2D AND 3D FINITE-ELEMENT PRE-PROCESSING AND POST-PROCESSING IN ORTHOPEDICS

The present widespread tomographic techniques based on computed tomogr aphy (CT), magnetic resonance imaging (MRI) and automatic 2D and 3D re constructions also involve numerous new points of view for planning su rgical techniques in orthopaedy. These require efficient pre- and post -processing methods. By pre-processing and post-processing is meant bo th the generation of a finite element mesh that numerically models hum an joints and the visualization of the results obtained as required by the surgeon. Since the numerical reconstructions of human joints are based on the finite element approximation of contact problems assuming linear elasticity, the main goal of pre-processing is to generate tri angular (2D) and tetrahedral (3D) meshes of objects with a 'reasonable ' boundary-human joints. In our paper we restrict ourselves, for the s ake of simplicity, to polygonal (resp. polyhedral) objects. The idea o f preprocessing is based on the modified method of Delaunay Mangulalia and on the so-called relaxation technique. After the generation of th e finite element mesh and after numerical simulation of surgical probl ems of orthopaedy, the results obtained as stress-strain fields, tempe rature, etc. may be visualized in a graphical form on the computer scr een as well as on other media. (C) 1997 Elsevier Science Ireland Ltd.