Khasian M, et al. - Tibiofemoral kinematics of 35 persons who had PS TKA with gradually variable radii (G-curve) design were assessed in order to evaluate the in vivo kinematics for individuals implanted with this type of TKA under different conditions of dialing living. They used fluoroscopy while performing three activities: weight-bearing deep knee bend (DKB), gait, and walking down a ramp. The individuals were evaluated for a range of motion, condylar translation, axial rotation, cam-spine engagement, and condylar lift-off. During DKB, average weight-bearing flexion was 111.4°. Study participants encountered consistent magnitudes posterior femoral rollback and external rotation of the femur with weight-bearing flexion. The difference is comparable to that previously reported for normal knee where the lateral condyle moves consistently posterior compared with the medial condyle. Patients encountered low overall mid flexion paradoxical anterior sliding and no occurrence of condylar lift-off leading to mid flexion stability.