In knee joint replacement, the fractured end of the bone and any remaining cartilage are removed and replaced with metal and plastic parts. Plastic acts like stiff cartilage and helps the joint to move freely. Also, the interconnected parts of the knee joint allow you to bend your knee and also to hold its steel.

Total (Complete) knee replacement
Most knee arthroplasty surgery involves a superficial joint replacement of the femur and a superficial joint in the tibia. Complete knee replacement may involve replacing the surface below the knee socket (patella) with a flat plastic prosthesis. Some surgeons prefer to preserve the normal patella of the knee where possible, but sometimes this decision must be made during surgery.

Integrated (partial) knee joint replacement
If arthritis affects only one side of your knee, partial replacement of the knee joint is usually performed for the inner part.
The knee consists of three parts: the middle, lateral, and knee bowl. If arthritis affects only one side of your knee, it is usually possible for the inner part of the knee to be replaced (partial replacement). Since this method has less interference with the knee than the full knee replacement method, it has a faster recovery and better performance. Partial knee replacement can be done by making a smaller incision than the complete knee replacement procedure and also a minimally invasive procedure. A smaller incision may reduce recovery time.