After TKA there are many factors that can affect the overall survival of the knee, including the type of knee replacement used, component positioning and the soft tissue structures around the knee. Poor surgical technique can cause ligament imbalance or component mal-alignment, which could lead to early implant failure.
The purpose of this research was to assess the effects of ligament imbalance and component mal-positioning on both the passive and active stability of various total knee designs. A fully mechanical testing rig was developed to perform a series of passive stability tests, allowing the strains of the primary knee ligaments to be altered as well as the simulation of femoral mal-alignment. Computational models were devised and validated against the experimental results; then being used to simulation normal gait. The effects of passive stability were directly compared to active stability, with alteration in kinematics and contact pressures being evaluated.
