RING FIXATORS IN TRAUMATOLOGY (AN ENGINEERING POINT OF VIEW) Karel Frydrýšek 1,2 , Jiří Kohut 2 , Vojtěch Bajtek 1 , Milan Šír 3 , Leopold Pleva 3 1 Department of Applied Mechanics, Faculty of Mechanical Engineering,VŠB-Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava-Poruba, Czech Republic, karel.frydrysek@vsb.cz, vojtech.bajtek@vsb.cz 2 Center for Advanced and Innovative Technologies, VŠB-Technical University of Ostrava, 17. listopadu 15, 708 00 Ostrava -Poruba, Czech Republic, iri.kohut@seznam.cz 3 Ostrava University Hospital, Trauma Cente r, 17. listopadu 1790, 708 52 Ostrava, Czech Republic & University of Ostrava, Faculty of Medicine, Dvořákova 7, 701 03 Ostrava, Czech Republic, milan.sir@fno.cz, leopold.pleva@fno.cz ABSTRACT This article focuses on ring (Ilizarov) external fixators in traumatology and orthopedics. External fixators are used in the treatment of complicated fractures, bone shortening and lengthening, corrections of angular deformities, and similar applications. An engineering/biomechanical point of view represents an essential perspective when taking account of the recommendations of medical specialists, designing materials for fixator components, developing surface treatment methods, optimizing design concepts, and conducting experimental verification. The article presents practical experience and results gained during cooperation between medical specialists and engineers (an overview of applicable materials, design, laboratory experiments, Finite Element Modeling). KEY WORDS External fixator, ring fixator, biomechanics, traumatology, orthopedics, materials, design, experiments, Finite Element Method 1. Introduction External fixators (see Fig. 1 and [1], [2] and [3]), used in traumatological and orthopedic applications for purposes of osteosynthesis, are prefabricated structures designed for limb bone fixation in humans and animals. The components of an external fixator are fixation screws, fixation wires, fixation rods, and linking elements (clamps). External fixators can be used to stabilize long bones during the treatment of open fractures, infected pseudoarthrosis and aseptic pseudoarthrosis. They can be used in situations when internal osteosynthesis is not an option, as well as in specific situations such as the correction of angular deformities, bone lengthening and shortening, or bone tissue replacement in cases of defective fracture healing. Figure 1 Application of an Ilizarov (ring) fixator Materials are a key factor in ensuring the full functionality of a fixator; see [4] and [5]. This article therefore focuses on the properties and suitability of materials used in the manufacture of fixators. The article also presents specific applications developed as part of cooperation between producers and hospitals; see [5], [6], [7] and [8]. The advantage of external fixators is that they can be removed simply and non-surgically after the completion of treatment (i.e. the bones are fixed to the frame by small wires or screws only until healing occurs); this is not possible with internal fixators (nails, plates, etc.); [1], [2] and [3]. Figure 2 Types of fixators (current development) Proceedings of the Sixth IASTED International Conference August 16 - 18, 2016 Campinas, Brazil Modelling, Simulation and Identification (MSI 2016) DOI: 10.2316/P.2016.840-035 204