An in vitro model of impaction during hip arthroplasty
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Impaction is required to properly seat press-fit implants and ensure initial implant stability and long term bone ingrowth, however excessive impaction or press-fit presents a high fracture risk in the acetabulum and femur. Current in-vitro impaction testing methods do not replicate the compliance of the soft tissues surrounding the hip, a factor that may be important in fracture and force prediction. This study presents the measurement of compliance of the soft tissues supporting the hip during impaction in operative conditions, and replicates these in vitro. Hip replacements were carried out on 4 full body cadavers while impact force traces and acetabular/femoral displacement were measured. Compliance was then simulated computationally using a Voigt model. These data were subsequently used to inform the design of a representative in-vitro drop rig. Effective masses of 19.7 kg and 12.7 kg, spring stiffnesses of 8.0 kN/m and 4.1 kN/m and dashpot coefficients of 595 N s/m and 322 N s/m were calculated for the acetabular and femoral soft tissues respectively. A good agreement between cadaveric and in-vitro peak displacement and rise time during impact is found. Such an in-vitro setup is of use during laboratory testing, simulation or even surgical training.
Date Issued
2019-01-03
Date Acceptance
2018-10-23
Citation
Journal of Biomechanics, 2019, 82 (1), pp.220-227
ISSN
0021-9290
Publisher
Elsevier
Start Page
220
End Page
227
Journal / Book Title
Journal of Biomechanics
Volume
82
Issue
1
Copyright Statement
© 2018 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Imperial College Healthcare NHS Trust- BRC Funding
National Institute for Health Research
Royal College Of Surgeons Of England
Royal College of Surgeons of England
Identifier
https://www.sciencedirect.com/science/article/pii/S0021929018308078
Grant Number
EP/K027549/1
EP/R042721/1
RDB04 79560
NIHR ACF
WSSU_P63898
Matching orthopaedic surgery to patients' individual bone mechanical properties
Subjects
Science & Technology
Life Sciences & Biomedicine
Technology
Biophysics
Engineering, Biomedical
Engineering
Hip arthroplasty
Impaction
In-vitro testing
Boundary conditions
Compliance
TROCHANTERIC SOFT-TISSUES
PRESS-FIT
FEMORAL FRACTURE
FORCE
INSERTION
DEFORMATION
STRENGTH
SYSTEM
RISK
BONE
Boundary conditions
Compliance
Hip arthroplasty
Impaction
In-vitro testing
Acetabulum
Aged, 80 and over
Arthroplasty, Replacement, Hip
Female
Femur
Hip Prosthesis
Humans
Male
Mechanical Phenomena
Femur
Acetabulum
Humans
Arthroplasty, Replacement, Hip
Hip Prosthesis
Aged, 80 and over
Female
Male
Mechanical Phenomena
Biomedical Engineering
0903 Biomedical Engineering
0913 Mechanical Engineering
1106 Human Movement and Sports Sciences
Publication Status
Published
Date Publish Online
2018-11-01