Waterproof Cast Liner

People that get orthopedic injuries like a broken bone are often athletic or like to exercise, and want to get right back into it. However, they’re inhibited by the non-waterproof casting material (cotton lined splints, plaster of paris, etc). I remembered seeing a product demo at school with a typical latex glove versus a glove made of expanded polytetrafluoroethylene, or ePTFE--Gore Technologies’ primary material--and seeing how dry the hand in the ePTFE glove was 10-15 minutes after the glove was submerged in warm water. Based on the product demo, I thought that ePTFE would be a great material for casts. After doing a quick search, I found out that a cast product made of ePTFE does exist. The product shown below is called the Aquacast Liner, and it is a cast/splint liner made of the waterproof material called ePTFE.

Figure 1: AquaCast liner used to line a cast for a leg injury.

ePTFE is a great material for an application like this because it is flexible and provides natural padding, depending on how thick the material is manufactured to be. What separates ePTFE from typical cotton liners are its breathable and hygienic characteristics. The material can have varying levels of permeability depending on the manufacturing method, and in this application it has a selective permeability, with millions of tiny pores that are large enough to let water vapor molecules pass through, but small enough that liquid water molecules cannot permeate through. This means that the liner will stay dry even when the skin wrapped up inside of it gets warm and produces sweat.

Figure 2: AquaCast liner used to line a cast for an arm injury.

The AquaCast liner is ideal for getting back into physical activity through less serious fractures or through the later stages of recovery, especially because ePTFE exhibits antibacterial functionality and odor-absorbency characteristics, as well as some stiffness/support.

A couple reasons that ePTFE isn’t being used for all cast liners are likely its higher cost in comparison to cotton, and possibly more difficult disposal methods. If you’re interested in learning more about AquaCast and ePTFE, check out these websites:

Aquacast

Gore Technologies: ePTFE