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Experimental validation of numerically predicted strain and micromotion in intact and implanted composite hemi-pelvises

Experimental validation of numerically predicted strain and micromotion in intact and implanted composite hemi-pelvises
Experimental validation of numerically predicted strain and micromotion in intact and implanted composite hemi-pelvises
The failure mechanisms of acetabular prostheses may be investigated by understanding the changes in load transfer due to implantation, and analysis of the implant-bone micromotion. Computational finite element (FE) models allow detailed mechanical analysis of the implant-bone structure, but their validity must be assessed as part of a verification process before they can be employed in pre-clinical investigations. To this end, in the present study, FE models of composite hemi-pelvises, intact and implanted with an acetabular cup, were experimentally verified. Strains and implant-bone micromotions in the hemi-pelvises were compared with those predicted by the equivalent FE models. Regression analysis indicated close agreement between the measured and FE strains, with a high correlation coefficient (0.95-0.98), a low standard error of the estimate (36-53µ?) and a low error in regression slope (7-11%). Measured micromotions along three orthogonal directions were small, less than 30µm, whereas the FE predicted values were found to be less than 85µm. Although the trends were similar, the observed deviations may be due to estimation of the interfacial press-fit used in the FE model, and additional artefacts in experimental micromotion measurement which are avoided in the FE model. This supports the FE model as a valid predictor of the experimentally measured strain in the composite pelvis models, confirming its suitability for further computational investigations on acetabular prostheses.
0954-4119
162-174
Ghosh, R.
8ecf4f08-db6a-433d-baa0-e20b1f1ca6f9
Gupta, S.
3eae7ae7-8915-4c1f-8f28-2882160b9a62
Dickinson, A.S.
10151972-c1b5-4f7d-bc12-6482b5870cad
Browne, M.
6578cc37-7bd6-43b9-ae5c-77ccb7726397
Ghosh, R.
8ecf4f08-db6a-433d-baa0-e20b1f1ca6f9
Gupta, S.
3eae7ae7-8915-4c1f-8f28-2882160b9a62
Dickinson, A.S.
10151972-c1b5-4f7d-bc12-6482b5870cad
Browne, M.
6578cc37-7bd6-43b9-ae5c-77ccb7726397

Ghosh, R., Gupta, S., Dickinson, A.S. and Browne, M. (2012) Experimental validation of numerically predicted strain and micromotion in intact and implanted composite hemi-pelvises. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 227 (2), 162-174. (doi:10.1177/0954411912461238).

Record type: Article

Abstract

The failure mechanisms of acetabular prostheses may be investigated by understanding the changes in load transfer due to implantation, and analysis of the implant-bone micromotion. Computational finite element (FE) models allow detailed mechanical analysis of the implant-bone structure, but their validity must be assessed as part of a verification process before they can be employed in pre-clinical investigations. To this end, in the present study, FE models of composite hemi-pelvises, intact and implanted with an acetabular cup, were experimentally verified. Strains and implant-bone micromotions in the hemi-pelvises were compared with those predicted by the equivalent FE models. Regression analysis indicated close agreement between the measured and FE strains, with a high correlation coefficient (0.95-0.98), a low standard error of the estimate (36-53µ?) and a low error in regression slope (7-11%). Measured micromotions along three orthogonal directions were small, less than 30µm, whereas the FE predicted values were found to be less than 85µm. Although the trends were similar, the observed deviations may be due to estimation of the interfacial press-fit used in the FE model, and additional artefacts in experimental micromotion measurement which are avoided in the FE model. This supports the FE model as a valid predictor of the experimentally measured strain in the composite pelvis models, confirming its suitability for further computational investigations on acetabular prostheses.

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More information

Published date: 19 October 2012
Organisations: Bioengineering Group

Identifiers

Local EPrints ID: 348556
URI: https://eprints.soton.ac.uk/id/eprint/348556
ISSN: 0954-4119
PURE UUID: f1dd8436-ace9-4ae4-8d2e-4acd4682db4e
ORCID for A.S. Dickinson: ORCID iD orcid.org/0000-0002-9647-1944
ORCID for M. Browne: ORCID iD orcid.org/0000-0001-5184-050X

Catalogue record

Date deposited: 14 Feb 2013 14:21
Last modified: 03 Dec 2019 02:00

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