Mechanobiological plastic model

Description

Plastics are experiencing increased interest in medical technology. Due to their mechanical properties, plastics correspond more closely to human tissue than metallic materials such as titanium or cobalt-chromium. The so-called mechanobiology of human soft tissue, especially cartilage and intervertebral discs, is thus better reproduced.

A biocompatible behaviour of implants for the shoulder or knee enables a (partial) replacement of the structures, promotes the life of implants and thus reduces the number of revision operations. In contrast to today's "state of the art" (titanium and cobalt-chrome), plastics are more difficult to characterise from a structural-mechanical point of view due to their strongly non-linear behaviour in the time and deformation range. The implants are stored and implanted at room temperature, but the human body has "operating conditions" of 37°C in a humid environment, which plays an important role for plastics in preclinical evaluation.

For the development of novel implants (such as shoulder prostheses or motion-preserving spinal implants), a biomechanical characterisation of the material is therefore of importance in order to be able to predict the behaviour of implant concepts in the early phase of development using the latest computer simulation (FEM) methods. The aim is therefore to validate a material model for thermoplastic Elastomers.

In the potent market segment of orthopaedics, the medical industry has a great need for know-how for the development of novel implant surfaces and hemiprostheses. Within the framework of the current project (Cartilage Friendly Hemiprosthesis KTI-LS 19298.1), the IMES biomechanics department developed a new concept of shoulder prosthesis. With the help of new findings in material modelling, the preclinical in-vitro characterisation of the implants can be improved and be made accessible to various companies.