Updated: Oct 5
What is Prosthesis?
Prosthesis, artificial substitute for a missing part of the body. The artificial parts that are most commonly thought of as prostheses are those that replace lost arms and legs, but bone, artery, and heart valve replacements are common, and artificial eyes and teeth are also correctly termed prostheses. The term is sometimes extended to cover such things as eyeglasses and hearing aids, which improve the functioning of a part. The medical specialty that deals with prostheses is called prosthetics.
Prosthesis vs. Prosthetic
Many people wonder how to use the terms “prosthesis” and “prosthetic” properly. A prosthesis is the substitute limb worn by the amputee, and and the plural of prosthesis is prostheses. Prosthetics refers to the field and science of creating prostheses.
Using a Prosthesis Device?
When an arm or other extremity is amputated or lost, a prosthetic device, or prosthesis, can play an important role in rehabilitation. For many people, an artificial limb can improve mobility and the ability to manage daily activities, as well as provide the means to stay independent.
Prostheses Parts and Types
There is a wide variety of prostheses that are designed to function — and in many cases look — like a natural arm, leg, hand, or foot. Although there are many different designs, most have similar parts.
Following are some of the most common types of prostheses:
Below The Knee (Transtibial) Amputation
Below the knee amputations are performed between the ankle and knee. The prosthesis is designed with moveable and adjustable joints and pylons. These components replicate a human thigh, ankle, and foot.
Above The Knee (Transfemoral) Amputation
Above the knee amputations are performed at or above the knee joint. The prosthesis is designed with moveable to joints and pylons to replicate a human knee, thigh, ankle, and foot.
Types of Prosthetic Legs
A wood or urethane foam prosthesis with a hard plastic shell. This prosthesis is heavier and less customizable than an endoskeletal prosthetic. But it is more durable and long-lasting.
A prosthesis with an inner support pylon made of light-weight materials such as aluminum or titanium. Feet and knees can be swapped out. This makes the endoskeletal prosthesis easily adjustable for different activities and active lifestyles.
For above-the-knee amputees, there are a variety of prosthetic knee joints available at different price points and with different functionality.
There are two basic types:
Single-axis knees: hinge-style knees that can only bend forward and backward.
Polycentric knees: also referred to as “fourbar” knees, they can rotate on multiple axes.
Fitting a Prosthetic Leg
The affected leg must be given time to heal before wearing a prosthesis. Most patients begin rehab with a temporary prosthesis within the first three months. A test prosthesis is specialized to help with physical therapy and gait training. It is customizable for adjustments as the patient progresses.
A plaster cast of the residual limb or a 3D laser scanner creates a custom prosthetic socket. The initial test socket is flexible to adjust to the reduction of swelling in the residual limb. It serves to minimize pressure and abrasion.
During rehab, your feedback on the fit provides the specialist with the information required to cast a final socket. They help you choose a prosthesis for your leg based on your lifestyle and activities.
Arm Amputation and Prosthetics
Arm amputations are either above or below the elbow. Arm prostheses that allow wearers to manipulate and grip objects to live independent lives. Electric prostheses can even move based on signals from the wearer’s muscles.
Below The Elbow (Transradial) Amputation
Below the elbow amputations are performed between the hand and elbow. Prostheses are designed to replace the forearm, wrist, and hand.
Above The Elbow (Transhumeral) Amputation
Above the elbow amputations are performed at or above the elbow. As most of the arm is removed, a hybrid prosthesis is the best option to provide the motion of the elbow and also provide grip.
Types of Prosthetic Arms:
A three-harness cable system prosthesis that allows the wearer to grasp objects, flex and lock the elbow. This is the least expensive type of arm prosthesis.
There are two varieties of body-powered prostheses that offer different hand functions:
Voluntary Open: opens the hand when applying tension to the cable
Voluntary Close: closes the hand when applying tension to the cable
An electrically powered prosthesis that resembles a real arm. The user controls it with electrical impulses through muscles in the residual limb. This option is more expensive than a body-powered prosthesis and it needs frequent recharging. It also requires a great deal of fine-tuning to get the prosthesis to interpret the electrical signals, and may not work for all people.
Most electric prosthetic arms provide basic grip functionality. But some of the latest electric prostheses have fully controllable fingers.
A combination of both body-powered and electrical components. This type of prosthesis is generally used for above the elbow amputations. It’s specialized to enable a greater range of motion and function for the wearer.
Fitting a Prosthetic Arm:
Fitting for a prosthesis will wait until the arm has fully healed. The residual limb is cast from either plaster or a 3D laser-model to create a test prosthetic socket.
The test socket is clear to allow for specialists to observe the skin during rehab. This allows them to see where the skin is coming into contact with the socket during movement. A specialist uses these observations to create a definitive socket. Then, they discuss what type of prosthetic arm is right for you and your lifestyle.
Choosing and Using a Prosthesis
A number of factors are involved in choosing a prosthesis.
The location and level of the amputation
The condition of the remaining limb
Your activity level, particularly for a prosthetic leg or foot
Your specific goals and needs
Using a Prosthetic Device
Prostheses are designed and fitted by a specialist called a prosthetist. The fitting process may begin in the hospital after amputation after the swelling has gone and down and the incision is healed. The fitting process depends on individual, some take weeks whereas some take months. Usually for an elderly, recovery is generally slower. If the patient is a diabetic, it takes even longer.
Stump management after wound is healed
Fabrication of prosthesis
Depending on your comfort and how well your wound is healing, you may begin to practice with your artificial limb as early as a few weeks after surgery. A physical or occupational therapist will train you on how to use and care for it.
It is vital for patients who choose to have a prosthetic limb fitted to be provided with proper care and information in order to better adjust to life with a prosthetic leg or arm.
Lifeforce provides review for patients. in any case of weird feeling or discomfort, do consult us immediately.