Although the volume of total knee arthroplasties (TKAs) performed in the United States continues to increase, recent reports have shown the percentage of patients who remain "unsatisfied" is as high as 15% to 30%.  A four-center study was designed to quantify the degree of residual symptoms and functional deficits in patients undergoing TKA with newer implant designs compared with a 10-year-old, cruciate-retaining (CR) TKA system introduced in 2003.  Two hundred thirty-seven CR, 137 rotating-platform, 88 gender-specific, and 65 high-flex TKAs were included in the analysis. 
TKAs