The Effect of Geometry on Patellar Tracking After TKA During Simulated Gait

Abnormal patellar tracking is the main cause of patellofemoral disorders and revision surgeries after total knee replacements (TKA) [1]. The decision to resurface or keep the natural patella has been an ongoing debate when performing TKA since patella morphology and femoral implant design affects patello-femoral (PF) kinematics during gait [2]. A previous study investigated the effects of resurfacing versus unresurfacing the patellae inter-specimen [3]. Error introduced in subject to subject studies can be reduced by performing a cadaveric study where PF kinematics for different patellae geometries are implanted in the same specimen. The purpose of this study was to measure PF kinematics in vitro during three simulated gait cycles with natural, unresurfaced, an anatomical design, and medialized dome patellae to determine the effects of different patellae design and gait cycles on PF kinematics.