Concerns have been raised that deformation of acetabular shells may disrupt the assembly process of modular prostheses. In this study we aimed to examine the effect that the strength of bone has on the amount of deformation of the acetabular shell. The hypothesis was that stronger bone would result in greater deformation. A total of 17 acetabular shells were inserted into the acetabula of eight cadavers, and deformation was measured using an optical measuring system. Cores of bone from the femoral head were taken from each cadaver and compressed using a materials testing machine. The highest peak modulus and yield stress for each cadaver were used to represent the strength of the bone and compared with the values for the deformation and the surgeon's subjective assessment of the hardness of the bone. The mean deformation of the shell was 129 µm (3 to 340). No correlation was found between deformation and either the maximum peak modulus (r² = 0.011, t = 0.426, p = 0.676) or the yield stress (r² = 0.024, t = 0.614, p = 0.549) of the bone. Although no correlation was found between the strength of the bone and deformation, the values for the deformation observed could be sufficient to disrupt the assembly process of modular acetabular components. Cite this article: Bone Joint J 2015; 97-B:473-7.
|Number of pages
|The Journal of Bone and Joint Surgery - British volume
|Early online date
|1 Apr 2015
|Published - Apr 2015
Bibliographical noteDate of Acceptance: 24/08/2014
©2015 The British Editorial Society of Bone & Joint Surgery.
The authors would like to thank N. Taylor (3D Measurement Company) for his
work with regard to data acquisition and processing of experimental data. We
would also like to thank Dr A. Blain of Newcastle University for performing the
The research was supported by the NIHR Newcastle Biomedical Research Centre. The authors P. Dold, M. Flohr and R. Preuss are employed by Ceramtec
GmbH. Martin Bone received a salary from the joint fund.
The author or one or more of the authors have received or will receive benefits
for personal or professional use from a commercial party related directly or
indirectly to the subject of this article.
This article was primary edited by G. Scott and first proof edited by J. Scott.