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5 Reasons Why Above-Knee Suction Sockets Lose Suspension

    Nowadays there are so many ways to suspend an above-the-knee prosthetic socket. One of the most popular is using suction with a one-way valve. Many above-knee amputees prefer this method because it can create the greatest sensation of oneness with their prosthesis, and when a suction socket fits well, it works exceedingly well. 

    Suction suspension is a effective method to suspend a prosthesis.

    The popularity of suction sockets is due in part to the fact that it doesn’t rely on expensive liners or other components to make it work. However, applying an above-knee suction socket requires the use of donning aids similar to either a nylon Launch Donning Sheath or a lotion to powder type product

    One of the issues with above-the-knee suction suspension is the difficulty in avoiding drastic size fluctuations in your residual limb. And as we all know, that's tough to do this time of year. The key is keeping the size of your residual limb within a very specific range. Understanding suction suspension offers little room for size changes requires you to stick to a prosthetic maintenance schedule to maintain the best socket fit and suspension. In this short read, we’ll discuss a few reasons why suction suspension fails and what you can do about it.

    1. Clogged One-Way Suction Valve

    Currently, there are too many variations of the suction valve available on the market, and most of them require cleaning. Often, dead skin, dirt, and grime can accumulate inside the valve and clog it, which affects suction. But most valves are easy to disassemble and clean. It’s important to have your Prosthetist check and clean your valve once every 3-4 months.

    2. Weight Change

    Both gaining and losing weight can affect how your residual limb sits inside your socket and directly impact your socket’s suction suspension. If you lose weight, your socket can become loose, introducing air into the socket and causing suspension failure. You can correct the effects of weight loss by using volume pads to tighten your socket. 

    Meanwhile, weight gain can also cause suction loss when you can no longer apply your socket onto your limb correctly. This causes an “adductor roll” to form along the inside brim, which creates its own set of uncomfortable issues. Essentially, suction failure happens when you’re unable to pull all of your skin inside the socket completely.  

    3. The Back Brim is Too Wide

    When the back or posterior brim is too wide, sitting down can create a loss of suction. This is because when the lip or shelf of the back brim hits the chair, the chair pushes into the back of your residual limb, which introduces air into the front part of the socket. This can be easily remedied by your Prosthetist by trimming the posterior brim so that when you sit on a hard surface, the shelf or lip doesn’t extend past your bottom.  

    4. Wallet Hallow

    Sometimes, the area in the back where most people place their wallets, can become loose and allow air into the system . And when this area is loose, you can expect to hear a “farting” sound. This can be remedied at home with volume pads which can effectively tighten the area and match the contouring of your femur better. 

    5. Unsuccessful Donning of Prosthesis

    Expecting to apply your prosthesis correctly on the first try doesn’t always work out. It can take multiple attempts to get your socket on successfully with all of your skin and tissue properly inside the socket. In these instances, consider using a different type of donning aid. 

    Many prefer to use powder and ace bandages while some prefer liquid powder or a nylon bag style donning aid. Experiment with different donning aids to find the one that works best for you. If you have questions about the different methods to apply a suction socket, contact us.  

    In summary, a suction suspending socket is a great way to hold your prosthesis in place and create that "bond." However, it requires a degree of upkeep, like maintaining your weight and a consistent prosthetic checkup schedule.

    What are your thoughts on suction suspension? Please leave a comment below.