This study focuses on people who are planning to receive a total knee arthroplasty (TKA, a surgical procedure also known as total knee replacement) in one of their knees. The purpose of the study is to evaluate the safety and effectiveness of 2 different ways of administering an anesthesia medication called EXPAREL (bupivacaine liposome injectable suspension). The study aims to determine whether both methods can provide an equal amount of pain relief for patients undergoing knee replacement surgery. The standard anesthesia treatment for TKA involves a surgical technique known as local infiltration analgesia (LIA), which uses a specific combination of pain-relieving medications that includes EXPAREL. During LIA, the anesthesia is administered with the use of several needle sticks to areas surrounding the knee joint. Researchers will evaluate the safety and effectiveness of using EXPAREL with LIA, while also using a specific surgical technique known as intra-articular posteromedial surgeon administered block (IPSA Block). The technique involves providing an injection of EXPAREL to the back of the knee, reaching into the joint space to provide pain relief. By using EXPAREL via IPSA Block with LIA, there is hope that this method will create a similar amount of pain relief when compared to LIA alone. Participants will receive EXPAREL administered in 1 of 2 ways; both methods are approved by the U.S. Food and Drug Administration (FDA).