Publication detail

In situ observation of lubricant film formation in THR considering real conformity: The effect of diameter, clearance and material

NEČAS, D. VRBKA, M. URBAN, F. GALLO, J. KŘUPKA, I. HARTL, M.

Original Title

In situ observation of lubricant film formation in THR considering real conformity: The effect of diameter, clearance and material

Type

journal article in Web of Science

Language

English

Original Abstract

The aim of the present study is to provide an analysis of protein film formation in hip joint replacements considering real conformity based on in situ observation of the contact zone. The main attention is focused on the effect of implant nominal diameter, diametric clearance and material. For this purpose, a pendulum hip joint simulator equipped with electromagnetic motors enabling to apply continuous swinging flexion–extension motion was employed. The experimental configuration consists of femoral component (CoCrMo, BIOLOX®forte, BIOLOX®delta) and acetabular cup from optical glass fabricated according to the dimensions of real cups. Two nominal diameters were studied, 28 and 36 mm, respectively, while different diametric clearances were considered. Initially, a static test focused on the protein adsorption onto rubbing surfaces was performed with 36 mm implants. It was found that the development of adsorbed layer is much more stable in the case of metal head, indicating that the adsorption forces are stronger compared to ceramic. A consequential swinging test revealed that the fundamental parameter influencing the protein film formation is diametric clearance. Independently of implant diameter, film was much thicker when a smaller clearance was considered. An increase of implant size from 28 mm to 36 mm did not cause a substantial difference in film formation; however, the total film thickness was higher for smaller implant. In terms of material, metal heads formed a thicker film, while this fact can be, among others, also attributed to clearance, which is more than two times higher in the case of ceramic implant.

Keywords

Hip joint replacement; head and cup diameter; diametric clearance; lubrication; film thickness; optical interferometry

Authors

NEČAS, D.; VRBKA, M.; URBAN, F.; GALLO, J.; KŘUPKA, I.; HARTL, M.

Released

1. 5. 2017

Publisher

Elsevier Ltd.

Location

United Kingdom

ISBN

1751-6161

Periodical

Journal of the mechanical behavior of biomedical materials

Year of study

69

Number

5

State

Kingdom of the Netherlands

Pages from

66

Pages to

74

Pages count

9

URL

BibTex

@article{BUT131037,
  author="NEČAS, D. and VRBKA, M. and URBAN, F. and GALLO, J. and KŘUPKA, I. and HARTL, M.",
  title="In situ observation of lubricant film formation in THR considering real conformity: The effect of diameter, clearance and material",
  journal="Journal of the mechanical behavior of biomedical materials",
  year="2017",
  volume="69",
  number="5",
  pages="66--74",
  doi="10.1016/j.jmbbm.2016.12.018",
  issn="1751-6161",
  url="http://www.sciencedirect.com/science/article/pii/S175161611630443X"
}