Simultaneous Versus Staged Knee Arthoplasty? There are an estimated 900,000 knee replacements (TKR) performed in the U.S. every year. This number is up from 754,000 TKRs in 2017, according to the Agency for Healthcare Research and Quality. https://t.co/KuLEaI3r0d https://t.co/0q1RBsDwEM