Kinematic component alignment in total knee arthroplasty leads to better restoration of natural tibiofemoral kinematics compared to mechanic alignment

摘要

PurposeKinematically aligned total knee arthroplasty is associated with superior pain relief, increased flexion and a more normal feeling knee. It was hypothesized that due to restoring the knee's natural anatomy, kinematically aligned knees show more physiological tibiofemoral kinematics than mechanically aligned knees.MethodsInvestigations were performed in nine healthy cadaveric knees of whole bodies fixed by the Thiel method. Tibiofemoral kinematics of healthy knees and after kinematically and mechanically aligned total knee arthroplasty were assessed between 0 degrees and 90 degrees of flexion by a navigational device.ResultsRegarding tibial internal rotation or femoral roll back, respectively, kinematically aligned total knee arthroplasties showed no significant differences between 0 degrees and 70 degrees of flexion in comparison to knees before total knee arthroplasty. In contrast, mechanically aligned total knee arthroplasties showed significant changes between 10 degrees and 90 degrees of flexion. Kinematically aligned knees showed a significant changed abduction/adduction between 20 degrees and 70 degrees of flexion, mechanically aligned knees within 20 degrees and 90 degrees of flexion.ConclusionIn the present study setting kinematically aligned total knee arthroplasties showed more natural and physiological tibiofemoral kinematic pattern with regard to tibial internal rotation or femoral rollback, respectively, and tibial adduction than mechanically aligned total knee arthroplasties. While these results may support promising early clinical results of kinematical alignment proposing a better function, long-term results especially implant survival need to be awaited.