Care and Use for a Below Knee Prosthesis Pin Locking Liner

below knee prosthetic

Posted on 3/18/2019 by Martin Ryan, C.P., CFO, FAAOP | Comments

 

How does a prostheses attach? Great question and one that has a number of possible styles for the below the knee patient.

Suspension systems in prosthetics come in a number of configurations. One system common today is the mechanical pin lock system. A pin is attached to the distal liner and inserted to a lock mechanism that provides the interface for suspension. The system is clinically referred to as the Below Knee Prosthesis with a Pin Locking Liner.

Pin lock suspension can be used with patella tendon bearing (PTB), total surface bearing or hydrostatic socket design. With pin lock liners, a silicone liner is rolled onto the residual limb creating a seal between the skin and the liner. The liner has a pin on the end that locks into the bottom of the prosthetic socket. A prosthetic sock may be worn over the silicone insert in order to allow for volume fluctuations.

PUTTING ON THE PROSTHESIS:

Turn the liner inside out. Make sure the liner is clean and dry and has no dirt on it that will irritate the skin.
Make sure a good portion of the bottom end of the liner is exposed and place it against the limb. (Figure 1) With light pressure, roll it up and over the limb. Make sure no air pockets exist between the liner and the skin.
Roll the liner up the limb. (Figure 2) Do not pull or tug. Be careful not to tear or puncture it with fingernails or jewelry.
Pay close attention to the placement of the pin. In most cases, it should be in line with the limb. Be careful not to pierce the liner with the pin.
When using a liner without a fabric cover, a lubricant may be necessary. Consult with your prosthetist to determine the best lubricant for your use.
Add the appropriate thickness of prosthetic sock over the liner, if necessary.
Push the residual limb into the prosthetic socket. The pin will insert into the lock and click down as the limb goes into the socket. It should take some effort to put on the prosthesis. If it clicks down easily, a thicker prosthetic sock may be needed. (Figure 3) 

REMOVAL OF YOUR PROSTHESIS:

Push and hold the lock button in and lift the limb out of the socket.
CLEANING AND MAINTENANCE:

The prosthetic socks and sheaths should be cleaned according to the manufacturer’s directions. The soft insert and the prosthetic socket may be wiped out with warm, soapy water or alcohol as needed. Clean socks should be worn every day.
TIPS AND PROBLEM SOLVING:

One of the most difficult concepts to master is how to determine the correct sock ply to wear. Wearing the correct amount of socks is critical for comfort and safety. Your prosthetist and physical therapist will supply you with general guidelines in wearing socks, but if you have questions do not hesitate to contact or visit your prosthetist.
OH NO, IT’S STUCK:

It can happen. You get stuck and the pin will not release. Many times, the sock has covered the pin and is providing in ability of the pin to release.
Do not panic. In most instances, some consistent pulling will release the pin and free the lock. Ask someone to assist you in this process if necessary.
In extreme cases, pour soaping water into the liner next to the skin breaking suction and allow it to release from the prostheses and work free.
Contact your prosthetist.
For more information on the Below Knee Prosthesis with a Pin Locking Liner, please contact a NovaCare Prosthetics & Orthotics centers near you.

By: Martin Ryan, C.P., CFO, FAAOP, is prosthetist for NovaCare Prosthetics & Orthotics. Marty is certified in advanced prosthetic designs for adults and pediatrics. He received prosthetic training at Northwestern University and the Rehabilitation Institute of Chicago. Marty is certified in prosthetics by the American Board for Certification and works out of NovaCare P&O’s Fond du Lac center in Wisconsin. NovaCare Prosthetics & Orthotics is part of the Select Medical Outpatient Division family of brands.