ABSTRACT
Objective By developing an automatic procedure for optimization of femoro-tibial contact area for knee prosthesis, to summarize the influence pattern of design parameters on contact area, and discover the relationship between the maximum contact stress and contact area. Methods A parametric finite element (FE) model was developed in the Isight software, which included three components: automatic parameter changes for the geometric model, automatic modeling in the FE software, and automatic FE calculation. The automatic workflow was realized, and then contact areas were statistically analyzed. Results The FE model was validated by using Tekscan pressure distribution system. When the femoral sagittal radius was gradually close to the tibial sagittal radius, the contact area gradually reached to the maximum 295 mm2. The femoral sagittal radius had a positive effect on contact area, while the tibial sagittal radius had a negative effect. The maximum contact stress had a linear relationship with contact area approximately. Conclusions This study analyzed the influence of femoro-tibial sagittal radius on contact stress and contact area, and the research findings would provide references for the design on reducing wear of tibial insert in clinic.
ABSTRACT
Objective To compare biomechanical properties between the anatomical clavicle plate and the reconstructed clavicle plate, and investigate the influence of pre-bending or repeated bending process on biomechanical properties of the reconstructed clavicle plate, so as to provide biomechanical evidence for treating midshaft clavicle fracture in clinic. Methods The reconstructed clavicle plate was bent by 1, 2, 3, 5 times respectively based on shape of the anatomical clavicle plate. The biomechanical differences in anatomical plate group, reconstructed plate group and pre-bending plate group were compared by static compression test. Results The fixation stiffness and strength of the anatomical plate were better than those of the reconstructed plate. There was no significant difference in stiffness and strength between the anatomical plate group and one-time bending group. Pre-bending had a great effect on mechanical properties of the clavicle plate, and stiffness and strength of the clavicle plate were obviously improved after one-time bending. The mechanical properties of the clavicle plate were obviously reduced by bending of the clavicle plate after one-time bending. Conclusions The stiffness and strength of the anatomical plate and one-time bending plate are higher than those of the normal reconstructed plate. It is recommended that surgeons should perform bending appropriately according to the patient’s clavicle anatomy when using the reconstructed clavicle plate for fracture fixation, and minimize the number of repeated bending to maintain stiffness and strength of the clavicle plate.