Mechanical wear and oxidative degradation analysis of retrieved ultra high molecular weight polyethylene acetabular cups

Dipankar Choudhury; Matúš Ranuša; Robert A Fleming; Martin Vrbka; Ivan Křupka; Matthew G Teeter; Josh Goss; Min Zou

doi:10.1016/j.jmbbm.2018.01.003

Mechanical wear and oxidative degradation analysis of retrieved ultra high molecular weight polyethylene acetabular cups

J Mech Behav Biomed Mater. 2018 Mar:79:314-323. doi: 10.1016/j.jmbbm.2018.01.003. Epub 2018 Jan 6.

Authors

Dipankar Choudhury¹, Matúš Ranuša², Robert A Fleming³, Martin Vrbka⁴, Ivan Křupka⁴, Matthew G Teeter⁵, Josh Goss¹, Min Zou⁶

Affiliations

¹ Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA 72701; Center for Advanced Surface Engineering, University of Arkansas, Fayetteville, AR, USA 72701.
² Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno, Czech Republic. Electronic address: Matus.Ranusa@vut.cz.
³ Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA 72701.
⁴ Central European Institute of Technology (CEITEC), Brno University of Technology, Brno, Czech Republic.
⁵ Medical Biophysics and Surgery, Schulich School of Medicine & Dentistry, Western University, 339 Windermere Road, London, Ontario, Canada, N6A 5A5.
⁶ Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA 72701; Center for Advanced Surface Engineering, University of Arkansas, Fayetteville, AR, USA 72701. Electronic address: mzou@uark.edu.

PMID: 29353775
DOI: 10.1016/j.jmbbm.2018.01.003

Abstract

The number of revision joint replacements has been increasing substantially over the last few years. Understanding their failure mechanism is extremely important for improving the design and material selection of current implants. This study includes ten retrieved and four new mildly cross-linked ultra-high molecular weight polyethylene (UHMWPE) acetabular liners. Among them, most of the prostheses (n = 5) were reported to be revised and replaced due to aseptic loosening, followed by painful joint (n = 2), dislocation (n = 1), intra articular ossification (n = 1), combination of wear (liner) and osteolysis (stem) (n=1). Surface deviations (wear, material inflation and roughness), oxidative degradation and change of material properties were measured using micro-computed tomography (micro-CT) scan, 3D laser scanning microscopy, raman spectroscopy and nanoindentation, respectively. Prostheses having eccentric worn areas had much higher linear wear rates (228.01 ± 35.51µm/year) compared to that of centrically worn prostheses (96.71 ± 10.83µm/year). Oxidation index (OI) showed similar trends to the surface penetration depth. Among them, sample 10 exhibited the highest OI across the contact area and the rim of the cup liner. It also had the lowest hardness/elasticity ratio. Overall, wear and creep, oxidative degradation and reduced hardness/elasticity ratio all contributed to the premature failure of the UHMWPE acetabular cup liners.

Keywords: Micro-CT; Nanoindentation; Oxidative degradation; Plasticity index; Raman spectroscopy; Retrieved prosthesis; Wear.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Acetabulum / surgery*
Aged
Arthroplasty, Replacement, Hip*
Female
Hip Prosthesis*
Humans
Male
Materials Testing
Middle Aged
Polyethylenes / chemistry
Prosthesis Design*
Prosthesis Failure

Substances

Polyethylenes
ultra-high molecular weight polyethylene