title: Biomechanical comparison of the strength of adhesion of polymethylmethacrylate cement to zirconia ceramic and cobalt-chromium alloy components in a total knee arthroplasty.
abstract: OBJECTIVE
  The purpose of this study was to clarify the biomechanical characteristics of cement-material interfaces for the zirconia ceramic and cobalt-chromium (Co-Cr) alloy femoral components used for total knee arthroplasty.
  
  
  METHODS
  In the first sub-study, we compared the strength of adhesion of the cement to flat plates, by tensile testing under dry and moistened conditions. In the second sub-study, we compared the maximum load of the cement-component complex by tensile testing. In the third sub-study, we compared the fatigue characteristics of the cement-component complex by use of a dynamic tensile testing machine.
  
  
  RESULTS
  Under dry conditions, the maximum strength of adhesion to the zirconia ceramic plate was the same as that to the Co-Cr alloy plate. Under moistened conditions, however, the strength of adhesion to the zirconia ceramic plate was significantly lower (p = 0.0017) whereas the strength of adhesion to the Co-Cr alloy plate was not reduced. Maximum load for the cement-component complexes for zirconia ceramic and Co-Cr alloy was no different under both dry and moistened conditions. Fatigue testing showed that cement-zirconia adhesion was stronger than cement-Co-Cr alloy adhesion (p = 0.0161).
  
  
  CONCLUSIONS
  The strength of adhesion of cement to zirconia ceramic is substantially weaker under wet conditions than under dry conditions. The mechanical properties of cement-zirconia ceramic component complexes and cement-Co-Cr alloy component complexes are equivalent.
authors.affiliation: Department of Orthopedics, Shimane University, School of Medicine, 89-1 Enya-cho, Izumo, Shimane, 693-8501, Japan, n-kuma@med.shimane-u.ac.jp.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kumahashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uchio
authors.forename: Nobuto
authors.initials: N
authors.lastname: Kitamura
authors.forename: Shigeru
authors.initials: S
authors.lastname: Satake
authors.forename: Mikio
authors.initials: M
authors.lastname: Iwamoto
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yasuda
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D001843:Bone Cements; D002516:Ceramics; D002858:Chromium Alloys; D006801:Humans; D008422:Materials Testing; D019904:Polymethyl Methacrylate; D013499:Surface Properties; D013718:Tensile Strength; D015040:Zirconium
chemical_list: D001843:Bone Cements; D002858:Chromium Alloys; D019904:Polymethyl Methacrylate; D015040:Zirconium; C028541:zirconium oxide