The University of Southampton
University of Southampton Institutional Repository

Efficient computational method for assessing the effects of implant positioning in cementless total hip replacements

Efficient computational method for assessing the effects of implant positioning in cementless total hip replacements
Efficient computational method for assessing the effects of implant positioning in cementless total hip replacements
he present work describes a statistical investigation into the effects of implant positioning on the initial stability of a cementless total hip replacement (THR). Mesh morphing was combined with design of computer experiments to automatically construct Finite Element (FE) meshes for a range of pre-defined femur-implant configurations and to predict implant micromotions under joint contact and muscle loading. Computed micromotions, in turn, are postprocessed using a Bayesian approach to: (a) compute the main effects of implant orientation angles, (b) predict the sensitivities of the considered implant performance metrics with respect to implant ante-retroversion, varus–valgus and antero-posterior orientation angles and (c) identify implant positions that maximise and minimise each metric. It is found that the percentage of implant area with micromotion greater than 50 ?m, average and maximum micromotions are all more sensitive to antero-posterior orientation than ante-retroversion and varus–valgus orientation. Sensitivities, combined with the main effect results, suggest that bone is less likely to grow if the implant is increasingly moved from the neutral position towards the anterior part of the femur, where the highest micromotions occur. The computed implant best position leads to a percentage of implant area with micromotion greater than 50 ?m of 1.14 when using this metric compared to 14.6 and 5.95 in the worst and neutrally positioned implant cases. In contrast, when the implant average/maximum micromotion is used to assess the THR performance, the implant best position corresponds to average/maximum micromotion of 9 ?m/59 ?m, compared to 20 ?m/114 ?m and 13 ?m/71 ?m in the worst and neutral positions, respectively. The proposed computational framework can be extended further to study the effects of uncertainty and variability in anatomy, bone mechanical properties, loading or bone–implant interface contact conditions.
0021-9290
1417-1422
Bah, Mamadou T.
b5cd0f47-016f-485c-8293-5f6bf8a7ef1a
Nair, Prasanth B.
d4d61705-bc97-478e-9e11-bcef6683afe7
Taylor, Mark
e368bda3-6ca5-4178-80e9-41a689badeeb
Browne, Martin
6578cc37-7bd6-43b9-ae5c-77ccb7726397
Bah, Mamadou T.
b5cd0f47-016f-485c-8293-5f6bf8a7ef1a
Nair, Prasanth B.
d4d61705-bc97-478e-9e11-bcef6683afe7
Taylor, Mark
e368bda3-6ca5-4178-80e9-41a689badeeb
Browne, Martin
6578cc37-7bd6-43b9-ae5c-77ccb7726397

Bah, Mamadou T., Nair, Prasanth B., Taylor, Mark and Browne, Martin (2011) Efficient computational method for assessing the effects of implant positioning in cementless total hip replacements. Journal of Biomechanics, 44 (7), 1417-1422. (doi:10.1016/j.jbiomech.2010.12.027).

Record type: Article

Abstract

he present work describes a statistical investigation into the effects of implant positioning on the initial stability of a cementless total hip replacement (THR). Mesh morphing was combined with design of computer experiments to automatically construct Finite Element (FE) meshes for a range of pre-defined femur-implant configurations and to predict implant micromotions under joint contact and muscle loading. Computed micromotions, in turn, are postprocessed using a Bayesian approach to: (a) compute the main effects of implant orientation angles, (b) predict the sensitivities of the considered implant performance metrics with respect to implant ante-retroversion, varus–valgus and antero-posterior orientation angles and (c) identify implant positions that maximise and minimise each metric. It is found that the percentage of implant area with micromotion greater than 50 ?m, average and maximum micromotions are all more sensitive to antero-posterior orientation than ante-retroversion and varus–valgus orientation. Sensitivities, combined with the main effect results, suggest that bone is less likely to grow if the implant is increasingly moved from the neutral position towards the anterior part of the femur, where the highest micromotions occur. The computed implant best position leads to a percentage of implant area with micromotion greater than 50 ?m of 1.14 when using this metric compared to 14.6 and 5.95 in the worst and neutrally positioned implant cases. In contrast, when the implant average/maximum micromotion is used to assess the THR performance, the implant best position corresponds to average/maximum micromotion of 9 ?m/59 ?m, compared to 20 ?m/114 ?m and 13 ?m/71 ?m in the worst and neutral positions, respectively. The proposed computational framework can be extended further to study the effects of uncertainty and variability in anatomy, bone mechanical properties, loading or bone–implant interface contact conditions.

This record has no associated files available for download.

More information

Published date: 2011
Organisations: Bioengineering Sciences

Identifiers

Local EPrints ID: 185469
URI: http://eprints.soton.ac.uk/id/eprint/185469
ISSN: 0021-9290
PURE UUID: 92fac607-8506-4a02-8881-a41a2ef042ad
ORCID for Martin Browne: ORCID iD orcid.org/0000-0001-5184-050X

Catalogue record

Date deposited: 10 May 2011 14:43
Last modified: 15 Mar 2024 02:50

Export record

Altmetrics

Contributors

Author: Mamadou T. Bah
Author: Prasanth B. Nair
Author: Mark Taylor
Author: Martin Browne ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×