Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions

Biomed Tech (Berl). 2016 Jun 1;61(3):281-9. doi: 10.1515/bmt-2014-0090.

Abstract

Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off.

MeSH terms

  • Adhesives / chemistry*
  • Arthroplasty, Replacement, Knee / standards*
  • Bone Cements / chemistry
  • Bone Cements / standards*
  • Ceramics / chemistry
  • Ceramics / standards*
  • Coated Materials, Biocompatible / chemistry
  • Humans
  • Knee Prosthesis / standards*
  • Prosthesis Design / standards*
  • Silicon Dioxide / chemistry*
  • Tensile Strength

Substances

  • Adhesives
  • Bone Cements
  • Coated Materials, Biocompatible
  • Silicon Dioxide