Prosthetics Options After an Above Knee Amputation

Above the Knee Prosthetic Leg Options

Prosthetic knees are necessary for above the knee amputees to regain use of the knee and ankle joints. Mechanical and computerized options are available, each with benefits and disadvantages.

Mechanical

• The single axis is the most straightforward type, allowing for knee flexion and extension. It’s a durable, lightweight option for those learning to use a prosthetic leg. While it’s a cost-effective choice, a single-axis prosthetic requires significant muscular strength, and locking and unlocking the knee while walking can be difficult, which can cause falls.
• A polycentric knee has several points of rotation around multiple axes and is a good fit for people who walk without a gait aid. It allows a person to sit with a bent knee, but it is heavier than a single-axis design and requires more energy to maintain balance while walking.
• The manual locking knee automatically locks the knee joint when it is bearing weight, providing stability for those with poor muscle control. A drawback to this prosthetic is that the user must swing their leg out or raise their hip for foot clearance while moving, which can lead to issues with the surrounding muscles and joints in the future.
• A weight-activated stance control prosthesis provides continuous friction while bearing weight, helping to prevent buckling when the user is standing and allowing the leg to swing freely when unweighted. It’s a stable choice for those who have control of their knee but tire after a few steps. The drawback to this type of prosthesis is that the friction causes a person to walk more slowly and take smaller steps.

Computerized

Computerized prostheses use microprocessors to collect feedback from the knee joint, automatically adjusting the speed and range of knee flexion. This creates symmetrical weight distribution, allowing for a more natural gait pattern that expends less energy. 

Computerized prostheses are more expensive than mechanical devices, and learning to walk with one can be more challenging. They also require regular maintenance and are most costly to repair if damaged.

What Parts Does a Prosthetic Leg Above the Knee Have?

Regardless of which type of prosthetic leg you choose, there are four universal components in a prosthetic leg.

1. Socket: A custom-made piece that joins your residual limb and the prosthesis. Made using various combinations of plastic and silicone to provide comfort and durability, a suction seal ensures a tight fit between the residual limb and the socket, and a cushioned liner helps reduce pressure and friction.
2. Knee Joint: This component replicates the movement of a natural knee for smooth, stable movement. It also offers a range of motion that allows you to sit and kneel.
3. Pylon: Also known as a shin tube, this piece connects the knee joint to the ankle and foot and uses lightweight materials like aluminum or titanium.
4. Foot and Ankle: Many types of ankle and foot prostheses accommodate various ability levels and activities. Our prosthetists can help you select the best option for you.

Contact Us for More Information on Above the Knee Prosthetic Legs

Durrett’s Orthotics & Prosthetics is a family-owned business with an experienced team that offers compassionate care, education, and connection to community resources. We provide services for children and adults from our state-of-the-art Edgewood, Kentucky, and Lawrenceburg, Indiana facilities.

Visit our patient info page for answers to many questions, then contact us to schedule an evaluation. Durrett’s Orthotics and Prosthetics proudly serves Erlanger, Florence, Covington, Fort Thomas, Union, Walton, Edgewood, Oakbrook, Taylorsport, Fort Mitchell, Hebron, Beaverlick, Burlington, Belleview, Independence, Newport, Verona, Elsmere, KY, and Cincinnati, OH.