Below the Knee

Below the Knee (Transtibial)

A below knee (BK) prosthesis will typically consist of a custom-made socket, a pylon and a foot. Sometimes a suspension sleeve or harness may also be necessary.

Although it varies considerably from person to person, new amputees usually begin the prosthetic fitting process a few weeks after surgery. Immediate Post Operative Care (IPOCare) is used in some cases and a socket or rigid dressing is placed on the limb during the first week following surgery. 

Your Hanger practitioner can utilize the Insignia laser scanning system to capture the precise shape and contour of your residual limb. Insignia stores a series of three-dimensional images that are sent to an automated carver, creating a precision form that is used to fabricate a temporary or test socket. Plaster casting is another, more hands-on process that is sometimes used to create a custom mold for the socket.  Your prosthetist will decide the most clinically appropriate means for creating your socket.

The use of a temporary prosthesis has many advantages.  It allows for swelling to subside and for the residual limb to heal completely, a process that can take up to six months and sometimes longer. A prosthetic sock or cushioning gel liner is worn between the socket and the body to protect the sensitive skin of the residual limb. Each day, the size of the residual limb will reduce as the swelling decreases. When this occurs, the user can add additional layers of socks to keep the socket from becoming too loose. If the socket gets too loose, it may be necessary to fabricate a new socket to address the change in volume.

The pylon of the temporary prosthesis typically does not have a cosmetic covering so it is easier for the prosthetist to make adjustments in the alignment.  People usually begin physical therapy and gait training while wearing the temporary prosthesis. During this time it is very important to locate any pressure spots or abrasions on the residual limb. When the volume of the residual limb stabilizes and the person has developed a steady level of activity, it’s usually time to move to a definitive prosthesis.

To cast your definitive ComfortFlex socket, we again may utilize Insignia for a final laser scan. Your practitioner will review the scanned images with you and together, you can make fine adjustments. Our patients tell us they like being involved in the fitting process and having their scanned images and anatomical data available at the click of a mouse. Again, some residual limbs may require a more hands-on method of plaster casting for the socket. Your prosthetist will determine the most clinically appropriate approach for creating the best socket for your individual needs.

Man walking on sidewalk with below-the-knee prosthetic leg

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