Elevated Vacuum Prosthetics

Elevated Vacuum Prosthetics serves as a center for information exchange regarding theory, research, application, and experience of this emerging technology.

Answers to Questions Posted on Listserv

by Jon Batzdorff on Monday, April 26, 2010 5:54 PM

There was an excellent set of questions posted by a colleague on the O and P listserv. I will reprint  them here and comment with my initials on each question:

 1. What sleeves have you found to be the best? Obviously, the sleeves tend to be one of the weakest points of the system, and I'm wondering which sleeves have had the greatest durability in actual practice, rather than just theory. I've had patients using the OWW Alpha Flex sleeve, but they haven't lasted longer than their warranty period yet.

JB: For transfemoral, flexiblity is unimportant so resitance to wear, tear, and puncture is key. I have has good success with the Harmony sleeve or its equivalent.  For transtibial, the ALPS Easy Sleeve or its equivalent has worked well.

2. Which of the electronic pumps do you prefer, and why? I got disgusted with the harmony ePulse, due to my having to send nearly every one of them back, but I've heard it's been retooled. I've only used two limblogics, and I wonder how well they do, and how reliable they are.

JB: I have heard no complaints from any pump other than the ePulse, which did not work. I have not tried it lately either. DAW has a new one which looks promising and attaches around the pylon resulting in no added build height.

 3. What do you think of the Harmony mechanical pump in comparison to the electronic ones?

JB: The harmony is an excellent choice if there is suffient room for it with the desired componentry.  

4. Is there some other elevated vacuum suspension mechanism you may know of that you prefer?

JB: Evolution has recently released some exciting componentry. One is a distal attachment plate with a built in resevoir for vacuum, and the other is a sealing liner that allows the prosthetist to decide on the vertical location of the seal  on the liner. They also offer custom made liners fro elevated vacuum.

5. Does your answer differ between AK and BK patients, and why?

JB: Choice of suspension mechanism certainly depends on AK and BK, due to the often limited space available bewteen the AK distal socket and the knee. Almost any system can be used, but it is much less cumbersome if the pump fits between socket and knee.  

6. Especially regarding BK patients, how effective have you found it for them vs other types of suspension?

JB: Harmony offers the advantage of no chargin required, very simple to use, and the built in vertical shock absorber.

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Categories: Liners , Transfemoral , Transtibial
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Elevated Vacuum Liners- How do I choose?

by Jon Batzdorff on Monday, January 25, 2010 5:45 PM

Elevated vacuum sockets use gel liners as a skin interface. One of the first decisions required when fitting elevated vacuum is which liner?   I have my answer and, as always, I invite others to share their experiences and opinions.  

There are many aspects which vary from liner to liner. Among them are thickness, flow, durometer, durability, surface tackiness, and how hygienic the material is.
The first issue is custom or not custom. The elevated vacuum socket, which is total contact and which applies a negative pressure of up to 29”Hg, will can cause serious damage to the residual limb if the liner is not total contact with evenly distributed pressures on the skin when applied. (Uneven liner pressures translate to uneven negative pressures when the vacuum is applied). The only way a precise fit can be assured is with a custom liner. 
For transtibial residual limbs with bony prominences and minimal soft tissue protection, I prefer a liner with optimal “flow” to minimize shear forces. I have used the custom TEC liner. The original TEC liner is no longer available. Otto Bock has re-named it the PUR liner and changed the formula. Otto Bock reports that it is more durable and has better flow than the original. They have tested it and gotten good feedback.
For transfemoral residual limbs that are well protected in soft tissue and don’t need the extra flow of the liner material, I prefer the platinum cure silicon liner. It is durable and hygienic and can be fabricated in our facility, giving us optimal control of the fit and the process.  
Naturally there are exceptions. I am currently fitting a bilateral transfemoral amputee who has adhesions, scarring, and prominent bone spurs. I am using bilateral custom PUR liners in this case. I am also sure that in some cases one can find and fit off-the-shelf gel liners that fit like a custom liner and are acceptable. It depends on the shape of the residual limb and the available contours of the particular liner selected. It is certainly a more convenient and cheaper option when it works out.
I am not intentionally endorsing any specific manufacturers but rather stressing the need for an accurate fit and the desired characteristics.
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Categories: Liners , Transfemoral , Transtibial
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