Even with Preservation of the Bicruciate Ligaments after Total Knee Arthroplasty, Patients Do Not Have Normal Knee Joint Extensor Muscles Capable of Absorbing Shock during Gait

[Purpose] To evaluate whether normal knee joint extensor muscle groups can absorb shock during the loading response phase of gait after total knee arthroplasty (TKA) preserving the bicruciate ligaments. [Participants and Methods] Eight TKA patients one year after surgery and 12 healthy elderly patients of the same age group were the subjects. Lower limb kinematics and kinetics were measured in the sagittal plane during walking using three-dimensional motion analysis. [Results] The vertical component of the ground reaction force, knee extension moment and centrifugal knee power during the loading response phase of gait were significantly lower in the TKA group than in the healthy group. The TKA group tended to have a lower knee flexion angle during walking than the healthy group. [Conclusion] Even with the preservation of bicruciate ligaments, the shock absorbing function of the knee joint extensor muscle group was not fully utilized during gait by the TKA patients.