A differential scanning calorimetry study of retrieved orthopedic implants made of ultrahigh molecular weight polyethylene

Halina Witkiewicz, Meng Deng, Tamas J Vidovszky, Mark E. Bolander, Michael G. Rock, Bernard F. Morrey, Shalaby W. Shalaby

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Differential scanning calorimetry (DSC) was used to examine thermal and thermooxidative properties of ultrahigh molecular weight polyethylene (UHMW- PE) of five acetabular components of failed orthopedic implants retrieved at revision of total hip arthoplasty. The results were compared with controls (unimplanted acetabular cups, a 20-year-old slab of UHMW-PE, and raw material). Profiles of exothermic peaks indicated increased levels of oxidation in all retrieved caps. In three retrieved cups, DSC revealed an additional peak of endotherm that was not seen in control samples. The additional endotherm peaks were not artifacts due to oxidation during scanning, heat buildup during culling of the samples, or the sterilization method after retrieval. The additional peak was associated with the bulk of the polymer that was extracted with hexane. It varied in relative area, depending on its original location of the sample in a cup, implicating local variability in the extent of changes in material property. The distribution of the changes suggests that, during implantation, tissue exposure and friction affected the level of oxidation and degree of crystallinity in the UHMW-PE to a greater degree than did loading alone. Overall results showed that DSC may be a useful tool in evaluating changes in the properties of UHMW-PE orthopedic components in vivo.

Original languageEnglish (US)
Pages (from-to)73-82
Number of pages10
JournalJournal of Biomedical Materials Research
Volume33
Issue number2
DOIs
StatePublished - Jun 1996
Externally publishedYes

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biomaterials

Fingerprint Dive into the research topics of 'A differential scanning calorimetry study of retrieved orthopedic implants made of ultrahigh molecular weight polyethylene'. Together they form a unique fingerprint.

  • Cite this