Thursday, March 31, 2011

Suction Liners

We continue our series on suspension with a look at suction type liners. Suction suspension liners come in a variety of forms, but they all share some common characteristics. The air is expelled through a one-way valve as the prosthetic is donned. The prosthesis is held onto the residual limb by the suction that was created when the air was removed. To remove the prosthetic, the valve is opened and air is introduced into the socket, thus breaking the seal.

Suspension liners come in a variety of forms. Every major prosthetic manufacturer produces a suction type suspension system, which is testament to the popularity of this suspension form. For our purposes, suction suspension systems will be broken down into two categories: those that require a sleeve and those which do not.

The original version of a suction suspension system involves a liner over the residual limb and the use of a sleeve worn over the socket and onto the skin above the prosthetic. The sleeve keeps air from being introduced into the socket, thus keeping the seal that is created when air is pushed through the one way valve.

The main drawback of the original suction suspension system lies with the sleeve. Some amputees complain that the sleeve does not stay in place and rolls down. Holes or tears in the sleeve compromise the integrity of the limb suspension.

The introduction of the seal-in liner in 2004 eliminated the necessity for the sleeve. These liners feature a rubberized gasket. The gasket creates the seal within the socket and suspension takes place further down the residual limb.

The seal-in liner has gained popularity, but it is not an appropriate system for every amputee. Those that have vast volume fluctuations throughout the day may find adding socks is cumbersome and difficult with this liner type. Many manufacturers recommend that the liners only be paired with a maximum of 8 ply.

The practitioners at OPC are experienced with a vast array of suction suspension liners. If you want to discuss these liners or if you feel like this type of system might be appropriate for you, give us a call.

Tuesday, March 29, 2011

Let's Talk About Suspension

At OPC we believe in an individual approach to prosthetics. The prosthetic devices that are manufactured need to be as unique as the patients who use them. Designing a prosthetic is a mixture of art and science.

Hand picking components to manufacturer custom prosthetics is only part of the process. The patient's suspension system, or the way in which the device is held onto the residual limb, must be carefully chosen. Personal preference, physical issues and strains on the prosthetic must all be weighed when determining the suspension system.

Amputees have a variety of suspension options. Each system has pros and cons which we will explore in today and Thursday's blog. Just like prosthetics, there is no "one size fits all" approach when it comes to prosthetic suspension.

One common suspension system is referred to as "vacuum assist." With this system, the air within the socket is mechanically expelled through a small pump. The prosthetic stays in place through the suction that is created by removing air. A small one-way valve can be depressed to allow air to enter into the socket, breaking the vacuum seal and allowing the device to be removed.

A vacuum system is a preferred suspension system for individuals with decreased circulation. Research has proven that the vacuum suspension promotes circulation by drawing blood into the residual limb. Increasing the blood flow helps to maintain the health of the limb.

Amputees struggling and frustrated with volume fluctuations throughout the day may benefit from a vacuum suspension system. Because the circulation is increased, the limb size does not change as drastically throughout the day. Maintaining an appropriate fit throughout the day reduces the amount of rubbing and "knocking" that can occur within the socket. Many of our patients appreciate that they are no longer reliant upon constant sock changes to maintain a socket fit.

All vacuum assist systems have drawbacks. The vacuum pump, which is frequently mounted into the socket, significantly increases the prosthetic weight. The sheer size of the apparatus must be considered when considering a candidate for this system. The amputee must have enough clearance for the vacuum to be mounted. Many times the component choices are limited because of the size requirements for the vacuum assist pump, forcing the amputee into low-profile designs.

A sleeve must be worn over the top of the socket to maintain the vacuum seal. Some amputees find the sleeve uncomfortable or bulky. Breakdown in the sleeve, the pump or the liner can all result in the suspension system failing. The patient with a vacuum system must remain cognizant and respectful of the technology that they are utilizing.

A vacuum assist suspension, including the Harmony system by Otto Bock, requires skilled practitioners to incorporate the components into the socket design. The practitioners at OPC are experienced fitting these systems. If you have questions about a vacuum assist suspension system, or if you think that you are a candidate, give us a call.

Thursday, March 24, 2011

Limb Loss and Weight

We are often asked how to compensate for an amputation when determining an ideal body weight. In order to find an accurate goal weight for the amputee, some math is going to be necessary. Don't worry, we'll try to make the calculations easy!

First, use the following chart to determine your "ideal body weight" range.

Male Female
Height Ideal Weight Height Ideal Weight
4' 6" 63 - 77 lbs. 4' 6" 63 - 77 lbs.
4' 7" 68 - 84 lbs. 4' 7" 68 - 83 lbs.
4' 8" 74 - 90 lbs. 4' 8" 72 - 88 lbs.
4' 9" 79 - 97 lbs. 4' 9" 77 - 94 lbs.
4' 10" 85 - 103 lbs. 4' 10" 81 - 99 lbs.
4' 11" 90 - 110 lbs. 4' 11" 86 - 105 lbs.
5' 0" 95 - 117 lbs. 5' 0" 90 - 110 lbs.
5' 1" 101 - 123 lbs. 5' 1" 95 - 116 lbs.
5' 2" 106 - 130 lbs. 5' 2" 99 - 121 lbs.
5' 3" 112 - 136 lbs. 5' 3" 104 - 127 lbs.
5' 4" 117 - 143 lbs. 5' 4" 108 - 132 lbs.
5' 5" 122 - 150 lbs. 5' 5" 113 - 138 lbs.
5' 6" 128 - 156 lbs. 5' 6" 117 - 143 lbs.
5' 7" 133 - 163 lbs. 5' 7" 122 - 149 lbs.
5' 8" 139 - 169 lbs. 5' 8" 126 - 154 lbs.
5' 9" 144 - 176 lbs. 5' 9" 131 - 160 lbs.
5' 10" 149 - 183 lbs. 5' 10" 135 - 165 lbs.
5' 11" 155 - 189 lbs. 5' 11" 140 - 171 lbs.
6' 0" 160 - 196 lbs. 6' 0" 144 - 176 lbs.
6' 1" 166 - 202 lbs. 6' 1" 149 - 182 lbs.
6' 2" 171 - 209 lbs. 6' 2" 153 - 187 lbs.
6' 3" 176 - 216 lbs. 6' 3" 158 - 193 lbs.
6' 4" 182 - 222 lbs. 6' 4" 162 - 198 lbs.
6' 5" 187 - 229 lbs. 6' 5" 167 - 204 lbs.
6' 6" 193 - 235 lbs. 6' 6" 171 - 209 lbs.
6' 7" 198 - 242 lbs. 6' 7" 176 - 215 lbs.
6' 8" 203 - 249 lbs. 6' 8" 180 - 220 lbs.
6' 9" 209 - 255 lbs. 6' 9" 185 - 226 lbs.
6' 10" 214 - 262 lbs. 6' 10" 189 - 231 lbs.
6' 11" 220 - 268 lbs. 6' 11" 194 - 237 lbs.
7' 0" 225 - 275 lbs. 7' 0" 198 - 242 lbs.

Now that you've found your ideal weight range, it's time to consider the impact of the limb loss on those numbers. The following chart lists the estimated weight percentages. The "percent loss" is the impact on the "ideal body weight."

Body Part

Percent Loss

Lower arm + hand
Entire arm
Lower leg + foot
Entire leg


A woman who is 5'5" should weigh between 113 to 138 pounds. If she is an above knee amputee those numbers are no longer accurate estimates. You need to figure out 16% of 138.

On your calculator, type in 138 (upper weight number) and press - (subtraction) 16 (percentage from the chart for an ak) and press the %. (138-16%) The calculator display should read 22.08. 16% of 138 pounds is 22.08 pounds.

Subtract 22.08 from 138 to determine the accurate ideal body weight for an above knee amputee woman who is 5'5". The ideal body weight for the hypothetical amputee is 115.92.

Depending upon how long your residual limb is you may want to increase or decrease the percentages slightly. Since the formula compensates for the loss of the limb, it is advisable to get weighed without wearing your prosthetic.

Tuesday, March 22, 2011

Going to Kansas City?

The Amputee Coalition of America (ACA) is planning its national conference for this June in Kansas City, Missouri. The conference, which in the past few years has been held late in the summer, will serve to kick off the summer season. Mark your calendars because this year the conference is scheduled from June 2 through June 5.

This conference is an opportunity to learn about new prosthetic and assistive devices, as well as your chance to speak directly with many of the manufacturers about their products. With a docket full of educational lectures ranging from running skills to liner care, there is certainly something for everybody. Activities such as the group dance and swimming help to break the ice among the participants.

Several patients who have attended the ACA Conference in the past remark about the instant camaraderie that was felt among the amputees. At the conference, limb loss is the norm. Many found it was refreshing to be among so many amputee peers--that it took some of the isolation away that is often felt when a limb is lost.

After this event, the ACA has noted that they only will host a national conference every other year. Hotel reservations are filling up fast, and several airlines have agreed to provide discounted fares. Check the ACA website for more information.

It should also be noted that the ACA is working to establish April as Limb Loss Awareness Month. The organization is soliciting grass root support to make this designation a reality. ACA is requesting that all amputees and their families contact the governor of their state to show their support for establishing Limb Loss Awareness Month. OPC supports this effort as we believe that Limb Loss Awareness Month can serve as a platform both to introduce important legislation and to accentuate issues surrounding living with an amputation. Your support is appreciated.

Thursday, March 17, 2011

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Limb Care

The residual limb is vulnerable to infections for a variety of reasons. Many amputees have decreased circulation through the limb, contributing to reduced sensitivity and increased healing time. If the amputee wears a prosthetic, the limb is often subjected to hours of containment in a tight fitting, airtight vessel (the liner and socket). These conditions are conducive to bacteria and fungal infections.

Maintaining a healthy skincare regime is imperative to minimize the risk of developing a sore, blister or infection. Utilizing a few easy hygiene recommendations daily will help to keep your residual limb healthy and prosthetic-ready.

1. After the prosthetic has been worn throughout the day, it is important to wash the limb in the evening. Although some amputees prefer to use an antibacterial soap, it is not necessary. We recommend using any soap that is used in the shower.

2. Perhaps more important than lathering the limb is thoroughly rinsing it. Be sure to remove all of the soap bubbles!

3. Pat your residual limb to dry after washing. Rubbing can lead to small cuts or fabric burns on the sensitive skin of the residual limb.

4. Thoroughly inspect the limb for any skin abnormalities (cuts, sores, blisters etc.). A small hand mirror may be useful to view the underside. If needed, apply Neosporin to any suspected skin breakdown.

5. Liberally apply a body lotion to cover the entire limb. If you are prone to dry skin, we recommend using Eucerin body cream instead of the fluid lotion. The cream is thicker and will be easier to apply after it has been slightly softened in the microwave for approximately 10 seconds.

6. The prosthetic liner should be hand washed daily with soap. Again, rinsing is perhaps more important than lathering. Soap scum can build up on the liner making it difficult to stay in place.

7. It is recommended, although not necessary, to dry the liner before donning. If you are wearing a prosthetic without a liner, it is advisable to wipe the inside of the socket with antibacterial gel or wipes.

8. After exercising, the residual limb and the liner should be washed and dried immediately.

Investing a few minutes a day in caring for your residual limb and prosthetic can help to avoid developing an infection. If you have any questions about how to care for your residual limb or prosthetic, give us a call.

Tuesday, March 15, 2011

To Shave or Not To Shave...

Much to the chagrin of many of our patients, we recommend that the residual limb remain unshaved. Cosmetically we realize that this is a difficult recommendation to heed. However, it is important to remember that hair is the body's first line of protection, and it is growing on our body for a reason.

Shaving leaves the residual limb vulnerable to a plethora of issues, including cuts and nicks. Small cuts may take longer to heal or may become infected because of the conditions that the limb is subjected to within the socket. Issues involving reduced circulation only serve to increase the risk of infection. A seemingly benign nick can quickly become an infected ulcer rendering the amputee without their prosthetic and forced to undergo medical interventions.

The pain of ingrown hairs is amplified when they develop on the residual limb. The amputee may experience discomfort when donning the device, and in some situations he or she may be forced to stop using the prosthesis. A small ingrown hair exposed to the oxygen-restricted, moist and constricting environment within the liner and prosthetic can quickly grow into an infected sore.

Laser hair removal is a good option for many amputees who are self-conscience about remaining unshaved. We have worked with several patients who have undergone the procedure with positive results. Although it can be pricey, many insurances have covered the procedure for amputees.

The procedure typically requires 2-4 visits in order to obtain results. The amputee may be without their prosthetic for 24 to 48 hours after each session depending upon the surface area covered and the coarseness of the hair shafts that are being treated.

Not everybody is a candidate for laser hair removal, so it is important to thoroughly investigate if this is a viable option. Those who are light skinned with dark hair typically yield excellent results. Patients with darker complexions and lighter hair are not always good candidates.

Maintaining the health of the limb and obtaining prosthetic success is paramount, and shaving puts both of these priorities at undue risk. If hair removal is cosmetically important to you, we recommend putting down the razor and investigating the safer alternative of laser hair removal.

Thursday, March 10, 2011

Vari-Flex foot

The Vari-Flex foot, by Ossur, is one of the most popular prosthetic feet on the market. This carbon fiber foot is designated for K-3 amputees although patients across the board have experienced benefits.

The Vari-Flex foot is part of the Flex foot family of products which were the first carbon fiber feet to be brought to the commercial prosthetic market. The introduction of this lightweight, strong and responsive material has revolutionized the field of prosthetic components.

Similar to the Javelin foot, the Vari-Flex foot features a split-toe design. This design allows for an increased ability to adjust to variations in terrain. The variability of movement provides increased stability and a more responsive experience for the wearer.

The carbon fiber extends through the foot shell to mimic the size of the sound foot. This extension allows for a more natural roll-over when walking. The extra length also increases stability and enhances the sense of balance for the amputee.

The Vari-Flex has recently been enhanced through the pairing with a foot shell featuring EVO. An EVO foot shell has a slightly curved bottom which assists the amputee through a slight rocking of the foot while walking. Instead of walking on a flat surface, the slightly curved foot makes rolling over the toes easier and creates a relaxed gait. The EVO technology is especially appreciated when the amputee is walking barefoot.

The Vari-Flex foot is one of the most popular feet on the prosthetic market. According to Elliot, "There is nothing wrong with that foot. It does everything well. It doesn't break down, it's super reliable, lightweight and durable. It's just a really good foot."

If you are interested in discussing a Vari-Flex foot, or if you want to explore other prosthetic options, give us a call. We offer complimentary Skype consultations for your convenience. At OPC, we have successfully fitted hundreds of Vari-Flex feet on our patients. Let's see what we can do for you!

Tuesday, March 8, 2011

Javelin Foot, by Endolite

Researching prosthetic components can be a daunting task. With the variety of features available, it is not uncommon for the amputee to become confused by the myriad of choices available. Using this blog to provide specific information, we are attempting to demystify prosthetic components.

The Javelin, by Endolite, is a K-3 foot designed for everyday wear. The absence of computerized components and moving parts makes this the ideal foot for all-terrain activities. Whether you are strolling in the woods, jumping in puddles or walking around the office, this foot can handle the environment.

The Javelin features a full split-toe design, increasing both prosthetic stability and the responsiveness of the device. The independent toe/ heel design of this foot provides the wearer with accurate feedback. The design also contributes to a more natural and responsive gait.

Engineered for ankle responsiveness, the Javelin simulates some ankle responses. Although this device does not provide the fluid ankle motions of the Echelon, it does respond when pressure is under the foot. The foot/ ankle responds according to the amount and location of the pressure that is perceived. The slight "give" provided through the design enables the amputee to walk with more natural ankle movements.

The Javelin is easy to cover cosmetically and has a 36 month warranty. The foot is approved for amputees weighing between 100 and 365 pounds. A low-profile design is available for those with a long residual limb.

On Thursday we will be exploring a similar prosthetic foot, the Vari-Flex by Ossur. Regardless of your prosthetic needs, be assured that the practitioners at OPC are qualified and experienced to work with all major components. We are ready to help you achieve your goals.

Thursday, March 3, 2011


Much to the chagrin of many amputees, there is not a "one leg fits all" prosthetic that meets the needs of every amputee. Different activity levels put unique strains on the components required for the prosthetic. Those who are involved in sports have different prosthetic requirements than the casual walker.

The K-Level system was devised by Medicare as an attempt to classify prosthetic components according to the patient population. Patients are assigned a K-Level, typically by their prosthetist, which is used as a guideline when choosing prosthetic components (i.e. feet or knees). An amputee's K-Level is designed to be fluid, meaning that an individual may move through a variety of K-Levels throughout his life.

Those with a K-O classification are not ambulatory. These amputees do not have the ability or the potential to walk. It is determined that a prosthetic will not enhance the independence or the life of these individuals.

K-1 amputees may benefit from a prosthetic to assist in transferring (such as from a wheelchair to a fixed chair). These individuals also have the potential to walk, albeit in a limited capacity, within their home or for short distances. Walking at various speeds and maneuvering around environmental obstacles is not deemed feasible.

K-2 amputees are considered community walkers. These individuals can accommodate for "low level" environmental obstacles including curbs, bumps and sidewalk cracks. They can walk for limited periods of time but cannot typically vary their walking speed.

If amputees have the ability to vary their speed and can traverse through a variety of environmental obstacles, they are considered to be a K-3. These individuals can walk through a variety of environments (grass, rocks, hills, sand etc.) without difficulty. The prosthetic is used for recreational and moderate exercise activities.

K-4 amputees rely upon their prosthetic to complete high impact activities such as running and jumping. Many children, active adults and athletes fall into this category.

The term "potential" was included in each K-Level description, providing the practitioner with a great deal of flexibility when assigning patient levels. In the following weeks we will be comparing prosthetic components in this blog. Since components are classified according to K-Levels we wanted to provide some background information.

Tuesday, March 1, 2011

Ertl (Bone Bridge)

For decades surgeons and prosthetists have been working in tandem to create a more comfortable prosthetic experience for amputees. In the 1920's a Hungarian surgeon developed a groundbreaking procedure which has revolutionized the way many perform below knee amputations. For those who have the ability to plan the time and date of their amputation, or if one is in need of a revision surgery, discussing the benefits of the Ertl (bone bridge) with your surgeon is worthwhile.

In the intact human leg, the tibia and fibula bones connect at the ankle. This connection not only completes the "bone circuit" but also increases the stability and strength of the structure. With most bk amputations, the tibia and the fibula bones are severed. A skin flap is brought over the bones, creating the residual limb. The tibia and fibula bones are left unconnected.

With the standard below knee amputation, the tibia and fibula bones are structurally weakened. Over time and with prosthetic stresses, the bones can rub creating pain, discomfort and fractures. This is commonly referred to as "chopsticking." Although certainly not impossible, it is difficult and painful for individuals with this type of amputation to bear weight directly on the bottom of the stump.

With an amputation done using the Ertl procedure, the tibia and fibula are joined by a piece of bone screwed into place. The bones eventually fuse giving the resulting residual limb a wider base. The wider base makes it easier for the amputee to bear weight. Amputees who have undergone the Ertl procedure do not experience as many difficulties maintaining a comfortable prosthetic fit. The structural integrity of the amputated limb is nearly restored to its pre-amputated strength because the bone circuit is reconnected.

The bone bridge procedure has some initial drawbacks. First, it requires more surgical skill to perform than the basic amputation and not all surgeons are competent with the procedure. Because of the increased complexity, the patient is in the operating room and under anesthesia for a longer period of time.

In our experience, amputees who have undergone an Ertl procedure have fewer prosthetic issues. Because volume fluctuations are minimal, the prosthetic fit is more consistent and the amputee is less reliant upon socks to obtain a comfortable socket. The bone bridge is able to bear weight, affording the individual the ability to put direct pressure onto the bottom of the limb. If you have questions about the Ertl procedure, we encourage you to talk with your surgeon to determine if it is appropriate.