Above-knee Prosthetics

An above-knee (AK) prosthesis consists of a custom-made socket combined with a supportive frame, knee unit, pylon, and foot. Sometimes a suspension sleeve or harness may also be necessary.  


A Hanger Clinic prosthetist is fitting a bilateral above-knee patient.Fitting and Scanning Process

Although it varies considerably from person to person, new amputees usually begin the prosthetic fitting process a few weeks after surgery.  A post-operative limb protector such as AmpuShield™ Post-Operative Limb Protectors is often used during the first week following surgery.

Your Hanger Clinic prosthetist may utilize a CAD or computer aided design approach to create the precise shape and contour of your residual limb.  By taking measurements of the patient’s residual limb, Hanger Clinic’s Insignia™ Laser Scanning System creates 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 effective means for casting your socket.

Temporary Prosthesis

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 shrink 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, a new test socket will be fabricated.  Test sockets allow you to work together with a lower extremity specialist at Hanger Clinic to fine-tune features like contouring, upper trim lines and the placement of cutouts on the socket frame.

The temporary prosthesis typically does not have a cosmetic covering so it is easier for the prosthetist to make adjustments to the alignment and to the knee. People usually begin physical therapy and gait training while wearing the temporary prosthesis. During this time it is very important to locate and address 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.

Definitive Prosthesis

To cast your definitive ComfortFlex™ socket, we again may utilize Insignia™ Laser Scanning System for a final socket design. Your clinician will review the 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 computer designed images and anatomical data available at the click of a mouse.  Again, some prosthetists will choose the more hands-on method of plaster casting for the socket.

Hanger Clinic’s lower extremity specialists are pleased to offer above-knee users a dynamic socket that is comfortable. Our thin, flexible socket slips into a supportive frame that is reinforced with lightweight carbon composite. Cutouts on the frame can help to relieve pressure points and allow muscles to naturally expand and contract during use.

Interested in a free evaluation? Call 1-877-4HANGER to find the closest Hanger Clinic location specializing in the orthotic solutions you need.