special subjects
Prosthesis Parts
Interface between the residual limb (stump) and prosthesis
The prosthesis attaches to the body by direct skin contact or by an interface made of various, thin cushion materials worn over the residual limb (stump). Agel cushion interface, worn over the residual limb, protects the skin and helps even out pressures. Custom molded interfaces may be necessary for irregular stump contours (because of, for example, deep scars, sharp bones, or burns). Ideally, people should have 2 identical interfaces so they can be alternated day to day. Alternating the interface helps it maintain its elasticity and shape and last longer. Interfaces are typically recommended to be replaced every 6 months and, for very active patients, every 3 to 4 months. Aprosthetic sockmay be worn instead of or with a gel interface. Socks are made of wool, nylon, or synthetic fabrics, sometimes with gel sandwiched between the layers of fabric. Socks are available in different thicknesses (plies). The residual limb changes size normally throughout the day as a result of activities, weather, and other factors. Prosthetic socks and special pads are used to manage those changes. By putting on one or more socks of different thicknesses or by taking socks off, a person can adjust the fit of the socket to make it more comfortable as the residual limb changes size during the day. When a comfortable, stable fit cannot be maintained with the use of prosthetic socks or special pads, the prosthetist (an expert who designs, fits, fabricates, and adjusts prostheses) can adjust the socket. 