Most of us think we have an idea of what a prosthetic looks like. There’s the obviously visual: the prosthetic socket, which contains the residual limb, along with different knees and feet that are also visible.
What may be surprising is there are many other, often unseen, components that play a crucial role in the fit and function of the prosthesis. Most amputees wear a prosthetic liner, which goes directly over their skin and gives them cushion and protection from the socket. This liner is typically made of 11mm gel at its thickest point and gets thinner toward the top. Over the liner, socks of varying thickness can be worn in order to adjust the fit of the socket. Often, the residual limb will fluctuate in volume throughout the day and socks will be worn in order to compensate for that change. In addition to this, most below-knee amputees wear a gel sleeve for suspension of the prosthesis. Sleeves are usually 3mm thick and span from the prosthetic socket all the way to the patient’s thigh to keep the prosthetic leg on. While using a prosthetic, almost all lower-limb amputees will wear liners, socks, and sleeves at some point.
Although these components are necessary to the prosthesis, they do come with some adverse effects.
SWEAT AND PROSTHETICS
Liners, socks and sleeves are vital components, but they add extra bulk to the patient’s residual limb, and in turn create a lot of heat. Amputees at the below-knee level will most likely wear a liner, socks, and a sleeve at the same time, trapping heat on the residual limb. This heat produces sweat that cannot evaporate and sits on and around the residual limb and prosthetic liner. Compounding this effect, amputees tend to produce more sweat in general as their body surface area has decreased anywhere from 10-15% with amputation. Because of this, their bodies work harder and produce more sweat to cool themselves down (3).
Another factor at play is the energy required to ambulate as an amputee. In order to walk and complete daily tasks, a below-knee amputee uses 10-40% more energy than an able-bodied person (3). This energy requirement is even higher for amputees at the above knee level. The increase in energy also causes an increase in sweat production. It is because of this, 70% of amputees consider sweating to be an issue, and up to two thirds claim sweating interferes with their daily activities (3).
WOUNDS CAN RESULT
Sweat is not only an inconvenience; it can be harmful to the residual limb. When sweat is trapped on the residual limb and liner, the environment around the limb is compromised. As the sweat cannot evaporate, the limb has a warm, moist, and nutrient rich environment, making it susceptible to bacteria growth (3). It also makes the skin softer and more fragile, and easier to breakdown. If this bacteria gets under the skin, it can cause a wound or infection, which can be hard to manage and often requires discontinued use of the prosthetic.
SILCARE LINER, A PROVEN SOLUTION
Because of these issues, the team at Blatchford created the Silcare Breathe liner. This liner has 14.6mm of gel at the bottom, tapering to 2mm at the top. Inside of the liner, the gel is specially finished to reduce friction and stress across the residual limb. It is also designed to stretch in both directions across the limb, further reducing friction and increasing comfort. What really sets this liner apart are the laser-drilled perforations equally spaced around the liner, allowing sweat and moisture to escape (1).
The Silcare Breathe liner offers many benefits. It allows sweat and moisture to be drawn away from the skin. When used with a one-way valve in the prosthetic socket, moisture can escape from both between the skin and liner; and between the liner and socket. Expelling this moisture reduces skin breakdown, decreases risk of infection, and increases overall patient comfort. With less moisture, patients experience less movement within the liner and greater proprioception of the prosthesis (1).
PROVEN EFFECTIVE
To show just how effective the Silcare line is, Blatchford has studied how it compares to standard liners on the market. Cyclist and runner Charlie Lewis is a high-level amputee who competes regularly. During the study, Charlie biked for 10 minutes with a standard liner and another 10 minutes with the Silcare Breathe liner.
The results showed that Charlie’s residual limb was 35.6 degrees cooler after the session with the Silcare liner, and his residual limb had much less perspiration on the skin. The perforations had clearly allowed the sweat to escape from the skin through the liner (2).
The Silcare liner technology is proven to be effective in reducing perspiration between the residual limb and prosthetic liner. This liner offers a solution to one of the most common issues lower limb amputees face while wearing a prosthesis. With it, amputees can worry less about sweat and continue with their active lifestyle
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RESOURCES
- (2021, February 25). Silcare Breathe Cushion Liner. Blatchford US & Canada - Mobility Made Possible. https://www.blatchfordus.com/products/silcare-breathe-cushion-liner/
- Case Study. (2015, October 12). Silcare Liners - Silicone Liners from Endolite. http://www.silcareliners.com/us/case-study
- McGrath, M., McCarthy, J., Gallego, A., Kercher, A., Zahedi, S., & Moser, D. (2019). The influence of perforated prosthetic liners on residual limb wound healing: a case report. Canadian Prosthetics & Orthotics Journal. https://doi.org/10.33137/cpoj.v2i1.32723