Tibiofemoral alignment in posterior stabilized total knee arthroplasty: Static alignment does not predict dynamic...

For total knee arthroplasty (TKA), neutral mechanical alignment produces balanced static knee loading. Dynamically, knee loading is affected by more than limb static alignment. We compared static and dynamic knee loading following TKA. Fifteen TKA patients were evaluated pre-operatively and 2 months and 2 years post-operatively. Tibiofemoral angles and medial tibial plateau loading were calculated. Pre-operatively, static medial load was greater for varus than valgus knees. Post-operatively, no relationship existed between tibiofemoral angle and static medial plateau load. Pre-operatively and post-operatively, dynamic medial load was not dependent on tibiofemoral angle. While all patients achieved equal static plateau load distributions at 2 years, only 47% had dynamic medial load distributions of 50 ± 10%. Static tibiofemoral alignment alone does not predict dynamic tibial loading.