Below Elbow Arm Prosthetics
Above Elbow Arm Prosthetics
Location is below the elbow and above the hand.
Conditions: Severe Trauma, Blood vessel disorder (atherosclerosis), Diabetes mellitus, malignancy, infection, congenital amputation, and gangrene.
Beginning the Process
The process to start getting a BE prosthesis can start as soon as a few days/weeks after the amputation. The patient can be fit with a BE Shrinker, which is optional in the case of upper extremity prosthetics. A shrinker is a compressive garment that is used to help shape the limb for prosthetic process and reduce edema in the residual limb. It is similar in concept to using ace wrap, but the benefit is that the same compression will be applied throughout the limb, even when donned by different people. This will also help to desensitize the limb to get it ready for a prosthetic socket. These shrinkers are usually made by Juzo and Compressogrip- Knite Rite. After surgery, the patient’s limb will change size and shape up to the next year. The shrinker will help stabilize the limb size earlier on and give the patient a more successful prosthetic experience.
Liners and Cast/Scan
The next step in the process is to have the patient fit with a liner, if deemed necessary. Liners may be used for upper extremity patients, but generally, patients will fit directly into a socket. If utilized, the liner is a soft interface that the patient wears over the skin. It is donned before the socket. The main function of the liner is to absorb the forces created when utilizing your prosthesis, to keep your residual limb healthy, and to allow you to wear the prosthesis for longer. There are off-the-shelf (OTS) and custom liners. If the residual limb is an uncommon shape or very boney, custom liners may be used. These are made by taking an impression of the patient’s limb via a plaster cast or scan using our several different scanners/software. The process of obtaining a custom liner takes longer than obtaining an OTS liner. If the shape of the limb is common, measurements are taken to order the proper sized OTS liner.
Once the liner is ready, or if the patient isn’t utilizing a liner, it is time to cast the patient for their first socket. Different casting methods will be used based upon the style or prosthesis that was previously decided upon by the prosthetist and patient. From here, the cast will be filled and modified appropriately to make your custom AE diagnostic prosthetic socket.
The first prosthetic socket you will receive will be called a diagnostic socket. This socket will be made of a clear plastic allowing us to evaluate the fit and see areas of pressure more easily. The socket will be donned at this appointment. Typically, these sockets are not taken home by the patient at this time, instead they are made to try on to check alignment, functionality, and comfort at the second diagnostic fitting appointment. A plastic diagnostic socket is used to start with as parts of the socket may need to be modified to appropriately contour to your limb. This can be easily done by heated and flaring the plastic.
Usually multiple sockets are needed for upper extremity, due to a more exact fit being required. The better the fit of your prosthesis, the better your outcome will be.
Once we have confirmed the diagnostic prosthetic socket fits the patient well, we can move on to the laminated socket. The laminated socket is fabricated using carbon fiber, which means it is much lighter than the plastic socket and has a higher tensile strength. Carbon fiber is also more durable, so the socket will be able to last up to a few years, depending on activity level and any limb changes. The patient can choose to have the socket custom designed/colored to meet their desire, which may be to have the socket color match their skin tone or have their favorite sports team logo on the socket. Depending on the style of prosthesis, there may be an inner socket may of Proflex, which is a softer plastic inside the outer carbon shell.
The prosthesis will be donned with the patient several times, allowing the patient to learn to don/doff it themselves. Size can be adjusted appropriately. Training will be performed to help the patient get use to using the limb. Occupational therapy will play an important part of training and strengthening their upper limb muscles outside of appointments with your prosthetist.
Myoelectric Prostheses (MP)
The MP of the upper extremity are sophisticated electronic prosthetic devices that contain microprocessors and motors to enable greater dexterity and functionality. These prostheses allow for greater pinch and grip forces not available with the standard hook and pulley systems.
Body powered prostheses work by utilizing cables that link the movement of the body to the prosthesis. Moving the arm a specific way causes tension to increase in the cables, and therefore allows for opening, closing, and bending.
Voluntary Opening and Closing: