Subject-specific Finite Element Models Can Predict Strain in the Human Medialcollateral Ligament under Valgus Loading

INTRODUCTION: Despite the many investigations of ligament function, the exact role of specific ligaments in maintaining joint stability, the cause and effect of injuries, and the efficacy of various reconstructive procedures remain unclear or unknown. This is partially due to inherent measurement limitations of experimental studies. The finite element (FE) method can predict spatial and temporal variations in stress, strain, and contact area/forces, and provides a standard framework for parameter studies such as evaluation of multiple treatments. This can reduce cost, time, and potentially accommodate intersubject variability that often limits sensitivity of experimental and clinical studies. The objective of this study was to develop and analyze FE models of MCL mechanics using subject-specific material properties, ligament/bone geometry, and in situ strains. Strains in the MCL under valgus knee loading were measured experimentally and predicted using subject-specific FE models at three knee flexion angles. The hypotheses were 1) subject-specific FE models could predict experimental measured MCL strains, and 2) accurate FE predictions of MCL strains could be obtained with average material properties and average in situ strains.