Study Description: Brief Summary: Chronic knee pain from osteoarthritis (OA) is commonly treated with total knee arthroplasty (TKA) when conservative therapies fail to provide pain relief. More than 600,000 TKAs are performed in the U.S. annually, a number that continues to increase. A logistic-regression model suggests that the incidence rate of TKA will increase by 143% in the United States by 2050 compared to 2012. Although TKA is successful in reducing knee pain and joint stiffness in most cases, it can be associated with a 7-35% incidence of persistent refractory post-surgical knee pain.