An Experimental and Virtual Approach to Hip Revision Prostheses

Abstract

(1) Introduction: The changes in the joint morphology inevitably lead to prosthesis, but the hip pathology is complex. The hip arthroplasty is a therapeutic solution and can be caused, most frequently, by primary and secondary coxarthrosis due to or followed by traumatic conditions. The main aim of this study was to find the method of revision hip prosthesis that preserves as much bone material as possible and has sufficiently good mechanical strength. (2) Materials and Methods: In this study, in a first step, the two revision prostheses were performed on bone components taken from an animal (cow), and then, they were tested on a mechanical testing machine until the prostheses physically failed, and the force causing their failure was determined. (3) Results: These prostheses were then modelled in a virtual environment and tested using the finite element method (FEM) in order to determine their behaviour under loading from normal human gait. Displacement, strain, and stress maps were obtained. (4) Discussion: Discussions on hip revision prostheses, method, and theory analysis are presented at the end of the paper. (5) Conclusions: Important conclusions are drawn based on comparative analyses. The main conclusion shows that the both orthopaedic prostheses provide a very good resistance.

Orthodontic System Modeled and Simulated with the Lingual Technique to Assess Tooth Forces

“…Additionally, 5 points were defined at a distance greater than 0.012 inches (0.3 mm) from the base of the bracket component ears, as shown in Figure 16. These points were necessary for the correct guidance of the orthodontic archwire during assembly and when defining its main curve [23][24][25][26][27][28][29][30][31][32][33][34][35]. In the end, with the help of several three-dimensional modeling techniques, the final model of the bracket component was obtained.…”

“…Additionally, 5 points were defined at a distance greater than 0.012 inches (0.3 mm) from the base of the bracket component ears, as shown in Figure 16 . These points were necessary for the correct guidance of the orthodontic archwire during assembly and when defining its main curve [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”