Liner Choices Create Comfort

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Comfort and more control can equal more mobility and confidence for lower-limb amputees. A key ingredient is the interface between socket and human skin provided by liners. As noted by the War Amps of Canada, liners greatly reduce pistoning in the socket, help accommodate volume fluctuation in the residual limb without compromising socket fit, and provide greater comfort with fewer skin abrasions. Locking liners also provide what the War Amps call the "most secure form of suspension" and improve the appearance of the limb because belts, straps, and neoprene sleeves are not needed to keep the limb in place.

The right liner helps amputees perform well in both occupational and leisure activities. Firefighter Karen Scruggs, a transfemoral amputee, finds Otto Bock's TF Adapt™ liner aids her in a high-risk profession. Karen is a member of the Amputee Firefighters Association, which provides advocacy, mutual support, and peer mentoring to firefighters, emergency medical personnel, and law enforcement officers who have suffered limb loss. For more information, visit AmpFireFtrAsso@aol.com (Photo courtesy of Otto Bock HealthCare)
The right liner helps amputees perform well in both occupational and leisure activities. Firefighter Karen Scruggs, a transfemoral amputee, finds Otto Bock's TF Adapt™ liner aids her in a high-risk profession. Karen is a member of the Amputee Firefighters Association, which provides advocacy, mutual support, and peer mentoring to firefighters, emergency medical personnel, and law enforcement officers who have suffered limb loss. For more information, visit AmpFireFtrAsso@aol.com (Photo courtesy of Otto Bock HealthCare)

Although revolutionary new developments aren't an everyday occurrence, liners have continued to improve. And one of the brightest spots in the picture is the variety of both off-the-shelf and custom options now available to amputees. "There's more accessibility--more models, more choices," says Kevin Carroll, MS, CP, FAAOP, vice president of Prosthetics for Hanger Prosthetics & Orthotics, Bethesda, Maryland. "That's great, because no liner is compatible with everyone."

Carroll also believes that liners overall have improved in durability, stain resistance, and comfort, although he notes that there are some out there that still tend to have a short life. Skin reactions to certain liner materials can be a problem. If an amputee has had previous skin problems with liners or has a history of allergies, the prosthetist may want to do a patch test with various liner materials first, Carroll says. The tackiness of a liner may be the problem, rather than allergy to the material. A nylon sheath against the skin is one solution; also careful hygiene, including following the manufacturer's directions for cleaning the liner, is highly important in avoiding skin problems.

Prosthetist's Brainchild: Freedom Innovations Liner

Transtibial amputee Shawn Whitaker is a big fan of Freedom Innovations' Evolution SP liner, which he says enables him to undertake a variety of athletic activities in comfort. (Photo courtesy of Freedom Innovations Inc.)
Transtibial amputee Shawn Whitaker is a big fan of Freedom Innovations' Evolution SP liner, which he says enables him to undertake a variety of athletic activities in comfort. (Photo courtesy of Freedom Innovations Inc.)

In the last two years or so, there have been some interesting developments in liner technology. For instance, Freedom Innovations Inc., Irvine, California, now offers a custom silicone liner, the Evolution SP, which the company says is comfortable, durable, and formulated to stay fresh and odor-free. According to the company, the liners are "the industry's first fully customized liners with standardized off-the-shelf prices."

The liner was created by Stan Patterson, CP, of Prosthetic & Orthotic Associates, Orlando, Florida. To read how Patterson developed the technology see "Prosthetist Inventor Seeks Solution" in this issue.

Why Aren't Custom Liners Used More?

Kevin Carroll is happy to see several different custom liners available today and believes they fill a real need in good patient care. "I'd be interested in knowing what percentage of amputees are in custom liners," he comments. Custom liners not only benefit patients with unusual, odd-shaped residual limbs, but also amputees who are coping with painful neuromas. For instance, a custom liner can be designed to take into account the location of the neuroma, whereas an off-the-shelf liner may not relieve pressure where it's needed.

However, Carroll examines the reasons why prosthetists aren't using "as many custom liners as we could or should." Reimbursement is a big problem. Although Medicare and many insurance companies will pay for one custom liner, they will only pay a standard off-the-shelf rate for the next one, because they figure the prosthetist already has the model/shape on hand, and so the next one will be less costly and time-consuming to fabricate.

Of course, prosthetists can save plaster casts, but then storage space is a problem, if they prefer to do in-house fabrication rather than outsourcing to a central fabrication facility. For instance, after a short time, a busy practice might have 40 or more casts hanging around, Carroll points out. And if the cast is given to the patient to keep, there is no guarantee that the patient will do so or will keep it from getting damaged.

Well, is computerized scanning and storing the computer file the answer? Not necessarily, Carroll notes. Although that might solve the cast storage space problem, fabricating another custom liner still involves lab time and expense, with reimbursement at only off-the-shelf level.

Another reason why custom liners aren't used as much as they could be is the time factor--often a big negative for both practitioner and patient, since the patient has to come in to be cast for the liner. Since the patient may have to travel a substantial distance to the facility, if a custom liner would help that particular patient, the practitioner may need to carefully explain the benefits to "sell" the patient on the idea, Carroll points out.

Custom liners can help make a big difference in quality of life for certain patients, Carroll says, noting the example of a young man who lost parts of all four limbs due to meningococcal meningitis. Now 18, he can look forward to a life of more mobility and opportunity, thanks to skilled prosthetic care that included carefully customized liners.

Although pleased with the variety of liners now available, Carroll would like to see more customized options in sleeves for hard-to-fit amputees, such as a very heavy patient with a large thigh area tapering down into a very small residual limb and socket.

OWW Offers Complete Package

The Alpha Max by OWW.
The Alpha Max by OWW.

The Ohio Willow Wood Company, Mt. Sterling, Ohio, now offers a "whole enchilada" approach to providing custom liners. Says the company, "Ohio Willow Wood introduces the first truly customized elastomer, gel-based liner, the Alpha ® DESIGN...[the liners] can be easily created through the use of OMEGA ™ Tracer 7.0 CAD system or from plaster casts. After capturing the limb shape, practitioners determine how much elastomer gel to apply throughout the liner and where." Prosthetists can add gel up to 12mm in thickness exactly where needed; for example, they can thin the gel down to 2mm behind the knee and apply up to 15mm over limb indentations.

Prosthetists can also choose the fabric style and color for the liners. Among fabric choices is the new Alpha MAX fabric, which when used in combination with the Stabilizing Strip, provides a one-two punch against movement and gel delamination, according to the company, which adds, "Both features work together to allow for circumferential stretch, while reducing any movement longitudinally in the socket."

The Amped Riders, an association of amputee skateboarders, snowboarders, and surfers, among others, noted in a product review: "The fabric on Alpha Spirit liners is more flexible than the Original fabric. Also, the Spirit fabric adheres to plastic hook, which allows for an improved suction suspension system. The highly abrasion-resistant Alpha MAX fabric makes it ideal for those who need maximum durability." (For more information, visit www.ampedriders.com .) The customized liners ship within 48 hours of order receipt.

Combined Concepts Create New Liner

Innovation is not always about creating something totally new; sometimes it can come from ingeniously using ideas that have been around for a while in a new way. For instance, Ossur, headquartered in Reykjavik, Iceland, with North American offices in Aliso Viejo, California, has combined the concept of a hypobaric seal with the concept of a roll-on liner to produce its Iceross ® Seal-In ™ Liners. The new liners eliminate the need for an external suspension sleeve, according to Ossur. "Liberation from the restriction of a sleeve offers substantially improved freedom of movement, increased comfort, and simplified maintenance," the company points out. Durability is also increased by eliminating the sleeve, "the weakest part of a traditional suction suspension system," according to the company. The Supplex ® cover has non-ravel stitching and high abrasion tolerance.

Iceross Seal-In liners incorporate a Hypobaric Sealing Membrane (HSM ™ ) that conforms to the shape of the internal socket wall, providing an airtight seal, the company explains. When the liner is donned and the socket is stepped into, air is expelled through a distal valve, creating hypobaric suction below the seal. "The proprietary matrix supports the HSM during donning by preventing elongation of the distal tissue," Ossur states. "A release button on the valve allows equalization of air pressure for easy removal of the prosthesis. Additionally, the matrix minimizes pistoning above and below the seal when suspension is required.

"With the HSM, the hypobaric pressure will always be in direct proportion to the suspension force needed, ensuring superior stability, comfort, and control," the company asserts.

The liners are available for both transtibial and transfemoral amputees in two durometers: the Iceross Dermo ® Seal-In, made of DermoGel silicone, and the Iceross Stabilo ™ Seal-In, made of DermoSil silicone. Both liners contain Active Skin Care ingredients to soothe and moisturize the skin.

Otto Bock: Something for Almost Everyone

Custom silicone liners by Otto Bock.
Custom silicone liners by Otto Bock.

Otto Bock HealthCare, Minneapolis, Minnesota, includes a large family of custom and off-the-shelf liners to meet the varying needs of amputees. Says the company, "We've developed a wide variety of sizes and shapes, available in different materials and configurations--so whether you are searching for silicone, urethane, or thermoplastic elastomers...we have a unique solution for your patient's situation." Custom liners are available in both urethane and silicone.

Otto Bock's proprietary silicone for custom liners is "significantly more durable than the standard silicones used in prefabricated liners," the company states. "This allows us to vary both thickness and durometer anywhere you choose." Also softer gel pads can be placed in the liner to target bony prominences and areas sensitive to skin breakdown. A distal connection or electrode can be embedded if desired.

"Custom urethane liners have been scientifically proven to reduce forces on the residual limb," the company points out. The material also provides high-level impact protection and resists thinning out under pressure.

Among Otto Bock's off-the-shelf liners are the Silicone Gel and TechnoGel™, which is made from aliphatic polyurethane to eliminate skin-sensitizing issues. For greater durability, the liners' fabric cover is constructed of ultra-high molecular weight (UHSW) polyethylene, the same fiber used to make bulletproof vests. These two liners can be used interchangeably.

Otto Bock's newest silicone gel liner, the TF Adapt ™ , is designed for transfemoral amputees and uses the same tough external fabric to extend liner life. A special matrix embedded in silicone "improves suspension by effectively eliminating pistoning," according to the company.

ESP Anatomical Design

Thermoliner cushion liner
Thermoliner cushion liner

ESP (Engineered Silicone Products) LLC, Sparta, New Jersey, founded in 1996 by Louis Haberman, CPO, includes the Aegis Streamline and Aegis Ultimate liners. ESP notes that these liners are distinguished by their contoured, anatomical design and pre-flexion at the knee, which it says provides a more "custom-like" fit and unrestricted range of motion in the knee.

ALPS Liner Easily Customizable

A recent innovation from ALPS, St. Petersburg, Florida, is its new Thermoliner ™ Locking Liner, which enables the prosthetist to customize and shape a gel interface to the configuration of the user. "By simply applying the Thermoliner Locking Liner over the positive and placing it in the oven for 30 minutes at 194 degrees F, the customization is complete," says the company. The liner can be pulled on like a sock, making donning easier and is adaptable to most users, including Symes and knee disarticulation amputees and amputees with difficult shapes and sizes. Among the company's other products are the Thermoliner Cushion Liner, three varieties of EasyLiner ™ , and the Clearpro ™ SSA.

New Matrix for Silipos Explorer

Silipos Explorer
Silipos Explorer

Silipos, New York, New York, has introduced new design features to its Explorer ® Pin and Cushion tri-block polymer gel prosthetic suspension liners. The liners now utilize a proprietary stabilizing matrix to reduce distal elongation during gait while maintaining distal conformity, even with irregularly shaped limbs. The EXPLORER ® Pin Liner gel system contains a medical grade mineral oil that gradually diffuses to moisturize and lubricates the skin. Silipos gels are clear, nontoxic, hypoallergenic, dermatologically tested, and do not support bacterial growth, the company states.

Coyote Custom Liners

Coyote Design & Manufacturing, Boise, Idaho, fabricates custom liners using a platinum cure silicone resin that has been tested for skin sensitivity and cytotoxicity. The silicone is a shore A-20 hardness, approximately the same as human skin. "This is harder than the typical gel liners on the market today," notes the company. "We feel this improves the stability within the socket and is a much more durable material." The company offers a latch and non-latch version with and without fabric reinforcement.

Medipro Aids Sensitive Skin

RELAX liner by Medipro
RELAX liner by Medipro

The Medipro ® Sensitive liner, made in Germany and distributed by SPS, Alpharetta, Georgia, features a minimal bridging between the silicone inner surface and the reinforced matrix, which assures less skin irritation and greater durability, according to the company. The liner also has a removable pin adjustment that allows the liner to be used with a locking pin or as a cushion liner, depending on amputee need and preference. A protective cap is included with each liner to replace the pin socket if desired.

Just a Sampling

These are just some of the companies offering custom and off-the-shelf liner options. Their inclusion in this article is meant as a representative sample for reader information only; The O&P EDGE does not endorse any specific companies or products. Contact information for the companies mentioned is included in the table below. Any companies not included in this article are invited to send us their contact information to be added to the online version.

Liners impact comfort dramatically, as Jack Uellendahl, CPO stated in First Step (Volume 2, 2001), published by the Amputee Coalition of America (ACA). "When used properly, they provide a cushioning effect within the socket, help to minimize friction forces, and provide even pressure distribution." The most appropriate selection for a particular amputee depends on a variety of factors that are best explored with his or her prosthetist, he adds. And the wide range of both custom and off-the-shelf liners now offer amputees more choices than ever before.


COMPANY NAME

COMPANY ADDRESS / PHONE

WEBSITE / EMAIL

Alps

2895 42nd Ave. North
St. Petersburg, FL 33714
727.528.8566; 800.574.5426 (toll-free)

www.easyliner.com
info@easyliner.com

Coyote Design

2513 Federal Way, Ste. 106
Boise, ID 83705
208.429.0026; 800.819.5980 (toll-free)

www.coyotedandm.com
info@coyotedesign.ws

ESP (Engineered Silicone Products)

23 Wilson Drive
Sparta, NJ 07871
973.300.5120; 888.932.7377 (toll-free)

www.wearesp.com
sales@wearesp.com

Freedom Innovations

7 Studebaker
Irvine, CA 92618
949.672.0034; 888.818.6777 (toll-free)

www.freedom-innovations.com

Medipro, Germany (available in US from SPS)

6025 Shiloh Rd., Ste. #A
Alpharetta, GA 30005
770.442.9870, ext. 3;
800.767.7776, ext. 3 (toll-free)

www.spsco.com

Ohio Willow Wood

15441 Scioto-Darby Rd., P.O. Box 130
Mt. Sterling, Ohio 43143
740.869.3377; 800.848.4930 (toll-free)

www.owwco.com
info@owwco.com

Ossur North America

27412 Aliso Viejo Pkwy
Aliso Viejo, CA 92656
949.362.3883; 800.233.6263

www.ossur.com
ossurusa@ossur.com

Otto Bock HealthCare

Two Carlson Parkway North, Suite 100
Minneapolis, MN 55447-4467
763.553.9464; 800.328.4058 (toll-free)

www.ottobockus.com

Silipos

Niagara Falls, and
366 Madison Avenue
New York City, New York 10017
212.687.3260; 800.229.4404 (toll-free)

www.silipos.com