Knee replacements generally consist of femoral, tibial and patellar components, as well as a liner that fits into the tibial tray. A variety of materials have been used in the fabrication of total knee prostheses, including:
- Metal alloys
- Ultrahigh molecular weight polyethylene patellar components and liners that are attached to the tibial tray. This is the same material that is used for ski bottoms, runners on snowmobiles, and cutting boards.
- Polymethylmethacrylate cement used for fixation
In some earlier designs, the entire tibial component was made of polyethylene. This is used less frequently today since metal-backed tibial components have been shown to reduce prosthesis-bone interface stresses. Current designs use metal tibial trays with variable thickness polyethylene liners.
Total knee replacement with polyethylene tibial component. Prosthesis photograph and radiograph.
Total knee replacement with metal femoral and tibial component. Patellar component and liner are made with polyethylene.