How Are Prosthetic Limbs Designed and Made?

Updated on May 23, 2022
How Are Prosthetic Limbs Designed and Made?

Prosthetics are invaluable in the medical world, able to offer a greater quality of life to amputees and those born with missing limbs. Because of this, understanding the nature of prosthetics is essential for physicians, even if it isn’t one’s area of expertise.

To help enhance our understanding of this field, we are answering the question of how prosthetic limbs are designed and made.

Discussion With a Prosthetist

Everyone in need of an artificial limb has a unique medical situation. As such, the first step in the process of designing and creating a prosthetic limb is to have an in-depth discussion with a prosthetist. This discussion should seek to answer questions like:

  • What is the muscle mass of the residual limb?
  • What is the state of the bones in the residual limb?
  • How active is the patient’s lifestyle?
  • What does the patient intend to do with the limb? (For example, walking vs. sports)
  • How realistic does the patient want the limb to appear?

This conversation will inform the types of artificial limbs that are feasible for a patient. For example, a prosthetist will be able to determine whether a patient can get a myoelectric prosthetic or just a simple functional prosthetic based on the answer to these questions.

Casting a Mold

Once a plan is in place, the prosthetist can create a mold of the residual limb. This is often done by taking several measurements, making a negative mold of algin, and filling it with a fast-drying plaster to create a positive mold. When the mold has dried, the prosthetist can remove it and smooth out the surface to prepare it for further processing.

Creating a Socket

In terms of prosthetics, a socket is a part that connects the residual limb with the rest of the artificial limb. A socket has to fit the residual limb well to avoid chafing or damaging the skin. For that reason, sockets are one product that is often made using CNC machines to ensure the accuracy of the design.

Using the mold as a reference, computer technology is able to carve a new mold to fit the body exactly. From here, prosthetists can cover the new socket with acrylic that is colored to match the patient’s skin tone.

Adding the Mechanics

With the socket complete, there is now a space to place the mechanics of the prosthetic limb—from carbon fiber appendages to aluminum joints. These components are also made using machining tools and CNC machines, depending on the types of prosthetic limbs you are trying to create.

Understanding the nature of artificial limbs as a physician is essential for treating amputee patients and others with missing limbs. Equipped with this knowledge, practices will be able to provide better, more empathetic care to their patients.