops are
not good to dunk into water, bang against a rock face, and they don't fare
well with getting jumped on while snowboarding. In fact, tell him that if he
would not bring a laptop with him for these activities, he probably shouldn't
bring the C-Leg. If he wants to do all of these activities, fit him with a
Mauch S-n-S and a Ferrier Coupler. That way he can use the same socket without
doffing it and can switch out his walking set-up for a sports set-up while
keeping his alignment. The only other knee I know of that can perform as well as
an S-n-S unit in these types of activities is the 3R80 rotary knee by OB.
However, be aware that big patients with long residuums can break the axis of
the knee with extreme torque.

Feet are another story. As long as there is no exposed wood, a dynamic
carbon foot is essentially water proof. Carbon doesn't rust. Use stainless or Ti
screws, nuts, and washers, and locktite 242 everything. Lithium grease is a
wonderful waterproofing agent for most applications.

Also make sure there is a way for the water to drain out of the componentry,
otherwise your patient will be lugging a heavy foot and pylon. Not to
mention it will leak out very slowly while they are driving home, sitting on the
couch, and finally going to bed. Drip, drip, drip... Most very active TFA's
will carry a towel and wipe down their rigs after getting out of the water.

One more thing, WD-40, which most people assume is a lubricant, is actually
designed to displace water. Water Displacement compound #40... WD-40. Give
anything prone to corrosion a spray of WD-40 and wipe off the excess, or spray
some onto an already wet surface and watch the water dissipate. WD-40 in the
bottom of a socket, or in a lock, will save lots of time and frustration for
your patient, and it will keep things moving smoothly. But you should know
that it evaporates very slowly and dust and dirt will stick to it like glue.

For more info: _ <URL Redacted>
( <URL Redacted>)
 
__________________
 
I'd love to hear what the listserv comes up with.

I have a patient who is a commercial plumber and I too am concerned about
getting a C-leg wet. He kneels on wet surfaces all the time and sometimes
throws down a towel and other times doesn't bother. He also has been known
to be standing under a leaking pipe that suddenly gives out and soaks his
clothing. He's wearing a Mauch SNS with a titanium frame that he can wipe
off if he gets it wet, but he wants a C-leg and I've been reluctant to try
it due to the water issues. The plugs are supposedly water-tight, but so
was my waterproof watch that leaked and was ruined when I accidently
showered with it on.
___________________
 
 
For swim componentry, the aulie knee is good, but go with the xt9 if he
plans on doing any water sports. The xt9 is not easy to walk in, so he may want
to bring it along with his everyday leg. Ask Freedom Innovations about their
swim foot/ ankle now available in titanium.
 
For snowboarding, the water is not as much of a concern, more a concern of
breaking an expensive c-leg. The xt9 works very well in combination with a
good adaptive snowboard lesson. Catech/ Mauch work as well if you max out the
flexion resistance.
 
For rock climbing, the xt9 works well or simply locking a mauch or catech
unit out. Cleg in 2nd mode works too, just remember to use a knee pad or it's
likely to get scratched up. With feet, the climbing shoe needs to fit snug.
Sometimes, taking the footshell off the foot and using a smaller climbing
shoe allows the tip of the toe to be stiffer.