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Influence of liner offset and locking mechanism on fatigue durability in highly crossâlinked polyethylene total hip prostheses
- Source :
- Journal of Biomedical Materials Research Part B: Applied Biomaterials. 108:1993-2004
- Publication Year :
- 2019
- Publisher :
- Wiley, 2019.
-
Abstract
- Highly cross-linked, ultrahigh molecular weight polyethylene (HXLPE) acetabular liners are inherently associated to a risk of fatigue failure due to femoral neck impingement. Different thicknesses and designs employed with HXLPE liners greatly affect mechanical loading scenario. The purpose of this study was to clarify the influence of liner offset (lateralization) and locking mechanism (presence/absence of anti-rotation tabs in the external surface) on fatigue durability in annealed and vitamin E-blended HXLPE liners with a current commercial design. Each liner tested had six anti-rotation tabs, which were engaged in the 6 of 12 recesses on the metal shell. The remaining six recesses had no direct contact with the liner, where HXLPE was mechanically unsupported by the metal backing. These mated and/or unmated rim regions in the offset (2, 3, 4-mm lateralized) liners were exposed to severe neck impingement until crack propagation was identified. Phase volume percentages (crystalline, amorphous, and intermediate phase contents) of HXLPE liners were compared before and after impingement in order to interpret differences in impingement micromechanics associated with the rim design variations. Our results showed that the presence of unmated recesses served as a stress concentrator due to the formation of millimeter-scale gaps between the liner and shell. Another potential design problem drawn from our study was liner offset associated with a small volume protruding above the metal rim. Therefore, surgeons should take special care in selecting locking designs and geometries especially when using HXLPE offset liners.
- Subjects :
- musculoskeletal diseases
Offset (computer science)
Materials science
Arthroplasty, Replacement, Hip
Biomedical Engineering
Total hip replacement
Shell (structure)
Biocompatible Materials
02 engineering and technology
Prosthesis Design
Spectrum Analysis, Raman
Biomaterials
Stress (mechanics)
03 medical and health sciences
0302 clinical medicine
Humans
Vitamin E
Composite material
Mechanical Phenomena
030222 orthopedics
Cross-linked polyethylene
technology, industry, and agriculture
Acetabulum
Fracture mechanics
equipment and supplies
021001 nanoscience & nanotechnology
Durability
Prosthesis Failure
Cross-Linking Reagents
Metals
Locking mechanism
Hip Prosthesis
Polyethylenes
0210 nano-technology
Subjects
Details
- ISSN :
- 15524981 and 15524973
- Volume :
- 108
- Database :
- OpenAIRE
- Journal :
- Journal of Biomedical Materials Research Part B: Applied Biomaterials
- Accession number :
- edsair.doi.dedup.....9c0a8b89adbba8beb24ebfe302e1a988