The effect of impaction energy on dynamic bone strains, fixation strength and seating of cementless acetabular cups
File(s)
Published version
Author(s)
Doyle, R
van Arkel, R
Jeffers, Jonathan
Type
Journal Article
Abstract
Seating a cementless acetabular cup via impaction is a balancing act; good cup fixation must be obtained to ensure adequate bone in‐growth and cup apposition, while acetabular fracture must be avoided. Good impaction technique is essential to the success of hip arthroplasty. Yet little guidance exists in the literature to inform surgeons on ‘how hard’ to hit. A drop rig and synthetic bone model were used to vary the energy of impaction strikes in low and high density synthetic bone, while key parameters such as dynamic strain (quantifying fracture risk), implant fixation and polar gap were measured. For high energy impaction (15 J) in low density synthetic bone a peak tensile strain was observed during impaction that was up to 3.4x as large as post‐strike strain, indicating a high fracture risk. Diminishing returns were observed for pushout fixation with increasing energy. 85% of the pushout fixation achieved using a 15 J impaction strike was attained by using a 7.5 J strike energy. Similarly polar gap was only minimally reduced at high impaction energies. Therefore it is suggested that higher energy strikes increase fracture risk, but do not offer large improvements to fixation or implant‐bone apposition. It may difficult be for surgeons to accurately deliver specific impaction energies, suggesting there is scope for operative tools to manage implant seating.
Date Issued
2019-11-01
Date Acceptance
2019-07-02
Citation
Journal of Orthopaedic Research, 2019, 37 (11), pp.2367-2375
ISSN
0736-0266
Publisher
Wiley
Start Page
2367
End Page
2375
Journal / Book Title
Journal of Orthopaedic Research
Volume
37
Issue
11
Copyright Statement
© 2019 The Authors. Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. This is an open access article under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is
properly cited.
properly cited.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Wellcome Trust
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/K027549/1
208858/Z/17/Z
EP/R042721/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Orthopedics
energy
fixation
fracture
impaction
stability
TOTAL HIP-ARTHROPLASTY
PRESS-FIT
PERIPROSTHETIC FRACTURES
TISSUE DIFFERENTIATION
INITIAL STABILITY
DEFORMATION
MICROMOTION
STIFFNESS
INSERTION
MODEL
energy
fixation
fracture
impaction
stability
0903 Biomedical Engineering
1103 Clinical Sciences
1106 Human Movement and Sports Sciences
Orthopedics
Publication Status
Published
Date Publish Online
2019-07-18