Minoda Y, et al. - Authors compared the patella–post impingement (PPI) between 12 contemporary posterior stabilized knee prostheses. They implanted 12 posterior stabilized knee prostheses in full-length sawbone models of the femur and tibia using a navigation system. Findings suggested a significant impact of the design of the tibial post on the PPI angle. Tibial–patellar clearance (TPC) ought to be prepared during surgery in order to avoid PPI during deep flexion. Smaller PPI angles were caused by shorter TPCs and larger PPI angles were caused by longer TPCs.