Mechanical alignment tolerance of a cruciate-retaining knee prosthesis under gait loading—A finite element analysis

Abstract

Component alignment is one of the most crucial factors affecting total knee arthroplasty’s clinical outcome and survival. This study aimed to investigate how coronal, sagittal, and transverse malalignment affects the mechanical behavior of the tibial insert and to determine a suitable alignment tolerance on the coronal, sagittal, and transverse planes. A finite element model of a cruciate-retaining knee prosthesis was assembled with different joint alignments (−10°, −7°, −5°, −3°, 0°, 3°, 5°, 7°, 10°) to assess the effect of malalignment under gait loading. The results showed that varus or valgus, extension, internal rotation, and excessive external rotation malalignments increased the maximum Von Mises stress and contact pressure on the tibial insert. The mechanical alignment tolerance of the studied prosthesis on the coronal, sagittal, and transverse planes was 3° varus to 3° valgus, 0°–10° flexion, and 0°–5° external rotation, respectively. This study suggests that each prosthesis should include a tolerance range for the joint alignment angle on the three planes, which may be used during surgical planning.

Investigation into the effect of deltoid ligament injury on rotational ankle instability using a three-dimensional ankle finite element model

“…The aforementioned limitations and variability in experimental methodologies across studies lead to substantial variation between results. Finite Element Analysis (FEA) has emerged as a complementary tool for biomechanical testing ( Park et al, 2019 ; Alastuey-López et al, 2021 ; Wang et al, 2022 ; Luan et al, 2023 ). FEA allows for individual variables to be controlled, provides a broader range of test conditions compared to cadaveric experiments, is not limited by sample availability, and is not subject to the same ethical considerations ( Zhang et al, 2011 ; Xu et al, 2012 ).…”