Design of an external fi xator, extension and angular corrector of tibia using the analytical method of hierarchy

Abstract

In this research, an external fi xation device was designed, capable of lengthening and angularly correcting the bad bone formation of the tibia through the process of osteosynthesis. In the design stage of the device, research related to: the process of bone formation, study of the background of existing fi xator models in the market, anthropometric study of the Venezuelan population, among other data, was reviewed. From the information, the concept and  various design proposals organized by systems were generated, requiring the application of the analytical process of hierarchy for the evaluation and objective selection of the fi nal proposal considering multiple criteria and attributes of the product design. After the selection, the design proposal was materialized through the use of CAD programs, allowing through these programs to defi ne geometries, shapes and materials of the different components of the fi xture, which were then validated through static stress and deformation analysis, fatigue studies and convergence of results carried out in CAE computer-assisted engineering programs. With the research carried out, it was possible to develop an external fi xator based on Venezuelan anthropometric measurements, with a 33 % reduction in its total weight compared to previous designs, as well as a notable simplifi cation in the manufacturing processes, benefi ting from the decrease in manufacturing costs.