Biomechanical Optimization of a Novel Circular External Fixator (Optimization of Circular External Fixator)

Abstract

The purpose of this study was to investigate biomechanical optimization of the newly designed circular external fixator (CEF) system, used in the orthopaedics surgery, that is capable of continuous compression at the fracture line. External fixators are devices applied from outside the body to treat bone and joint injuries as well as to correct skeletal deformities. In this study, the effects of parametric changes on CEF mounted for the fracture were investigated with using response surface optimization (RSO) module in ANSYS software using the finite element method. The pressure acting on fracture line is an essential factor on fracture healing. The RSO module showed that the contribution of the parameters on this essential factor was as follows in the descending order; pre-load, spring coefficient, wire diameter and angle between the wires. According to the results of the numerical study; (a) there was a positive correlation between the wire diameter and the normal stress at the fracture line. The increase in wire diameter and pre-loading caused an increase in the normal stress at the fracture line. (b) The angle between the wires has a relatively little effect on the whole system. (c) The most effective parameters on the system were determined as the pre-loading and spring coefficient.