Apr

9

2012

Below Knee Prosthesis – Where is Your Pain?

Posted By: mark

 

Common Fitting Problems
The recommendations outlined on this page are meant as a guide to help patients remedy prosthetic fitting problems assuming they have a properly fitted prosthesis.  These solutions will not be effective if the prosthesis was never fit or aligned correctly and/or if your limb has experienced significant volume changes.

Limb shrinkage is the most common reason a well-fitting prosthesis can become uncomfortable.  When a limb shrinks its shape changes relative to the original mold obtained during the casting process.  This allows pressures inside the socket to move from weight tolerant areas to intolerant areas.

If you have a well-fitting prosthesis, residual limb pain due to shrinkage can usually be solved by adjusting the amount of sock ply that you are wearing.  By layering different ply of sock, the wearer is able to temporarily restore the original size of there limb in order to keep pressures evenly distributed on weight-tolerant areas.

Where red marks are OK!

While newer fitting techniques allow us to fit sockets that utilize the entire surface of the limb for applying pressure, broad redness can still occur in these areas.  Redness and discomfort on bony areas is not acceptable.

Generally speaking, fitting solutions can often be summed up with the following recommendation:  Primary Weight-Bearing Areas

“Add or remove sock ply until the prosthesis is comfortable and if this doesn’t work contact a Prosthetist.”

Adding or removing sock ply to maintain the comfort of a prosthesis is only effective if the prosthesis was originally fit correctly or if your limb hasn’t experienced significant shrinkage.

 

 

CONDYLE PRESSURE (sides of the knee)

Excessive limb shrinkage

Tissue on the bottom of the limb shrinks more than the tissue on the sides of the knee primarily due to the large calf muscle behind the leg.   When a wearer adds the correct ply of sock to tighten the bottom of the socket it applies too much pressure on the sides of the knee.  When this occurs a new socket is usually required for restoring proper fit.  However, this is a case when you would contact your prosthetist for possible solutions.  The socket can usually be padded to increase pressure in tolerant areas, and reduce the amount of socks that you are wearing. Pain/redness on sides of the knee

Sides of the socket were originally fit too tight

Pain can also occur in a newer prosthesis if the area was fit too tight.  This would be the direct result of a Prosthetists error and should be corrected to your satisfaction.

 

DISTAL ANTERIOR TIBIA

Not wearing enough socks

Pressure on this area of the bone is the most common area for discomfort in this type of prosthesis.  In a properly fitting socket, a patient can add socks one ply at a time until the pressure goes away.

Heel on shoe is too high

If socks don’t eliminate the discomfort you can also try putting on a shoe with a lower heel height but only if you have recently changed to a higher heeled shoe.  Changing shoes is a very common problem for many people with limb loss.  If you are unsure of how to manage different shoes, you should talk to your prosthetist about how to use heel wedges.

Prosthesis was not fit properly

If sock and shoe solutions don’t help there may be another fitting problem.  Newer fitting techniques can contribute toPain/redness on Distal Tibia pressure on this bone if the Prosthetist did not make the corrent modifications to the prosthesis to begin with.

Prosthesis was not aligned properly

The prosthesis may not be aligned correctly.  If there was too much socket flexion built into the prosthesis the resultant force will directed onto this area.  Generally, walking down hill will increase discomfort in this area while walking up hill will decrease the discomfort.  Regardless, if you are unable to remedy the problem on you own you’ll need to see a Prosthetist.

 

DISTAL END OF LIMB

Not wearing enough socks

Pain on this portion of your limb is most likely caused by dropping to far into the socket because your limb has shrunk.  Try adding socks one ply at a time until the prosthesis fits comfortably.  If you’ve had this discomfort since the prosthesis was new, you should talk to a Prosthetist.

Socket originally made with insufficient inside depth Pain on bottom of limb

The socket not having the correct inside depth can also cause this pain. The limb hits the bottom of the socket before the upper section seats properly into its intended area.

 

DISTAL (BOTTOM) KNEE CAP

Not wearing enough sock ply

Pain on the bottom of the kneecap is usually an indication that your limb is dropping too far into the socket.  Add a sock ply one at a time until the socket is comfortable.

Heel on shoe is too low

Changing to a shoe with a lower heel may also cause pressure in this area.  Try using a heel wedge in the back of the shoeSharp pain/redness on bottom of knee cap or switch back to your previous shoes.

Prosthesis was not fitted properly

If sock or shoe solutions don’t increases your comfort you should contact a Prosthetist.  There is a chance that the prosthesis was aligned incorrectly to begin with.  Many times a small alignment adjustment can decreased this discomfort.

 

TIBIAL TUBERCLE

Wearing too many or too few socks

This problem can occur by either sinking too far into the socket or being held too far out of the socket.  Try adding or removing socks to relieve the discomfort.

Not enough relief built into socket during fittingPain/redness on Tibial Tubercle

If you continue having pain on this bone it is most likely a flaw in the socket design and you should see a Prosthetist.

 

DISTAL POSTERIOR CALF
Wearing too few socks
Typically, this discomfort is the result of limb shrinkage that can usually be remedied by applying one sock at a time until the pain goes away.

Socket originally made too short
The socket not having the correct inside depth can also cause this pain; the limb hits the bottom before the upper section seats properly into its intended area.

Bottom 1/3 of socket too loose due to limb shrinkage

Pain in this area can also be caused by the end of the Tibia pressing on the back bottom of socket when a patient has pressure on the toe of prosthesis, especially when taking a long step with their good leg.

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5 Comments on “Below Knee Prosthesis – Where is Your Pain?”

  1. [...] Also review our April 9th Blog topic called: “Below Knee Prosthesis – Where is Your Pain?” [...]

  2. Tom Miller says:

    I am a BKA patient with my amputation being almost 5yrs ago. My pain starts after wearing my prosthetic for a couple of hours and
    It starts on the right side of my stump above the end and below my knee its like an extreme Charlie HORSE and gets so bad I have to get off of it. I have yet to be comfortable in my prosthesis since my surgery,—– HELP!!!

  3. Thanks for finally talking about > Below Knnee Prosthesis – Where is Your
    Pain? | Advanced Prosthetics Center Blog < Liked it!

  4. Rosella says:

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  5. barb eaton says:

    I have a patient who has alot of play lateral and medial in the ankle area of the foot. she is a below knee amputee. this tends to make her knock kneed when walking. and appears unstable. She has stated that she feels unsteady when walking esp. when turning. When I tried to tighten the shoe and put some cloths between the shoe and the plastic foot it seems to help. Should there be that much movement in the ankle/foot part of the prosthesis, med/lat. ?