Behind the Scenes: The Making of a Custom Prosthetic Leg

P&O Care, Inc. is unique in that they have three on-site lab facilities that enable them to quickly fabricate prosthetic devices.

Once the patient’s doctor issues a prescription and one of P&O Care’s thoroughly trained practitioners has taken careful measurements, P&O Care can finish a prosthetic leg in little over a week.

Making an Above the Knee (AK) or a Below the Knee (BK) prosthetic leg involves both an art and a science. P&O Care's goal is to make a leg that is the most comfortable and that provides the most optimal performance for their patients.

The Steps in Making a Prosthetic Socket

The first step in making a prosthetic socket involves the P&O Care practitioner making a cast (known as a negative mold) of the patient's residual limb and taking notes and measurements. Plaster bandages are wrapped around the residual limb and allowed to dry.

Then they take the negative cast back to the lab where it is placed in the “sand box” and filled with plaster. Once the plaster has hardened, the negative mold is cut away, leaving an exact replica of the patient's limb (the positive mold).

Next comes the most critical step in making a good fitting, comfortable prosthesis. Referring to his or her comprehensive notes and measurements, the practitioner modifies the positive mold by adding and taking away plaster to address pressure-tolerant and sensitive areas of the patient’s limb.

After the practitioner's modifications are made, plastic or foam is heated and pulled over the mold to create a flexible inner liner. Next, the practitioner selects a suspension system that will hold the leg on and makes some necessary adjustments. At this point, the technician will align the socket with the components that will attach to the knee and foot.

The last step is the lamination of the rigid frame: the inner liner is sealed, covered in plastic and wrapped with layers of carbon fiber, nyglass or nylon. Then it is covered with a second plastic bag and attached to a funnel. A vacuum hose attached to the bottom pulls a quick hardening resin mixture down over the molded fabric. The resin hardens and the plaster mold inside the socket is removed. Now, it’s ready for the rest of the leg.