Details
| Original language | English |
|---|---|
| Pages (from-to) | 31-37 |
| Number of pages | 7 |
| Journal | Clinical biomechanics |
| Volume | 61 |
| Early online date | 7 Nov 2018 |
| Publication status | Published - Jan 2019 |
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.
Keywords
- Bone remodeling, Finite element analysis, Short-stemmed implant, Total hip arthroplasty
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biophysics
- Medicine(all)
- Orthopedics and Sports Medicine
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In: Clinical biomechanics, Vol. 61, 01.2019, p. 31-37.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - ‘Pre-launch’ finite element analysis of a short-stem total hip arthroplasty system consisting of two implant types
AU - Lerch, Matthias
AU - Windhagen, Henning
AU - Kurtz, Agnes Elisabeth
AU - Budde, Stefan
AU - Behrens, Bernd Arno
AU - Bouguecha, Anas
AU - Almohallami, Amer
N1 - 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 , Lüdinghausen, Germany.
PY - 2019/1
Y1 - 2019/1
N2 - 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.
AB - 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.
KW - Bone remodeling
KW - Finite element analysis
KW - Short-stemmed implant
KW - Total hip arthroplasty
UR - http://www.scopus.com/inward/record.url?scp=85056669161&partnerID=8YFLogxK
U2 - 10.1016/j.clinbiomech.2018.11.002
DO - 10.1016/j.clinbiomech.2018.11.002
M3 - Article
C2 - 30458330
AN - SCOPUS:85056669161
VL - 61
SP - 31
EP - 37
JO - Clinical biomechanics
JF - Clinical biomechanics
SN - 0268-0033
ER -