A Guide to Sealing Sleeve Repair

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By Travis Petersen, CPOA
Figure 1

For those of you who work with vacuum or suction suspension systems, you may have realized that the sealing sleeve is the weak link. Constantly replacing sealing sleeves is costly, but if a sealing sleeve only has a few small holes in it, it can be repaired quickly and inexpensively.

Many times the holes may be too small to see with the naked eye. To find the holes, turn the sleeve inside out and stretch it over a conical-shaped object, such as an old liner drier or a prosthetic cone, and spray it with a 50/50 mixture of alcohol and water (Figure 1). This will seep through the holes and wet the fabric, making a visible spot and cleaning the inside of the sleeve simultaneously. Make sure to mark any holes with a marker so that when you turn the sleeve right-side out you can still identify their locations. If there are only one or two holes close together, the repair will be easy. If there are many holes, it may not be worth repairing the sleeve. It is also important to note that if the fabric is pulling away from the gel, you will not be able to repair the sleeve.

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The next step is to patch the sleeve. To do this, you will need a material called plastisol, which is an inexpensive liquid vinyl that can be purchased online from fishing suppliers (Figure 2). It is the same material that is used to make plastic worms for fishing. Pour about 1/4 cup of the plastisol into a coffee mug and heat it in a microwave oven for 60 to 90 seconds. It will turn clear and will be in a liquid state when it is ready to use; if you overheat it, it will turn yellow but will still be useable. However, if it is not hot enough, it will be too viscous to pour. Plastisol gels as it cools, so once it's heated you need to work quickly to pour it.

I use a piece of a prosthetic pylon for my mold, but you can use any piece of pipe of a size that will cover the holes; a pipe of about 1 and 1/4 inches in diameter is sufficient. The pipe should be about 2 inches long, or short enough so you can see how much plastisol you are pouring in. Place the pipe over the hole on the fabric side, with ample room around the hole to form a seal. You only need about 1/8-inch thickness of plastisol over the hole and 1/4 inch around the hole. When you see the fabric change color, giving it a wet look, you will know that the plastisol has contacted the underlying gel material, forming a seal around the hole (Figure 3). Never pour hot plastisol directly onto a hole on the underside of the sleeve, nor pour thinner onto a hole as that will crack the existing gel and make the hole larger.

After the plastisol has cooled, which only takes about a minute, you can remove the pylon. Use the same pipe to make a fabric patch to cover the gel patch. Place the pylon on a polyester fabric of your choosing. I use a fabric that is similar to the sleeve color. Use a scalpel and cut around the outside edge of the pylon to make your patch. For improved aesthetics, you can trim the plastisol patch around the edge so it is beveled; this also makes stitching on the cloth patch easier. Next, you will need to hand stitch the fabric patch to the sleeve cloth (Figure 4). This needs to be done carefully so as to not poke another hole in the sleeve. After the patch is stitched and tied off, you may use a soldering iron to burn the ends of the thread to clean it up. Be careful not to burn the fabric.

Your patch is now ready to be tested for suction; I use a special suction cone device I created for this purpose, which has a nylon stockinette covering for wicking. (Author's note: See sidebar below for assembly instructions.)  I pull the sleeve over the cone and lay it flat around the edges to ensure a good seal. Then I evacuate the air using a hand pump, and if the patch is good, the suction should hold steady. Make sure that the patched hole is over the nylon to test whether the patch is sealed correctly (Figure 5).

If you are successful in patching the liner, you can reassemble the prosthesis. The whole process of patching the sleeve takes about 15 to 20 minutes, so you can get your patient up and going in no time at all. I have many patients who have patches on their sleeves that are still holding six to nine months later. The plastisol will harden slightly over time, but it has not shown signs of wearing out. Good luck!

parts list

Travis Petersen, CPOA, works as an assistant and technician at Alpha-Omega Orthotics & Prosthetics, Springfield, Missouri. He has also worked as a technician for other companies in Missouri. He can be contacted at

diagram

To assemble a suction cone, put a sealing sleeve over an old prosthetic cone and mark where the edges of the sleeve are. Remove the sleeve and mark in between the edge lines, making a 3- to 4-inch band in the middle. Drill a hole in the middle of the 3- to 4-inch band into which the nipple will be threaded. Drill a hole at the base of the cone that is large enough through which the vacuum line can be pulled. Drill a hole at the top of the cone that is big enough to insert the Hg gauge into, and then thread the nipple into it. Thread the nipple so the barb is on the inside of the cone. Cut pieces of hose that are long enough to connect between the Hg gauge, the nipple, and the T-nipple, and then connect them as pictured in the diagram. Then, cut a piece of hose long enough to go from the T-nipple through the hole at the base and extend out 4 to 5 inches. Connect the extruding hose to the check valve. Connect the hand pump to the check valve, and then test the system for suction by placing your finger over the test hole and pumping. If the gauge holds steady, then you know there are no leaks. Take your finger off the hole, and if the vacuum drops, then you know the system works properly. If the pressure stays, then you know that the check valve is on backward. After you have tested the system, use some electrical tape to fasten a band of stockinette around the middle of the cone so that air will wick away from where your patches will be on the sleeves.