Medical aspects of prosthetics in lower limb amputees with use of digital technologies

Abstract

Introduction Digital technologies used for lower limb amputation patients wearing prostheses are mostly experimental due to the complexity involved in model development of the stump socket. The objective was to develop a technique for additive manufacturing of lower limb prosthetic sockets to minimize negative results using a three-dimensional model of a prosthetic socket and considering anatomy and functionality of the stump. Methods The review included 20 lower limb amputees who were assigned to 3 groups depending on the method of stump scanning. Results The results of prosthetics were evaluated with the stump scanned naked (n = 9), covered with a silicone cloth (n=6) and with the use of embedded components (n = 5). The results of clinical and instrumental examination showed the advantage of the scanning method offered. The symmetry index for the time of foot roll-over was 0.55 ± 0.14 in the first group, 0.63 ± 0.07 in the second group, and 0.85 ± 0.04 in the third group. Discussion The best results of prosthetics in third group were associated with the most favorable load distribution in the receiving cavity of the prosthetic socket due to embedded components. In these cases, processing the digital model was simplified with no need to unload bone prominences. With scanning of a naked stump, processing a digital model was complicated and required professional skills. This solution had the potential to prevent any sort of direct physical contact to avoid inadequate modeling of the computer model of the prosthetic socket. The use of a silicone liner allowed reducing the pressure on the bone prominences. With a sharply skeletonized stump, the elastic properties of the liner were not enough and could cause injury to the tissues. Conclusions The findings suggested that improved quality of prosthetics was dependent on the technique used to scan the stump. The use of pre-installed embedded components allowed for effective load distribution in the prosthetic socket and created favorable conditions for prosthetic use.

Keywords

• additive technologies
• prosthetic socket
• prosthesis
• scanning
• below knee amputation
• digital model