May 17 2016 - New (To Me) Knee

17:00
I just spent a few hours with Bradley, my prosthetic guy.
The loaner Mauch knee was swapped for a loaner Total Knee 2000. A totally different concept in prosthetic knees.
My own Mauch Knee is still in Iceland getting repaired.
Tomorrow I will spend many hours with Bradley. I need a new socket. He wants to do completely new measurements as if from scratch. So tonight I will wear the silicone liner, AND in addition, I'll wrap the stump,  so that tomorrow it will be as small as possible.
The current socket is too big. I have to use 3 wool socks between the liner and the socket just to get it to fit. But that means the socket is more "sloppy" and doesn't fit tight.
With this new knee, I can feel the stump banging into the sides of the socket. Like a bell clanger.

The Total Knee 2000 is a polycentric knee. It uses lots of funny mechanical motion to do a few things.
It more mimics the motion of a real knee. The bottom part slides back as the knee bends, just like a real leg. It polycentric design also makes the leg get shorter as it bends. This makes it less likely to catch the toe on something because the leg is shorter while the leg is swinging forward. It also makes it lock much more solidly than the Mauch knee does.
The Mauch Knee uses hydraulics to cause resistance for the knee to unlock. So if it does unlock, it gives a warning of increased resistance in bending. You will still fall, but you have more warning, and you fall slower.
The Total Knee 2000 has like 2 possible states. Locked solid, and floppy.
The lock is much more positive than the Mauch Knee. With any weight on the heel it is locked solid. Very secure. Put weight on the toe, and it is floppy loose. Like no resistance to fold up.

Here is a short video showing the Total Knee 2000 motion.

https://youtu.be/FO_BTNMnJFM

I am actually fibbing a bit. The Total Knee 2000 has a very small hydraulic reservoir than feeds some small orifices, that create slight resistance to motion. I can't feel it, but the book says it is there.
The Total knee also uses colored rubber blocks to create the resistance to breaking loose force when standing with knee locked. This makes it easier or harder to enter floppy mode from locked mode.
The Mauch knee does all that with hydraulics.

Bradley has just been on an Ossur conference. There they told and showed all the newest innovations by the company. The companies newest prosthetic is called the "Pro-Flex". It is an intelligent ankle and foot unit. It allows 27 degrees of movement to the flexing of the ankle. It progressive increases resistance to the flexing to allow the weight to be on the toe, or on the heel. They claim it allows walking up and down slopes.
But it is still VERY expensive. To many zeros on the right of the price.

At the conference were many people from the different medical aids. Ossur showed many statistics regarding above knee amputation co-morbidities. They gave lots of examples and statistics showing that a medical aid paying extra for an active ankle actually saves the medical aid company money. Many above knee amputees soon have problems with the good knee because of the added stress put on the good knee. The Pro-Flex ankle reduces stress on the good knee by up to 70%. They also showed that a knee brace on the good knee saves money in the long run.

I'll know more tomorrow. Now for drugs to stop the PLP.
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