'Natural Knee', polyethylene, replacement tibia joint component, porous coated, by Sulzer Orthopedics Incorporated, Texas, United States, 1998.

Knee joints may need to be replaced because of disease, damage or injury. This particular white prosthetic is used to replace the lower part of the knee joint at the top of the tibia bone. The replacement is made from polyethylene, a material that the human body does not recognise (so it will not be attacked by the immune system and rejected).

Knee replacements are expected to last between ten and fifteen years. Sulzer Orthopedics Inc made the prosthetic and donated the joint to the Science Museum’s collections. It is shown here with other knee and hip replacements (1999-828, 1999-831, 1999-832).