Advantages of Kinematically Aligned Total Knee Arthroplasty: A Biomechanical Perspective

To date, several biomechanical approaches have been used to assess knee kinematics and kinetics of kinematically aligned (KA) total knee arthroplasty (TKA) knees. Most of these assessments favor KA TKA over mechanically aligned TKA, supporting promising medium-term clinical results for calipered KA TKA. Although realistic boundary conditions for varus inclination of tibial joint line and varus limb alignment remain to be clarified, varus joint line inclination (medial proximal tibial angle <87 degrees) alone does not seem to increase knee adduction moment (KAM) and subsequent medial contact stress, while varus limb alignment carries a risk of increasing KAM. Preserving the original joint line and native ligament balance using calliper control of the bony resection undoubtedly gives the benefit of a natural feeling to the knee; however, further clinical studies are warranted to assess the long-term impact of KA TKA.