title: [Changes in crystallinity by sterilization and processing of ultrahigh molecular polyethylene used in endoprosthetics].
abstract: OBJECTIVE
  We wanted to analyze crystallinity changes during sterilization in raw and in UHMWPE components for total joint arthroplasty manufactured.
  
  
  METHODS
  To analyze the crystallinity DSC measurements and to determine the relative crystallinity infrared spectroscopy was performed. The DSC measurements were based on a comparison between the melting enthalpy of one known material to the unknown material.
  
  
  RESULTS
  The raw manufactured non-sterilized sample showed a value for the DSC-measured crystallinity of 55.5%; the sample after gamma-sterilization without air was 56.0%, and with air 56.5%. The crystallinity after ethylene-oxide sterilization was 57.7% and after autoclavation 57.9%. The manufacturing time from the raw to the arthroplasty part showed some what different results. The average crystallinity of the samples differed between 55.4% and 61.6%. The best results were achieved in ETO-sterilized samples and one gamma-sterilized sample without air. The highest values were seen for the Hylamer.
  
  
  CONCLUSIONS
  In summary, the best values for crystallinity were seen in both raw and completed arthroplasty products with ETO sterilization. For medical use cancerogenous factors must be excluded. Gamma-sterilization without air can be accepted as well. Increasing the crystallinity too much can lead to more wear debris.
authors.affiliation: Klinik und Poliklinik für Allgemeine Orthopädie, Westfälische Wilhelms Universität, Münster.
authors.forename: S
authors.initials: S
authors.lastname: Fuchs
authors.forename: T
authors.initials: T
authors.lastname: Schmidt
authors.forename: S
authors.initials: S
authors.lastname: Haftka
authors.forename: J
authors.initials: J
authors.lastname: Jerosch
mesh_terms: D003460:Crystallization; D006622:Hip Prosthesis; D006801:Humans; D011095:Polyethylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013055:Spectrophotometry, Infrared; D013242:Sterilization / Q000379:methods*
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene
vernacular_title: Kristallinitätsveränderungen durch Sterilisierung und Verarbeitung des in der Endoprothetik verwendeten ultrahochmolekularen Polyethylens.