EFFECTS OF THE FIXATION METHODS OF MENISCUS ALLOGRAFT ON THE MECHANICAL CHARACTERISTIC OF LIGAMENTS AND BONE IN TIBIOFEMORAL JOINT

Based on MRI images of the normal human knee at four flexion angles(0°/25°/60°/80°), the finite element models of the normal tibiofemoral joint and two medial meniscus transplantation models (2-tunnel fixation and 3-tunnel fixation) were built in this paper. The internal and external rotation torque of 10N?m were applied to models for the finite element simulation and the stress and displacement distributions were obtained. The maximum tensile stress on ligaments, the tension in ligaments, the maximum displacement of ligaments and the maximum Von Mises stress on the femur and tibia in transplantation models were respectively compared with those in the normal model to determine the effect of 2/3-tunnel fixation on ligaments. Results showed that two fixation methods both improved ligaments’ abnormal mechanical behavior caused by the removal of meniscus, especially after 3-tunnel fixation to improve even more apparently. Compared with 2-tunnel fixation, 3-tunnel fixation caused smaller changes in the maximum tensile stress on ligaments and in the tension of ligaments. Although 3-tunnel fixation made the average deformation of ligaments at four flexion angles under two kinds of loads experience greater changes, the average percent changes were only less than 10%. Both of the two fixation methods affected the stress distribution of femur and tibia. By contrast, 3-tunnel fixation affected less apparently. On the whole, 3-tunnel fixation was better for the restoration of ligaments’ mechanical characteristics and the stress distribution of femur and tibia was more closely to the normal. Results are expected to provide reference data for the clinical application of meniscus allograft transplantation and postoperative analysis.