Initial fixation of a femoral knee component: an in vitro and finite element study. (2nd February 2009)

• Record Type: Journal Article
• Authors: Burgers, Travis A.; Mason, Jim; Ploeg, Heidi-Lynn
• Is Part Of: International journal of experimental and computational biomechanics. Volume 1:Number 1(2009)
• Page Start: 23
• Page End: 44
• Publication Date: 2009-02-02
• Subjects: distal femur -- femoral knee components -- initial fixation -- implant loosening -- in vitro testing -- finite element analysis -- FEA -- press-fit -- cementless -- experimental biomechanics -- computational biomechanics -- knee arthroplasty -- knee implants -- bone implant modelling -- strain measurements -- plasticity; Human mechanics -- Periodicals; Biomechanics -- Computer simulation -- Periodicals; Biomechanics -- Methodology -- Periodicals; 612.76
• Languages: English
• ISSNs: 1755-8735

Abstract

Loosening is the primary cause of total knee arthroplasty implant failure; therefore, to investigate this failure mode, femoral knee components were implanted in vitro on three cadaveric femurs. Bone-implant finite element (FE) models were created to predict the initial fixation of the interface of each femur. Initial fixation of the femoral knee component was successfully measured with the strain-gauged implants. Specimen-specific FE models were calibrated using the in vitro strain measurements and used to assess initial fixation. Initial fixation was shown to increase with bone density. The geometry of the implant causes the distal femur to deform plastically. It also causes higher stresses in the lateral side and higher pressures on the lateral surfaces. The implementation of plasticity in the bone material model in the FE model decreased these strains and pressures considerably from a purely elastic model, which demonstrated the importance of including plasticity.