A fixed 2 mm adjustment for worn distal femoral cartilage when the cartilage of the unworn compartment is ≥3 mm does not negatively affect outcome scores after kinematically aligned total knee arthroplasty

PURPOSE: A goal of kinematic alignment (KA) total knee arthroplasty (TKA) is to align the femoral component to restore the distal and posterior femoral joint lines to prearthritic. To restore the joint line on the worn distal condyle, the resection thickness is adjusted by 2 mm for cartilage loss based on the reported average cartilage thickness on magnetic resonance imaging. It remains unclear whether a 2 mm fixed adjustment is ideal for all patients, especially those with thicker cartilage. This study examined whether a 2 mm fixed adjustment in patients with cartilage thickness ≥3.0 mm negatively affects the Forgotten Joint Score (FJS), Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) compared to those with cartilage thickness