title: Computer simulating a clinical trial of a load-bearing implant: an example of an intramedullary prosthesis.
abstract: Computational modelling is becoming ever more important for obtaining regulatory approval for new medical devices. An accepted approach is to infer performance in a population from an analysis conducted for an idealised or 'average' patient; we present here a method for predicting the performance of an orthopaedic implant when released into a population--effectively simulating a clinical trial. Specifically we hypothesise that an analysis based on a method for predicting the performance in a population will lead to different conclusions than an analysis based on an idealised or 'average' patient. To test this hypothesis we use a finite element model of an intramedullary implant in a bone whose size and remodelling activity is different for each individual in the population. We compare the performance of a low Young's modulus implant (E=20 GPa) to one with a higher Young's modulus (200 GPa). Cyclic loading is applied and failure is assumed when the migration of the implant relative to the bone exceeds a threshold magnitude. The analysis for an idealised of 'average' patient predicts that the lower modulus device survives longer whereas the analysis simulating a clinical trial predicts no statistically-significant tendency (p=0.77) for the low modulus device to perform better. It is concluded that population-based simulations of implant performance-simulating a clinical trial-present a very valuable opportunity for more realistic computational pre-clinical testing of medical devices.
authors.affiliation: Trinity Centre for Bioengineering, School of Engineering, Trinity College, Dublin 2, Ireland. pprender@tcd.ie
authors.forename: P J
authors.initials: PJ
authors.lastname: Prendergast
authors.forename: P E
authors.initials: PE
authors.lastname: Galibarov
authors.forename: C
authors.initials: C
authors.lastname: Lowery
authors.forename: A B
authors.initials: AB
authors.lastname: Lennon
mesh_terms: D001696:Biomechanical Phenomena; D016723:Bone Remodeling; D001842:Bone and Bones / Q000166:cytology / Q000503:physiopathology; D002986:Clinical Trials as Topic; D003198:Computer Simulation; D020342:Finite Element Analysis; D019736:Prostheses and Implants; D011475:Prosthesis Failure; D016474:Weight-Bearing