‘Pre-launch’ finite element analysis of a short-stem total hip arthroplasty system consisting of two implant types

authored by: Matthias Lerch, Henning Windhagen, Agnes Elisabeth Kurtz, Stefan Budde, Bernd Arno Behrens, Anas Bouguecha, Amer Almohallami
Abstract: Background: We applied a previously established and validated numerical model to a novel short-stemmed implant for a ‘pre-launch’ investigation. Methods: The implant system consists of two different implant geometries for valgus/varus-positioned proximal femurs with differences in volume distribution, head/neck angle, and calcar alignment. The aim of the design was to achieve a better adaption to the anatomic conditions, resulting in a favourable load transfer. The implant type G showed the best fit to our model, but both stem geometries were implanted; the implant type B was used to compute an ‘imperfection scenario’. Findings: Apparent bone density decreased by 4.3% in the entire femur with the implant type G, and by 12.3% with the implant type B. Bone mass loss was pronounced in the proximal calcar region. Apparent bone density increased at the lateral cortical ring and in the minor trochanter. The apparent bone density in the imperfection scenario was very similar to that of a straight stem, indicating a distal load transfer. Interpretation: No adverse effects of the A2 short-stemmed implant system on bone remodeling could be detected. The overall bone density reduction was acceptable, and wedge fixation was not observed, indicating that there was no distal load transfer. The simulation of an incongruous implant indicates the sensitivity of our model in response to modifications of implant positioning. Correct implant selection and positioning is crucial when using the A2 system.
Organisation(s): Institute of Metal Forming and Metal Forming Machines
External Organisation(s): Hannover Medical School (MHH)
University of Sfax
PROFIL Verbindungstechnik GmbH & Co. KG
Type: Article
Journal: Clinical biomechanics
Volume: 61
Pages: 31-37
No. of pages: 7
ISSN: 0268-0033
Publication date: 01.2019
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Biophysics, Orthopedics and Sports Medicine
Electronic version(s): https://doi.org/10.1016/j.clinbiomech.2018.11.002 (Access: Closed)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{49ae9407306b42dbb70e7f300de164fc,
title = "{\textquoteleft}Pre-launch{\textquoteright} finite element analysis of a short-stem total hip arthroplasty system consisting of two implant types",
abstract = "Background: We applied a previously established and validated numerical model to a novel short-stemmed implant for a {\textquoteleft}pre-launch{\textquoteright} investigation. Methods: The implant system consists of two different implant geometries for valgus/varus-positioned proximal femurs with differences in volume distribution, head/neck angle, and calcar alignment. The aim of the design was to achieve a better adaption to the anatomic conditions, resulting in a favourable load transfer. The implant type G showed the best fit to our model, but both stem geometries were implanted; the implant type B was used to compute an {\textquoteleft}imperfection scenario{\textquoteright}. Findings: Apparent bone density decreased by 4.3% in the entire femur with the implant type G, and by 12.3% with the implant type B. Bone mass loss was pronounced in the proximal calcar region. Apparent bone density increased at the lateral cortical ring and in the minor trochanter. The apparent bone density in the imperfection scenario was very similar to that of a straight stem, indicating a distal load transfer. Interpretation: No adverse effects of the A2 short-stemmed implant system on bone remodeling could be detected. The overall bone density reduction was acceptable, and wedge fixation was not observed, indicating that there was no distal load transfer. The simulation of an incongruous implant indicates the sensitivity of our model in response to modifications of implant positioning. Correct implant selection and positioning is crucial when using the A2 system.",
keywords = "Bone remodeling, Finite element analysis, Short-stemmed implant, Total hip arthroplasty",
author = "Matthias Lerch and Henning Windhagen and Kurtz, {Agnes Elisabeth} and Stefan Budde and Behrens, {Bernd Arno} and Anas Bouguecha and Amer Almohallami",
note = "Funding information: One author (Matthias Lerch) has received a speaker honorarium from ImplanTec. The Institute of Forming Technology and Machines at the Leibniz University Hannover received research grants from ImplanTec. Author Henning Windhagen, Author Agnes Kurtz, and Author Stefan Budde declare that they have no conflict of interest. This research was supported by ImplanTec Germany , L{\"u}dinghausen, Germany.",
year = "2019",
month = jan,
doi = "10.1016/j.clinbiomech.2018.11.002",
language = "English",
volume = "61",
pages = "31--37",
journal = "Clinical biomechanics",
issn = "0268-0033",
publisher = "Elsevier Ltd.",
}