Innovations in Computational Biomechanics
Dr Andrew T M Phillips, Lecturer, Imperial College London

The first in-vivo tests assessing the effectiveness of original (ivory) and modern designs (metal and polyethylene) of prosthetic hip components were carried out on humans. Current prosthesis designs for various joints are all indebted in some way to the work of John Charnley in the 1960s. However, recent developments in prosthesis designs, for example the introduction of new materials at the bearing surfaces, and prosthesis-bone interfaces undergo more extensive in-vitro and in-vivo animal testing.

Since the late 1970s in-silico testing has also emerged as a technology for assessing new implant designs. However the technology has suffered the recognised computational problem of ‘rubbish in, rubbish out’ and it is perhaps only recently that it has matured enough to become a useful tool.

Verification and validation of computational models has become an ever focused upon area. However this has raised further questions of what to validate the models against. Are we now reaching a point where it is no longer acceptable to validate computational models against laboratory experiments, given that both are considerably removed from the in-vivo situation?

Have in-silico models advanced far enough to be used in combination with, or with more confidence than in-vitro testing? What is being done, and what needs to be done to reach this point?