Determining the most representative topographic variables in locally manufactured sockets for patients with transfemoral amputation

Abstract

The degree of comfort of a patient with transfemoral amputation is directly related to the Coefficient of Friction (COF) at the Socket-Stump interface. It has been experimentally proven that surface characteristics of the element contacting the skin have an impact on the COF.  Based on the gypsum model of a patient with transfemoral amputation, six sockets are manufactured in companies from several cities of the country (Bogotá, Medellín, and Cali) with the purpose of determining the topographic changes based on the manufacture process. General procedure to manufacture the socket is established, the areas exercising the biggest stress on the stump are identified based on finite-element models, and samples are taken from sockets. Through a roughness tester, surface of samples is characterized having Ra, Rq, and Rpc as tribological parameters. It is concluded that due to the highly artisanal degree of the manufacture process tribological characteristics significantly vary from one socket to another, which allows having a possibility to perform, in the future, manufacture protocols to include surface texture on specific areas of sockets in order to modify coefficients of friction and increase patients’ comfort.