How does total knee replacement work?

The surgeon removes worn areas from the ends of the thigh bone and shin bone and places shaped metal components over them. A plastic spacer sits between these surfaces to provide a smooth gliding interface. The back of the kneecap may also be resurfaced when appropriate. Components can be fixed with bone cement or another method selected for the bone and implant design.

The goal is to reduce pain from damaged joint surfaces and improve useful movement, not to recreate every feature of a natural knee. Knee osteoarthritis is a common reason for considering the operation. A partial knee replacement may suit disease limited to one compartment, while robotic knee replacement describes a planning or assistance method rather than a different joint.

Prehabilitation can help you practise exercises, walking with aids and home adjustments before surgery. After the operation, early ankle and leg movement, safe walking and a structured exercise plan help restore strength and knee motion. Keep the wound protected and take medicines exactly as prescribed. Post-operative rehabilitation guides progression; physiotherapy may continue after formal visits to support balance, stairs and daily tasks. [Prehabilitation](/treatments/physiotherapy-and-rehabilitation/prehabilitation/) and [Post-Operative Rehabilitation](/treatments/physiotherapy-and-rehabilitation/post-operative-rehabilitation/) provide related information.

Seek urgent help for chest pain, breathlessness, a cold or severely swollen foot, sudden inability to bear weight, or a knee that becomes acutely deformed. Contact your surgical team for fever, wound drainage, spreading redness, worsening calf pain, new numbness or pain that is not controlled by the agreed plan.

Ask which compartments are damaged, whether partial replacement is suitable, how the implant will be fixed, what knee movement is expected, and which exercises and warning signs matter during recovery.