There will be ten subjects with the MicroPort implant and ten with the DePuy Attune implant; however, we will increase enrollment to 24 subjects (12 in each group) to ensure that researchers acquire the necessary 20 usable datasets for analysis and also to account for any subjects that may drop out of the study. All TKAs should be judged clinically successful based on the surgeon's evaluation and each patient's Forgotten Knee Score. Each subject should have a well-functioning prosthesis, be at least six months post-operative, and should have good-to-excellent post-operative passive flexion.