What Is Knee Replacement Surgery? Knee replacement surgery, also known as knee arthroplasty, involves replacing damaged cartilage and bone in the knee joint with artificial implants. The procedure is designed to reduce pain, improve joint function, and help patients return to daily activities with greater comfort. Depending on the extent of joint damage, your orthopedic surgeon may recommend: Total Knee Replacement (TKR) Partial Knee Replacement (PKR) Revision Knee Replacement (for previously replaced joints)