Desarrollo de prótesis de núcleo pulposo - modelo de elementos finitos de una unidad funcional de la columna vertebral y caracterización de materiales

Abstract

The development of a prosthetic device for the replacement of the nucleus pulposus of the intervertebral disc is being widely studied in the recent years, with a great variety of designs and materials used. In this work is shown an approach to the elaboration of prosthesis for the nucleus pulposus, following the principal requirements about biomechanics and biocompatibility. For this, a 3-D model of a functional spinal unit (FSU) of the lumbar spine was made, with the aim of study de biomechanics of the intervertebral disc. A 3-D reconstruction of the L4-L5 segment was built using Axial Computarized Tomographies. Stress analyses of the model was perform using the Finite Element Method. The selection of the material to use in the prosthesis elaboration is of great importance for the biocompatibility of the device. Therefore, a research about chitosan hidrogels crosslinked whit genipin is being started. Both of these materials are proved to be biocompatible, giving a hint about their possible use. Mechanical testing in compression shown the fragility of the chitosan hidrogels, but their morphology could make them able for other biomedical applications. The reaction kinetics between chitosan and genipin was studied with dinamic rheometry, showing the change of the hidrogels from a liquid solution to a viscoelastic solid. © Springer-Verlag Berlin Heidelberg 2007.