Total knee replacement, also known as total knee arthroplasty, is a surgical procedure in which damaged or worn surfaces of the knee joint are removed and replaced with artificial components made of metal and durable plastic. The knee is the largest joint in the body and plays a critical role in walking, climbing stairs, and rising from a seated position. When severe joint damage disrupts these functions, replacing the joint surfaces can significantly reduce pain and improve mobility. This procedure is most commonly performed to relieve pain and disability caused by advanced arthritis, including osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis. It may also be considered when chronic knee pain persists despite nonsurgical treatments such as medications, physical therapy, injections, activity modification, or assistive devices. Candidates for total knee replacement often experience pain at rest or during activity, stiffness, swelling, deformity of the knee, or difficulty performing everyday tasks. During surgery, the orthopedic surgeon makes an incision over the knee and removes damaged cartilage and a small amount of underlying bone from the ends of the femur (thighbone) and tibia (shinbone). These surfaces are then resurfaced with metal implants that recreate the shape of the joint, and a medical-grade plastic spacer is placed between them to allow smooth movement. In some cases, the undersurface of the kneecap (patella) is also resurfaced, depending on the patient’s anatomy and degree of damage. Implants may be fixed to the bone using cemented, uncemented, or hybrid techniques based on bone quality and stability needs. Total knee replacement is typically performed under general or regional anesthesia and usually takes one to two hours. After surgery, patients are monitored in a recovery area and begin guided movement soon after to promote circulation, reduce complications, and restore function. Hospital stays vary, with some patients returning home the same day and others requiring a short inpatient stay or rehabilitation support. Recovery includes a structured rehabilitation program focused on strengthening the muscles around the knee, restoring range of motion, and safely returning to daily activities. Many patients experience substantial pain relief and improved function within the first few months, with continued progress over the first year. While total knee replacement is considered one of the most successful procedures in modern medicine, potential risks include blood clots, infection, nerve injury, implant loosening, or wear over time. With appropriate activity modification and follow-up care, knee replacements can provide long-lasting improvement in quality of life.