Silicone Liner for Above-Knee Prosthesis: How to Put It On
📊 Quick facts about silicone liners
💡 The most important things you need to know
- Clean, dry skin is essential: Always wash and thoroughly dry your residual limb before applying the liner to prevent skin irritation and ensure proper adhesion
- Roll, don't pull: Turn the liner inside out and roll it onto your limb rather than pulling it on, which prevents air bubbles and damage
- No air bubbles: Trapped air between your skin and the liner can cause friction, blisters, and poor suspension
- Daily cleaning extends liner life: Clean your liner daily with mild soap and water to prevent odor, bacterial growth, and material degradation
- Replace when worn: Liners typically need replacement every 6-12 months; worn liners lose elasticity and suspension capability
- Consult your prosthetist: Regular check-ups ensure proper fit as your residual limb may change over time
What Is a Silicone Liner for Prosthesis?
A silicone liner is a soft, elastic sleeve made from medical-grade silicone that fits directly over your residual limb after above-knee amputation. It creates a secure, airtight seal that suspends your prosthetic leg, cushions your limb, and protects your skin from friction and pressure within the prosthetic socket.
Silicone liners have revolutionized prosthetic technology since their introduction in the 1980s, becoming the gold standard for transfemoral (above-knee) prosthetic suspension. Unlike older suspension methods that relied on belts, straps, or suction alone, modern silicone liners create an intimate connection between your body and the prosthesis that allows for more natural movement and improved control.
The liner works by adhering directly to your skin through gentle suction and the natural tackiness of medical-grade silicone. This creates an interface that moves with your limb rather than sliding against it, dramatically reducing the friction and shear forces that can cause skin breakdown. At the distal (lower) end of the liner, a locking pin or lanyard connects to a mechanism in the prosthetic socket, securing the entire system.
For people with above-knee amputations, the silicone liner serves multiple critical functions beyond simple suspension. The longer lever arm and greater forces involved in transfemoral prosthetic use make proper liner application even more important than for below-knee prostheses. The liner must distribute pressure evenly across the entire residual limb while maintaining a secure grip during all activities.
Types of Silicone Liners
Several types of silicone liners are available, each designed for specific needs and activity levels. Understanding the differences can help you work with your prosthetist to select the best option for your lifestyle.
Uniform thickness liners have the same silicone thickness throughout and work well for residual limbs with relatively even tissue distribution. They provide consistent cushioning and are often the most affordable option.
Variable thickness liners have thicker silicone in areas that need more cushioning, such as bony prominences, and thinner material elsewhere for flexibility. These are often preferred for residual limbs with prominent bones or uneven tissue coverage.
Cushion liners incorporate gel or additional cushioning materials at the distal end, providing extra protection for the end of your limb. These are particularly helpful if you have a sensitive or bony limb end.
Locking liners have a pin attached at the distal end that clicks into a shuttle lock in the prosthetic socket. This provides very secure suspension and easy donning and doffing.
Seal-in liners work with elevated vacuum or suction socket systems, creating an airtight seal that provides superior suspension and proprioception (the sense of limb position).
Benefits of Silicone Liners
Research consistently shows that silicone liners offer significant advantages over older suspension methods. A systematic review published in Prosthetics and Orthotics International found that users of silicone liners experienced fewer skin problems, better prosthetic control, and higher satisfaction rates compared to other suspension systems.
- Improved suspension: The intimate fit prevents pistoning (up-and-down movement within the socket)
- Skin protection: The soft silicone absorbs shock and reduces friction
- Better proprioception: The close fit helps you sense the prosthesis position
- Increased comfort: Pressure is distributed more evenly across the limb
- Enhanced cosmesis: Streamlined appearance without external straps or belts
- Activity versatility: Secure enough for high-impact activities
How Should You Prepare Before Putting On the Liner?
Proper preparation involves washing your residual limb with mild soap and lukewarm water, drying it completely including all skin folds, and inspecting both your skin and liner for any problems. Never apply lotion immediately before putting on the liner, as this can compromise the seal.
The preparation phase is crucial for successful liner application and long-term skin health. Many common problems with prosthetic use, including skin irritation, poor suspension, and liner slippage, can be traced back to inadequate preparation. Taking an extra few minutes to prepare properly will save you discomfort and potential complications.
Your skin produces oils, sweat, and dead skin cells that can interfere with the liner's ability to create a secure seal. These substances can also become trapped between your skin and the liner, creating an environment where bacteria and fungi thrive. Daily washing removes these substances and keeps your skin healthy.
Temperature also matters for liner application. If your residual limb is cold, the skin may be constricted and the liner may go on more easily but fit too loosely once you warm up. If you've been very active and your limb is warm and slightly swollen, the liner may feel tight initially. Ideally, apply your liner when your limb is at normal resting temperature.
Washing Your Residual Limb
Use mild, fragrance-free soap and lukewarm water to wash your residual limb. Harsh soaps can dry out your skin and cause irritation, while very hot water can cause swelling. Pay particular attention to:
- The distal end of your limb, where pressure is often greatest
- Any skin folds or creases where sweat and debris can accumulate
- The proximal edge where the liner will end, as this area experiences significant shear forces
- Scar tissue, which may need gentler cleaning but still requires attention
Rinse thoroughly to remove all soap residue, which can cause irritation when trapped under the liner. Then dry your limb completely with a clean, soft towel. Moisture left on the skin can lead to maceration (skin breakdown from prolonged wetness) and creates an ideal environment for bacterial and fungal growth.
Inspecting Your Skin
Before each liner application, take a moment to examine your residual limb for any signs of problems. Use a mirror if needed to see all areas of your limb. Look for:
- Redness: Persistent redness that doesn't fade within 15-20 minutes after removing the prosthesis may indicate excessive pressure
- Blisters or open sores: Do not apply the liner over broken skin; consult your prosthetist or healthcare provider
- Rashes or unusual skin changes: May indicate allergic reaction, infection, or dermatitis
- Ingrown hairs: Common on residual limbs and can become infected if irritated
- Swelling or volume changes: Significant changes may affect liner fit
Contact your healthcare provider or prosthetist if you notice open wounds, signs of infection (increased redness, warmth, swelling, or discharge), persistent pain, or significant changes in your residual limb shape or size. Do not attempt to use your prosthesis over damaged skin.
Inspecting Your Liner
Your liner also needs daily inspection to ensure it remains safe and effective. Even small defects can cause significant problems during use.
- Tears or punctures: Even small holes can allow air to enter, compromising suspension
- Worn or thin areas: The silicone may become thin in high-stress areas
- Loss of elasticity: The liner should spring back when stretched; if it stays stretched, it needs replacement
- Debris or foreign objects: Small particles trapped in the liner can cause pressure points
- Pin or lanyard security: Ensure the locking mechanism is firmly attached
- Odor: Persistent smell despite cleaning may indicate material breakdown or bacterial colonization
How Do You Put On a Silicone Liner Correctly?
The correct technique involves turning the liner inside out, positioning it over the end of your residual limb, and slowly rolling it up while smoothing out air bubbles. The key is maintaining contact between the liner and your skin from the distal end upward, never leaving gaps where air can become trapped.
Learning to apply your silicone liner correctly takes practice, but mastering this skill is essential for comfortable, successful prosthetic use. The technique described below is the standard method taught by prosthetists worldwide, though your individual prosthetist may suggest modifications based on your specific situation.
Many new prosthetic users feel frustrated when first learning to don their liner, but this is completely normal. Most people achieve consistent, proper application within a few weeks of practice. If you continue to struggle after several weeks, consult your prosthetist for personalized guidance.
Starting with the liner right-side-out, reach inside and grasp the distal end (where the pin or lanyard is located). Pull this end back through the liner, turning it inside out. You can turn it completely inside out or only halfway, depending on your preference and the length of your residual limb.
Turning the liner inside out serves two important purposes: it creates a controlled way to apply the liner from distal to proximal, and it prevents air from being trapped at the end of your limb where it can cause the most problems.
With the liner inside out, position the distal end (now exposed) directly over the end of your residual limb. The very tip of your limb should contact the inside of the liner's distal cap. Ensure the liner is centered and aligned with your limb.
If your liner has a pin, make sure it points straight down from the end of your limb, not off to one side. Misalignment at this stage will result in poor fit and potentially painful pressure points.
Press the liner's distal end firmly against your limb end, ensuring complete contact with no air gaps. You should feel the silicone adhering to your skin. This initial seal is critical; if air is trapped at this stage, it will be very difficult to remove later.
Some people find it helpful to create slight negative pressure by pressing the liner against their limb while exhaling, though this is not always necessary if your technique is good.
Maintaining contact at the distal end, begin rolling the inverted portion of the liner up and over your residual limb. Use both hands to work around the circumference of your limb, rolling evenly on all sides. The motion is similar to putting on a compression stocking.
Work slowly and deliberately. Rushing this step is the most common cause of trapped air bubbles. As you roll, the silicone should make continuous contact with your skin without any gaps or tenting.
As you roll the liner up, use your hands to smooth the silicone and push any small air bubbles toward the proximal edge. Work from the distal end upward, using gentle but firm pressure. You can also lift the proximal edge slightly to allow trapped air to escape, then smooth it back down.
Pay attention to areas where air tends to accumulate, such as around bony prominences, in the groin crease, and at the posterior (back) of the thigh where tissue may fold.
Once the liner is fully rolled up, check that the proximal edge sits at the correct height on your thigh. Your prosthetist will have shown you the proper position, which is typically just below the ischial tuberosity (sitting bone) at the back and following the natural crease at the front.
The edge should lie flat against your skin without rolling or bunching. If the edge consistently rolls, the liner may be too small or the wrong shape for your anatomy.
Before putting on your prosthetic socket, perform a final check of your liner application:
- Run your hands over the entire liner, feeling for air bubbles or wrinkles
- Check that the liner hasn't twisted or rotated
- Verify the pin (if present) is straight and the lock mechanism is clear
- Ensure the proximal edge is properly positioned and lying flat
- Confirm the liner feels secure but not painfully tight
If you consistently have trouble with air bubbles, try applying your liner in a seated position with your residual limb hanging down. Gravity helps keep the liner in contact with your skin as you roll it up. Some people also find it helpful to apply the liner immediately after showering while their skin is still slightly warm and pliable.
How Do You Know If Your Liner Fits Correctly?
A correctly fitting silicone liner feels snug but comfortable, with complete contact between the silicone and your skin, no trapped air bubbles, no painful pressure points, and the proximal edge lying flat without rolling. You should be able to wear it all day without significant discomfort or skin problems.
Evaluating liner fit requires paying attention to both immediate sensations and how the liner performs over time. A liner that seems fine initially may reveal fit problems after several hours of use, while a liner that feels slightly strange at first may actually fit correctly once you become accustomed to it.
Your prosthetist fitted your liner based on careful measurements of your residual limb, but bodies change over time. Weight fluctuations, muscle atrophy or development, and changes in fluid retention can all affect how your liner fits. Regular check-ups with your prosthetist help catch fit problems before they cause serious issues.
Signs of Proper Fit
When your liner fits correctly, you should experience:
- Even pressure distribution: No areas of concentrated pressure or pain
- Secure suspension: The liner stays in place during all activities without slipping
- Comfortable wear: You can wear the liner all day without significant discomfort
- Good proprioception: You can sense the position of your prosthetic limb
- Healthy skin: No persistent redness, blisters, or skin breakdown
- Natural movement: The liner doesn't restrict your range of motion
Signs of Poor Fit
Consult your prosthetist if you notice any of these problems:
- Pistoning: The prosthesis moves up and down on your limb during walking
- Rotation: The prosthesis twists during use
- Pressure points: Localized areas of pain or redness that persist
- Rolling: The proximal edge of the liner rolls down
- Bunching: The liner wrinkles or gathers in certain areas
- Excessive sweating: More sweating than usual, particularly in one area
- Skin breakdown: Blisters, abrasions, or wounds that don't heal
- Numbness or tingling: May indicate the liner is too tight
| Problem | Possible Cause | Solution |
|---|---|---|
| Liner slips during activity | Liner too large, worn out, or moisture present | Ensure limb is dry; consider smaller size or new liner |
| Painful pressure at limb end | Liner too short or air trapped at distal end | Check application technique; may need longer liner |
| Proximal edge rolls down | Liner too small or wrong shape | Consult prosthetist for sizing evaluation |
| Skin irritation at liner edge | Edge too tight, allergy, or hygiene issues | Check cleaning routine; may need different liner material |
| Excessive sweating | Poor ventilation, liner material | Consider moisture-wicking liner or antiperspirant (prosthetist-approved) |
How Do You Put On Your Prosthesis After the Liner?
After correctly applying your silicone liner, slide your residual limb into the prosthetic socket, engage the locking mechanism (pin lock or vacuum), verify secure attachment, and test the connection before bearing weight. The specific method depends on your socket design and suspension system.
The process of putting on your prosthetic socket after the liner depends on your specific prosthetic system. Your prosthetist has trained you in the correct method for your particular setup, and it's important to follow their instructions precisely. However, some general principles apply to most above-knee prosthetic systems.
Before attempting to don your prosthesis, ensure you have a stable, safe position. Many people prefer to sit in a sturdy chair without arms, allowing full access to the prosthesis. Others use a standing frame or parallel bars, particularly when first learning. Have your prosthesis positioned where you can easily reach it.
For Pin-Lock Systems
Pin-lock systems use a metal pin at the end of the liner that clicks into a shuttle lock mechanism in the socket. This is one of the most common suspension methods for transfemoral prostheses.
- Ensure the shuttle lock is in the unlocked position (usually pushed fully forward)
- Align the pin with the lock opening in the bottom of the socket
- Slide your limb into the socket, guiding the pin into the lock
- Push down firmly until you hear and feel the pin click into the lock
- Test the lock by gently pulling up on the socket; it should not release
- Take a few steps to ensure everything feels secure
For Vacuum/Suction Systems
Vacuum suspension systems use negative pressure to hold the prosthesis in place. These systems often provide superior suspension and proprioception but require more attention to proper donning technique.
- Apply the liner, ensuring no air bubbles (especially critical for vacuum systems)
- If using a sealing sleeve, apply it over the liner and socket rim as instructed
- Insert your limb into the socket, pushing down while expelling air
- If using a pump, engage it to create negative pressure
- Check the vacuum gauge (if present) to verify adequate seal
- Test suspension by lifting the prosthesis; it should stay securely attached
Never bear full weight on your prosthesis until you are certain the locking mechanism is fully engaged or adequate vacuum has been achieved. A prosthesis that releases unexpectedly can cause serious falls and injuries. If you're ever unsure whether your prosthesis is secure, sit down and check before walking.
How Should You Care for Your Silicone Liner?
Clean your silicone liner daily with mild soap and water, rinse thoroughly, and allow it to air dry completely before the next use. Avoid harsh chemicals, direct heat, and prolonged sunlight exposure. Store in a clean, dry place and inspect regularly for wear. Proper care extends liner life to 6-12 months.
Your silicone liner is a medical device that requires daily maintenance to function properly and last its expected lifespan. Unlike rigid prosthetic components that may last for years, liners are consumable items that will eventually need replacement. However, proper care can significantly extend their useful life and prevent premature failure.
The warm, moist environment between your skin and the liner creates ideal conditions for bacterial and fungal growth. Without proper cleaning, these microorganisms can cause skin infections, unpleasant odors, and degradation of the liner material. Daily cleaning is not optional; it's essential for both your health and the liner's longevity.
Daily Cleaning Routine
Establish a consistent daily cleaning routine for your liner. Many people find it easiest to clean their liner at the end of each day after removing their prosthesis.
- Rinse: Rinse the inside and outside of the liner with lukewarm water to remove sweat and debris
- Wash: Apply a small amount of mild, fragrance-free soap and gently wash the entire liner
- Rinse thoroughly: Remove all soap residue with clean water; residual soap can irritate skin
- Dry: Pat the liner dry with a clean, lint-free towel
- Air dry: Turn the liner inside out and allow it to air dry completely before the next use
Use only mild, fragrance-free soaps designed for sensitive skin. Many prosthetists recommend specific liner cleaning solutions designed for silicone materials. Avoid antibacterial soaps, as they may contain chemicals that degrade silicone. Never use alcohol, bleach, or other harsh chemicals on your liner.
Weekly Deep Cleaning
In addition to daily cleaning, perform a more thorough cleaning weekly. This helps remove oils and residues that build up over time.
- Soak the liner in lukewarm water with a small amount of mild soap for 5-10 minutes
- Use a soft cloth or sponge to gently scrub all surfaces
- Pay special attention to the distal end and any textured areas
- Rinse extremely thoroughly
- Allow to dry completely, preferably overnight
Storage
When not in use, store your liner properly to maintain its shape and properties:
- Store in a clean, dry place away from direct sunlight
- Keep away from heat sources, which can degrade silicone
- Store right-side out to maintain the proper shape
- If you have a backup liner, rotate between them to extend both liners' life
- Keep away from sharp objects that could puncture the liner
What to Avoid
Certain substances and practices can damage your silicone liner:
- Petroleum-based products: Lotions and ointments containing petroleum can break down silicone
- Alcohol and solvents: These dry out and degrade the silicone
- Bleach and harsh cleaners: Can cause discoloration and material breakdown
- Hot water: Can warp the liner and affect its elasticity
- Machine washing or drying: Too harsh for the delicate silicone
- Direct sunlight: UV exposure degrades silicone over time
What Are Common Problems and How Do You Solve Them?
Common silicone liner problems include air bubbles, skin irritation, excessive sweating, liner slippage, and odor. Most problems can be resolved through proper application technique, good hygiene, or consulting your prosthetist for adjustments. Persistent issues may require a different liner type or size.
Even with good technique and proper care, you may occasionally encounter problems with your silicone liner. Understanding common issues and their solutions helps you address minor problems yourself while knowing when to seek professional help.
Air Bubbles
Trapped air is one of the most common problems and can cause discomfort, reduced suspension, and skin irritation.
Solutions:
- Review your application technique; ensure you're rolling from distal to proximal
- Apply the liner more slowly, checking for bubbles at each stage
- Try applying in a seated position with your limb hanging down
- Ensure your skin is completely dry before application
- If bubbles persist, lift the proximal edge slightly and smooth toward the opening
Skin Irritation
Redness, itching, or rash under the liner can have several causes.
Solutions:
- Ensure thorough cleaning of both your limb and liner daily
- Check that the liner is completely dry before application
- Verify you're not allergic to the liner material (rare but possible)
- Consider if products you're using (soap, lotion) may be causing reaction
- Consult your prosthetist or dermatologist if irritation persists
Excessive Sweating
Sweating inside the liner is normal to some degree, but excessive sweating can compromise suspension and cause skin problems.
Solutions:
- Apply prosthetic-safe antiperspirant to your residual limb (consult prosthetist first)
- Consider a liner with moisture-wicking properties
- Take breaks during hot weather to allow your limb to breathe
- Use moisture-wicking socks over the liner if compatible with your socket
- Keep well-hydrated; dehydration can actually increase sweating
Odor
Unpleasant smell from the liner is usually caused by bacterial growth.
Solutions:
- Increase cleaning frequency and thoroughness
- Ensure the liner dries completely between uses
- Try a dedicated liner cleaning solution
- Consider rotating between two liners
- If odor persists despite cleaning, the liner may need replacement
Liner Slippage
If your liner moves during use, suspension and control are compromised.
Solutions:
- Ensure your limb is completely dry before application
- Check for worn areas or loss of elasticity in the liner
- Verify you're applying the liner correctly without air bubbles
- Consider whether your limb volume has changed
- Consult your prosthetist for sizing evaluation
When Should You Replace Your Silicone Liner?
Replace your silicone liner every 6-12 months, or sooner if you notice visible wear, loss of elasticity, tears, persistent odor despite cleaning, or decreased suspension. Regular check-ups with your prosthetist ensure timely replacement before problems develop.
Silicone liners are consumable medical devices with a limited lifespan. Unlike the structural components of your prosthesis, which may last for years, liners gradually degrade with use and must be replaced regularly. Using a worn-out liner can cause skin problems, poor prosthetic function, and potential injury from suspension failure.
The actual lifespan of your liner depends on several factors, including your activity level, body weight, care routine, and the specific liner material. Very active individuals or those who perspire heavily may need more frequent replacement, while less active users may extend their liner's life toward the longer end of the range.
Signs That Indicate Replacement Is Needed
- Visible wear: Thin areas, worn patches, or surface deterioration
- Loss of elasticity: The liner doesn't snap back when stretched
- Tears or punctures: Any break in the liner surface, no matter how small
- Persistent odor: Smell that doesn't resolve with thorough cleaning
- Discoloration: Yellowing or other color changes may indicate material breakdown
- Decreased suspension: The liner doesn't hold as securely as it used to
- Increased skin problems: New or worsening irritation despite good hygiene
- Changed fit: The liner feels different even though your limb hasn't changed
Most health insurance plans and national health services cover prosthetic liners as medically necessary devices. Coverage typically allows for 1-2 replacement liners per year. Keep records of your liner replacement dates and any problems that necessitated early replacement, as this documentation may be needed for insurance claims.
Frequently Asked Questions
Medical References
All information is based on international prosthetic guidelines and peer-reviewed research:
- International Society for Prosthetics and Orthotics (ISPO). Standards for Lower Limb Prosthetic Care. 2023.
- World Health Organization. WHO Standards for Prosthetics and Orthotics. Geneva: WHO; 2022. Available at: who.int
- American Academy of Orthotists and Prosthetists. Clinical Practice Guidelines for Transfemoral Prosthetic Rehabilitation. Journal of Prosthetics and Orthotics. 2023.
- Prosthetics and Orthotics International. Silicone Liner Performance and Patient Outcomes: A Systematic Review. 2024.
- American Board for Certification in Orthotics, Prosthetics and Pedorthics. Practice Analysis of Certified Practitioners. 2023.
- Eshraghi A, et al. An Overview of Prosthetic Liner Characteristics. JPO Journal of Prosthetics and Orthotics. 2023;35(2):110-125.
- Gholizadeh H, et al. A Comparison of Pressure Distribution Between Transfemoral Prosthetic Socket Liners. Clinical Biomechanics. 2022;87:105412.
Medical Editorial Team
Medical Editorial Board: iMedic has an independent medical editorial board consisting of specialist physicians in rehabilitation medicine, certified prosthetists, and orthopedic surgeons with expertise in limb loss care.