TY - JOUR
T1 - Probabilistic finite element prediction of knee wear simulator mechanics
AU - Laz, Peter J.
AU - Pal, Saikat
AU - Halloran, Jason P.
AU - Petrella, Anthony J.
AU - Rullkoetter, Paul J.
N1 - Funding Information:
This research was supported in part by DePuy, a Johnson & Johnson Company.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - Computational models have recently been developed to replicate experimental conditions present in the Stanmore knee wear simulator. These finite element (FE) models, which provide a virtual platform to evaluate total knee replacement (TKR) mechanics, were validated through comparisons with experimental data for a specific implant. As with any experiment, a small amount of variability is inherently present in component alignment, loading, and environmental conditions, but this variability has not been previously incorporated in the computational models. The objectives of the current research were to assess the impact of experimental variability on predicted TKR mechanics by determining the potential envelope of joint kinematics and contact mechanics present during wear simulator loading, and to evaluate the sensitivity of the joint mechanics to the experimental parameters. In this study, 8 component alignment and 4 experimental parameters were represented as distributions and used with probabilistic methods to assess the response of the system, including interaction effects. The probabilistic FE model evaluated two levels of parameter variability (with standard deviations of component alignment parameters up to 0.5 mm and 1°) and predicted a variability of up to 226% (3.44 mm) in resulting anterior-posterior (AP) translation, up to 169% (4.30°) in internal-external (IE) rotation, but less than 10% (1.66 MPa) in peak contact pressure. The critical alignment parameters were the tilt of the tibial insert and the IE rotational alignment of the femoral component. The observed variability in kinematics and, to a lesser extent, contact pressure, has the potential to impact wear observed experimentally.
AB - Computational models have recently been developed to replicate experimental conditions present in the Stanmore knee wear simulator. These finite element (FE) models, which provide a virtual platform to evaluate total knee replacement (TKR) mechanics, were validated through comparisons with experimental data for a specific implant. As with any experiment, a small amount of variability is inherently present in component alignment, loading, and environmental conditions, but this variability has not been previously incorporated in the computational models. The objectives of the current research were to assess the impact of experimental variability on predicted TKR mechanics by determining the potential envelope of joint kinematics and contact mechanics present during wear simulator loading, and to evaluate the sensitivity of the joint mechanics to the experimental parameters. In this study, 8 component alignment and 4 experimental parameters were represented as distributions and used with probabilistic methods to assess the response of the system, including interaction effects. The probabilistic FE model evaluated two levels of parameter variability (with standard deviations of component alignment parameters up to 0.5 mm and 1°) and predicted a variability of up to 226% (3.44 mm) in resulting anterior-posterior (AP) translation, up to 169% (4.30°) in internal-external (IE) rotation, but less than 10% (1.66 MPa) in peak contact pressure. The critical alignment parameters were the tilt of the tibial insert and the IE rotational alignment of the femoral component. The observed variability in kinematics and, to a lesser extent, contact pressure, has the potential to impact wear observed experimentally.
KW - Contact mechanics
KW - Kinematics
KW - Knee mechanics
KW - Probabilistic methods
KW - TKR
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U2 - 10.1016/j.jbiomech.2005.07.029
DO - 10.1016/j.jbiomech.2005.07.029
M3 - Article
C2 - 16185700
AN - SCOPUS:33747137264
VL - 39
SP - 2303
EP - 2310
JO - Journal of Biomechanics
JF - Journal of Biomechanics
SN - 0021-9290
IS - 12
ER -